PRODUCT DATASHEET AAT2603 Total Power Solution for Portable Applications General Description Features The AAT2603 is a highly integrated power management solution for handheld mobile systems. It provides six regulated voltages from a single-cell Lithium-ion/polymer battery or a 5V supply. * VIN Range: 2.7V to 5.5V * Two Step-Down Regulators DC-DC1(Buck1): 1.2A, Low Dropout Voltage * Externally Adjustable: VFBB1 = 0.6V VOUT Range: 0.6V to VINB1 * Fixed: VOUT = 3.3V Factory Programmable to any Two Voltage Levels from 0.6V to 4.0V * DC-DC2(Buck2): 0.6A, Low Dropout Voltage * Externally Adjustable: VFBB2 = 0.6V VOUT Range: 0.6V to VINB2 * Fixed: VOUT = 1.0V[SELB2='0']/1.3V[SELB2='1'] Factory Programmable to any Two Voltage Levels from 0.6V to 4.0V Fixed 1.5MHz Switching Frequency Internally Compensated Current Mode Control High Efficiency over the Entire Load Range Four LDO Regulators * LDO1: 400mA LDO * LDO2: 400mA LDO * LDO3: 200mA, Low Noise LDO * LDO4: 200mA, Low Noise LDO * Fast Turn-On and Turn-Off time * Short Circuit and Over-Current Protection * Over-Temperature Protection * Temperature Range: -40C to +85C * TQFN44-28 Package The six outputs are produced by six regulators; two switching step-down regulators and four low-dropout (LDO) regulators. Each voltage regulator has its own independent enable pin. The high efficiency step-down regulators are fully integrated and switch at a high 1.5 MHz fixed frequency. They automatically transition to variable frequency operation at light loads for improved efficiency. DC-DC1 (Buck1) is designed for high output current and low dropout voltage (200mV at 1.2A). DC-DC2 (Buck2) is a 600mA regulator with a two step dynamic output voltage capability. One option allows the output voltage of DC-DC2 (Buck2) to be set to either 1.0V or 1.3V with the SELB2 logic pin. LDO regulators LDO1 and LDO2 can supply up to 400mA of load current with output voltages adjustable down to 1.5V. LDO regulators LDO3 and LDO4 can supply up to 200mA of current and provide good noise and power supply rejection. LDO3 and LDO4 have output voltages externally adjustable down to 1.2V. The AAT2603 is available in a Pb-free thermally enhanced 28-pin TQFN44 package and is rated for operation over the -40C to +85C temperature range. Applications * * * * * 2603.2008.06.1.0 Handheld GPS Handheld Instruments PDAs and Handheld Computers Portable Media Players Smart Phones www.analogictech.com 1 PRODUCT DATASHEET AAT2603 Total Power Solution for Portable Applications Typical Application Circuit 2.7V to 5.5V L1 3.3H INB1 3.3V: 1.2A LX1 C INB1 4.7F C OUTB1 22F FBB 1 INB2 L2 1.2H CINB2 4.7F 1.0V & 1.3V: 600mA LX2 AIN COUTB2 10F FBB 2 CAIN 2.2F 1.5V (Minimum): 400mA OUTL1 INL 12 C INL12 2.2F C OUTL1 4.7F FBL 1 100k INL 34 AAT2603 OUTL2 CINL34 2.2F 1.5V (Minimum): 400mA C OUTL2 4.7F FBL 2 ENB1 100k ENB2 C OUTL3 4.7F ENL 2 FBL3 100k ENL 3 ENL 4 2 C OUTL4 4.7F FBL4 100k BYP AGND 1.2V (Minimum): 200mA OUTL4 SELB 2 C BYP 10nF 1.2V (Minimum): 200mA OUTL3 ENL 1 PGND 1 PGND2 www.analogictech.com 2603.2008.06.1.0 PRODUCT DATASHEET AAT2603 Total Power Solution for Portable Applications Pin Descriptions Pin # Symbol 1 LX2 2 ENB2 3 FBB2 4 5 ENL3 AGND 6 FBL3 7 8 9 OUTL3 INL34 OUTL4 10 FBL4 11 ENL4 12 BYP 13 ENL1 14 FBL1 15 16 17 OUTL1 INL12 OUTL2 18 FBL2 19 ENL2 20 AIN 21 FBB1 22 23 ENB1 SELB2 24 LX1 25 PGND1 26 INB1 27 INB2 28 PGND2 EP 2603.2008.06.1.0 Function DC-DC2 (Buck2) switching node. Connect the output inductor to LX2. Connected internally to the drains o f both high-side and low-side switches. DC-DC2 (Buck2) enable input. Active high. DC-DC2 (Buck2) feedback input. For externally adjustable versions, connect a resistor divider from Buck2 output to FBB2 to AGND to set the Buck2 output voltage. LDO3 enable input. Active high. Analog ground. Connect AGND to PGND1 and PGND2 as close as possible to the device. LDO3 feedback input. Connect a resistor divider from OUTL3 to FBL3 to AGND to set the LDO3 output voltage. LDO3 output. Should be closely decoupled to AGND with a 4.7F or greater capacitor. LDO3 and LDO4 input. Should be closely decoupled to AGND with a 2.2F or greater capacitor. LDO4 output. Should be closely decoupled to AGND with a 4.7F or greater capacitor. LDO4 feedback input. Connect a resistor divider from OUTL4 to FBL4 to AGND to set the LDO4 output voltage. LDO4 enable input. Active high. Reference Bypass. Bypass BYP to AGND with a 0.01F or greater capacitor to reduce the LDO1 output noise. LDO1 enable input. Active high. LDO1 feedback input. Connect a resistor divider from OUTL1 to FBL1 to AGND to set the LDO1 output voltage. LDO1 output. Should be closely decoupled to AGND with a 4.7F or greater capacitor. LDO1 and LDO2 input. Should be closely decoupled to AGND with a 2.2F or greater capacitor. LDO2 output. Should be closely decoupled to AGND with a 4.7F or greater capacitor. LDO2 feedback input. Connect a resistor divider from OUTL2 to FBL2 to AGND to set the LDO2 output voltage. LDO2 enable input. Active high. Analog voltage input. AIN is the bias supply for the device. Should be closely decoupled to AGND with a 2.2F or greater capacitor. DC-DC1 (Buck1) feedback input. For externally adjustable versions, connect a resistor divider from Buck1 output to FBB1 to AGND to set the Buck1 output voltage. DC-DC1 (Buck1) enable input. Active high. Dynamically adjusts the output voltage of DC-DC2 (Buck2) (Logic High=1.3V, Logic Low=1.0V) DC-DC1 (Buck1) switching node. Connect the output inductor to LX1. Connected internally to the drains of both high-side and low-side switches. DC-DC1 (Buck1) power ground. Connected internally to the source of the Buck1 N-channel synchronous rectifier. Connect PGND1 to PGND2 and AGND as close as possible to the device. DC-DC1 (Buck1) power input. Connected internally to the source of the Buck1 P-channel switch. Should be closely decoupled to PGND1 with a 4.7F or greater capacitor. DC-DC2 (Buck2) power input. Connected internally to the source of the Buck2 P-channel switch. Should be closely decoupled to PGND2 with a 4.7F or greater capacitor. DC-DC2 (Buck2) power ground. Connected internally to the source of the Buck2 N-channel synchronous rectifier. Connect PGND2 to PGND1 and AGND as close as possible to the device. Exposed paddle (bottom). Connect to ground as close as possible to the device. www.analogictech.com 3 PRODUCT DATASHEET AAT2603 Total Power Solution for Portable Applications Pin Configuration TQFN44-28 (Top View) ENB1 SELB2 LX1 PGND1 INB1 INB2 PGND2 28 LX2 ENB2 FBB2 ENL3 AGND FBL3 OUTL3 27 26 25 24 23 22 1 21 2 20 3 19 EP 4 18 5 17 6 16 7 15 8 9 10 11 12 13 FBB1 AIN ENL2 FBL2 OUTL2 INL12 OUTL1 14 FBL1 ENL1 BYP ENL4 FBL4 OUTL4 INL34 Part Number Descriptions Output Voltage1 Part Number DC-DC1 (Buck1) DC-DC2 (Buck2) (SELB2 = Low) DC-DC2 (Buck2) (SELB2 = High) LDOs 1-4 AAT2603INJ-1-T1 AAT2603INJ-2-T1 AAT2603INJ-3-T1 Ext. Adj. (VFBB1 = 600mV) 3.3V Ext. Adj. (VFBB1 = 600mV) Ext. Adj. (VFBB2 = 600mV) 1.0V 1.0V Ext. Adj. (VFBB2 = 775mV) 1.3V 1.3V Ext. Adj. (VFBLX = 1.2V) Ext. Adj. (VFBLX = 1.2V) Ext. Adj. (VFBLX = 1.2V) Absolute Maximum Ratings1 TA = 25C unless otherwise noted. Symbol Description INBX, INLXX, AIN to AGND ENBX, ENLX, FBBX, FBLX, BYP to AGND LX1 to PGND1 LX2 to PGND2 PGNDX to AGND, PGND1 to PGND2 Operating Temperature Range Storage Temperature Range Maximum Soldering Temperature (at leads, 10 sec) Value Units -0.3 to 6.0 -0.3 to VAIN+0.3 -0.3 to VINB1+0.3 -0.3 to VINB2+0.3 -0.3 to 0.3 -40 to 150 -65 to 150 300 V V V V V C C C Value Units 50 C/W W Recommended Operating Conditions Symbol JA PD Description Thermal Resistance Maximum Power Dissipation 2 1. Stresses above those listed in Absolute Maximum Ratings may cause permanent damage to the device. Functional operation at conditions other than the operating conditions specified is not implied. Only one Absolute Maximum rating should be applied at any one time. 4 www.analogictech.com 2603.2008.06.1.0 PRODUCT DATASHEET AAT2603 Total Power Solution for Portable Applications Electrical Characteristics1 VAIN = VINB1 = VINB2 = VINL12 = VINL34 = 3.6V, CBYP = 10nF, TA = -40C to 85C, unless noted otherwise. Typical values are at TA = 25C. Symbol Description Power Supply Input Voltage Range VIN IQ Quiescent Current ISHDN Input Shutdown Current UVLO Under-Voltage Lockout Conditions Min Typ 2.7 VENB1 = VENL3 = 3.6V, No Load , VFBB1 = VFBL3 = 3.6V VENx = AGND VIN rising VIN falling Hysteresis Oscillator Frequency FOSC tS,BYP Bypass Filter Startup Time VENB1 = 3.6V DC-DC1 (Buck1): 1.2A Step-Down Converter VOUT_RANGE Output Voltage Range TA = 25C, 20mA Load Output Voltage Accuracy VOUT_ACC TA = -40C to 85C, 20mA Load VOUT_TOL Output Voltage Tolerance 0A to 1.2A Load; VIN = 2.7V to 5.5V TA = 25C, 20mA Load VFBB1_ACC Feedback Voltage Accuracy TA = -40C to 85C, 20mA Load VOUT/IOUT Load Regulation 0A to 1.2A Load VOUT/VIN Line Regulation VIN = 2.7V to 5.5V ISHDN Shutdown Current VENB1 = GND ILX_LEAK LX Leakage Current VINB1 = 5.5V, VLX1 = 0V to VINB1 ILIM P-Channel Current Limit RDS(ON)H High Side Switch On-Resistance Low Side Switch On-Resistance RDS(ON)L tS Start-Up Time Enable to Output Regulation DC-DC2 (Buck2): 600mA Step-Down Converter VOUT_RANGE Output Voltage Range TA = 25C, 20mA Load VOUT_ACC Output Voltage Accuracy TA = - 40C to 85C, 20mA Load VOUT_TOL Output Voltage Tolerance 0mA to 600mA Load; VIN = 2.7V to 5.5V TA = 25C, 20mA Load Feedback Voltage Accuracy SELB2 = '0 TA = -40C to 85C, 20mA Load VFBB2_ACC TA = 25C, 20mA Load Feedback Voltage Accuracy SELB2 = '1' TA = -40C to 85C, 20mA Load VOUT/IOUT Load Regulation 0mA to 600mA Load VOUT/VIN Line Regulation VIN = 2.7V to 5.5V ISHDN Shutdown Current VENB2 = GND ILX_LEAK LX Leakage Current VINB2 = 5.5V, VLX2 = 0 to VINB2 ILIM P-Channel Current Limit High Side Switch On-Resistance RDS(ON)H RDS(ON)L Low Side Switch On-Resistance tS Start-Up Time Enable to Output Regulation 100 Max Units 5.5 200 1.0 2.6 V A A V V mV MHz s VINB1 +1.5 +2.5 +3.0 0.609 0.615 V % % % V V % %/V A A A m m s 1.8 250 1.5 200 0.6 -1.5 -2.5 -3.0 0.591 0.585 0.6 0.6 0.4 0.2 1.0 1.0 1.7 145 200 200 0.6 -1.5 -2.5 -3.0 0.591 0.585 0.763 0.756 0.6 0.6 0.775 0.775 0.2 0.2 VINB2 +1.5 +2.5 +3.0 0.609 0.615 0.787 0.794 1.0 1.0 1.3 230 180 200 V % % % V V % %/V A A A m m s 1. The AAT2603 is guaranteed to meet performance specification from -40C to +85C and is assured by design, characterization and correlation with statistical process controls. 2603.2008.06.1.0 www.analogictech.com 5 PRODUCT DATASHEET AAT2603 Total Power Solution for Portable Applications Electrical Characteristics1 VAIN = VINB1 = VINB2 = VINL12 = VINL34 = 3.6V, CBYP = 10nF, TA = -40C to 85C, unless noted otherwise. Typical values are at TA = 25C. Symbol Description Conditions 400mA LDO Regulators (LDO1, LDO2) VOUT_RANGE Output Voltage Range VFB_ACC VFB_TOL VOUT/IOUT VOUT/VIN IOUT(MAX) ILIM VDO PSRR tS 200mA LDO VOUT_RANGE VFB_ACC TA = 25C, 1mA Load TA = -40C to 85C, 1mA Load 0mA to 400mA Load, VIN = 2.7V to 5.5V 1mA to 400mA Load VIN = 3.3V to 5.5V, 100mA Load Feedback Voltage Accuracy Feedback Voltage Tolerance Load Regulation Line Regulation Maximum Output Current Output Current Limit Dropout Voltage Power Supply Rejection Ratio Start-Up Time Regulators (LDO3, LDO4) Output Voltage Range Min Typ 1.5 1.2 1.2 1.2 Max Units VINL12 1.218 1.23 1.236 V V V V % %/V mA mA mV dB s 0.3 0.08 400 1000 300 50 200 400mA Load f < 10KHz, COUTL1,2 = 4.7F, 10mA Load VBYP already enabled; COUT = 4.7F Feedback Voltage Accuracy Feedback Voltage Tolerance VFB_TOL VOUT/IOUT Load Regulation VOUT/VIN Line Regulation IOUT(MAX) Maximum Output Current ILIM Output Current Limit VDO Dropout Voltage PSRR Power Supply Rejection Ratio eN RMS Output Noise tS Start-Up Time Logic Inputs/Outputs VEN(H) Input Logic High Voltage VEN(L) Input Logic Low Voltage IEN Logic Input Current Thermal TSD Over-Temperature Shutdown Threshold TSD(HYS) Over-Temperature Shutdown Hysteresis TA = 25C, 1mA Load TA = -40C to +85C, 1mA Load 0mA to 200mA Load, VIN = 2.7V to 5.5V 0mA to 200mA Load VIN = 3.3V to 5.5V, 100mA Load 1.2 1.182 1.17 1.164 500 VINL34 1.218 1.23 1.236 0.2 0.02 200 1500 200 50 45 200 200mA Load f < 10KHz, COUTL3,4 = 4.7F, 10mA Load Power BW: 100~100KHz VBYP already enabled; COUT = 4.7F 350 1.4 0.4 1.5 VEN = 1.4V2 140 15 V V V V % %/V mA mA mV dB Vrms s V V A C C 1. The AAT2603 is guaranteed to meet performance specification from -40C to +85C and is assured by design, characterization and correlation with statistical process controls. 2. The enable pins have internal 1.6M pull-down resistors. 6 www.analogictech.com 2603.2008.06.1.0 PRODUCT DATASHEET AAT2603 Total Power Solution for Portable Applications Typical Characteristics--DC-DC1 (Buck1) Efficiency vs. Output Current Load Regulation (VOUTB1 = 3.3V; L = 3.3H) (VOUTB1 = 3.3V; L = 3.3H) 0.4 Output Voltage Error (%) 100 90 Efficiency (%) 80 70 60 50 40 30 VIN = 5V VIN = 4.2V VIN = 3.6V 20 10 0 0.1 1 10 100 1000 VIN = 5V VIN = 4.2V VIN = 3.6V 0.2 0 -0.2 -0.4 0.1 10000 1 Output Current (mA) Line Regulation 10000 (VOUTB1 = 3.3V; VIN = 4.2V) 0.4 IOUT = 1.2A IOUT = 600mA IOUT = 300mA IOUT = 100mA IOUT = 10mA IOUT = 1mA IOUT = 0.1mA 0.2 0 Output Voltage Error (%) Output Voltage Error (%) 1000 Output Voltage Error vs. Temperature 0.4 -0.2 -0.4 3.6 4.4 4 4.8 IOUT = 1.2A IOUT = 0.1mA 0.2 0 -0.2 -0.4 -40 5.2 -15 Input Voltage (V) 10 35 60 85 Temperature (C) P-Channel RDS(ON) vs. Input Voltage Load Transient (VOUTB1 = 3.3V) (VOUTB1 = 3.3V; VIN = 4.2V; IOUTB1 = 100mA to 1200mA; CFF = 0pF) 250 Output Voltage (AC Coupled) (top) 0.4 200 150 100 T = 120C T = 100C T = 85C T = 25C 50 3.1 3.5 3.9 4.3 4.7 5.1 0 -0.2 1.5 -0.4 1 0.5 0 5.5 Input Voltage (V) 2603.2008.06.1.0 0.2 Output Current (bottom) P-Channel RDS(ON) (m) 100 Output Current (mA) (VOUTB1 = 3.3V; L = 3.3H) 0 2.7 10 Time (100s/div) www.analogictech.com 7 PRODUCT DATASHEET AAT2603 Total Power Solution for Portable Applications Typical Characteristics--DC-DC1 (Buck1) Load Transient Load Transient (VOUTB1 = 3.3V; VIN = 4.2V; IOUTB1 = 100mA to 1200mA; CFF = 100pF) (VOUTB1 = 3.3V; VIN = 4.2V; IOUTB1 = 600mA to 1200mA; CFF = 0pF) 0.2 0.1 1.5 -0.2 1 0.5 0 Output Voltage (AC Coupled) (top) -0.1 0 -0.1 -0.2 1.5 1 0.5 0 Time (100s/div) Time (50s/div) Load Transient Line Transient (VOUTB1 = 3.3V; VIN = 4.2V; IOUTB1 = 600mA to 1200mA; CFF = 100pF) (VOUTB1 = 3.3V; VIN = 4.2V to 5V; IOUTB1 = 700mA) 1 0.5 0 Input Voltage (top) Output Voltage (AC Coupled) (top) 1.5 Output Current (bottom) 0 -0.1 4 0.1 0 -0.1 Output Voltage (AC Coupled) (bottom) 5 0.1 -0.2 Output Current (bottom) 0 Output Current (bottom) Output Voltage (AC Coupled) (top) 0.1 -0.2 Time (100s/div) Time (50s/div) Soft-Start (VOUTB1 = 3.3V; VIN = 4.2V; IOUTB1 = 1.2A) 4 2 0 4 3 2 1 Output Voltage (bottom) Enable Voltage (top) 6 0 Time (100s/div) 8 www.analogictech.com 2603.2008.06.1.0 PRODUCT DATASHEET AAT2603 Total Power Solution for Portable Applications Typical Characteristics--DC-DC2 (Buck2) Efficiency vs. Output Current Efficiency vs. Output Current (VOUTB2 = 1.3V; L = 1.5H) (VOUTB2 = 1V; L = 1.2H) 100 100 90 90 80 Efficiency (%) Efficiency (%) 80 70 60 50 40 VIN = 5V VIN = 4.2V VIN = 3.6V VIN = 2.7V 30 20 10 70 60 50 40 VIN = 5V VIN = 4.2V VIN = 3.6V VIN = 2.7V 30 20 10 0 0 0.1 1 10 100 1000 0.1 1 10 Output Current (mA) Load Regulation Load Regulation (VOUTB2 = 1.3V; L = 1.5H) (VOUTB2 = 1V; L = 1.2H) Output Voltage Error (%) Output Voltage Error (%) 0.4 VIN = 5V VIN = 4.2V VIN = 3.6V VIN = 2.7V 0.2 0 -0.2 -0.4 0.1 1 100 10 VIN = 5V VIN = 4.2V VIN = 3.6V VIN = 2.7V 0.2 0 -0.2 -0.4 0.1 1000 1 10 Output Current (mA) 100 1000 10000 Output Current (mA) Line Regulation Line Regulation (VOUTB2 = 1.3V; L = 1.5H) (VOUTB2 = 1V; L = 1.2H) 0.6 0.6 IOUT = 600mA IOUT = 300mA IOUT = 100mA IOUT = 10mA IOUT = 1mA IOUT = 0.1mA 0.4 0.2 0 Output Voltage Error (%) Output Voltage Error (%) 1000 Output Current (mA) 0.4 -0.2 -0.4 -0.6 2.7 100 3.1 3.5 3.9 4.3 4.7 5.1 5.5 0.2 0 -0.2 -0.4 -0.6 2.7 3.1 3.5 3.9 4.3 4.7 5.1 5.5 Input Voltage (V) Input Voltage (V) 2603.2008.06.1.0 IOUT = 600mA IOUT = 300mA IOUT = 100mA IOUT = 10mA IOUT = 1mA IOUT = 0.1mA 0.4 www.analogictech.com 9 PRODUCT DATASHEET AAT2603 Total Power Solution for Portable Applications Typical Characteristics--DC-DC2 (Buck2) Output Voltage Error vs. Temperature Switching Frequency vs. Input Voltage (VOUTB2 = 1.3V; VIN = 3.6V) (VOUTB2 = 1.3V; IOUTB2 = 600mA) Switching Frequency (MHz) Output Voltage Error (%) 0.6 IOUT = 600mA IOUT = 0.1mA 0.4 0.2 0 -0.2 -0.4 -0.6 -40 -15 10 35 60 85 1.505 1.5 1.495 1.49 1.485 1.48 1.475 1.47 1.465 1.46 2.7 3.9 4.3 4.7 5.1 5.5 Load Transient (VOUTB2 = 1.3V) (VOUTB2 = 1.3V; VIN = 3.6V; IOUTB2 = 100mA to 600mA; CFF = 0pF) 0.05 Output Voltage (AC Coupled) (top) 0.1 350 300 250 200 150 T = 120C T = 100C T = 85C T = 25C 100 50 3.1 3.5 3.9 4.3 4.7 5.1 0 -0.05 -0.1 1 0.5 Output Current (bottom) P-Channel RDS(ON) (m) 3.5 P-Channel RDS(ON) vs. Input Voltage 400 0 2.7 3.1 Input Voltage (V) Temperature (C) 0 5.5 Input Voltage (V) Time (50s/div) Load Transient Load Transient (VOUTB2 = 1.3V; VIN = 3.6V; IOUTB2 = 100mA to 600mA; CFF = 100pF) (VOUTB2 = 1.3V; VIN = 3.6V; IOUTB2 = 300mA to 600mA; CFF = 0pF) -0.1 1 0.5 0 0 -0.05 Time (50s/div) 10 1 0.5 Output Current (bottom) -0.05 Output Voltage (AC Coupled) (top) 0.05 0 Output Current (bottom) Output Voltage (AC Coupled) (top) 0.1 0.05 0 Time (20s/div) www.analogictech.com 2603.2008.06.1.0 PRODUCT DATASHEET AAT2603 Total Power Solution for Portable Applications Typical Characteristics--DC-DC2 (Buck2) Load Transient Line Transient (VOUTB2 = 1.3V; VIN = 3.6V; IOUTB2 = 300mA to 600mA; CFF = 100pF) (VOUTB2 = 1.3V; VIN = 3.6 to 4.2V; IOUTB2 = 300mA) 1 0.5 0 Input Voltage (top) Output Voltage (AC Coupled) (top) -0.05 Output Current (bottom) 0 0.3 5 0.25 4 0.2 3 0.15 2 0.1 1 0.05 0 0 -1 -0.05 -2 -0.1 Output Voltage (AC Coupled) (bottom) 0.05 6 Time (50s/div) Time (20s/div) Soft-Start 4 2 0 1.5 1 0.5 Output Voltage (bottom) Enable Voltage (top) (VOUTB2 = 1.3V; VIN = 3.6V; IOUTB2 = 600mA) 0 Time (100s/div) 2603.2008.06.1.0 www.analogictech.com 11 PRODUCT DATASHEET AAT2603 Total Power Solution for Portable Applications Typical Characteristics--LDO1/LDO2 Load Regulation Load Regulation (VOUTL1&2 = 3V; VIN = 3.6V) (VOUTL1&2 = 1.5V; VIN = 3.6V) 0.4 Output Voltage Error (%) Output Voltage Error (%) 0.4 0.2 0 -0.2 -0.4 0.1 1 10 100 0.2 0 -0.2 -0.4 0.1 1000 1 Output Current (mA) Line Regulation Output Voltage Error (%) 0.4 IOUT = 400mA IOUT = 100mA IOUT = 10mA IOUT = 1mA IOUT = 0.1mA 0.2 0 -0.2 -0.4 2.7 3.1 3.5 3.9 4.3 4.7 5.1 5.5 0.2 0 -0.2 IOUT = 400mA IOUT = 0.1mA -0.4 -40 -15 Input Voltage (V) 10 35 60 85 Temperature (C) Load Transient Load Transient (VOUTL1&2 = 2.8V; VIN = 3.6V; IOUTL1&2 = 1mA to 50mA) (VOUTL1&2 = 2.8V; VIN = 3.6V; IOUTL1&2 = 1mA to 200mA) 0.1 0.02 0.05 0.05 0 0 -0.05 -0.1 0.4 0.2 Output Current (bottom) -0.04 Output Current (bottom) 0 -0.02 Output Voltage (AC Coupled) (top) 0.04 0 -0.05 -0.2 Time (100s/div) 12 1000 (VOUTL1&2 = 2.8V; VIN = 3.6V) 0.4 Output Voltage Error (%) 100 Output Voltage Error vs. Temperature (VOUTL1&2 = 1.5) Output Voltage (AC Coupled) (top) 10 Output Current (mA) Time (100s/div) www.analogictech.com 2603.2008.06.1.0 PRODUCT DATASHEET AAT2603 Total Power Solution for Portable Applications Load Transient Line Transient (VOUTL1&2 = 2.8V; VIN = 3.6V; IOUTL1&2 = 1mA to 400mA) (VOUTL1&2 = 2.8V; VIN = 3.6 to 4.2V; IOUTL1&2 = 400mA) 5 0.1 4 -0.1 -0.2 0.5 0 3 0.2 0.1 0 Output Voltage (bottom) 0 Input Voltage (top) 0.2 Output Current (bottom) Output Voltage (AC Coupled) (top) Typical Characteristics--LDO1/LDO2 -0.1 -0.2 Time (20s/div) Time (200s/div) Soft-Start 4 2 0 3 2 1 Output Voltage (bottom) Enable Voltage (top) (VOUTL1&2 = 2.8V; VIN = 3.6V; IOUTL1&2 = 400mA) 0 Time (500s/div) 2603.2008.06.1.0 www.analogictech.com 13 PRODUCT DATASHEET AAT2603 Total Power Solution for Portable Applications Typical Characteristics--LDO3/LDO4 Load Regulation Load Regulation (VOUTL3&4 = 3V; VIN = 3.6V) (VOUTL3&4 = 1.2V; VIN = 3.6V) 0.4 Output Voltage Error (%) Output Voltage Error (%) 0.4 0.2 0 -0.2 0.2 0 -0.2 -0.4 -0.4 0 1 100 10 0.1 1000 1 Output Current (mA) Output Voltage Error vs. Temperature (VOUTL3&4 = 1.2V) (VOUTL3&4 = 2.8V; VIN = 3.6V) 0.4 0.4 IOUT = 400mA IOUT = 100mA IOUT = 10mA IOUT = 1mA IOUT = 0.1mA 0.2 Output Voltage Error (%) Output Voltage Error (%) 1000 Output Current (mA) Line Regulation 0 -0.2 -0.4 2.7 3.1 3.5 3.9 4.3 4.7 5.1 5.5 0.2 0 -0.2 IOUT = 200mA IOUT = 0.1mA -0.4 -40 Input Voltage (V) -15 10 35 60 85 Temperature (C) Load Transient Load Transient (VOUTL3&4 = 2.8V; VIN = 3.6V; IOUTL3&4 = 1mA to 50mA) (VOUTL3&4 = 2.8V; VIN = 3.6V; IOUTL3&4 = 1mA to 100mA) 0.02 0.05 Output Voltage AC Coupled) (top) -0.02 0 -0.02 -0.04 0.1 Output Current (bottom) 0 -0.01 Output Current (bottom) Output Voltage (AC Coupled) (top) 0.01 0 0 Time (100s/div) 14 100 10 Time (100s/div) www.analogictech.com 2603.2008.06.1.0 PRODUCT DATASHEET AAT2603 Total Power Solution for Portable Applications Typical Characteristics--LDO3/LDO4 Load Transient Line Transient (VOUTL3&4 = 2.8V; VIN = 3.6V; IOUTL3&4 = 1mA to 200mA) (VOUTL3&4 = 2.8V; VIN = 3.6 to 4.2V; IOUTL3&4 = 200mA) 5 0.2 0 Input Voltage (AC Coupled) (top) -0.05 4 3 0.15 0.1 0.05 0 Output Voltage (bottom) 0 Output Current (bottom) Output Voltage (AC Coupled) (top) 0.05 -0.05 -0.1 Time (100s/div) Time (20s/div) Soft-Start (VOUTL3&4 = 2.8V; VIN = 3.6V; IOUTL3&4 = 200mA) 4 2 0 3 2 1 Output Voltage (bottom) Enable Voltage (top) 6 0 Time (500s/div) 2603.2008.06.1.0 www.analogictech.com 15 PRODUCT DATASHEET AAT2603 Total Power Solution for Portable Applications Functional Block Diagram AIN INB 2 INB 1 LX1 ENB1 DC-DC1 (Buck1) ENB2 FBB 1 PGND 1 ENL 1 ENL 2 LX2 Interface and Support DC-DC2 (Buck2) ENL 3 FBB 2 PGND 2 ENL 4 OUTL 1 SELB 2 LDO1 FBL 1 BYP OUTL 2 LDO2 FBL 2 INL12 OUTL 3 LDO3 FBL 3 OUTL 4 INL34 LDO4 FBL 4 AGND Functional Description The AAT2603 is a highly integrated voltage regulating power management unit for mobile handsets or other portable devices. It includes two switch-mode step-down converters (600mA [DC-DC2] and 1.2A [DC-DC1]), and four low-dropout (LDO) regulators (two: 200mA, two: 400mA). It operates from an input voltage between 2.7V and 5.5V making it ideal for lithium-ion or 5V regulated power sources. All six converters have separate enable pins for ease of use. Step-Down Converters The AAT2603 switch-mode, step-down converters are constant frequency peak current mode PWM converters with internal compensation. The input voltage range is 16 2.7V to 5.5V. The output voltage range is 0.6V to VIN. The high 1.5MHz switching frequency allows the use of small external inductor and capacitor. The step-down converters offer soft-start to limit the current surge seen at the input and eliminate output voltage overshoot. The current across the internal P-channel power switch is sensed and turns off when the current exceeds the current limit. Also, thermal protection completely disables switching if internal dissipation becomes excessive, thus protecting the device from damage. The junction over-temperature threshold is 140C with 15C of hysteresis. DC-DC1 (Buck1) is designed for a peak continuous output current of 1.2A. The high-side power switch has been designed with a low RDSON of 145m to allow for a minimum dropout voltage of 174mV at full load current. www.analogictech.com 2603.2008.06.1.0 PRODUCT DATASHEET AAT2603 Total Power Solution for Portable Applications It was designed to maintain over 90% efficiency at its maximum rated output current load of 1.2A with a 3.3V output. Peak efficiency is above 95%. Buck1 has excellent transient response, load and line regulation. Transient response time is typically less than 20s. The peak input current is limited to 1.7A. DC-DC2 (Buck2) is a 600mA step-down regulator designed to dynamically shift between two output voltages by toggling the SELB2 pin. The internal reference voltage of the buck regulator is changed based on the position of the SELB2 pin. Buck2 is designed to maintain over 85% efficiency at its maximum rated output current of 600mA with a 1.2V output. Peak efficiency is above 90%. Buck2 has excellent transient response, load and line regulation. The peak inductor current is limited to 1.3A. The two step-down converters on the AAT2603 have highly flexible output voltage programming capability. The output voltages can be factory programmed to preset output voltages or set by external resistors. The "Part Number Descriptions" table lists the available voltage options for step-down converters Buck1 and Buck2. Option 1 has externally adjustable output voltages for both step-down converters. The dynamic voltage scaling for Buck2 is still useable with external feedback resistors. When SELB2 is in the low position the feedback voltage is compared to a 600mV reference, while when SELB2 is high the reference voltage is 775mV. For most other options, the output voltages of Buck2 are factory programmed. LDO Regulators Application Information DC-DC1/DC-DC2 The step-down converter uses peak current mode control with slope compensation to maintain stability for duty cycles greater than 50%. The output inductor value must be selected so the inductor current down slope meets the internal slope compensation requirements. Table 1 displays suggested inductor values for various output voltages. Manufacturer's specifications list both the inductor DC current rating, which is a thermal limitation, and the peak current rating, which is determined by the saturation characteristics. The inductor should not show any appreciable saturation under normal load conditions. Some inductors may meet the peak and average current ratings yet result in excessive losses due to a high DCR. Always consider the losses associated with the DCR and its effect on the total converter efficiency when selecting an inductor. It is recommended that the inductor current rating exceed the current limit of the step-down converter. See Table 2 for example inductor values/vendors. Input Capacitor Select a 4.7F to 10F X7R or X5R ceramic capacitor for the input; see Table 3 for suggested capacitor components. To estimate the required input capacitor size, determine the acceptable input ripple level (VPP) and solve for CIN (CINB1/CINB2). The calculated value varies with input voltage and is a maximum when VIN is double the output voltage. The AAT2603 includes four LDO regulators. The regulators operate from the 2.7V to 5.5V input voltage to a regulated output voltage. The LDO regulators have adjustable output voltages set by resistors. Each LDO consumes 50uA of quiescent current. The two 200mA LDO regulators are stable with a small 4.7F ceramic output capacitor. The low 200mV dropout voltage at 200mA load allows a regulated output voltage approaching the input voltage. Low output noise voltage and high power supply rejection make these regulators ideal for powering noise sensitive circuitry. The two 400mA LDO regulators are stable with a small 4.7F ceramic output capacitor. The low 300mV dropout voltage at 400mA load allows a regulated output voltage approaching the input voltage. These LDOs offer high power supply rejection. 2603.2008.06.1.0 CIN = V VO * 1- O VIN VIN VPP - ESR * FS IO VO V 1 * 1 - O = for VIN = 2 * VO VIN VIN 4 CIN(MIN) = 1 VPP - ESR * 4 * FS IO Always examine the ceramic capacitor DC voltage coefficient characteristics when selecting the proper value. For example, the capacitance of a 10F, 6.3V, X5R ceramic capacitor with 5.0V DC applied is actually about 6F. www.analogictech.com 17 PRODUCT DATASHEET AAT2603 Total Power Solution for Portable Applications Part Number/ Type Manufacturer TDK Inductance (H) Rated Current (A) DCR (m) (max) 1.2 1.8 2.2 3.3 1 1.8 2.7 3.3 1.2 1.8 2.2 2.7 3.3 1 1.5 2.2 3.3 4.3 3.6 3.2 2.5 2.6 2.35 2.03 1.8 2.8 2.45 2.35 1.95 1.8 4 3.7 3.2 2.9 25 32 40 60 30 50 60 65 20 25 28 30 35 19 (typ) 22 (typ) 29 (typ) 36 (typ) LTF5022 WE-TPC Type M Wurth Electronik WE-TPC Type MH Murata LQH55D Size (mm) LxWxH 5x5.2x2.2 4.8x4.8x1.8 4.8x4.8x2.8 5x5.7x4.7 Table 1: Suggested Inductor Components. Configuration Output Voltage Inductor Value Adjustable and Fixed Output Voltage 1V, 1.2V, 1.3V 1.5V, 1.8V 2.5V 2.8V, 3.3V 1.0H to 1.2H 1.5H to 1.8H 2.2H to 2.7H 3.3H The input capacitor RMS ripple current varies with the input and output voltage and will always be less than or equal to half of the total DC load current. VO V * 1- O = VIN VIN Table 2: Inductor Values for Specific Output Voltages. D * (1 - D) = 0.52 = 1 2 for VIN = 2 * VO. The maximum input capacitor RMS current is: IRMS = IO * Manufacturer AVX TDK Murata Taiyo Yuden VO V * 1- O VIN VIN Part Number Value Voltage 0603ZD105K 0603ZD225K C1608X5R1E105K C1608X5R1C225K C1608X5R1A475K C2012X5R1A106K C3216X5R1A226K GRM188R61C105K GRM188R61A225K GRM219R61A106K GRM31CR71A226K LMK107BJ475KA 1F 2.2F 1F 2.2F 4.7F 10F 22F 1F 2.2F 10F 22F 4.7F 10 10 25 16 10 10 10 16 10 10 10 10 Temp. Co. Case X5R 0603 0603 X5R 0805 1206 X5R X7R X5R 0603 0805 1206 0603 Table 3: Suggested Capacitor Components. 18 www.analogictech.com 2603.2008.06.1.0 PRODUCT DATASHEET AAT2603 Total Power Solution for Portable Applications IRMS(MAX) = VO * 1- IO 2 VO V The term V appears in both the input voltage ripple and input capacitor RMS current equations and is a maximum when VO is twice VIN. This is why the input voltage ripple and the input capacitor RMS current ripple are a maximum at 50% duty cycle. IN IN The input capacitor provides a low impedance loop for the edges of pulsed current drawn by the AAT2603 stepdown switching regulators. Low ESR/ESL X7R and X5R ceramic capacitors are ideal for this function. To minimize stray inductance, the capacitor should be placed as closely as possible to the IC. This keeps the high frequency content of the input current localized, minimizing EMI and input voltage ripple. A laboratory test set-up typically consists of two long wires running from the bench power supply to the evaluation board input voltage pins. The inductance of these wires, along with the low-ESR ceramic input capacitor, can create a high Q network that may affect converter performance. This problem often becomes apparent in the form of excessive ringing in the output voltage during load transients. Errors in the loop phase and gain measurements can also result. Since the inductance of a short PCB trace feeding the input voltage is significantly lower than the power leads from the bench power supply, most applications do not exhibit this problem. In applications where the input power source lead inductance cannot be reduced to a level that does not affect the converter performance, a high ESR tantalum or aluminum electrolytic should be placed in parallel with the low ESR, ESL bypass ceramic. This dampens the high Q network and stabilizes the system. Output Capacitor The output capacitor limits the output ripple and provides holdup during large load transitions. A 10F to 22F X5R or X7R ceramic capacitor typically provides sufficient bulk capacitance to stabilize the output during large load transitions and has the ESR and ESL characteristics necessary for low output ripple. A 10F X5R or X7R ceramic capacitor is required for DC-DC2 and a 22F X5R or X7R ceramic capacitor is required for DC-DC1; see Table 3 for suggested capacitor components. 2603.2008.06.1.0 The output voltage droop due to a load transient is dominated by the capacitance of the ceramic output capacitor. During a step increase in load current, the ceramic output capacitor alone supplies the load current until the loop responds. Within several switching cycles, the loop responds and the inductor current increases to match the load current demand. The relationship of the output voltage droop during the several switching cycles to the output capacitance can be estimated by: COUT = 3 * ILOAD VDROOP * FS Once the average inductor current increases to the DC load level, the output voltage recovers. The above equation establishes a limit on the minimum value for the output capacitor with respect to load transients. The internal voltage loop compensation also limits the minimum output capacitor value to 10F for DC-DC2 and 22F for DC-DC1. This is due to its effect on the loop crossover frequency (bandwidth), phase margin, and gain margin. Increased output capacitance will reduce the crossover frequency with greater phase margin. The maximum output capacitor RMS ripple current is given by: IRMS(MAX) = 1 VOUT * (VIN(MAX) - VOUT) L * FS * VIN(MAX) 2* 3 * Dissipation due to the RMS current in the ceramic output capacitor ESR is typically minimal, resulting in less than a few degrees rise in hot-spot temperature. Feedback Resistor Selection Resistors R1 and R2 of Figure 1 program the output to regulate at a voltage higher than 0.6V. To limit the bias current required for the external feedback resistor string while maintaining good noise immunity, the minimum suggested value for R2 is 59k. Although a larger value will further reduce quiescent current, it will also increase the impedance of the feedback node, making it more sensitive to external noise and interference. Table 42 summarizes the resistor values for various output voltages with R2 set to either 59k for good noise immunity or 221k for reduced no load input current. www.analogictech.com 19 PRODUCT DATASHEET AAT2603 Total Power Solution for Portable Applications 1.5V VOUT R1 = V -1 * R2 = 0.6V - 1 * 59k = 88.5k REF The AAT2603 step-down regulators, combined with an external feedforward capacitor (CFF in Figure 1), deliver enhanced transient response for extreme pulsed load applications. Output Capacitor VDC-DC1/VDC-DC2 CFF For proper load voltage regulation and operational stability, a capacitor is required between pins VOUTLX and AGND. The COUTLX capacitor connection to the LDO regulator ground pin should be made as direct as practically possible for maximum device performance. R1 VFBB1/VFBB2 R2 Figure 1: AAT2603 DC-DC1/DC-DC2 External Resistor Output Voltage Programming. VOUT (V) R2 = 59k R1 (k) R2 = 221kW R1 (k) 0.9 1.0 1.1 1.2 1.3 1.4 1.5 1.8 1.85 2.0 2.5 3.3 29.4 39.2 49.9 59.0 68.1 78.7 88.7 118 124 137 187 267 113K 150K 187K 221K 261K 301K 332K 442K 464K 523K 715K 1.00M Table 4: Feedback Resistors for DC-DC1 and DC-DC2. LDO1/LDO2/LDO3/LDO4 Input Capacitor Typically, a 2.2F or larger capacitor is recommended for CINL12/CINL34/CAIN in most applications. The input capacitor should be located as close to the input (INL12/INL34/ AIN) of the device as practically possible. CINL12/CINL34/ CAIN values greater than 2.2F will offer superior input line transient response and will assist in maximizing the highest possible power supply ripple rejection. 20 Ceramic, tantalum, or aluminum electrolytic capacitors may be selected for CINL12/CINL34/CAIN. There is no specific capacitor ESR requirement for CINL12/CINL34/CAIN. However, for 200mA/400mA LDO regulators output operation, ceramic capacitors are recommended for CINL12/CINL34/CAIN due to their inherent capability over tantalum capacitors to withstand input current surges from low impedance sources such as batteries in portable devices. The AAT2603 LDO regulators have been specifically designed to function with very low ESR ceramic capacitors. Although the device is intended to operate with these low ESR capacitors, it is stable over a very wide range of capacitor ESR, thus it will also work with higher ESR tantalum or aluminum electrolytic capacitors. However, for best performance, ceramic capacitors are recommended. Typical output capacitor values for maximum output current conditions range from 4.7F to 10F. If desired, COUTLX may be increased without limit. Bypass Capacitor and Low Noise Applications A bypass capacitor pin is provided to enhance the very low noise characteristics of the AAT2603 LDO3 and LDO4 regulators. The bypass capacitor is not necessary for operation of the AAT2603. However, for best device performance, a small ceramic capacitor should be placed between the bypass pin (BYP) and the device analog ground pin (AGND). The value of CBYP should be 10nF. For lowest noise and best possible power supply ripple rejection performance a 10nF capacitor should be used. To practically realize the highest power supply ripple rejection and lowest output noise performance, it is critical that the capacitor connection between the BYP pin and AGND pin be direct and PCB traces should be as short as possible. Refer to the PCB Layout Recommendations section of this datasheet for examples. www.analogictech.com 2603.2008.06.1.0 PRODUCT DATASHEET AAT2603 Total Power Solution for Portable Applications There is a relationship between the bypass capacitor value and the LDO regulator turn-on time. In applications where fast device turn-on time is desired, the value of CBYP should be reduced. In applications where low noise performance and/or ripple rejection are less of a concern, the bypass capacitor may be omitted. The fastest device turn-on time will be realized when no bypass capacitor is used. DC leakage on this pin can affect the LDO regulator output noise and voltage regulation performance. For this reason, the use of a low leakage, high quality ceramic (NPO or C0G type) or film capacitor is highly recommended. Feedback Resistor Selection Resistors R1 and R2 of Figure 2 program the output to regulate at a voltage higher than 1.5V for LDO1/LDO2 and 1.2V for LDO3/LDO4. To limit the bias current required for the external feedback resistor string while maintaining good noise immunity, the minimum suggested value for R2 is 100k. Although a larger value will further reduce quiescent current, it will also increase the impedance of the feedback node, making it more sensitive to external noise and interference. Tables 5 and 6 summarize the resistor values for various output voltages with R2 set to 100k. 1.5V VOUT R1 = V -1 * R2 = 1.2V - 1 * 100k = 24.9k REF VOUT (V) R2 = 100k R1 (k) 1.3 1.4 1.5 1.6 1.7 1.8 1.9 2 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 3 3.1 3.2 3.3 8.25 16.5 24.9 33.2 41.2 49.9 59 66.5 75 82.5 90.9 100 107 118 124 133 140 150 158 165 174 Table 5: Feedback Resistor Values for LDO3 and LDO4. VOUT (V) R2 = 100k R1 (k) 1.5 1.6 1.7 1.8 1.9 2 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 3 3.1 3.2 3.3 24.9 33.2 41.2 49.9 59 66.5 75 82.5 90.9 100 107 118 124 133 140 150 158 165 174 VOUTLX R1 VFBLX R2 Figure 2: AAT2603 LDO1/LDO2/LDO3/LDO4 External Resistor Output Voltage Programming. Table 6: Feedback Resistor Values for LDO1 and LDO2. 2603.2008.06.1.0 www.analogictech.com 21 PRODUCT DATASHEET AAT2603 Total Power Solution for Portable Applications Thermal Calculations There are three types of losses associated with the AAT2603 total power management solution [two stepdown and four LDO regulators]: switching losses, conduction losses, and quiescent current losses. Conduction losses are associated with the RDS(ON) characteristics of the internal power switches/FETs of both of the stepdown regulators and the power loss associated with the voltage difference across the pass switch/FET of the four LDO regulators. Switching losses are dominated by the gate charge of the power output switching devices. At full load, assuming continuous conduction mode (CCM), a simplified form of the losses is given by the following (quiescent and switching losses are ignored, since conduction losses are so dominant): PDC-DC1 = PDC-DC2 = IO12 * (RDS(ON)H1 * VOB1 + RDS(ON)L1 * [VINB1 - VOB1]) VINB1 Since RDS(ON) and conduction losses all vary with input voltage, the dominant losses should be investigated over the complete input voltage range. Given the total conduction losses, the maximum junction temperature (125C) can be derived from the JA for the TQFN44-28 package which is 50C/W. TJ(MAX) = PTOTAL * JA + TA TJ(MAX): PTOTAL: JA: TA: Layout The suggested PCB layout for the AAT2603 is shown in Figures 4 and 5. The following guidelines should be used to help ensure a proper layout. 1. IO22 * (RDS(ON)H2 * VOB2 + RDS(ON)L2 * [VINB2 - VOB2]) VINB2 2. PLDO1 = ILDO1 * (VINL12 - VOL1) PLDO2 = ILDO2 * (VINL12 - VOL2) 3. PLDO3 = ILDO3 * (VINL34 - VOL3) PLDO4 = ILDO4 * (VINL34 - VOL4) PTOTAL = PDC_DC1 + PDC_DC2 + PLDO1 + PLDO2 + PLDO3 + PLDO4 PDC-DCX: Power dissipation of the specific DC-DC regulator IOX: Output current of the specific DC-DC regulator RDS(ON)HX: Resistance of the internal high-side switch/FET RDS(ON)LX: Resistance of the internal low-side switch/FET VOBX: Output voltage of the specific DC-DC regulator VINBX: Input voltage of the specific DC-DC regulator PLDOX: Power dissipation of the specific LDO regulator ILDOX: Output current of the specific LDO regulator VINLXX: Input voltage of the specific LDO regulator VOLX: Output voltage of the specific LDO regulator PTOTAL: Total power dissipation of the AAT2603 22 Maximum junction temperature Total conduction losses Thermal impedance of the package Ambient temperature 4. 5. The input capacitors (C1, C2, C7, C13, and C16) should connect as closely as possible to INB1 (Pin 26), INB2 (Pin 27), AIN (Pin 20), INL12 (Pin 16), INL34 (Pin 8), and AGND/PGND1/PGND2 (Pins 5, 25, and 27). C3/C18 (step-down regulator output capacitors) and L1/L2 should be connected as closely as possible. The connection of L1/L2 to the LX1/LX2 pins should be as short as possible. The feedback trace or FBXX pin (Pins 3, 6, 10, 14, 18, and 21) should be separate from any power trace and connect as closely as possible to the load point. Sensing along a high current load trace will degrade DC load regulation. If external feedback resistors are used, they should be placed as closely as possible to the FBXX pin (Pins 3, 6, 10, 14, 18, and 21) to minimize the length of the high impedance feedback trace. The resistance of the trace from the load return to the PGND1/PGND2 (Pins 25 and 28) should be kept to a minimum. This will help to minimize any error in DC regulation due to differences in the potential of the internal signal ground and the power ground. For good thermal coupling, PCB vias are required from the pad for the TDFN44-28 exposed paddle to the ground plane. www.analogictech.com 2603.2008.06.1.0 PRODUCT DATASHEET AAT2603 Total Power Solution for Portable Applications VIN C2 J1 3-Prong Header 1 ENL1 2 VIN C18 OUTB1 L1 ENB1 2 SELB2 GND 3 3 C1 J2 3-Prong Header 1 C17 R1 ENB1 GND INL12 16 OUTL1 15 AGND 6 FBL3 7 OUTL3 FBL1 ENL1 BYP ENL4 VIN C16 R4 ENL2 C15 R3 C14 OUTL2 C13 VIN GND OUTL1 14 13 12 11 3 9 3 R2 ENB1 OUTL2 17 OUTL3 GND 22 18 C5 ENL4 SELB2 FBL2 ENL3 5 10 2 23 19 8 ENL3 2 LX1 ENL2 FBL4 R10 AIN FBB2 INL34 J6 3-Prong Header 1 ENB2 20 OUTL4 J5 3-Prong Header 1 21 3 R12 R9 FBB1 LX2 2 4 ENL3 3 24 ENB2 C4 PGND1 R11 25 1 INB1 3 ENB2 2 L2 INB2 ENL2 2 1 PGND2 1 J4 3-Prong Header 26 28 J3 3-Prong Header 27 C3 OUTB2 U1 AAT2603 VIN R5 C11 C12 C6 C7 ENL1 C8 ENL4 C10 R6 OUTL4 R7 J7 3-Prong Header 1 2 R8 C9 SELB2 3 Figure 3: AAT2603 Evaluation Board Schematic. 2603.2008.06.1.0 www.analogictech.com 23 PRODUCT DATASHEET AAT2603 Total Power Solution for Portable Applications Figure 4: AAT2603 Evaluation Board Top Side PCB Layout. Figure 5: AAT2603 Evaluation Board Bottom Side PCB Layout. 24 www.analogictech.com 2603.2008.06.1.0 PRODUCT DATASHEET AAT2603 Total Power Solution for Portable Applications Ordering Information Output Voltage1 DC-DC1 (Buck1) DC-DC2 (Buck2) (SELB2 = Low) DC-DC2 (Buck2) (SELB2 = High) Ext. Adj. (VREF = 600mV) 3.3V Ext. Adj. (VREF = 600mV) Ext. Adj. (VVREF = 600mV) 1.0V Ext. Adj. (VVREF= 775mV) 1.3V 1.0V 1.3V Package TQFN44-28 TQFN44-28 TQFN44-28 Marking2 Part Number (Tape and Reel)3 3AXYY AAT2603INJ-1-T1 AAT2603INJ-2-T1 AAT2603INJ-3-T1 All AnalogicTech products are offered in Pb-free packaging. The term "Pb-free" means semiconductor products that are in compliance with current RoHS standards, including the requirement that lead not exceed 0.1% by weight in homogeneous materials. For more information, please visit our website at http://www.analogictech.com/about/quality.aspx. 1. Buck 1 and Buck 2 output voltages can be factory programmed to most common output voltages. Contact your local sales representative for availability and minimum order quantities. 2. XYY = assembly and date code. 3. Sample stock is generally held on part numbers listed in BOLD. 2603.2008.06.1.0 www.analogictech.com 25 PRODUCT DATASHEET AAT2603 Total Power Solution for Portable Applications Package Information TQFN44-28 Pin 1 Dot by Marking C0.3 2.600 0.050 4.000 0.050 Detail "A" 4.000 0.050 2.600 0.050 Top View Bottom View 0.400 0.050 0.430 0.050 0.750 0.050 0.230 0.050 0.203 REF 0.050 0.050 Side View Pin 1 Indicator Detail "A" 1. The leadless package family, which includes QFN, TQFN, DFN, TDFN and STDFN, has exposed copper (unplated) at the end of the lead terminals due to the manufacturing process. A solder fillet at the exposed copper edge cannot be guaranteed and is not required to ensure a proper bottom solder connection. Advanced Analogic Technologies, Inc. 3230 Scott Boulevard, Santa Clara, CA 95054 Phone (408) 737-4600 Fax (408) 737-4611 (c) Advanced Analogic Technologies, Inc. AnalogicTech cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in an AnalogicTech product. No circuit patent licenses, copyrights, mask work rights, or other intellectual property rights are implied. AnalogicTech reserves the right to make changes to their products or specifications or to discontinue any product or service without notice. Except as provided in AnalogicTech's terms and conditions of sale, AnalogicTech assumes no liability whatsoever, and AnalogicTech disclaims any express or implied warranty relating to the sale and/or use of AnalogicTech products including liability or warranties relating to fitness for a particular purpose, merchantability, or infringement of any patent, copyright or other intellectual property right. In order to minimize risks associated with the customer's applications, adequate design and operating safeguards must be provided by the customer to minimize inherent or procedural hazards. Testing and other quality control techniques are utilized to the extent AnalogicTech deems necessary to support this warranty. Specific testing of all parameters of each device is not necessarily performed. AnalogicTech and the AnalogicTech logo are trademarks of Advanced Analogic Technologies Incorporated. All other brand and product names appearing in this document are registered trademarks or trademarks of their respective holders. 26 www.analogictech.com 2603.2008.06.1.0