Features * DC/DC Step-up Converter (BOOST) 3.3V to 5.2V, 1A, up to 90% Efficiency. Can be Used as BUCK/BOOST in SEPIC Configuration * DC/DC Step-down (BUCK) Synchronous Converter 0.9V to 3.4V, 500mA, up to 90% Efficiency, Pulse Skipping Capabilities for High Efficiency at Light Load Currents * Two Low-Drop-Out Regulators 1.3V, 1.5V to 1.8V, 2.5V to 2.8V (100 mV Step), 3.3V, 200 mA Maximum Load * Ultra-low Power Real-time Clock (RTC) and Backup Battery Management * * * * * * * * * - 2.6V RTC LDO for Backup Battery Charging - 32 kHz Crystal RTC Oscillator (1 A) - RTC Circuit for Time and Date Information Activation of the Power Management Modules via Dedicated Enable Pin Automatic Start-up Sequences, POK Signal Indicating When Start-up is Completed Activation and Control of the Power Management Modules in Dynamic Mode (via SPI or TWI) or in Static Mode (On/Off of the Four Power Supplies) ITB Signal Indicating Short-circuits in DC/DC Converters Very Low Quiescent Current Minimum External Components Count Supply: from 2.8V to 5.25V (typ: Li-Ion Battery 3V to 4.2V) Available in a 32-pin 5x5 QFN Package Applications Include: - WLAN Portable Devices - Multimedia Devices - Portable Music Players 1. Description The AT73C224-x is a family of ultra low cost Power Management Unit, available in a small outline QFN 5x5mm package. The AT73C224-x family is optimized for portable applications, typically powered by a Li-Ion battery. The AT73C224-x device is also suitable to operate from a standard 3.3V to 5.25V voltage rail. It includes four power supplies and a very low power Realtime Clock (RTC). In normal mode (main battery present), the backup battery is recharged through a 2.6V RTC LDO. The AT73C224-x series offer different automatic start-up sequences (with varying orders of power-on and specific default output values) and different soft management modes: dynamic (via SPI or TWI) with register access or static, with access to power on/off of the four power supplies. Each AT73C224-x device is equipped with a very low power bandgap reference, low power 32 kHz and 1 MHz oscillators and an internal LDO used to generate the internal supply (VINT) equal to 2.8V. Auxiliary cells, such as a power-on reset (POR) and a voltage monitor are used to control the system power-on (battery plugged in) and power-off (battery unplugged). The four power supplies are named: BOOST1, BUCK2, LDO3 and LDO4. Table 1-1 lists the different devices available in the AT73C224-x series. Power Management and Analog Companions (PMAAC) AT73C224-A AT73C224-B AT73C224-C AT73C224-D AT73C224-E AT73C224-F AT73C224-G AT73C224-H 4x Channels Power Supply: DC/DC BOOST DC/DC BUCK . 2x LDOs RTC 6266A-PMAAC-08-Sep-08 For more details concerning the Automatic start-up sequences, see Section 5.2. For more details concerning the Management Modes, see Section 5.3. . Table 1-1. Part Number AT73C224-x device series Automatic Start-up Sequence Management Mode Order of power-on and output default values. Comments AT73C224-A 1 - BUCK2= 1.8V 2 - LDO4 = 2.8V 3 - LDO3 = 2.7V Dynamic BOOST1 can be activated after Start-up sequence by a user command. AT73C224-B 1 - BUCK2 = 1.2V 2 - LDO4 = 1.8V 3 - LDO3 = 1.8V Dynamic BOOST1 can be activated after Start-up sequence by a user command. AT73C224-C 1 - LDO4 = 2.8V 2 - BUCK2 = 1.8V 3 - LDO3 = 2.7V Dynamic BOOST1 can be activated after Start-up sequence by a user command. AT73C224-D 1 - LDO4 = 1.8V 2 - BUCK2 = 1.2V 3 - LDO3 = 1.8V Dynamic BOOST1 can be activated after Start-up sequence by a user command. AT73C224-E 1 - BOOST11 = 5.2V 2 - LDO4 = 3.3V 3 - LDO3 = 3V Dynamic BUCK2 can be activated after Start-up sequence by a user command. LDO3 & LDO4 are supplied by BOOST1. (See Section 4. "Application examples", Figure 4-3 on page 7: Application Schematic 3.) AT73C224-F 1 - BUCK2 = 1.8V 2 - LDO4 = 2.8V 3 - LDO3 = 2.7V Static Same as AT73C224-A. AT73C224-G 1 - LDO4 = 2.8V 2 - BUCK2= 1.8V 3- LDO3 = 2.7V Static Same as AT73C224-C. AT73C224-H 1 - BOOST1 = 5.2V 2 - LDO4 = 3.3V 3 - LDO3 = 3V Static Same as AT73C224-E. 2 AT73C224 6266A-PMAAC-08-Sep-08 AT73C224 2. Block Diagram Figure 2-1. Block Diagram LDO3 2 VDD3 1 VO3 3 GNDANA 23 24 10 32 VDD4 VO4 VBACKUP XOUT 29 CK32 26 27 28 13 14 15 8 6 VDD1 VSENSE1 BOOST1 VOUT 3.3V-5.2V ILOAD 1A LDO4 DL1 VOUT 1.3V 1.5V-1.8V 2.5V-2.8V 3.3V ILOAD 200 mA VO1 22 21 20 18 VBAT_LDORTC 30 31 25 VOUT 1.3V 1.5V-1.8V 2.5V-2.8V 3.3V ILOAD 200 mA XIN VDD2 POR RTC BUCK2 RTC OSC VOUT 0.9V-3.4V ILOAD 500 mA VDDIO D1 D2 D3 D4 POK ITB Digital Interface (TWI / SPI) P SW2 N GND2 VO2 VDD0 16 17 11 PMC Status Register GND/AVSS VBG 9 RTC LDO VBG Die Paddle OSC 900kHz POR, VMON (Voltage Monitor) LPVBG (Low power VBG) EN 12 VINT Regulator VCAPP VCAPN 4 7 VINT 5 3 6266A-PMAAC-08-Sep-08 3. Pinout Table 3-1. AT73C224 Pinout Pin Name I/O Pin # Type Function Comments VO3 O 1 Analog LDO3 output voltage Ext. 2.2 F capacitor (mandatory) VDD3 PS 2 Power LDO3 supply voltage GNDANA PS 3 Ground Analog ground VCAPP I/O 4 Analog Not connected VINT PS 5 Power Output of the internal LDO Ext. 470 nF capacitor (mandatory) VDD0 PS 6 Analog Supply of the internal LDO Must be connected to the main battery (mandatory) VCAPN I/O 7 Analog Not connected VBG O 8 Analog Bandgap reference voltage VDD2 PS 9 Power BUCK2 supply voltage VBAT_LDORTC PS 10 Power LDO_RTC Supply voltage VO2 I 11 Analog BUCK2 output voltage EN I 12 Digital Enable signal Internal 100 K pull up D4 I 13 Digital Digital interface Internal 100 K pull up POK O 14 Digital Power Ok: indicates when start-up is completed ITB/RDY I/O 15 Digital User Interrupt, GPIO and Shutdown control SW2 O 16 Analog BUCK2 inductor (NMOS switcher output) GND2 PS 17 Ground BUCK2 ground VO1 I 18 Analog BOOST1 output voltage DH1 O 19 Analog Not connected DL1 O 20 Analog BOOST1 NMOS control signal VSENSE1 I 21 Analog BOOST1 current limitation sense voltage VDD1 PS 22 Power BOOST1 supply voltage VDD4 PS 23 Power LDO4 supply voltage VO4 O 24 Analog LDO4 output voltage VDDIO PS 25 Digital supply Supply voltage for Digital I/O D1 I 26 Digital Digital interface open drain D2 I/O 27 Digital Digital interface open drain D3 I 28 Digital Digital interface open drain CK32 O 29 Digital 32 kHz RTC output clock XOUT I/O 30 Analog RTC crystal oscillator output XIN I/O 31 Analog RTC crystal oscillator input VBACKUP O 32 Analog Backup Battery and RTC supply GND/AVSS PS 33 Ground Main GND and AVSS ground 4 Should not be resistively loaded Must be connected to the main battery (mandatory) Internal 100 K pull up Must be connected to the main battery Ext. 2.2 F capacitor (mandatory) die paddle connected to ground (mandatory) AT73C224 6266A-PMAAC-08-Sep-08 AT73C224 4. Application examples Figure 4-1. Application Schematic 1: Microcontroller with 5V VBUS for 2 USB Host Transceivers LDO3 = 2.7V R2 C13 D1 VDDIO D2 D3 CK32 SW2 ITB/RDY POK VO1 USB HOST transceiver GND/AVSS Die Paddle uP uP uP Pushbutton BOOST1 = 5V (VBUS USB) GND2 USB HOST transceiver L2 BUCK2 = 1.8V VO2 C2 SPI / TWI VCORE C16 POK ITB/RDY D1 SDI /Adrress C7 Q1 nc SCS / GND VBAT Microcontroller C1 DL1 SDO / TWD VBAT VO1 RST Li-Ion Battery VBG D1 L1 SCK / TWCK VBAT VCAPN VDD2 C10 VDDIO C6 R1 DH1 EN VDD0 nc VBAT VSENSE1 AT73C224-A D4 VBAT C5 XIN VDD1 VINT C14 3V to 4.2V VDD4 GNDANA VCAPP C9 LDO4 = 2.8V VDD3 VO2 nc C4 VO4 VBAT_LDORTC C8 XOUT VBACKUP VO3 VBAT C3 C12 uP uP uP 32 1 (AUX ADC, PLL) VBAT X1 C11 ITB/RDY Rechargeable Backup Battery (NBL type) D2 D3 D4 In the Application Schematic 1, the AT7373C224-A is used: the BOOST(VO1) supplies the "VBUS" of two USB transceivers, the BUCK(VO2) supplies the digital core of the microcontroller, the LDO3 supplies the I/Os of the microcontroller and LDO4 supplies analog cells, such as auxiliary ADC or PLL. For external components, see Table 4-1. 5 6266A-PMAAC-08-Sep-08 Figure 4-2. Application Schematic 2: Supply of a Microprocessor and External Analog Cells BOOST1 = 5V Analog Cells R2 D1 D2 VDDIO VBAT AT73C224-B D1 L1 VO1 ITB/RDY SW2 Die Paddle BUTTON L2 BUCK2 = 1.2V VO2 C16 RST C2 SPI / TWI VCORE POK ITB/RDY D1 SDI /Adrress Li_Ion Battery GND/AVSS uP uP uP SCS / GND C13 Microcontroller BOOST1 = 5V GND2 SDO / TWD C7 nc SCK / TWCK VBAT POK VDD2 VBAT Q1 VO1 EN VBG C1 DL1 DH1 VDDIO C6 R1 VSENSE1 VCAPN C10 VBAT D3 VCAPP VDD0 nc CK32 VDD1 D4 C5 3V to 4.2V XIN VDD4 GNDANA VBAT_LDORTC VBAT C9 LDO4 = 1.8V VDD3 VINT C14 C4 VO4 VO2 nc XOUT VBACKUP VO3 VBAT C8 C12 uP uP uP 32 1 C3 VO4 X1 C11 ITB/RDY Rechargeable Backup Battery (NBL type) VBAT D2 D3 D4 In the Application Schematic 2, the AT73C224-B is used: the BOOST (VO1) supplies the "VBUS" of one USB transceiver and supplies also LDO3 and LDO4. The BUCK(VO2) supplies the digital core of the microcontroller and the LDOs supply the I/Os and Analog cells, such as auxiliary ADC or PLL. For external components, see Table 4-1. 6 AT73C224 6266A-PMAAC-08-Sep-08 AT73C224 Figure 4-3. Application Schematic 3: BOOST in SEPIC Configuration (BUCK/BOOST) BOOST1 = 3.3V Analog Cells R2 D1 VDDIO D2 AT73C224-B R1 D1 C15 L1 VO1 nc SW2 Die Paddle L2 BUCK2 = 1.2V VO2 C16 RST C2 SPI / TWI VCORE POK ITB/RDY D1 SDI /Adrress ITB/RDY GND/AVSS uP uP uP BUTTON Microcontroller BOOST1 = 3.3V GND2 SCS / GND C13 L3 SDO / TWD C7 Q1 SCK / TWCK VBAT POK VDD2 VBAT C1 DL1 DH1 VDDIO C6 VO1 EN VBG Li_Ion Battery VBAT VSENSE1 VCAPN C10 VBAT D3 VCAPP VDD0 nc CK32 VDD1 D4 C5 3V to 4.2V XIN VDD4 GNDANA VBAT_LDORTC VBAT C9 LDO4 = 1.8V VDD3 VINT C14 C4 VO4 VO2 nc XOUT VBACKUP VO3 VBAT C8 C12 uP uP uP 32 1 C3 VO4 X1 C11 ITB/RDY Rechargeable Backup Battery (NBL type) VBAT D2 D3 D4 In the Application Schematic 3, the BOOST (VO1) is in SEPIC configuration (BUCK/BOOST) and generates a 3.3V output voltage for analog cells. The BUCK (VO2) supplies the core of the microcontroller, and LDO4 supplies the I/Os. Note that, in the SEPIC configuration, the maximum load current on VO1 should not exceed 300 mA. For external components, see Table 4-1. 7 6266A-PMAAC-08-Sep-08 Table 4-1. External Components Schematic reference Manufacturer C1 Tantalum TPS Case B AVX C2 Tantalum TPS Case A AVX Value (R) 100 F 33 F (R) C3, C4 GRM155R60J225ME15 C1005X5R0J225MT Murata TDK 2.2 F C6 GRM21BR60J226ME39 C2012X5R0J226MT Murata TDK 22 F C5, C7, C8, C9, C11, C13 GRM155R60J105KE19 C1005X5R0J105KT Murata TDK 1 F C10 GRM155R61A104KA01 C0603X5R0J104KT Murata TDK 100 nF C12, C14 GRM155R60J474KE18 C1005X5R1A474KT Murata TDK 470 nF C15 GRM188R60J475KE19 C1608X5R0J475KT Murata TDK 4.7 F C16 GRM188R60J106ME47 C1608X5R0J106MT Murata TDK 10 F L1 744773022 Wurth(R) Elektronik 2.2 H L1, L3 (in SEPIC config.) 744773068 Wurth Elektronik 6.8 H L2 B82467-G0682-M D1 MBRM120LT1 Q1 Si1470DH X1 FX135B-327 R1 (can be printed on the board (Cu line)) R2 8 Reference LR2010R050J MR-CRG0402J2k2 Epcos(R) 6.8 H (R) On Semiconductor Vishay(R) Fox 32.768 kHz Welwyn 50 m TycoTM Electronics 2 k AT73C224 6266A-PMAAC-08-Sep-08 AT73C224 5. Detailed Description The AT73C224-x is a family of Power Management Units with four power supplies and an ultra low-power Real-time Clock. By choosing a specific ordering code "x" from A to H, different automatic start-up sequences and management modes can be selected. The start-up sequence includes the order of power-on, as well as the default value of the power supplies (see Section 5.2 "Automatic Start-up Sequences and Shut-down"). The user can afterwards change this default value via SPI or TWI, if the dynamic mode has been chosen (see Section 5.3 "Digital Control and Protocol"). 5.1 Core The core of the AT73C224-x device integrates the following blocks: * Power-On-Reset for the backup battery. * Internal switch and LDO dedicated to the backup battery. The output of the LDO_RTC is set to 2.6V and the switch is on when the main battery higher than 2.8V (charge of the backup battery).See Section 7.7 for electrical details. * Real-Time-Clock digital bloc + 32 kHz oscillator. * Power-On-Reset for the main battery. * Voltage Monitor (VMON) of the main battery. * Digital Power Management Control (PMC) for automatic start-up sequences. Digital output POK indicates when start-up is completed, whereas ITB digital output signal informs the user (typically the microcontroller) of a default in the DC/DCs (short-circuit) or too low main battery value. * TWI and SPI protocol blocs. * DC/DC Step-up converter BOOST1: A 3.3V to 5.2V(100 mV step), 1A, asynchronous DC/DC Step-up Converter available for overall system requirements. The DC/DC can be implemented through proper external components in BUCK/BOOST (SEPIC) configuration. The output voltage can be programmed via the internal registers. BOOST1 is supplied directly by the battery. * DC/DC Step-down converter BUCK2: A 0.9V to 3.4V, 500 mA fully integrated synchronous PWM DC/DC Step-down Converter. The output voltage can be programmed via the internal registers. A Pulse Skipping mode is available in order to improve efficiency at very light load current values. In order to guarantee very low supply voltage functionality, the controller is supplied by the max voltages between the main battery and the output of BOOST1 (VO1). BUCK2 can be directly supplied by the battery or by the output of BOOST1. * LDO3: A 1.3V, 1.5V to 1.8V (100 mV of step), 2.5V to 2.8V (100 mV of step), 3.3V, 200 mA - Low Drop out regulators. The output voltage can be programmed via the internal registers. LDO3 can work with supply from 1.8V up to 5.5V. This LDO can be supplied by the battery, by the output of BOOST1, or by the output of BUCK2. * LDO4: same functionality than LDO3. * Main Bandgap: 1.18V reference voltage. * 900 kHz Oscillator. * Internal LDO (VINT) at 2.8V for internal supply. 9 6266A-PMAAC-08-Sep-08 5.2 5.2.1 Automatic Start-up Sequences and Shut-down Start-up/Wakeup If the backup battery (only) is present, the RTC is running (1.2 A). This mode is called "Backup mode". When the main battery is plugged in and voltage is higher than 2.8V, the LDO_RTC recharges the backup battery through an internal switch (if the main battery is lower than 2.8V, nothing happens, RTC still running). This mode is called "Standby mode". Note that when the battery is plugged in (and higher than 2.8V), a reset of the RTC is performed only if the backup battery was lower than 1.8V. Now, the system waits for wake-up information coming from the pushbutton (EN pin) or an RTC alarm. When one of the previous conditions occurs, the automatic start-up sequence starts (without any external commands). Different automatic start-up sequences can be chosen from the AT73C224-x family (see Figure 5-1 on page 11 and Figure 5-2 on page 12). When the automatic start-up sequence has been completed, the POK signal (which is an open drain signal) goes high, thus implementing a sort of POR for the user (i.e., a microcontroller) and enters into "Normal mode". Note: Power On is controlled by default by an external pushbutton, connected on EN pin (the EN pad has an internal 100 k pull up). A switch can also be used as shown bellow but should be a request from the customer . EN (Default: Pushbutton) EN (On request: switch) 5.2.2 Shut-down Static and Dynamic modes are explained in detail in Section 5.3. 5.2.2.1 Static Mode In Static mode, the Power-off condition is an OR between the following conditions: main battery lower than 2.8V or electrical default in the DC/DC (short-circuit). When Power-off condition occurs, POK signal is cleared, then the AT73C224-x device waits for the signal ITB/RDY to shut down all power supplies. 5.2.2.2 10 Dynamic Mode In Dynamic mode, Power-off condition is an OR between the following conditions: electrical default in the DC/DC (short-circuit) or software shutdown. When main battery lower than 2.8V, an interrupt is generated on signal ITB/RDY. It is the responsibility of the host microcontroller to perform a software shut-down by properly writing the AT73C224-x device registers through the serial interface. After that, the POK signal is cleared, and all is turned off. A check on the pushbutton is then performed to assure that it has been released, thus avoiding continuous on-off-on behavior. The "normal" shutdown is performed by software. Note that the microcontroller has to write the proper register to enable the power off (see Section 6. "Register Tables"). AT73C224 6266A-PMAAC-08-Sep-08 AT73C224 Figure 5-1 illustrates the complete automatic start-up sequence of the AT73C224-A and AT73C224-F, whereas Figure 5-2 illustrates the automatic start-up sequence of the other AT73C224-x device versions. Figure 5-1. Start up Sequence of the AT73C224-A and AT73C224-F VBAT POR (internal Vth = 1.6V) VMON (internal Vth = 2.8V) EN (Wake-up of the system) (Pushbutton) 30 ms min VINT (internal supply) PWRGDINT (internal- Vth = 1.6V) VBG 36 ms typ. Automatic Start-up Sequence: BUCK2 (Default value: 1.8V) 3ms LDO4 (Default value: 2.8V) 3ms LDO3 (Default value: 2.7V) 3ms 45ms typ POK -> uP (Start-up sequence completed) BOOST1 User Command: . AT73C224-A: Through Dynamic mode (using TWI or SPI) . AT73C224-F: Through Static mode (using D1 pin) 11 6266A-PMAAC-08-Sep-08 Figure 5-2. Automatic Start-up Sequence of all Other Versions of the AT73C224-x Device Series POK (Automatic Start-up sequence completed) V BUCK2 (Default value: 1.2V) 3ms LDO4 (Default value: 1.8V) 3ms LDO3 (Default value: 1.8V) 3ms BOOST1 User Command: . AT73C224-B: Through Dynamic mode (using TWI or SPI) AT73C224-B, AT73C224-G BUCK2 (Default value: 1.8V) LDO4 (Default value: 2.8V) LDO3 (Default value: 2.7V) BOOST1 User command: . AT73C224-C: Through Dynamic mode (using TWI or SPI) . AT73C224-G: Through Static mode (using D1 pin) AT73C224-C, AT73C224-H BUCK2 (Default value: 1.2V) LDO4 (Default value: 1.8V) LDO3 (Default value: 1.8V) BOOST1 User Command: . AT73C224-D: Through Dynamic mode (using TWI or SPI) AT73C224-D, AT73C224-I BUCK2 User command: . AT73C224-E: Through Dynamic mode (using TWI or SPI) . AT73C224-H: Through Static mode (using D2 pin) LDO4 (Default value: 3.3V) LDO3 (Default value: 3V) BOOST1 (Default value: 5.2V) 12 AT73C224-E, AT73C224-J AT73C224 6266A-PMAAC-08-Sep-08 AT73C224 5.3 Digital Control and Protocol The AT73C224-x family offers a choice of devices in static mode or dynamic mode (see Table 11 on page 2). In dynamic mode, the user can manage the chip via SPI or TWI. The selection between SPI or TWI is done at start-up via the D4 pin (see Section 5.3.2 on page 14). 5.3.1 Static Mode When the AT73C224-x is established in Static Mode, the digital interface signals, D1 to D4, directly drive the enable of the four supplies. During start-up, these enable signals are driven by the internal state machine. To ensure a safe transition between the start-up state and the established state, a handshake protocol must be respected. This transition period is especially important in a microcontroller environment, as the microcontroller controlling the D1-D4 signals may require an unknown period of time to actually drive these pins. In Static Mode, the ITB/RDY pin is configured as an input with controllable pull-up resistor. When the internal state machine completes the supply start-up, it latches the value of ITB/RDY and then sets the POK signal to 1. This means that start-up is accomplished. The state machine then checks for changes on ITB/RDY. If no changes are detected, the control of the four supply channels remains with the state machine. If a change is detected the internal pullup is disconnected and the control is passed on to D1-D4, with the assignment shown in Table 5-2 below. Table 5-1. D1-D4 Signal Assignment Digital Interface Signal Supply Enable D1 Enables BOOST1 D2 Enables BUCK2 D3 Enables LDO3 D4 Enables LDO4 The illustrations in Figure 5-3, Figure 5-5 and Figure 5-5 represent possible static mode scenarios. Figure 5-3. Fully Static Mode 0 or 1 D1 D2 D3 D4 ITB/RDY Open or 1 POK Power OK Since ITB/RDY is 1 or open (weak internal pullup), the state of each supply channel is determined by the internal state machine (Automatic Start-up sequence and default values for the three power supplies). In this configuration, the 4th power supply is off and can not be used. D1D4 is not considered, but must be valid. The POK signal can be used as a global system reset. 13 6266A-PMAAC-08-Sep-08 Figure 5-4. Configurable Static Mode 0 1 D1 D2 D3 D4 ITB/RDY POK Power OK The state of each channel is determined by the internal state machine during the start-up sequence. POK is looped back onto ITB/RDY. When this signal changes from 0 to 1 (i.e., the start-up is completed), the control of each supply channel is passed on to D1-D4. This allows changing the output values defined by the state machine. This mode can be used when the 4th channel is needed. Figure 5-5. GPIO (C Controlled) D1 D2 D3 D4 ITB/RDY POK I/O I/O I/O I/O C I/O RST or NMI When the system is powered, the microcontroller is not necessarily well configured and may be unable to drive D1-D4 correctly. Since ITB/RDY is not actively controlled, its state is an unknown logic level. If ITB/RDY is in hi-Z, the weak internal pullup pulls the level to 1. The power channels are controlled by the internal state machine. After some initialization time, the microcontroller configures its GPIOs to drive D1-D4 as wished. At the end of the software configuration, the microcontroller changes the level of ITB/RDY to 0 in order to get control on the four power channels through D1-D4. 5.3.2 Dynamic Mode For the devices of the AT73C224-x family that work in dynamic mode, supply management can be performed by the SPI or TWI digital interface. Selection between the two digital interfaces is done through D4 pin when the AT73C224-x is enabled. Pin D4 is a digital input pin that features a controllable pull-up resistor with active low control signal. When the AT73C224-x starts, the pullup is disabled until a push button event is detected. The state machine enables the pull-up resistor on D4, waits for a time and then checks back on the value on the pad. * If D4 is high (i.e., the level externally applied on D4 is HZ or logic 1), SPI interface is selected. D4 will become SCS. * If D4 is low (i.e., D4 is externally grounded), TWI interface is selected. D4 is not used. After signal dynamic has been determined the state machine disables the pull-up resistor to save power and the D4 pin can be normally used (if SPI has been selected). 14 AT73C224 6266A-PMAAC-08-Sep-08 AT73C224 The selection between SPI versus TWI is performed once, each time the start-up sequence is executed. A timing diagram of the interface selection is shown in Figure 5-6. Care must be taken to leave enough time between the activation of the pullup and the moment when D4 is sampled back. This time is necessary to load the capacitance of the net layout where D4 is connected through the pull-up resistor (100 k typ.). This time is in the order of magnitude of 1 s (10 pF * 100 k), i.e. only a few cycles of the 900 kHz oscillator are needed. Figure 5-6. Dynamic Mode Interface Selection D4 Hz SPI selected, D4 => SCS D4 pull-up control signal dynamic D4 D4 pull-up control signal dynamic TWI selected SCS = Serial Chip Select Table 5-2. Digital Interface Selection Digital Signal Interface SPI Selection TWI Selection Pad Signal Direction Signal Direction D1 I SCK In TWCK In D2 BIDIR SDO Out TWD I/O D3 I SDI In Select the 7-bit fixed address In D4(1) I SCS In grounded - Note: 5.3.2.1 1. On D4, I = Input pad with controllable pull-up resistor. SPI Operation When SPI mode is selected, the control interface to the AT73C224-x chip is a 4-wire interface modeled after commonly available microcontroller and serial-peripheral devices. The interface consists of a serial clock (SCK), chip select (SCS), serial data input (SDI) and serial data output (SDO). Data is transferred one byte at a time with each register access consisting of a pair of byte transfers. Figure 5-7 below illustrates read and write operations in SPI mode. 15 6266A-PMAAC-08-Sep-08 Figure 5-7. SPI Read and Write Operations SCK SCS SDI 0 A6 A5 A4 A3 A2 A1 A0 D7 D6 D5 D4 D3 D2 D1 D0 Hz SDO SPI Write SCK SCS SDI 1 A6 A5 A4 A3 A2 A1 A0 Hz SDO D7 D6 D5 D4 D3 D2 D1 D0 SPI Read The first byte of a pair is the command/address byte. The most significant bit of this byte indicates register read when 1 and register write when 0. The remaining seven bits of the command/address byte indicate the address of the register to be accessed. The second byte of the pair is the data byte. During a read operation, the SDO becomes active and the 8-bit contents of the register are driven out MSB first. The SDO will be in high impedance on either the falling edge of SCK following the LSB or the rising edge of SCS, whichever occurs first. SDI is a don't care during the data portion of read operations. During write operations, data is driven into the AT73C224-x via the SDI pin, MSB first. The SDO pin will remain in high impedance during write operations. Data always transitions with the falling edge of the clock and is latched on the rising edge. The clock should return to a logic high when no transfer is in progress. * Continuous clocking: In normal operation, the SCK should not transition out of byte transfer periods. However, in test mode, the SCK is used as the main clock. This implies that all data transfers must be controlled by the assertion of the SCS pin. * 3-wire operation: SDI and SDO can be treated as two separate lines or wired together if the master is capable of tri-stating its output during the data-byte transfer of a read operation. * SCK vs internal clock rates: It is very likely that the bit rate commanded by SCK will be much higher than the internal clock (900 kHz/64) used to read and write the registers. This implies that a minimal delay between byte transfers must be imposed to allow some time to decode the address and actually access the physical register. It is not acceptable to sample SCK with the internal clock. 16 AT73C224 6266A-PMAAC-08-Sep-08 AT73C224 5.3.2.2 TWI Operation The TWI interface allows a microcontroller to proceed to read or write accesses to the internal registers of the AT73C224-x. Unlike the SPI, the TWI operation is based on a standard which defines a data-link layer and an addressing scheme. The TWI implementation used in the AT73C224-x conforms to this standard, with the following restrictions: * slave only * bit rate: 400 kbps max * 7-bit fixed address: the default value is 1001001 (D3 is high). But the external D3 bit can modify it. When D3 is low, the 7-bit fixed address is 1001000. * TWCK is an input pin for the clock * TWD is a bidirectional pin driving (open drain with external resistor connected to VDDIO) or receiving the serial data. The data put on TWD line must be 8 bits long. Data is transferred MSB first. Each byte must be followed by an acknowledgement. Each transfer begins with a Start condition and terminates with a STOP condition. * A high-to-low transition on TWD while TWCK is high defines a START condition. * A low-to-high transition on TWD while TWCK is high defines a STOP condition. Figure 5-8. TWI Start/Stop Condition TWD TWCK START Figure 5-9. STOP TWI Protocol TWD TWCK START Address R/W Ack Data Ack Data Ack STOP After the host initiates a START condition, it sends the 7-bit slave address, as defined above, to notify the slave device. A Read/Write bit follows (Read = 1, Write = 0). The device acknowledges each received byte. The first byte sent after device address and R/W bit is the address of the device register the host wants to read or write. For a write operation, the data follows the internal address. For a read operation, a repeated START condition needs to be generated followed by a read on the device. Write and Read operations are shown in Figure 5-8 and Figure 5-9. 17 6266A-PMAAC-08-Sep-08 The TWI abbreviations are defined below. S = Start A = Acknowledge P = Stop N = Not Acknowledge W = Write ADDR = Device Address R = Read IADDR = Internal Address Figure 5-10. Write Operation TWD S ADDR W A IADDR A DATA A P Figure 5-11. Read Operation TWD S 5.3.3 ADDR W A IADDR A S ADDR R A DATA N P Interrupt Controller In dynamic mode, the ITB/RDY pin is an output and operates as an interrupt to an external microcontroller. The output logic is active low (a 0 level means interrupt). Several sources can potentially trigger an interrupt: * the RTC, when a real-time alarm event occurs (see Section 7.8 "Real-time Clock (RTC)" for more details) * the push-button, when its state changes * the power monitor, when it detects a failure or main battery lower than 2.7V * the boost, when it detects a failure * the buck, when it detects a failure Each of these sources can be individually masked to disable the corresponding interrupt. All the interrupt logic can also be globally disabled when the microcontroller needs to enter an uninterruptible state. The interrupt enable/disable logic is controlled through two independent registers. Refer to Section 6. "Register Tables" for detailed register and bit assignment. IRQ_EN is used to enable the interrupts, while IRQ_DIS is used to disable the interrupts. This strategy allows the controlling software to handle the interrupt mask completely independently for each interrupt source while avoiding read-modify-write operations. The register IRQ_MSK can be read to know the current interrupt mask. The sequence shown below in Table 5-3 shows an example of interrupt masking/unmasking. Table 5-3. Interrupt Masking/Unmasking Action What it Does Contents of IRQ_MSK Reset Disables all interrupts individually and globally. 00000000 Write 00000101 in IRQ_EN Enables the RTC interrupt and the power failure interrupt individually. The interrupts are still globally masked, no interrupt can be triggered yet. 00000101 Write 00000000 in IRQ_EN Nothing happens, only bits set at one have an effect. 00000101 Write 10000000 in IRQ_EN Enables the interrupts globally. The ITB pin will toggle to 0 if either the RTC or the power monitor requests an interrupt. 10000101 Write 00000001 in IRQ_DIS Disables the RTC interrupt. The power failure interrupt remains active. 10000100 18 AT73C224 6266A-PMAAC-08-Sep-08 AT73C224 Once the interrupt request is active on the ITB/RDY pin, the microcontroller has to handle it. To determine the reason for being interrupted, it reads the interrupt status register IRQ_STA (this action resets ITB/RDY). In this register, each potential interrupt source has a bit which indicates if it is responsible for triggering the request. Once the source is identified, the microcontroller performs the handling routine in an applicationdependant manner. It then needs to acknowledge the interrupt source to avoid being interrupted again for the same reason. 19 6266A-PMAAC-08-Sep-08 6. Register Tables Default values appear beneath the bit fields in the register description tables that follow. 6.1 System Registers 6.1.1 7-bit Fixed Address for TWI Register Name: TWIADDR Access Type: Read-only Address: 0x01 7 ALT 1 6 1 5 0 4 3 2 1 0 0 ADDR 1 0 0 1 * ADDR: Reads the TWI address currently in use. This field can be used to check the connectivity of the TWI, or to identify the AT73C224-x device. When ALT bit is 0, ADDR contains the alternate address (0x48). When ALT is 1, ADDR contains the default address (0x49). * ALT: Indicates if the TWI address is the default or the alternate. 0: the default address is selected. 1: the alternate address is selected. The reset value depends on the configuration of the fuses. When the fuses are blank, the reset value is 0 (manufacturing default). 6.1.2 Button Status Register Register Name: BT_SR Access Type: Read-only Address: 0x02 7 6 5 4 3 2 1 0 - - - - - - HIGH 0 LOW 0 * Low: 0: the button input has not been seen low. 1: the button input has been seen low. * High: 0: the button input has not been seen high. 1: the button input has been seen high. 20 AT73C224 6266A-PMAAC-08-Sep-08 AT73C224 6.1.3 Button Status Clear Command Register Register Name: BT_SCCR Access Type: Write-only Address: 0x03 7 6 5 4 3 2 1 0 - - - - - - HIGH 0 LOW 0 A minimum of 3 clock cycles of 15 kHz clock must be waited after any write operation before doing a new register access. * Low: 0: no effect. 1: clears LOW in BT_SR. * High: 0: no effect. 1: clears HIGH in BT_SR. 6.1.4 Button Interrupt Enable Register Register Name: BT_IER Access Type: Write-only Address: 0x04 7 6 5 4 3 2 1 0 - - - - - - HIGH 0 LOW 0 A minimum of 3 clock cycles of 15 kHz clock must be waited after any write operation before doing a new register access. * Low: 0: no effect. 1: the button low interrupt is enabled. * High: 0: no effect. 1: the button high interrupt is enabled. 21 6266A-PMAAC-08-Sep-08 6.1.5 Button Interrupt Disable Register Register Name: BT_IDR Access Type: Write-only Address: 0x05 7 6 5 4 3 2 1 0 - - - - - - HIGH 0 LOW 0 A minimum of 3 clock cycles of 15 kHz clock must be waited after any write operation before doing a new register access. * Low: 0: no effect. 1: the button low interrupt is disabled. * High: 0: no effect. 1: the button high interrupt is disabled. 6.1.6 Button Interrupt Mask Register Register Name: BT_IMR Access Type: Read-only Address: 0x06 7 6 5 4 3 2 1 0 - - - - - - HIGH 0 LOW 0 * Low: 0: the button low interrupt is disabled. 1: the button low interrupt is enabled. * High: 0: the button low interrupt is disabled. 1: the button low interrupt is enabled. 6.1.7 Software Shutdown Command Register Register Name: SHUTDN Access Type: Write-only Address: 0x07 7 6 5 4 3 2 1 0 - - - - - - - LOW 0 A minimum of 3 clock cycles of 15 kHz clock must be waited after any write operation before doing a new register access. 0: no effect. 1: shutdown the whole chip. 22 AT73C224 6266A-PMAAC-08-Sep-08 AT73C224 6.2 PMU Registers 6.2.1 BOOST Command Register Register Name: BST_CLR Access Type: Read/Write Address: 0x10 7 6 5 4 3 2 1 0 - - - - - - - EN(*) A minimum of 3 clock cycles of 15 kHz clock must be waited after any write operation before doing a new register access. * EN: Writing EN to 1 starts the BOOST/SEPIC converter. Writing En to 0 stops the BOOST/SEPIC converter. (*): Default value depends on the chosen AT73C224-x device (see Section 5.2). 23 6266A-PMAAC-08-Sep-08 6.2.2 BOOST Configuration Register Register Name: BST_CFG Access Type: Read/Write Address: 0x11 7 6 5 4 - - - - 3 2 1 0 1 1 ISHORT 1 0 * ISHORT: Selects the overcurrent threshold. When the external sense resistor is 50 mOhms, the lookup table below applies. ISHORT Threshold (Amps) 0000b 0.5 0001b 1.0 0010b 1.5 0011b 2.0 0100b 2.5 0101b 3.0 0110b 3.5 0111b 4.0 1000b 4.5 1001b 5.0 1010b 5.5 1011b 6.0 1100b 6.5 1101b 7.0 At the startup, it is recommended to put 1 Amp over current threshold in order not to generate a reset of the product. 24 AT73C224 6266A-PMAAC-08-Sep-08 AT73C224 6.2.3 BOOST Voltage Register Register Name: BST_VOLT Access Type: Read/Write Address: 0x12 7 6 - - 5 4 3 2 1 0 VOUT(*) * VOUT: Selects the output voltage of the regulator following the table below. VOUT should always be higher than VDD1 in BOOS T configuration (Application schematic 1). It can be programmed lower in SEPIC configuration (Application Schematic 2). VOUT [5:0] VOUT [V] VOUT [5:0] VOUT [V] 000000 not permitted 010101 3.3 000001 not permitted 010110 3.4 000010 not permitted 010111 3.5 000011 not permitted 011000 3.6 000100 not permitted 011001 3.7 000101 not permitted 011010 3.8 000110 not permitted 011011 3.9 000111 not permitted 011100 4.0 001000 not permitted 011101 4.1 001001 not permitted 011110 4.2 001010 not permitted 011111 4.3 001011 not permitted 100000 4.4 001100 not permitted 100001 4.5 001101 not permitted 100010 4.6 001110 not permitted 100011 4.7 001111 not permitted 100100 4.8 010000 not permitted 100101 4.9 010001 not permitted 100110 5.0 010010 not permitted 100111 5.1 010011 not permitted 101000 5.2 010100 3.2 -- (*): Default value depends on the chosen AT73C224-x device (see Section 5.2). The chosen value should always be higher than the supply of the cell (VDD1). 25 6266A-PMAAC-08-Sep-08 6.2.4 BUCK2 Control Register Register Name: BCK_CTROL Access Type: Read/Write Address: 0x13 7 6 5 4 3 2 1 0 - - - - - - BYP EN(*) A minimum of 3 clock cycles of 15 kHz clock must be waited after any write operation before doing a new register access. * EN: Writing EN to 1 starts the BUCK converter. Writing EN to 0 stops the BUCK converter. (*): Default value depends on the chosen AT73C224-x device (see Section 5.2). * BYP: Writing BYP to 1 puts the BUCK2 output voltage to VDD2. Writing BYP to 0 configures the BUCK2 in Normal operation (default). 26 AT73C224 6266A-PMAAC-08-Sep-08 AT73C224 6.2.5 BUCK2 Configuration Register Register Name: BCK_CFG Access Type: Read/Write Address: 0x14 7 6 OUTZ 1 SLIM 1 5 4 3 2 MODE 0 1 0 0 0 ISHORT 0 1 0 * ISHORT: Selects the overcurrent threshold. When the external sense resistor is 50 mOhms, the lookup table below applies. ISHORT Threshold (Amps) 0000b 1.01 0001b 1.08 0010b 1.15 0011b 1.22 0100b 1.29 0101b 1.36 0110b 1.43 0111b 1.5 1000b 1.57 1001b 1.64 1010b 1.71 1011b 1.78 1100b 1.85 1101b 1.92 1110b 1.99 1111b 2.06 * MODE: Selects the PWM pulse skipping mode. MODE Operation 00 Auto 01 PWM 10 Pulse skipping 11 Pass-through * SLIM: Selects the power-up mode. 0: current limitation. 1: slow start. 27 6266A-PMAAC-08-Sep-08 * OUTZ: Defines the state of the voltage output when the converter is off. 0: the output is forced to ground. 1: the output is left floating (Hz). 28 AT73C224 6266A-PMAAC-08-Sep-08 AT73C224 6.2.6 BUCK2 Voltage Register Register Name: BCK_VOLT Access Type: Read/Write Address: 0x15 7 6 5 - - - 4 3 2 1 0 VOUT(*) * VOUT: Selects the output voltage of the regulator following the table below. VOUT [4:0] VOUT [V] VOUT [4:0] VOUT [V] 00000 0.9 10000 1.28 00001 1.0 10001 1.42 00010 1.1 10010 1.56 00011 1.2 10011 1.7 00100 1.3 10100 1.86 00101 1.4 10101 2.00 00110 1.5 10110 2.14 00111 1.6 10111 2.29 01000 1.7 11000 2.43 01001 1.8 11001 2.57 01010 1.9 11010 2.71 01011 2.0 11011 2.86 01100 2.1 11100 3.00 01101 2.2 11101 3.14 01110 2.3 11110 3.30 01111 2.4 11111 3.42 (*): Default value depends on the chosen AT73C224-x device (see Section 5.2). 29 6266A-PMAAC-08-Sep-08 6.2.7 LDO3 Control Register Register Name: LDO3_CTRL Access Type: Read/Write Address: 0x16 7 6 5 4 3 2 1 0 - - - - - - - EN(*) A minimum of 3 clock cycles of 15 kHz clock must be waited after any write operation before doing a new register access. * EN: Writing EN to 1 starts the LDO3 regulator. Writing EN to 0 stops the LDO3 regulator. (*): Default value depends on the chosen AT73C224-x device (see Section 5.2). 6.2.8 LDO3 Configuration Register Register Name: LDO3_CFG Access Type: Read/Write Address: 0x17 7 6 5 4 3 2 1 0 - - - - - MODE 1 OUTZ 1 - * OUTZ: Defines the state of the voltage output when the regulator is off. 0: the output is forced to ground. 1: the output is left floating (Hz). This bit should be at 1 when LDO is on. * MODE: 0: RF mode, IMAX = 100 mA. 1: Smoother mode, IMAX = 200 mA. 30 AT73C224 6266A-PMAAC-08-Sep-08 AT73C224 6.2.9 LDO3 Voltage Register Register Name: LDO3_VOLT Access Type: Read/Write Address: 0x18 7 6 5 4 - - - - 3 2 1 0 VOUT(*) * VOUT Selects the output voltage of the regulator following the table below. VOUT [3:0] VOUT [V] 1000 1.3 0000 1.5 0001 1.6 0010 1.7 0011 1.8 0100 2.5 0101 2.6 0110 2.7 0111 2.8 1001 3.3 1010 4.9 others - (*): Default value depends on the chosen AT73C224-x device (see Section 5.2). 31 6266A-PMAAC-08-Sep-08 6.2.10 LDO4 Control Register Register Name: LDO4_CTRL Access Type: Read/Write Address: 0x19 7 6 5 4 3 2 1 0 - - - - - - - EN(*) A minimum of 3 clock cycles of 15 kHz clock must be waited after any write operation before doing a new register access. * EN: Writing EN to 1 starts the LDO4 regulator. Writing EN to 0 stops the LDO4 regulator. (*): Default value depends on the chosen AT73C224-x device (seeSection 5.2). 6.2.11 LDO4 Configuration Register Register Name: LDO4_CFG Access Type: Read/Write Address: 0x1A 7 6 5 4 3 2 1 0 - - - - - MODE 1 OUTZ 1 - * OUTZ: Defines the state of the voltage output when the regulator is off. 0: the output is forced to ground. 1: the output is left floating (Hz). This bit should be at 1 when LDO is on. * MODE: 0: RF mode, IMAX = 100 mA. 1: Smoother mode, IMAX = 200 mA. 32 AT73C224 6266A-PMAAC-08-Sep-08 AT73C224 6.2.12 LDO4 Voltage Register Register Name: LDO4_VOLT Access Type: Read/Write Address: 0x1B 7 6 5 4 - - - - 3 2 1 0 1 1 VOUT(*) 0 1 * VOUT Selects the output voltage of the regulator following the table below. VOUT[3:0] VOUT [V] 1000 1.3 0000 1.5 0001 1.6 0010 1.7 0011 1.8 0100 2.5 0101 2.6 0110 2.7 0111 2.8 1001 3.3 1010 4.9 others - (*): Default value depends on the chosen AT73C224-x device (see Section 5.2). 33 6266A-PMAAC-08-Sep-08 6.2.13 PMU Status Register Register Name: PMU_SR Access Type: Read-only Address: 0x1C 7 6 5 4 3 2 1 0 - 0 - 0 PF2 0 PG2 0 - 0 PF1 0 PG1 0 SHORT1 0 * SHORT1: 0: no overcurrent condition. 1: an overcurrent condition has been detected on the BOOST/SEPIC1 converter. * PG1: 0: no power good condition on BOOST/SEPIC1. 1: the power good condition has been met on BOOST/SEPIC1. * PF1: 0: no power failure condition on BOOST/SEPIC1. 1: the power failure condition has been met on BOOST/SEPIC1. * PG2: 0: no power good condition on BUCK2. 1: the power good condition has been met on BUCK2. * PF2: 0: no power failure condition on BUCK2. 1: the power failure condition has been met on BUCK2. 34 AT73C224 6266A-PMAAC-08-Sep-08 AT73C224 6.2.14 PMU Status Clear Command Register Register Name: PMU_SCCR Access Type: Write-only Address: 0x1D 7 6 5 4 3 2 1 0 - - PF2 - PG2 - - PF1 - PG1 - SHORT1 - A minimum of 3 clock cycles of 15 kHz clock must be waited after any write operation before doing a new register access. * SHORT1: 0: no effect. 1: clears SHORT1 in the PMU_SR. * PG1: 0: no power good condition on BOOST/SEPIC1. 1: clears PG1 in the PMU_SR. * PF1: 0: no effect. 1: clears PF1 in the PMU_SR. * PG2: 0: no effect. 1: clears PG2 in the PMU_SR. * PF2: 0: no effect. 1: clears PF2 in the PMU_SR. 35 6266A-PMAAC-08-Sep-08 6.2.15 PMU Interrupt Enable Register Register Name: PMU_IER Access Type: Write-only Address: 0x1E 7 6 5 4 3 2 1 0 - - - - PF2 0 PG2 0 - - PF1 0 PG1 0 SHORT1 0 A minimum of 3 clock cycles of 15 kHz clock must be waited after any write operation before doing a new register access. * SHORT1: 0: no effect. 1: the overcurrent detection interrupt on BOOST/SEPIC1 is enabled. * PG1: 0: no effect. 1: the power good interrupt of BOOST/SEPIC1 is enabled. * PF1: 0: no effect. 1: the power fail interrupt of BOOST/SEPIC1 is enabled. * PG2: 0: no effect. 1: the power good interrupt of BUCK2 is enabled. * PF2: 0: no effect. 1: the power fail interrupt of BUCK2 is enabled. 36 AT73C224 6266A-PMAAC-08-Sep-08 AT73C224 6.2.16 PMU Interrupt Disable Register Register Name: PMU_IDR Access Type: Write-only Address: 0x1F 7 6 5 4 3 2 1 0 - - PF2 - PG2 - - PF1 - PG1 - SHORT1 - A minimum of 3 clock cycles of 15 kHz clock must be waited after any write operation before doing a new register access. * SHORT1: 0: no effect. 1: the overcurrent detection interrupt on BOOST/SEPIC1 is disabled. * PG1: 0: no effect. 1: the power good interrupt of BOOST/SEPIC1 is disabled. * PF1: 0: no effect. 1: the power fail interrupt of BOOST/SEPIC1 is disabled. * PG2: 0: no effect. 1: the power good interrupt of BUCK2 is disabled. * PF2: 0: no effect. 1: the power fail interrupt of BUCK2 is disabled. 37 6266A-PMAAC-08-Sep-08 6.2.17 PMU Interrupt Mask Register Register Name: PMU_IMR Access Type: Read-only Address: 0x20 7 6 5 4 3 2 1 0 - - PF2 0 PG2 0 - PF1 0 PG1 0 SHORT1 0 A minimum of 3 clock cycles of 15 kHz clock must be waited after any read operation before doing a new register access. * SHORT1: 0: the overcurrent detection interrupt on BOOST/SEPIC1 is disabled. 1: the overcurrent detection interrupt on BOOST/SEPIC1 is enabled. * PG1: 0: the power good interrupt of BOOST/SEPIC1 is disabled. 1: the power good interrupt of BOOST/SEPIC1 is enabled. * PF1: 0: the power fail interrupt of BOOST/SEPIC1 is disabled. 1: the power fail interrupt of BOOST/SEPIC1 is enabled. * PG2: 0: the power good interrupt of BUCK2 is disabled. 1: the power good interrupt of BUCK2 is enabled. * PF2: 0: the power fail interrupt of BUCK2 is disabled. 1: the power fail interrupt of BUCK2 is enabled. 38 AT73C224 6266A-PMAAC-08-Sep-08 AT73C224 6.3 Interrupt Registers 6.3.1 Interrupt Enable Register Register Name: IRQ_EN Access Type: Write-only Address: 0x30 7 6 5 4 3 2 1 0 ALL - - DC2 - DC1 - - PWR - PB - RTC - A minimum of 3 clock cycles of 15 kHz clock must be waited after any write operation before doing a new register access. * RTC: Enables the RTC interrupt when written to 1. Writing 0 has no effect. * PB: Enables the push-button interrupt when written to 1. Writing 0 has no effect. * PWR: Enables the power failure interrupt when written to 1. Writing 0 has no effect * DC1: Enables the BOOST/SEPIC1 interrupt when written to 1. Writing 0 has no effect. * DC2: Enables the BUCK2 interrupt when written to 1. Writing 0 has no effect. * ALL: Writing to 1 globally enables all the interrupt sources that had been previously enabled individually. The interrupt setting for each source is restored. Writing 0 has no effect. 39 6266A-PMAAC-08-Sep-08 6.3.2 Interrupt Disable Register Register Name: IRQ_DIS Access Type: Write-only Address: 0x31 7 6 5 4 3 2 1 0 ALL - - DC2 - DC1 - - PWR - PB - RTC - A minimum of 3 clock cycles of 15 kHz clock must be waited after any write operation before doing a new register access. * RTC: Disables the RTC interrupt when written to 1. Writing 0 has no effect. * PB: Disables the push-button interrupt when written to 1. Writing 0 has no effect. * PWR: Disables the power failure interrupt when written to 1. Writing 0 has no effect * DC1: Disables the BOOST/SEPIC1 interrupt when written to 1. Writing 0 has no effect. * DC2: Disables the BUCK2 interrupt when written to 1. Writing 0 has no effect. * ALL: Writing to 1 globally disables all the interrupt sources. The individual setting of each interrupt source is saved. Writing 0 has no effect. 40 AT73C224 6266A-PMAAC-08-Sep-08 AT73C224 6.3.3 Interrupt Mask Register Register Name: IRQ_MSK Access Type: Read-only Address: 0x32 7 6 5 4 3 2 1 0 ALL 0 - 0 DC2 0 DC1 0 - 0 PWR 0 PB 0 RTC 0 This register summarizes the result of the successive interrupt enable/disable commands performed by writing into IRQ_EN/IRQ_DIS. * RTC: 0: the RTC interrupt is masked. 1: the RTC interrupt is unmasked. * PB: 0: the push-button interrupt is masked. 1: the push-button interrupt is unmasked. * PWR: 0: the power failure interrupt is masked. 1: the power failure interrupt is unmasked. * DC1: 0: the BOOST/SEPIC1 interrupt is masked. 1: the BOOST/SEPIC1 interrupt is unmasked. * DC2: 0: the BUCK2 interrupt is masked. 1: the BUCK2 interrupt is unmasked. * ALL: 0: the interrupt sources are globally masked. 1: the interrupt sources are globally unmasked. 41 6266A-PMAAC-08-Sep-08 6.3.4 Interrupt Status Register Register Name: IRQ_STA Access Type: Read-only Address: 0x33 7 6 5 4 3 2 1 0 - 0 - 0 DC2 0 DC1 0 - 0 PWR 0 PB 0 RTC 0 A minimum of 3 clock cycles of 15 kHz clock must be waited after any write operation before doing a new register access. Reading IRQ de-asserts the ITB signal. * RTC: 1: signals a pending interrupt request from the RTC. * PB: 1: signals a pending interrupt request from the push-button. * PWR: 1: signals a pending interrupt request from the power monitor. * DC1: 1: signals a pending interrupt request from the BOOST/SEPIC1. * DC2: 1: signals a pending interrupt request from the BUCK2. 42 AT73C224 6266A-PMAAC-08-Sep-08 AT73C224 6.4 RTC Registers 6.4.1 RTC Control Register Register Name: RT_CR Access Type: Read/Write Address: 0x40 7 6 5 CALEVSEL 0 4 TIMEVSEL 0 0 0 3 2 1 0 - - UPDCAL 0 UPDTIM 0 * UPDTIM: Writing 1 requests the RTC to stop the time counter so that it can be safely updated. The time counter is actually stopped only when ACKUPD is set in RTC_SR. Writing 0 restarts the time counter. * UPDCAL: Writing 1 requests the RTC to stop the calendar counter so that it can be safely updated. The calendar counter is actually stopped only when ACKUPD is set in RTC_SR. Writing 0 restarts the calendar counter. * TIMEVSEL: Selects the type of event to cause TIMEV to change in RTC_SR. 00 minute change 01 hour change 10 every day at midnight 11 every day at noon * CALEVSEL: Selects the type of event to cause CALEV to change in RTC_SR. 00 week change every Monday at time 00:00:00 01 month change every 1st of each month at time 00:00:00 10 11 year change every 1st of January at time 00:00:00 43 6266A-PMAAC-08-Sep-08 6.4.2 RTC Reset Register Register Name: RT_RR Access Type: Read/Write Address: 0x41 7 6 5 4 3 2 1 0 RST 0 - - - - - - - RST: RST = 0, Normal Operation RST=1, Reset the RTC 6.4.3 RTC Mode Register Register Name: RT_MR Access Type: Read/Write Address: 0x44 7 6 5 4 3 2 1 0 - - - - - - - HRMOD 0 * HRMOD: 0: 24-hour mode. 1: 12-hour mode. 44 AT73C224 6266A-PMAAC-08-Sep-08 AT73C224 The three Time writing registers are only writable concomitantly and must be written in the order as shown below: 1. RT_SEC 2. RT_MIN 3. RT_HOUR 6.4.4 Real-time Second Register Register Name: RT_SEC Access Type: Read/Write Address: 0x48 7 6 5 4 3 2 1 0 0 SEC 0 0 0 0 - 0 0 * SEC: The range is 0-59 encoded in Binary Coded Decimal (BCD). The lowest four bits encode the units, the higher bits encode the tens. This field must not be written unless the time counter has been stopped. 6.4.5 Real-time Minute Register Register Name: RT_MIN Access Type: Read/Write Address: 0x49 7 6 5 4 3 2 1 0 0 MIN 0 0 0 0 - 0 0 * MIN The range is 0-59 encoded in BCD. The lowest four bits encode the units, the higher bits encode the tens. This field must not be written unless the time counter has been stopped. 6.4.6 Real-time Hour Register Register Name: RT_HOUR Access Type: Read/Write Address: 0x4A 7 6 5 4 3 - AMPM 0 0 0 0 2 1 0 0 0 0 HOUR * HOUR: Depending on bit AMPM, the range can be 1-12 or 0-23, encoded in BCD. The lowest four bits encode the units, the higher bits encode the tens. This field must not be written unless the time counter has been stopped. * AMPM: This bit controls/reflects the AM/PM indicator in 12-hour mode. 0: AM. 1: PM. 45 6266A-PMAAC-08-Sep-08 The four Date writing registers are only writable concomitantly and must be written in the order as shown below: 1. RT_CENT 2. RT_YEAR 3. RT_MONTH 4. RT_DATE 6.4.7 Real-time Century Register Register Name: RT_CENT Access Type: Read/Write Address: 0x4C 7 6 - - 5 4 3 2 1 0 0 0 1 CENT 0 1 1 * CENT: The range is 19 - 20, encoded in BCD. The lowest four bits encode the units, the higher bits encode the tens. 6.4.8 Real-time Year Register Register Name: RT_YEAR Access Type: Read/Write Address: 0x4C 7 6 5 4 3 2 1 0 1 0 0 0 YEAR 1 0 0 1 * YEAR: The range is 1 - 12, encoded in BCD. The lowest four bits encode the units, the higher bits encode the tens. 6.4.9 Real-time Month Register Register Name: RT_Month Access Type: Read/Write Address: 0x4E 7 6 1 DAY 0 5 0 4 0 3 2 1 0 0 MONTH 0 0 1 * MONTH: The range is 1 - 12, encoded in BCD. The lowest four bits encode the units, the higher bits encode the tens. * DAY: The range is 1-7 and represents the day of the week. The relationship between the coding of this field and the actual day of the week, is user-defined. Especially, writing to this bit has no effect on the date counter. 46 AT73C224 6266A-PMAAC-08-Sep-08 AT73C224 6.4.10 Real-time Date Register Register Name: RT_DATE Access Type: Read/Write Address: 0x4F 7 6 1 DAY 0 5 0 4 1 3 2 1 0 1 DATE 0 0 0 * DATE: The range is 1 - 31, encoded in BCD and represents the day of the month. The lowest four bits encode the units, the higher bits encode the tens. 47 6266A-PMAAC-08-Sep-08 The three Time Alarm writing registers are only writable concomitantly and must be written in the order as shown below: 1. RT_SECA 2. RT_MINA 3. RT_HOURA 6.4.11 Real-time Second Alarm Register Register Name: RT_SECA Access Type: Read/Write Address: 0x50 7 6 SECEN 0 0 5 0 4 3 2 1 0 0 SEC 0 0 0 0 * SEC: This field is the alarm field corresponding to the BCD-encoded second counter. * SECEN 0: the second-matching alarm is disabled. 1: the second-matching alarm is enabled. 6.4.12 Real-time Minute Alarm Register Register Name: RT_MINA Access Type: Read/Write Address: 0x51 7 6 5 4 3 2 1 0 MINEN 0 0 0 0 MIN 0 0 0 0 * MIN: This field is the alarm field corresponding to the BCD-encoded minute counter. * MINEN 0: the minute-matching alarm is disabled. 1: the minute-matching alarm is enabled. 48 AT73C224 6266A-PMAAC-08-Sep-08 AT73C224 6.4.13 Real-time Hour Alarm Register Register Name: RT_HOURA Access Type: Read/Write Address: 0x52 7 6 HOUREN 0 AMPM 0 5 4 3 2 1 0 0 0 0 HOUR 0 0 0 * HOUR: This field is the alarm field corresponding to the BCD-encoded hour counter. * AMPM: This field is the alarm field corresponding to the BCD-encoded hour counter. * HOUREN 0: the hour-matching alarm is disabled. 1: the hour-matching alarm is enabled. 49 6266A-PMAAC-08-Sep-08 The two Date Alarm writing registers are only writable concomitantly and must be written in the order as shown below: 1. RT_MONTHA 2. RT_DATEA 6.4.14 Real-time Month Alarm Register Register Name: RT_MONTHA Access Type: Read/Write Address: 0x56 7 6 5 MTHEN 0 - - 4 3 2 1 0 0 0 MONTH 0 0 1 2 1 0 0 0 1 * MONTH: This field is the alarm field corresponding to the BCD-encoded month counter. * MTHEN 0: the month-matching alarm is disabled. 1: the month-matching alarm is enabled. 6.4.15 Real-time DATE Alarm Register Register Name: RT_DATEA Access Type: Read/Write Address: 0x56 7 6 DATEEN 0 - 5 4 3 DATE 0 0 0 * DATE: This field is the alarm field corresponding to the BCD-encoded day of the month counter. * DATEEN: 0: the day of the month-matching alarm is disabled. 1: the day of the month-matching alarm is enabled. 50 AT73C224 6266A-PMAAC-08-Sep-08 AT73C224 6.4.16 RTC Status Register Register Name: RTC_SR Access Type: Read-only Address: 0x58 7 6 5 4 3 2 1 0 - - - CALEV 0 TIMEV 0 SEC 0 ALARM 0 ACKUPD 0 * ACKUPD: 0: time and calendar registers should not be updated. 1: time and calendar can be updated safely (clock stopped). * ALARM: 0: no alarm matching condition occurred. 1: an alarm matching condition occurred. * SEC: 0: no second event has occurred since last clear. 1: at least one second event occurred since last clear. * TIMEV: 0: no time event has occurred since last clear. 1: at least one time event occurred since last clear. The time event is selected by the TIMEVSEL field in RTC_CR and can be any of the following events: minute change, hour change, noon, midnight (day change). * CALEV: 0: no calendar event occurred since last clear. 1: at least one calendar event occurred since last clear. The calendar event is selected in the CALEVSEL field in RTC_CR and can be any of the following events: week change, month change, or year change. 51 6266A-PMAAC-08-Sep-08 6.4.17 RTC Status Clear Command Register Register Name: RTC_SCCR Access Type: Write-only Address: 0x5C 7 6 5 4 3 2 1 0 - - - CALCLR 0 TIMCLR 0 SECCLR 0 ALRCLR 0 ACKCLR 0 * ACKCLR: 0: no effect. 1: clears the ACKUPD bit in RTC_SR. * ALCLR: 0: no effect. 1: clears the ALARM bit RTC_SR. * SECCLR: 0: no effect. 1: clears the SEC bit RTC_SR. * TIMCLR: 0: no effect. 1: clears the TIMEV bit RTC_SR. * CALCR: 0: no effect. 1: clears the CALEV bit RTC_SR. 52 AT73C224 6266A-PMAAC-08-Sep-08 AT73C224 6.4.18 RTC Interrupt Enable Register Register Name: RTC_IER Access Type: Write-only Address: 0x60 7 6 5 4 3 2 1 0 - - - CALEN 0 TIMEN 0 SECEN 0 ALREN 0 ACKEN 0 * ACKEN: 0: no effect. 1: the acknowledge for update interrupt is enabled. * ALREN: 0: no effect. 1: the alarm interrupt is enabled. * SECEN: 0: no effect. 1: the second periodic interrupt is enabled. * TIMEN: 0: no effect. 1: the selected time event interrupt is enabled. * CALEN: 0: no effect. 1: the selected calendar event interrupt is enabled. 53 6266A-PMAAC-08-Sep-08 6.4.19 RTC Interrupt Disable Register Register Name: RTC_IDR Access Type: Write-only Address: 0x64 7 6 5 4 3 2 1 0 - - - CALDIS 0 TIMDIS 0 SECDIS 0 ALRDIS 0 ACKDIS 0 * ACKDIS: 0: no effect. 1: the acknowledge for update interrupt is disabled. * ALRDIS: 0: no effect. 1: the alarm interrupt is disabled. * SECDIS: 0: no effect. 1: the second periodic interrupt is disabled. * TIMDIS: 0: no effect. 1: the selected time event interrupt is disabled. * CALDIS: 0: no effect. 1: the selected calendar event interrupt is disabled. 54 AT73C224 6266A-PMAAC-08-Sep-08 AT73C224 6.4.20 RTC Interrupt Mask Register Register Name: RTC_IMR Access Type: Read-only Address: 0x68 7 6 5 4 3 2 1 0 - - - CAL 0 TIM 0 SEC 0 ALR 0 ACK 0 * ACK: 0: the acknowledge for update interrupt is disabled. 1: the acknowledge for update interrupt is enabled. * ALR: 0: the alarm interrupt is disabled. 1: the alarm interrupt is enabled. * SEC: 0: the second periodic interrupt is disabled. 1: the second periodic interrupt is enabled. * TIM: 0: the selected time event interrupt is disabled. 1: the selected time event interrupt is enabled. * CAL: 0: the selected calendar event interrupt is disabled. 1: the selected calendar event interrupt is enabled. 55 6266A-PMAAC-08-Sep-08 6.4.21 RTC Valid Entry Register Register Name: RTC_VER Access Type: Read-only Address: 0x6C 7 6 5 4 3 2 1 0 - - - - NVCALA NVTIMA NVCAL NVTIM * NVTIM: 0: no invalid data has been detected in the time registers. 1: invalid data has been detected. * NVCAL: 0: no invalid data has been detected in the calendar registers. 1: invalid data has been detected. * NVTIMA: 0: no invalid data has been detected in the time alarm registers. 1: invalid data has been detected. * NVCALA: 0: no invalid data has been detected in the calendar alarm registers. 1: invalid data has been detected. 56 AT73C224 6266A-PMAAC-08-Sep-08 AT73C224 7. Electrical Characteristics With external components as listed in Table 4-1, Ta = -40C to 85C typical values are at Ta = 25C (unless otherwise specified). 7.1 Absolute Maximum Ratings Table 7-1. Absolute Maximum Ratings Operating Temperature (Industrial).............-40C to + 85C Storage Temperature..................................-55C to + 150C Power Supply Input........................................-0.3V to + 5.5V I/O Input.......................................................... -0.3V to + 5.5V *NOTICE: Stresses beyond those listed under "Absolute Maximum Ratings" may cause permanent damage to the device. This is a stress rating only and functional operation of the device at these or other conditions beyond those indicated in the operational sections of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. ESD (all pins)-..................................................................2 KV 7.2 Recommended Operating Conditions Table 7-2. Recommended Operating Conditions Parameter Condition Min Max Unit Operating Temperature -40 85 C Power Supply Input 2.8 5.25 V 57 6266A-PMAAC-08-Sep-08 7.3 Digital I/Os Digital I/Os are supplied by VDDIO. VDDIO is an input and must be externally connected. . Table 7-3. VDDIO Referred Digital I/Os Symbol Parameter VDDIO Conditions Min Typ Max Unit Operating Supply Voltage 1.75 3.6 5.25 V VIL Input Low Level Voltage -0.3 0.3x VDDIO V VIH Input High Level Voltage 0.7x VDDIO VDDIO + 0.3 V VOL Output Low Level Voltage 0.75x VDDIO VOH Output high Level Voltage Io Output Current Rp Pull-Up or Pull Down resistance when applicable V 90 120 0.25x VDDIO V 8 mA 150 k VDDIO referred pins EN, D1, D3, D4: CMOS inputs. Only VIH and VIL parameters are applicable. VDDIO referred pins POK: CMOS output. Only VOL, VOH parameters are applicable. VDDIO referred pin ITB, D2: CMOS BiDir. All parameters applicable. 7.4 Current Consumption Versus Modes Table 7-4. Status Quiescent Current in Different Operating Modes Conditions Battery Current Typ Max Off No battery is present N/A N/A Backup mode No Main Battery is present Backup battery present (and charged): . Running: RTC (dig + oscillator 32 kHz) - supply: vbackup pin 1 A 2 A Main Battery plugged in and higher than 2.8V Backup battery present (and charged) . Power supplies off (BOOST1, BUCK2, LDO3, LDO4) . Running: RTC, LDO_RTC - supply: vbat_ldortc POR, LPBG, VMON - supply: vdd0 pin 4A 9A 7A 17A Stand by 58 AT73C224 6266A-PMAAC-08-Sep-08 AT73C224 7.5 BOOST1: Step-up Converter Table 7-5. BOOST1 Electrical Characteristics Symbol Parameter VDD1 Conditions Min Typ Max Unit Operating Supply Voltage 2.8 3.6 5.25 V Fs Converter Frequency 400 900 1400 kHz IO Load Current 1 A VO1 Output Voltage BST_VOLT register (@12) - Step 100 mV VDD1 < VO1 3.2 5.2 V Error Output voltage precision Iload > 100 mA -10 -10 % Isc Shutdown Current BST_CLR register (@10); EN = 0 1 A (1) ILIM Current Limitation BST_CFG register (@11) 2.8_3.3_1A Efficiency at VDD1 = 2.8 V IO = 1 A, VDD1 = 2.8V, VO1 = 3.3V 90 % h3.6_5.2_1A Efficiency at VDD1 = 3.6 V IO = 1 A, VDD1 = 3.3V, VO1 = 5.2V 85 % tSTART Start-up Time No load 200 s VO1_5.2V Ripple Voltage peak-to-peak, IO = 1 A, VO1 = 5.2V Bandwidth = 20 MHz 200 mV VO1_5.2V Static Line Regulation VDD1: 2.8 to 4.2V - IO = 1 A - VO1 = 5.2V 200 mV VO1_5.2V Static Load Regulation VDD1: 3.6V - IO: 100 mA to 900 mA VO1 = 5.2V 50 mV Note: 0.5 7 A 1. Before the BOOST is turned on, it is recommended to establish low current limitation (typic: 1 Amp) to avoid current peak on main supply. 59 6266A-PMAAC-08-Sep-08 7.5.1 BOOST1: Typical Characteristics Figure 7-1. Efficiency BOOST1 - VO1 = 5V - 100 95 90 VDD1 = 4.2V VDD1 = 3.6V 85 VDD1 = 3V 80 VDD1 = 2.8V 75 70 65 60 0.01 0.1 1 Iload (A) 60 AT73C224 6266A-PMAAC-08-Sep-08 AT73C224 Figure 7-2. Load Regulation BOOST1 - VO1 = 5V - 5.32 5.3 5.28 5.26 5.24 5.22 5.2 5.18 VDD1 = 4.2V 5.16 VDD1 = 3.6V 5.14 5.12 5.1 VDD1 = 3V 5.08 5.06 VDD1 = 2.8V 5.04 5.02 0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8 0.9 1 Iload (A) The BOOST1 cell can be implemented using proper external components. (See Figure 4-3 "Application Schematic 3: BOOST in SEPIC Configuration (BUCK/BOOST)".) 61 6266A-PMAAC-08-Sep-08 7.6 BUCK2: Step-down Converter Table 7-6. BUCK2 Electrical Characteristics Symbol Parameter VDD2 Operating Supply Voltage Fs Converter Frequency ILOAD Load Current VO2 Output Voltage Error Output Voltage Precision ISC Shutdown Current BCK_CTROL register (@13), EN = 0 ISTB Stand-by Current BCK_CTROL register (@13), EN = 1, clock not present IMAX Short Circuit Current BCK_CFG register (@14) IPWM-PSK PWM - Pulse SKipping Current Threshold Automatic mode- VDD2 = 3.6V- VO2 = 1.8V 70 mA v Ripple Voltage PWM mode 10 mV TR Rise Time Bandgap already started, slow-start power up selected 1 ms VDC Static Line Regulation ILOAD = 500 mA, VDD2 from 2.8V to 5V PWM mode 80 mV VDC Static Load Regulation 1 mA (VO2 + 0.2V) Min Typ Max Unit 2.8 3.6 5.25 V 400 900 1400 kHz 0.5 A 0.9(1) 3.4 V -10 10 % 1 6 A 20 50 A 2 A 1 1. for device commanded in Dynamic Mode only. For devices commanded in Static Mode, the minimum voltage is 1.8V. The BUCK2 is a Pulse Width Modulator (PWM) / Pulse-Skipping (PSK) synchronous regulator that can be used to provide an accurate 0.9V to 3.4V programmable output voltage at 500 mA of maximum load current. Integrated current sensing is used to sense the DC/DC converter load current used for the overcurrent circuit protection and for the PWM / PSK mode selector. By default, the BUCK2 is in Automatic Mode: according to the load current value, the regulator is either in Pulse-Skipping mode (light load) or in PWM mode (high load). In dynamic mode, the user can select PWM or PSK mode, using the bits 4 and 5 of the BCK_CFG register (see Section 6 Register Tables). Note that the Automatic mode should not be used for output voltages below 1.8V. 62 AT73C224 6266A-PMAAC-08-Sep-08 AT73C224 7.6.1 BUCK2: Typical Characteristics Figure 7-3. Efficiency Manual/Automatic Modes Efficiency VO2 = 1.2V - Manual Mode: PSK/PWM VDD2 = 2.8V VDD2 = 3.6V VDD2 = 4.2V Efficiency (%) Efficiency (%) Efficiency VO2 = 0.9V - Manual Mode: PSK/PWM 100 95 90 85 80 75 70 65 60 55 50 45 40 35 30 25 20 15 10 5 0 0.001 VDD2 = 5V VDD2 = 2.8V PWM PSK VDD2 = 3.6V VDD2 = 4.2V VDD2 = 5V 0.01 Iload (A) 0.1 1 100 95 90 85 80 75 70 65 60 55 50 45 40 35 30 25 20 15 10 5 0 0.001 VDD2 = 5V VDD2 = 2.8V PWM PSK VDD2 = 3.6V VDD2 = 4.2V VDD2 = 5V 0.01 0.1 1 Efficiency VO2 = 3.3V - Manual Mode: PSK/PWM 100 95 90 85 VDD2 = 4.2V 80 VDD2 = 2.8V VDD2 = 3.6V VDD2 = 4.2V 75 VDD2 = 5V 70 Efficiency (%) Efficiency (%) VDD2 = 3.6V VDD2 = 4.2V Iload (A) Efficiency VO2 = 1.8V - Manual Mode: PSK/PWM 100 95 90 85 80 75 70 65 60 55 50 45 40 35 30 25 20 15 10 5 0 0.001 VDD2 = 2.8V VDD2 = 5V VDD2 = 2.8V PWM PSK VDD2 = 3.6V 65 60 55 50 PWM PSK 45 40 VDD2 = 4.2V 35 VDD2 = 4.2V 30 VDD2 = 5V 25 20 0.01 0.1 VDD2 = 5V 15 0.001 1 0.01 Iload (A) 0.1 1 Iload (A) Efficiency VO2 = 1.8V - Automatic Mode Efficiency VO2 = 3.3V - Automatic Mode 100 100 95 95 90 90 Efficiency (%) Efficiency (%) 85 80 75 70 VDD2 = 2.8V 65 VDD2 = 3.6V 60 VDD2 = 4.2V 55 VDD2 = 5V 85 VDD2 = 4.2V 80 VDD2 = 5V 75 70 65 50 60 45 0.001 0.01 Iload (A) 0.1 1 0.001 0.01 0.1 1 Iload (A) 63 6266A-PMAAC-08-Sep-08 7.6.2 BUCK2: Load Regulation of VO2 Figure 7-4. Load Regulation Load Regulation: VO2 = 0.9V (PWM mode) Load Regulation: VO2 = 1.2V (PWM mode) 0.93 1.23 0.92 1.22 VDD2 = 2.8V 1.21 VDD2 = 2.8V 0.9 VO2 (V) VO2 (V) 0.91 1.2 0.89 VDD2 = 3.6V 0.88 VDD2 = 4.2V 1.18 0.87 VDD2 = 5V 1.17 VDD2 = 3.6V 1.19 VDD2 = 4.2V VDD2 = 5.5V 1.16 0.86 1.15 0.85 0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5 0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 0.45 0.5 0.45 0.5 I load (A) I load (A) Load Regulation: VO2 = 3.3V (PWM mode) Load Regulation: VO2 = 1.8V (PWM Mode) 3.3 1.84 3.29 VDD2 = 2.8V 1.82 3.28 VDD2 = 4.2V 1.8 VO2 (V) VO2 (V) 3.27 VDD2 = 3.6V 1.78 VDD2 = 4.2V 3.26 3.25 1.76 3.24 1.74 VDD2 = 5.5V VDD2 = 5.5V 3.23 3.22 1.72 0 0.05 0.1 0.15 0.2 0.25 I load (A) 64 0.3 0.35 0.4 0.45 0.5 0 0.05 0.1 0.15 0.2 0.25 0.3 0.35 0.4 I load (A) AT73C224 6266A-PMAAC-08-Sep-08 AT73C224 7.7 LDO3 & LDO4 LDO3 and LDO4 are low-drop-out voltage regulators that can provide a 1.3V, 1.5V to 1.8V (step 100 mV), 2.5V to 2.8V (100 mV step) or 3.3V output voltage. Two kinds of applications are defined: "RF" mode (high PSRR and low noise) with 100 mA maximum load and "Smoother" mode with 200 mA maximum load. By default, the LDOs are configured in RF mode. If the load is higher than 100 mA, the user should pass into Smoother mode (see the register tables in Section 6.2.8 "LDO3 Configuration Register" and Section 6.2.11 "LDO4 Configuration Register"). An external 2.2 F ceramic capacitor is needed for the stability of each LDO. Table 7-7. LDO3 and LDO4 Electrical Characteristics Symbol Parameter Conditions VDD3&4 Operating Supply Voltage ILOAD_S Smoother Load current In Smoother mode ILOAD_RF RF Load current In RF mode Typ Max Unit 2.8 3.6 5.25 V 0 200 mA 0 100 mA 1.3 3.3 V -8 8 % 1 A Selection in LDO3_VOLT @ 18 and LDO4_VOLT @ 1B VO3, VO4 Output Voltage Vo Accuracy ILOAD=10mA ISC Shutdown Current GND output (LDO3_CFG@17 and LDO4_CFG@1A) IQQ Quiescent Current No load tR Rise Time VDC Line Regulation Static VDC n PSRR Min VDD3 > VO3 + 200mV VDD4 > VO4 + 200mV 20 A 100 s 2.8V < VDD3 < 5.25V, full load 10 mV Load Regulation Static 10 mA