ACT2801/ACT2801C Rev 4, 07-Aug-14 5V/1.5A Backup Battery Pack Manager FEATURES APPLICATIONS * Dedicated Single Chip Solution for Mobile Power * * * * * With Minimal Component Count 5V/1.5A Constant Output Current Limit in Boost Mode 1.5A Switching Charger Limit Programmable 4.1V to 4.35V Battery Voltage 95% Boost Efficiency (Vbat=4.1V) * * * * Adaptive to 10mA-2400mA Input Sources * Battery Disconnection at Output Short * <10A Low Battery Leakage Current at HZ GENERAL DESCRIPTION ACT2801/ACT2801C is a space-saving and highperformance low-profile single-chip solution for backup battery pack and standalone battery charger. ACT2801/ACT2801C integrates all the functions that a backup battery pack needs, including switching charger, boost converter and LED indication. Mode During Storage * Boost Auto Turn-off at No Load and Push * * * * * * * * * * * * Backup Battery Pack Power Bank Mobile Power Standalone Battery Charger with USB Output Button Turn-on Battery Over Current, Over Voltage, Over Temperature and Short Circuit Protections Boost Auto Startup with Load Detection Up to 2.0A Input Current Limit with Prioritized Power Path to Output 5V+/-100mV Output Voltage in Boost Mode 1.1MHz/0.55MHz Switching Frequencies 2.2uH SMD Inductor and Low Profile Ceramic Capacitor 4 LEDs Battery Level and Status Indication Battery Impedance Compensation Full Cycle of Battery Charge Management Preconditioning, Fast Charge, Top off and End of Charge Charge Current Foldback at 110C Die Temperature IC Over Temperature Protection at 160C QFN4x4-24 Package ACT2801/ACT2801C operates at 1.1MHz for switching charger and 0.55MHz for boost converter allowing tiny external inductor and capacitors. ACT2801/ACT2801C provides a direct power path from input to output with programmable current limit while providing power to switching charger. Output has higher priority than battery charger if the programmed input current limit is reached. ACT2801/ACT2801C charges battery with full cycle of preconditioning, fast charge with constant current and constant voltage until end of charge. The battery charger is thermally regulated at 110C with charge current foldback. ACT2801/ACT2801C boost converter steps battery voltage up to 5V. Boost converter features high efficiency, constant current regulation, short circuit protection and over voltage protection. ACT2801/ACT2801C provides 3.5mA constant currents to drive 4 LEDs to indicate battery level and charge status. Battery impedance is compensated for battery level indication. Boost CC/CV Curve Output Voltage (V) 5.5 VBAT =3.7V 5.0 VBAT =3.2V 4.5 4.0 VBAT =4.1V 3.5 3.0 0 200 400 600 800 1000 1200 1400 Output Current (mA) Innovative PowerTM -1- www.active-semi.com Copyright (c) 2014 Active-Semi, Inc. ACT2801/ACT2801C Rev 4, 07-Aug-14 ORDERING INFORMATION PART NUMBER OUTPUT CHARGE CURRENT LOW BATTERY LEVEL ALARM FLASHLIGHT PB TURN OFF BOOST PACKAGE ACT2801QL-T0550 (Not Recommended for New Designs) 5V/1.5A 1.5A No No Yes QFN44-24 ACT2801QL-T1026 5V/1.5A 1.5A Yes No Yes QFN44-24 ACT2801CQL-T 5V/1.5A 1.5A Yes Yes No QFN44-24 PIN CONFIGURATION Innovative PowerTM -2- www.active-semi.com Copyright (c) 2014 Active-Semi, Inc. ACT2801/ACT2801C Rev 4, 07-Aug-14 PIN DESCRIPTIONS PIN NAME DESCRIPTION 1 HZ Boost/high-Z mode enable pin, internally pulled up by a 3M resistor to battery. When HZ pin is pulled ground, boost is enabled if VIN is not present. 2 PB Push button input, connect a push button from this pin to AGND, internally pulled up by a 3M resistor to battery. PB starts up boost converter if HZ pin is grounded and VIN is not present. For ACT2801C, if this pin is pushed for 3s, flashlight is enabled. 3 AGND Logic Ground. AGND must be connected to PGND externally through ground plane. 4 nPG Drive external P-FET to protect output short circuit and leakage during shutdown. nPG pin is pulled up to VOUT internally. nPG pin is pulled low if VOUT is in the range. 5 ILIM Input current limit setting pin. Connect a resistor from this pin to AGND to set the input current limit. The current setting ranges from 0.5A-2.0A. 6 VIN USB or AC adaptor input. When VIN is valid, charge and power path is enabled. 7, 8 VOUT 9, 10 SW 11 PGND Power ground. PGND is connected to the source of low-side N-channel MOSFET and the MOSFET's gate driver. PGND must be connected to AGND externally through ground plane. 12 BAT Battery input. Connected to the battery pack positive terminal to provide power in HighZ mode. Bypass to PGND with a high quality ceramic capacitor placed as close to the IC as possible. 13 CSP Positive terminal of charge current sense input. Kevin sense is required with 10nF ceramic capacitor right across CSP and CSN pins. 14 CSN Negative terminal of charge current sense input. 15 IOST Output current setting. Connect a resistor from this pin to AGND to set output constant current. The current setting ranges from 0.5A-1.5A. 16 ICST Fast charge current setting pin. Connect a resistor from this pin to AGND to set the charge current. The current setting ranges from 0.5A-1.5A. 17 BTV Battery termination voltage setting. Connect a resistor from this pin to AGND to program battery charge termination voltage. 18 LED1 Battery level indicator. An internal 3.5mA sink current limit is built in. 19 LED2 Battery level indicator. An internal 3.5mA sink current limit is built in. 20 LED3 Battery level indicator. An internal 3.5mA sink current limit is built in. 21 LED4 Battery level indicator. An internal 3.5mA sink current limit is built in. 22 RIMC Battery impendence compensation input. Connect to a resistor from this pin to APNG to program the battery impedance. 23 BLVS Battery level voltage shift. Connect a resistor from this pin to AGND to shift the battery LED indication thresholds. 24 TH/FLD Output pin. Bypass to PGND with a high quality low ESR and ESL ceramic capacitor placed as close to the IC as possible. Internal switch to output inductor terminal. TH: ACT2801 Temperature sensing input. Connect to battery thermistor terminal. If no use, put 10K pulled down resistor. FLD: ACT2801C Open-drain flashlight driver. A internal switch can handle up to 50mA. 25 Innovative PowerTM EP Exposed pad. Must be soldered to ground on the PCB. -3- www.active-semi.com Copyright (c) 2014 Active-Semi, Inc. ACT2801/ACT2801C Rev 4, 07-Aug-14 ABSOLUTE MAXIMUM RATINGSc PARAMETER VALUE UNIT -0.3 to 6.5 V Junction to Ambient Thermal Resistance 40 C/W Maximum Power Dissipation 2.5 W Operating Ambient Temperature -40 to 85 C Operating Junction Temperature -40 to 150 C Storage Junction Temperature -40 to 150 C 300 C All the Pin to PGND and AGND Lead Temperature (Soldering 10 sec.) c: Do not exceed these limits to prevent damage to the device. Exposure to absolute maximum rating conditions for long periods may affect device reliability. Innovative PowerTM -4- www.active-semi.com Copyright (c) 2014 Active-Semi, Inc. ACT2801/ACT2801C Rev 4, 07-Aug-14 ELECTRICAL CHARACTERISTICS (VIN = 5V, TA = 25C, unless otherwise specified.) PARAMETER TEST CONDITIONS MIN TYP MAX UNIT Input Current Limit Input Voltage Range 4.5 VIN Over Voltage Protection VIN rising, VIN_OVP Input Voltage Validation Time VIN_UVLO<VIN<VIN_OVP Input Current Limit Setting Range RILIM=1.2k--4.8k Input Current Setting RILIM=1.5k 5.5 6.0 5.5 V 6.5 V 32 0.5 ms 2.0 1.6 Input Current Limit Gain A A 2000 Leakage Current from VOUT to VIN in Boost Mode 3.0V<VBAT<4.35V, Ta=25 0 10 A Battery Discharge Current in High-Z Mode 3.0V<VBAT<4.35V, Ta=25 7.5 15 A Power Switches VIN-to-VOUT FET on Resistance 90 m VOUT-to-SW FET on Resistance 70 m SW-to-PGND FET on Resistance 75 m Buck Converter Switching Frequency High Side Switch Peak Current Limit -15% 1.1 4.5 6 A 100 ns Minimum On-time +15% MHz Over Temperature Protection (OTP) OTP rising 160 OTP Hysteresis OTP falling 35 Charge Mode Charge Current Setting Range Rcs=50m, RICST=20k--60.4k Charge Current Setting (ICHRG) Rcs=50m, RICST=39k 0.5 -10% Thermal Regulation Temperature Battery Adjust Voltage(VBAJ) Rbtv=25k End of Charge (EOC) Voltage -0.5% 975 1.5 A +10% mA 110 0.1 V 4.1+VBAJ 0.5% V EOC Voltage Accuracy Rbtv=0 4.1 V Battery Over Voltage Threshold VBAT rising 4.6 V Battery Over Voltage Threshold Hysteresis VBAT falling 200 mV Fast Charge Current VBAT=3.5V ICHRG A Precondition Charge Current 2.5VVBAT2.8V, Percent of ICHRG 10 % Innovative PowerTM -5- www.active-semi.com Copyright (c) 2014 Active-Semi, Inc. ACT2801/ACT2801C Rev 4, 07-Aug-14 ELECTRICAL CHARACTERISTICS (VIN = 5V, TA = 25C, unless otherwise specified.) PARAMETER Precondition Voltage Threshold TEST CONDITIONS MIN VBAT rising, Rbtv=0 Precondition Voltage Threshold Hysteresis TYP MAX UNIT 2.8 V 130 mV Low VBAT Charge Current VBAT=1V, RICST=39k 200 mA EOC Current Threshold Percent of the fast charge current 13 % 200 mV Charge Restart Voltage Threshold TH Upper Temperature Voltage Threshold Cold detect NTC thermistor ACT2801-T0550/ACT2801-T1026 1.5 V TH Lower Temperature Voltage Threshold Hot detect NTC thermistor ACT2801-T0550/ACT2801-T1026 0.3 V TH Hysteresis ACT2801-T0550/ACT2801-T1026 50 mV TH Internal Pull-up Current ACT2801-T0550/ACT2801-T1026 60 A Charge Current Foldback Charge Current Reduction Threshold1 of Vout1 Starting foldback point Charge Current Reduction Threshold2 of Vout1 4.59 Stop foldback point, RCS=50m, RICST=39k 4.7 4.81 4.57 V V Boost Mode Input Voltage Operation Range 3.0 Switching Frequency -15% 0.55 4.5 V +15% MHz Input Voltage UVLO VBAT rising 3.3 V Input Voltage UVLO Hysteresis VBAT falling 400 mV Output Voltage (VOUT) Ta=25 Output Voltage Accuracy All conditions Output Voltage Transient Response Vbat=3.7V, 80mA-1A-80mA, 0.1A/us Output Over Voltage Protection VOUT rising 5.7 V Output Over Voltage Protection Hysteresis VOUT falling 300 mV Output Current Regulation Range Rcs=50m, RIOST=37.5k--113k Output Current Setting Rcs=50m, RIOST=97.6k 1.3 A The Maximum Voltage Across VRcs All conditions 200 mV 100 ns 5.6 A 400 s 4.97 5.05 5.10 V -3 VOUT 2 % 5.25 V 4.75 0.5 Minimum On-Time Low Side Switch Peak Current Limit VBAT=3.2V, VOUT=5V Soft-Startup Time Innovative PowerTM -6- 4.0 1.5 A www.active-semi.com Copyright (c) 2014 Active-Semi, Inc. ACT2801/ACT2801C Rev 4, 07-Aug-14 ELECTRICAL CHARACTERISTICS (VIN = 5V, TA = 25C, unless otherwise specified.) PARAMETER Under Voltage Protection (UVP Threshold) TEST CONDITIONS MIN TYP MAX UNIT VOUT falling 4.25 V VOUT rising 4.6 V 3 ms UVP Blanking Time During Startup UVP Sense Detection Time VOUT falling 20 s Restart After UVP Hiccup mode 2 s Light Load Current Shut off Threshold VBAT=3.7V, Rcs=50m, RIOST=97.6k 40 Light Load Current Detect Time ACT2801C/ACT2801-T1026 45 s Light Load Current Detect Time ACT2801-T0550 90 s HZ Pin High Voltage HZ voltage rising 0.9 HZ Pin Low Voltage HZ voltage falling 0.4 PB Turn on Boost Time 1.4 mA V 0.75 V 3 M ACT2801-T1026 1.5 s ACT2801-T0550 3.0 s ACT2801C 30 ms ACT2801-T0550/ACT2801-T1026 100 ms 2 s HZ Internal Pull-up Resistor PB Turn off Boost Time 100 Mode Transition Transition Waiting Time between Charge Mode and Boost Mode TRANTIME Battery Level Indication Battery Impedance Compensation Range 40 500 Battery Impedance Compensation Rcs=50m, RIMC=100k 200 PB High Input Voltage PB voltage rising 0.9 PB Low Input Voltage PB voltage falling PB Internal Pull-up Resistor 0.4 m m 1.4 V 0.75 V 3 M 5 s LED Indication Time PB is pushed and released LED Flash Frequency Charging, LED flash 1s on and 1s off 0.5 Hz Flashlight Voltage UVLO Flashlight rising, ACT2801C 3.3 V Flashlight Voltage UVLO Threshold Flashlight falling, ACT2801C 2.9 V Flashlight Driver Current the current at FLD pin, ACT2801C 50 mA PB Turn on Flashlight Time ACT2801C 3.0 s PB Turn off Flashlight Time ACT2801C 3.0 s Flashlight Driver Innovative PowerTM -7- www.active-semi.com Copyright (c) 2014 Active-Semi, Inc. ACT2801/ACT2801C Rev 4, 07-Aug-14 FUNCTIONAL BLOCK DIAGRAM FOR ACT2801-T0550/ACT2801-T1026 FUNCTIONAL BLOCK DIAGRAM FOR ACT2801C Innovative PowerTM -8- www.active-semi.com Copyright (c) 2014 Active-Semi, Inc. ACT2801/ACT2801C Rev 4, 07-Aug-14 FUNCTIONAL DESCRIPTION flow chart as shown in Figure 1, and ACT2801C system operation flow chart as shown in Figure 2. ACT2801/ACT2801C is a complete battery charging and discharging power management solution for applications of single-cell lithium-based backup battery pack or power bank. There is a power path from input to output with programmable input current limit. When output is over loaded, the input switch Q1 starts going into linear mode and thus output voltage starts to drop. If output voltage drops below 4.25V, the input switch Q1 turns off and restart in 2 seconds. Any transitions between boost mode and charge mode go through HZ mode by turning off all the switches Q1-Q3 into HZ mode for 2 seconds before enabling the other mode. The modes are determined by HZ pin and VIN pin as shown in the table 1. A valid VIN voltage forces ACT2801/ACT2801C into charge mode. Boost mode is enabled if HZ pin is pulled low and VIN is invalid or not present. For ACT2801-T0550/ ACT2801-T1026, when HZ=0, if PB is pulled low for more than 100ms, boost converter is enabled; For ACT2801C, when HZ=0, if PB is pulled low for more than 30ms, boost converter is enabled. With the advanced ACT2801/ACT2801C architecture, a synchronous buck/boost converter is connected from VOUT to switching node (SW). With the bidirectional architecture, the converter could be configured as either buck to charge battery or boost to discharge battery. With switching charger and discharger, the higher charge current and higher conversion efficiency are achieved. Table 1: Mode Selection Modes of Operation ACT2801/ACT2801C has 3 operation modes: charge mode, boost mode and high-impedance (HZ) mode. In charge mode, the input current limit Q1 is enabled and Q2 and Q3 operate as a buck converter to charge battery. In boost mode, Q2 and Q3 operate as boost converter to step battery voltage up to +5V at VOUT, and the current limit switch Q1 is turned off, and the reverse current from VOUT to VIN is blocked. In HZ mode, all the switches are turned off and the drainage current from battery is very low. ACT2801 system operation HZ PIN 0 0 1 1 VIN Valid 0 1 0 1 Mode Boost Charge HZ Charge Flashlight ACT2801C has an flashlight function. Once PB is pressed for 3 seconds, the flashlight is switched on. The driver will deliver up to 50mA current to the flashlight. During flashlight on, if PB is pressed for 3 seconds, flashlight will be switched off. Figure 1: ACT2801 System Operation Flow Chart Innovative PowerTM -9- www.active-semi.com Copyright (c) 2014 Active-Semi, Inc. ACT2801/ACT2801C Rev 4, 07-Aug-14 FUNCTIONAL DESCRIPTION Figure 2: ACT2801C System Operation Flow Chart Input Current Limit When the input current reaches the programmed value, switch Q1 goes into linear mode and output voltage starts to drop. When output voltage drops to 4.25V, hiccup mode is triggered and switch Q1 turns off and restart in 2 seconds. Switching Battery Charger ACT2801/ACT2801C is configured in charge mode (buck mode) when VIN is valid. In this mode, a battery is charged with preconditioning, fast charge, top-off and end of charge (EOC). The typical charge management is shown in Figure 3 and Figure 4. CC/CV Regulation Loop There are CC/CV regulation loops built in ACT2801/ ACT2801C, which regulates either current or voltage as necessary to ensure fast and safe charging of the battery. In a normal charge cycle, this loop regulates the current to the value set by the external resistor at the ICST pin. Charging continues at this current until the battery cell voltage reaches the termination voltage. At this point the CV loop takes over, and charge current is allowed to decrease as necessary to maintain charging at the termination voltage. at a reduced current, 10% of the programmed maximum fast charge constant current. Once VBAT reaches the precondition threshold voltage the state machine jumps to the fast charge state. Fast Charge If battery voltage is above preconditioning threshold, buck converter charges battery with constant current. In fast charge state, the ACT2801/ ACT2801C charges at the current set by the external resistor connected at the ICST pin. During a normal charge cycle fast charge continues in CC mode until VBAT reaches the charge termination voltage, at which point the ACT2801/ACT2801C charges in top off state. Top Off With the battery voltage approaches the EOC voltage set by the BTV pin. Charge current decreases as charging continues. In the top off state, the cell is charged in constant voltage (CV) mode. During a normal charging cycle charging proceeds until the charge current decreases below the end of charge (EOC) threshold, defined as 13% of fast charge current. When this happens, the state machine terminates the charge cycle and jumps to the EOC state. Precondition Charge End of Charge A new charging cycle begins with the precondition state, and operation continues in this state until VBAT exceeds the precondition threshold voltage. When operating in precondition state, the cell is charged When charges current decreases to 13% of set fast charge current, the buck converter goes into end of charge mode and keep monitoring the battery voltage. Innovative PowerTM - 10 - www.active-semi.com Copyright (c) 2014 Active-Semi, Inc. ACT2801/ACT2801C Rev 4, 07-Aug-14 FUNCTIONAL DESCRIPTION Recharge When battery voltage drops by 200mV below the end of charge voltage, the charger is reinitiated with constant current charge. Figure 3. Typical Li+ Charge Profile and ACT2801/ACT2801C Charge States A: PRECONDITION STATE B: FAST-CHARGE STATE C: TOP-OFF STATE D: END-OF-CHARGE STATE Figure 4. Charger State Diagram Innovative PowerTM - 11 - www.active-semi.com Copyright (c) 2014 Active-Semi, Inc. ACT2801/ACT2801C Rev 4, 07-Aug-14 the compensated impedance. Those thresholds are programmed by a resistor connected from BLVS pin to AGND as shown in Figure 6. The following equation shows the LED4 voltage threshold: APPLICATIONS INFORMATION Battery Charge Termination Voltage Battery charge termination voltage is set by a resistor Rbtv connected from BTV pin to AGND as shown in Figure 5. The battery charge termination voltage is estimated as the following equation: VBAT (V ) = 4.1(V ) + Rbtv x 4 x 10 -6 (V ) VBATLED4 (V ) = 3.5(V ) + 0.01( mA ) x RBLVS ( k ) (2) (1) Rbtv is selected based on the battery voltage rating. 1% accuracy resistor is recommended for Rbtv. Figure 6. Battery level voltage shift setting circuit As long as LED4 is set, all the other 3 LED thresholds is fixed as shown in the table 3: Table 3: 4 LED Voltage Thresholds Figure 5. Battery terminal voltage setting circuit LED Status Indication 4 LEDs ON/OFF and flash show the charge status and the remained capacity level as shown in the table 2. The LED status is based on battery voltage and operation modes. When battery voltage is low, LED1 is flashing. In charge mode, when a battery is fully charged, flashing stops and all the 4 LEDs are solid on. RBLVS (ohm) 50K 60K 70K 80K LED1 3.35V 3.45V 3.55V 3.65V LED2 3.60V 3.70V 3.80V 3.90V LED3 3.75V 3.85V 3.95V 4.05V LED4 4.00V 4.10V 4.20V 4.30V Input Current Limit An external resistor is used to set the input current limit connected from ILIM pin to AGND as shown in Figure 7. Input current limit has built-in soft startup and current foldback control loop. The input current limit is estimated as the following equation: Battery level voltage shift (BLVS pin) LED1-4 voltage thresholds are adjusted from HZ mode during charging and discharging based on I ILIM (A) = 2 . 4 (V) R ILIM (k ) (3) Table2: LED Indication ACT2801: PB time>100ms ACT2801C: PB time>30ms (Boost or HZ Mode) Charge Mode LED LED1 LED2 LED3 LED4 LED1 LED2 LED3 LED4 VBAT<2.9V Flash Off Off Off Off Off Off Off 2.9VVBAT<LED1(ACT2801-T0550) Flash Off Off Off Off Off Off Off 2.9VVBAT<LED1 (ACT2801-T1026/ACT2801C) Flash Off Off Off Flash Off Off Off LED1VBAT<LED2 On Flash Off Off On Off Off Off LED2VBAT<LED3 On On Flash Off On On Off Off LED3VBAT<LED4 On On On Flash On On On Off VBATLED4 On On On Flash On On On On VBATLED4 (End of Charge) On On On On On On On On Innovative PowerTM - 12 - www.active-semi.com Copyright (c) 2014 Active-Semi, Inc. ACT2801/ACT2801C Rev 4, 07-Aug-14 2.1 VIN = 5.0V Vbat=3.7V ICHRG (A) 1.8 1.5 1.2 0.9 0.6 0.3 0 Figure 7. 20 30 40 50 60 70 80 Battery fast charge current setting Boost Output Constant Current Boost output current is set by a resistor connected from IOST pin to AGND as shown in Figure 12. The boost output current is estimated as the following equation: 3.0 IILIM (A) 10 Figure 11. Input current limit at various resistor curve is shown in Figure 8. VIN = 5.0V 2.5 0 RICST (k) Input current limit setting circuit 2.0 1.5 IIOST (A) = 1.0 2 R (k ) ( A ) x IOST 3 Rcs (m ) (5) 0.5 0 0.7 1.2 1.7 2.2 2.7 3.2 3.7 4.2 4.7 RILIM (k) Figure 8. Input current limit setting The ILIM pin voltage is proportional to input current until input current is limited, as shown in Figure 9. Figure 12. 1.4 1.2 VIN = 5.0V RILIM=1.5k Figure 13 gives out boost output current with various RIOST. 0.8 0.6 1.9 0.4 1.6 0.2 1.3 0.2 0.4 0.6 0.8 1.0 1.2 1.4 IOUT (A) VILIM (V) 1.0 0 0 1.6 Input Current (A) Figure 9. 1.0 0.4 20 40 60 80 100 120 140 RIOST (k) Battery fast charge current is set by a resistor connected from ICST pin to AGND as shown in Figure 10. Figure 11 gives out different fast charge current with various RICST. The battery fast charge current is estimated as the following equation: Figure 13. Boost output current setting The IOST pin voltage is proportional to output current until output current is limited, as shown in Figure 14. 900 (4) VBAT = 3.7V RIOST=97.6k 750 VIOST (mV) RICST ( k ) Rcs( m ) VBAT = 3.7V CVout=4.5V 0.7 VILIM VS. input current Battery Fast Charge Current Ic( A ) = 1.25( A ) x Boost output current setting circuit 600 450 300 150 0 Figure 10. Innovative PowerTM 0 0.2 0.4 0.6 0.8 1.0 1.2 Output Current(A) Battery fast charge current setting Figure 14. - 13 - VIOST VS. output current www.active-semi.com Copyright (c) 2014 Active-Semi, Inc. ACT2801/ACT2801C Rev 4, 07-Aug-14 resonance as shown in Figure 17. Battery Impedance Compensation An external resistor is used to set the impedance from 40m to 500m as shown in Figure 15. RIMC is corresponding to battery impedance. Higher RIMC gives higher compensation voltage which is positively proportional to battery charge/discharge current. Select RIMC based on battery impedance: Figure 17. 25 x R (m ) RIMC(k ) = Rcs (m ) (6) VBAT (V ) = BAT(V ) - IBAT ( A ) x R( m ) x10-3 (7) Figure 15. Input over voltage surge protection circuit External Input Over Voltage Protection Considering the maximum voltage rating at VIN pin, the external OVP circuit as shown in Figure 18 is recommended if input voltage may go higher than 7V. With the enhanced OVP circuit, the design can pass UN38.3. Battery impedance compensation setting circuit The battery impedance as shown in the table 4 according to the RIMC and Rcs: Figure 18. Table 4: Battery Impedance RIMC(K) Battery Impedance R(m) 50 100 200 Rcs=25m 50 100 200 Rcs=50m 100 200 400 Input over voltage protection LEDs on in Boost Mode LEDs can be always on during boost mode, the schematic is shown in Figure19. Boost Output Plug-in Auto Detection Figure 16 provides a solution for auto plug-in detection. Figure 19. LEDs on in boost mode circuit Inductor and Capacitor Selection Figure 16. ACT2801/ACT2801C supports SMD components. 2.2uH inductor is recommended. Input side, 4.7uF ceramic capacitor in series with 2.7 resistor are recommended, on battery side, 22uF ceramic capacitors is recommended while on output side, 2*22uF ceramic capacitors are recommended. Boost output auto detection circuit Input Over Voltage Surge In the case of pure ceramic input capacitor is chosen, if the input cable is long, stray inductance may cause over voltage spikes as twice as the steady-state voltage when input source is plugged in. Below input circuit is recommended to avoid input voltage surge. R1 resistor is added in series with capacitor C1 to damp the potential LC Innovative PowerTM - 14 - Battery Temperature Monitoring ACT2801 continuously monitors the temperature of the battery pack by sensing the resistance of its thermistor, and suspends charging if the temperature of the battery pack exceeds the safety limits. www.active-semi.com Copyright (c) 2014 Active-Semi, Inc. ACT2801/ACT2801C Rev 4, 07-Aug-14 In a typical application, the TH pin is connected to the battery pack's thermistor input as shown in Figure 20. The ACT2801 injects a 60A current out of the TH pin into the thermistor, so that the thermistor resistance is monitored by comparing the voltage at TH to the internal VTHL and VTHH thresholds of 0.3V and 1.5V, respectively. When VTH > VTHH or VTH < VTHL charging and the charge timers are suspended. When VTH returns to the normal range, charging and the charge timers resume. The threshold is given by: 60AxRNOMxkHOT=0.3V RNOMxkHOT=5k 60AxRNOMxkCOLD=1.5V RNOMxkCOLD= 25k where RNOM is the nominal thermistor resistance at room temperature, and kHOT and kCOLD are the ratios of the thermistor's resistance at the desired hot and cold thresholds, respectively. Figure 20. Innovative PowerTM Battery thermal circuit - 15 - www.active-semi.com Copyright (c) 2014 Active-Semi, Inc. ACT2801/ACT2801C Rev 4, 07-Aug-14 PC Board Layout Guidance When laying out the printed circuit board, the following checklist should be used to ensure proper operation of the IC. 1. Arrange the power components to reduce the AC loop size, VIN pin, Vout pin, SW pin and the schottky diode. 2. Place input decoupling ceramic capacitor C3 and R10 as close to VIN pin as possible. Resistor R10 is added in series with capacitor C3 to damp the potential LC resonance . 3. Use copper plane for power GND for best heat dissipation and noise immunity. 4. Place CSP and CSN capacitor C6 (10nF) close to CSP and CSN pin as possible, use Kevin Sense from sense resistor R2 and R2A to CSP and CSN pins. 22uF decoupling capacitor is added close to BAT pin. 5. Place the ceramic capacitor C2 and D1 as close to VOUT and PGND as possible, SW goes under the C2 (recommend C2 to use 1206 size). SW pad is a noisy node switching. It should be isolated away from the rest of circuit for good EMI and low noise operation. 6. Thermal pad is connected to GND layer through vias (recommend 4X4 pins and the aperture is 10mil). Ground plane, PGND and AGND is single point connected under the ACT2801/ ACT2801C thermal pad through vias to limited SW area. 7. From BAT pin to the Battery positive terminal, need to lay the divided line to ensure the battery voltage accuracy of sampling. 8. RC snubber is recommended to add across SW to PGND to reduce SW spike below 7V. 2A /20V schottky is added to across VOUT and SW pins. A demo board PCB layout example is shown in the figure 21. Figure 21. PCB Layout Bottom Layer Top Layer Innovative PowerTM - 16 - www.active-semi.com Copyright (c) 2014 Active-Semi, Inc. ACT2801/ACT2801C Rev 4, 07-Aug-14 Figure 22. Typical application circuit (Input current limit 2.0A, fast charge current limit 1.5A, boost output constant current limit 1.3A) Innovative PowerTM - 17 - www.active-semi.com Copyright (c) 2014 Active-Semi, Inc. ACT2801/ACT2801C Rev 4, 07-Aug-14 Table 5: BOM List ITEM REFERENCE DESCRIPTION 1 L1 SWPA4020S1R0NT 2.2uH 3.4A (4*4*2mm) 1 Sunlord 2 Q1 SI2333DDS, Rdson=28m at VGS = - 4.5 V 1 Vishay 3 D1 SR22, Vf=0.5V, 20V Schottky 1 Panjit 4 D2 1N4148, Vf=0.7V, 75V Schottky 1 Vishay 5 C2,C5 Ceramic Capacitor, 22uF/10V, X7R, 1206 2 Murata/TDK 6 C3 Ceramic Capacitor, 4.7uF/10V, X7R, 1206 1 Murata/TDK 7 C4 Ceramic Capacitor, 0.1uF/10V, X7R, 0603 1 Murata/TDK 8 C6 Ceramic Capacitor, 10nF/10V, X7R, 0402 1 Murata/TDK 9 C7 Ceramic Capacitor, 4.7nF/10V, X7R, 0603 1 Murata/TDK 10 C8 Ceramic Capacitor, 1uF/10V, X7R, 0603 1 Murata/TDK 11 C9,C10 Ceramic Capacitor, 39pF/10V, X7R, 0603, Optional 2 Murata/TDK 12 C11,C12 Ceramic Capacitor, 2.2uF/10V, X7R, 0603 2 Murata/TDK 13 C13 Ceramic Capacitor, 4.7uF/10V, X7R, 0603 1 Murata/TDK 14 R1 Chip Resistor, 1.2k, 1/16W, 1%, 0402 1 Murata/TDK 15 R2 Chip Resistor, 50m, 1/4W, 1%, 1206 1 Murata/TDK 16 R3 Chip Resistor, 97.6k, 1/16W, 1%, 0402 1 Murata/TDK 17 R4 Chip Resistor, 60.4k, 1/16W, 1%, 0402 1 Murata/TDK 18 R5 Chip Resistor, 25k, 1/16W, 1%, 0402 1 Murata/TDK 19 R6 Chip Resistor, 10k, 1/16W, 1%, 0402 1 Murata/TDK 20 R7 Chip Resistor, 60k, 1/16W, 1%, 0402 1 Murata/TDK 21 R8 Chip Resistor, 100k, 1/16W, 1%, 0402 1 Murata/TDK 22 R9 Chip Resistor, 0.47, 1/8W, 5%, 0805 1 Murata/TDK 23 R10 Chip Resistor, 2.7, 1/4W, 5%, 1206 1 Murata/TDK 24 R11 Chip Resistor, 200k, 1/10W, 5%, 0603 1 Murata/TDK 25 R12,R13 Chip Resistor, 715k, 1/10W, 5%, 0603 2 Murata/TDK 26 R14 Chip Resistor, 100k, 1/10W, 5%, 0603 1 Murata/TDK 27 R15 Chip Resistor, 2.2, 1/10W, 5%, 0603 1 Murata/TDK 28 R16 Chip Resistor, 100, 1/10W, 5%, 0603 1 Murata/TDK 29 R18,R19 Chip Resistor, 22, 1/10W, 5%, 0603, Optional 2 Murata/TDK 30 LED1,LED2, LED3,LED4 LED, 0603, Blue 4 LED Manu 31 PB Push Button Switch 1 Nikkai Omron 32 USB 10.2*14.6*7mm, 4P 1 33 Micro-USB MICRO USB 5P/F SMT B 1 34 U1 IC, ACT2801, T-QFN 44-24 1 Innovative PowerTM - 18 - QTY MANUFACTURER ACT www.active-semi.com Copyright (c) 2014 Active-Semi, Inc. ACT2801/ACT2801C Rev 4, 07-Aug-14 R12 PB R16 HZ LED1 R5 PB AGND R11 R13 C12 BTV R4 ACT2801C nPG R3 IOST R1 C11 ICST Input USB ILIM CSN + D- VIN CSP C6 C9 C10 R10 D+ - D2 R14 C3 C8 C2 R18 R19 D1 Q1 + D- R2 L1 C4 D+ - R9 R15 C13 USB Output C7 C5 BAT Figure 23. Typical application circuit (Input current limit 2.0A, fast charge current limit 1.5A, boost output constant current limit 1.3A) Innovative PowerTM - 19 - www.active-semi.com Copyright (c) 2014 Active-Semi, Inc. ACT2801/ACT2801C Rev 4, 07-Aug-14 Table 6: BOM List ITEM REFERENCE DESCRIPTION 1 L1 SWPA4020S1R0NT 2.2uH 3.4A (4*4*2mm) 1 Sunlord 2 Q1 SI2333DDS, Rdson=28m at VGS = - 4.5 V 1 Vishay 3 D1 SR22, Vf=0.5V, 20V Schottky 1 Panjit 4 D2 1N4148, Vf=0.7V, 75V Schottky 1 Vishay 5 C2,C5 Ceramic Capacitor, 22uF/10V, X7R, 1206 2 Murata/TDK 6 C3 Ceramic Capacitor, 4.7uF/10V, X7R, 1206 1 Murata/TDK 7 C4 Ceramic Capacitor, 0.1uF/10V, X7R, 0603 1 Murata/TDK 8 C6 Ceramic Capacitor, 10nF/10V, X7R, 0402 1 Murata/TDK 9 C7 Ceramic Capacitor, 4.7nF/10V, X7R, 0603 1 Murata/TDK 10 C8 Ceramic Capacitor, 1uF/10V, X7R, 0603 1 Murata/TDK 11 C9,C10 Ceramic Capacitor, 39pF/10V, X7R, 0603, Optional 2 Murata/TDK 12 C11,C12 Ceramic Capacitor, 2.2uF/10V, X7R, 0603 2 Murata/TDK 13 C13 Ceramic Capacitor, 4.7uF/10V, X7R, 0603 1 Murata/TDK 14 R1 Chip Resistor, 1.2k, 1/16W, 1%, 0402 1 Murata/TDK 15 R2 Chip Resistor, 50m, 1/4W, 1%, 1206 1 Murata/TDK 16 R3 Chip Resistor, 97.6k, 1/16W, 1%, 0402 1 Murata/TDK 17 R4 Chip Resistor, 60.4k, 1/16W, 1%, 0402 1 Murata/TDK 18 R5 Chip Resistor, 25k, 1/16W, 1%, 0402 1 Murata/TDK 19 R7 Chip Resistor, 60k, 1/16W, 1%, 0402 1 Murata/TDK 20 R8 Chip Resistor, 100k, 1/16W, 1%, 0402 1 Murata/TDK 21 R9 Chip Resistor, 0.47, 1/8W, 5%, 0805 1 Murata/TDK 22 R10 Chip Resistor, 2.7, 1/4W, 5%, 1206 1 Murata/TDK 23 R11 Chip Resistor, 200k, 1/10W, 5%, 0603 1 Murata/TDK 24 R12,R13 Chip Resistor, 715k, 1/10W, 5%, 0603 2 Murata/TDK 25 R14 Chip Resistor, 100k, 1/10W, 5%, 0603 1 Murata/TDK 26 R15 Chip Resistor, 2.2, 1/10W, 5%, 0603 1 Murata/TDK 27 R16 Chip Resistor, 100, 1/10W, 5%, 0603 1 Murata/TDK 28 R17 Chip Resistor, 51, 1/10W, 5%, 0603 1 Murata/TDK 29 R18,R19 Chip Resistor, 22, 1/10W, 5%, 0603, Optional 2 Murata/TDK 30 LED1,LED2, LED3,LED4 LED, 0603, Blue 4 LED Manu 31 LED Flashlight 1 LED Manu 32 PB Push Button Switch 1 Nikkai Omron 33 USB 10.2*14.6*7mm, 4P 1 34 Micro-USB MICRO USB 5P/F SMT B 1 35 U1 IC, ACT2801C, T-QFN 44-24 1 Innovative PowerTM - 20 - QTY MANUFACTURER ACT www.active-semi.com Copyright (c) 2014 Active-Semi, Inc. ACT2801/ACT2801C Rev 4, 07-Aug-14 TYPICAL PERFORMANCE CHARACTERISTICS CONT'D (Schematic as show in Figure 22, Ta = 25C, unless otherwise specified) Battery Charge V/I Profile Charge Current VS. Output Current Input Current (mA) 1800 1500 Input Current 1200 VIN = 5.0V ICHRG = 1.5A 1500 Charge Current (mA) VIN = 5.0V VBAT = 3.5V ACT2801-002 1800 ACT2801-001 2100 Charge Current 900 600 1200 900 600 300 300 0 0 0 300 600 900 1200 1500 1800 0 0.5 1.0 1.5 Output Current(mA) 3.5 4.0 4.5 VIN = 5.0V ICHRG = 1.5A ACT2801-004 100.0 ACT2801-003 90.0 91.0 Efficiency(%) Efficiency(%) 3.0 Boost Efficiency 91.5 90.5 90.0 80.0 VBAT = 3.2V VBAT = 3.7V VBAT = 4.1V 70.0 60.0 50.0 89.5 89.0 40.0 3.0 3.2 3.4 3.6 3.8 4.0 0 4.2 200 400 600 800 1000 1200 Vbat (V) Output Current (mA) Battery Charge Current VS. Temperature Battery Leakage VS. Temperature (HZ Mode) Battery Leakage (A) 1500 1200 900 600 300 20.0 15.0 VBAT = 3.5V VBAT = 4.1V 10.0 5.0 0 0 -20 ACT2801-006 VIN = 5.0V VBAT = 3.5V 1400 25.0 ACT2801-005 1800 Battery Charge Current (mA) 2.5 Vbat (V) Charge Efficiency 92.0 2.0 0 20 40 60 80 100 120 -20 140 20 40 60 80 100 120 Temperature (C) Temperature (C) Innovative PowerTM 0 - 21 - www.active-semi.com Copyright (c) 2014 Active-Semi, Inc. ACT2801/ACT2801C Rev 4, 07-Aug-14 TYPICAL PERFORMANCE CHARACTERISTICS CONT'D Boost Output Constant Current Limit VS. Temperature Boost Output Voltage VS. Temperature 1350 1300 1250 1200 1150 0 30 60 90 120 5.3 5.2 5.1 5.0 4.9 150 -30 0 30 60 90 120 Temperature (C) Boost Output Voltage VS. Output Current Boost Output Constant Current Limit VS. VBAT VBAT = 3.2V 5.05 5.00 4.95 4.90 0 200 400 600 800 1000 1200 1330 1325 1320 1315 1310 1305 1300 3.0 1400 3.2 3.4 3.6 3.8 4.0 Boost Output Current (mA) Vbat (V) Boost Standby Current VS. Battery Voltage Battery Leakage VS. Battery Voltage (HZ Mode) Battery Leakage (A) 7.0 0.49 0.48 0.47 0.46 6.0 5.0 4.0 3.0 2.0 1.0 0 0.45 2.8 ACT2801-012 0.50 4.2 8.0 ACT2801-011 051 150 ACT2801-010 ACT2801-009 5.10 VBAT = 4.1V Boost Output Constant Current mA) Temperature (C) 5.15 Standby Current (mA) VBAT = 3.5V VOUT = 5.05V 4.8 -30 Boost Output Voltage (V) 5.4 Boost Output Voltage (V) VBAT = 3.5V CV = 4.5V Rcs=50m(1%) ACT2801-008 1400 ACT2801-007 Boost Output Constant Current (mA) (Schematic as show in Figure 22, Ta = 25C, unless otherwise specified) 3.1 3.4 3.7 4.0 4.3 0 4.6 2.0 3.0 4.0 5.0 Battery Voltage(V) Battery Voltage(V) Innovative PowerTM 1.0 - 22 - www.active-semi.com Copyright (c) 2014 Active-Semi, Inc. ACT2801/ACT2801C Rev 4, 07-Aug-14 TYPICAL PERFORMANCE CHARACTERISTICS CONT'D (Schematic as show in Figure 22, Ta = 25C, unless otherwise specified) Boost Load Transient (80mA-1A-80mA) Boost Load Transient (80mA-1A-80mA) CH1 ACT2801-014 ACT2801-013 VBAT = 3.4V VOUT = 5.0V IIOST = 1.3A VBAT = 4.1V VOUT = 5.0V IIOST = 1.3A CH1 CH2 CH2 CH1: VOUT, 200mV/div CH2: IOUT, 500mA/div TIME: 1ms/div CH1: VOUT, 200mV/div CH2: IOUT, 500mA/div TIME: 1ms/div SW and Output Waveforms in Boost Mode SW and Output Waveforms in Boost Mode CH1 CH1 ACT2801-016 VBAT = 4.1V VOUT = 5.0V IOUT = 1.0A ACT2801-015 VBAT = 3.4V VOUT = 5.0V IOUT = 1.0A CH2 CH2 CH1: VOUT, 10mV/div CH2: VSW, 2V/div TIME: 400ns/div CH1: VOUT, 10mV/div CH2: VSW, 2V/div TIME: 400ns/div Transition Between Buck Mode and Boost Mode VIN = 5.0V VBAT = 4.1V ACT2801-017 CH1 VIN VnPG CH2 CH3 VOUT CH1: VIN, 5V/div CH2: VnPG, 5V/div CH3: VOUT, 2V/div TIME: 1s/div Innovative PowerTM - 23 - www.active-semi.com Copyright (c) 2014 Active-Semi, Inc. ACT2801/ACT2801C Rev 4, 07-Aug-14 PACKAGE OUTLINE QFN44-24 PACKAGE OUTLINE AND DIMENSIONS SYMBOL DIMENSION IN MILLIMETERS DIMENSION IN INCHES MIN MAX MIN MAX A 0.800 1.000 0.032 0.040 A1 0.000 0.050 0.000 0.002 A3 b 0.200 REF 0.180 0.300 0.008 REF 0.007 0.012 D 4.000 BSC 0.160 BSC E 4.000 BSC 0.160 BSC D2 2.500 2.800 0.098 0.110 E2 2.500 2.800 0.098 0.110 e L R K 0.500 BSC 0.350 0.450 0.200 TYP 0.200 --- 0.020 BSC 0.014 0.018 0.008 TYP 0.008 --- Active-Semi, Inc. reserves the right to modify the circuitry or specifications without notice. Users should evaluate each product to make sure that it is suitable for their applications. Active-Semi products are not intended or authorized for use as critical components in life-support devices or systems. Active-Semi, Inc. does not assume any liability arising out of the use of any product or circuit described in this datasheet, nor does it convey any patent license. Active-Semi and its logo are trademarks of Active-Semi, Inc. For more information on this and other products, contact sales@active-semi.com or visit http://www.active-semi.com. is a registered trademark of Active-Semi. Innovative PowerTM - 24 - www.active-semi.com Copyright (c) 2014 Active-Semi, Inc.