ACT2801QL-T0550 - ACTIVE-SEMI

Innovative PowerTM - 1 - www.active-semi.com

FEATURES

• 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

• <10µA Low Battery Leakage Current at HZ

Mode During Storage

• Boost Auto Turn-off at No Load and Push

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 110°C Die

Temperature

• IC Over Temperature Protection at 160°C

• QFN4x4-24 Package

APPLICATIONS

• Backup Battery Pack

• Power Bank

• Mobile Power

• Standalone Battery Charger with USB Output

GENERAL DESCRIPTION

ACT2801/ACT2801C is a space-saving and high-

performance 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.

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 110°C 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.

5V/1.5A Backup Battery Pack Manager

Rev 4, 07-Aug-14

ACT2801/ACT2801C

Output Voltage (V)

Output Current (mA)

0 200 400 600

800 1000 1400

1200

5.5

5.0

4.5

4.0

3.5

3.0

Boost CC/CV Curve

VBAT =4.1V

VBAT =3.7V

VBAT =3.2V

Rev 4, 07-Aug-14

Innovative PowerTM - 2 - www.active-semi.com

ACT2801/ACT2801C

ORDERING INFORMATION

PART NUMBER OUTPUT CHARGE

CURRENT

LOW BATTERY

LEVEL ALARM

PB TURN

OFF BOOST PACKAGE

ACT2801QL-T0550

(Not Recommended

for New Designs)

5V/1.5A 1.5A No Yes QFN44-24

ACT2801QL-T1026 5V/1.5A 1.5A Yes Yes QFN44-24

ACT2801CQL-T 5V/1.5A 1.5A Yes No QFN44-24

FLASHLIGHT

No

Yes

PIN CONFIGURATION

Rev 4, 07-Aug-14

Innovative PowerTM - 3 - www.active-semi.com

ACT2801/ACT2801C

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 Output pin. Bypass to PGND with a high quality low ESR and ESL ceramic capacitor

placed as close to the IC as possible.

9, 10 SW Internal switch to output inductor terminal.

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 High-

Z 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

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 EP Exposed pad. Must be soldered to ground on the PCB.

Rev 4, 07-Aug-14

Innovative PowerTM - 4 - www.active-semi.com

ACT2801/ACT2801C

ABSOLUTE MAXIMUM RATINGSc

PARAMETER VALUE UNIT

All the Pin to PGND and AGND -0.3 to 6.5 V

Junction to Ambient Thermal Resistance 40 °C/W

Maximum Power Dissipation 2.5 W

Operating Junction Temperature -40 to 150 °C

Storage Junction Temperature -40 to 150 °C

Lead Temperature (Soldering 10 sec.) 300 °C

Operating Ambient Temperature -40 to 85 °C

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.

Rev 4, 07-Aug-14

Innovative PowerTM - 5 - www.active-semi.com

ACT2801/ACT2801C

PARAMETER TEST CONDITIONS MIN TYP MAX UNIT

Input Current Limit

Input Voltage Range 4.5 5.5 V

VIN Over Voltage Protection VIN rising, VIN_OVP 5.5 6.0 6.5 V

Input Voltage Validation Time VIN_UVLO<VIN<VIN_OVP 32 ms

Input Current Limit Setting Range RILIM=1.2k—4.8k 0.5 2.0 A

Input Current Setting RILIM=1.5k 1.6 A

Input Current Limit Gain 2000

Leakage Current from VOUT to VIN in Boost

Mode 3.0V<VBAT<4.35V, Ta=25℃ 0 10

µA

Battery Discharge Current in High-Z Mode 3.0V<VBAT<4.35V, Ta=25℃ 7.5 15

µA

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 -15% 1.1 +15% MHz

High Side Switch Peak Current Limit 4.5 6 A

Minimum On-time 100 ns

Over Temperature Protection (OTP) OTP rising 160 ℃

OTP Hysteresis OTP falling 35 ℃

Charge Mode

Charge Current Setting Range Rcs=50m, RICST=20k—60.4k 0.5 1.5 A

Charge Current Setting (ICHRG) Rcs=50m, RICST=39k -10% 975 +10% mA

Thermal Regulation Temperature 110 ℃

Battery Adjust Voltage(VBAJ) Rbtv=25k 0.1 V

End of Charge (EOC) Voltage -0.5% 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 2.5VVBAT2.8V, Percent of ICHRG 10 %

ELECTRICAL CHARACTERISTICS

(VIN = 5V, TA = 25°C, unless otherwise specified.)

Rev 4, 07-Aug-14

Innovative PowerTM - 6 - www.active-semi.com

ACT2801/ACT2801C

PARAMETER TEST CONDITIONS MIN TYP MAX UNIT

Precondition Voltage Threshold VBAT rising, Rbtv=0 2.8 V

Precondition Voltage Threshold Hysteresis 130 mV

Low VBAT Charge Current VBAT=1V, RICST=39k 200 mA

EOC Current Threshold Percent of the fast charge current 13 %

Charge Restart Voltage Threshold 200 mV

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 µA

Charge Current Foldback

Charge Current Reduction Threshold1 of Vout1 Starting foldback point 4.59 4.7 4.81 V

Charge Current Reduction Threshold2 of Vout1 Stop foldback point, RCS=50m,

RICST=39k 4.57 V

Boost Mode

Input Voltage Operation Range 3.0 4.5 V

Switching Frequency -15% 0.55 +15% MHz

Input Voltage UVLO VBAT rising 3.3 V

Input Voltage UVLO Hysteresis VBAT falling 400 mV

Output Voltage (VOUT) Ta=25℃ 4.97 5.05 5.10 V

Output Voltage Accuracy All conditions -3 VOUT 2 %

Output Voltage Transient Response Vbat=3.7V, 80mA-1A-80mA, 0.1A/us 4.75 5.25 V

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 0.5 1.5 A

Output Current Setting Rcs=50m, RIOST=97.6k 1.3 A

The Maximum Voltage Across VRcs All conditions 200 mV

Minimum On-Time 100 ns

Low Side Switch Peak Current Limit VBAT=3.2V, VOUT=5V 4.0 5.6 A

Soft-Startup Time 400 µs

ELECTRICAL CHARACTERISTICS

(VIN = 5V, TA = 25°C, unless otherwise specified.)

Rev 4, 07-Aug-14

Innovative PowerTM - 7 - www.active-semi.com

ACT2801/ACT2801C

PARAMETER TEST CONDITIONS MIN TYP MAX UNIT

Under Voltage Protection (UVP Threshold)

VOUT falling 4.25 V

VOUT rising 4.6 V

UVP Blanking Time During Startup 3 ms

UVP Sense Detection Time VOUT falling 20 µs

Restart After UVP Hiccup mode 2 s

Light Load Current Shut off Threshold VBAT=3.7V, Rcs=50m, RIOST=97.6k 40 100 mA

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 1.4 V

HZ Pin Low Voltage HZ voltage falling 0.4 0.75 V

HZ Internal Pull-up Resistor 3 M

PB Turn off Boost Time ACT2801-T1026 1.5 s

ACT2801-T0550 3.0 s

PB Turn on Boost Time

ACT2801C 30 ms

ACT2801-T0550/ACT2801-T1026 100 ms

Mode Transition

Transition Waiting Time between Charge

Mode and Boost Mode TRANTIME 2 s

Battery Level Indication

Battery Impedance Compensation Range 40 500 m

Battery Impedance Compensation Rcs=50m, RIMC=100k 200 m

PB High Input Voltage PB voltage rising 0.9 1.4 V

PB Low Input Voltage PB voltage falling 0.4 0.75 V

PB Internal Pull-up Resistor 3 M

LED Indication Time PB is pushed and released 5 s

LED Flash Frequency Charging, LED flash 1s on and 1s off 0.5 Hz

Flashlight Driver

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

ELECTRICAL CHARACTERISTICS

(VIN = 5V, TA = 25°C, unless otherwise specified.)

Rev 4, 07-Aug-14

Innovative PowerTM - 8 - www.active-semi.com

ACT2801/ACT2801C

FUNCTIONAL BLOCK DIAGRAM FOR ACT2801-T0550/ACT2801-T1026

FUNCTIONAL BLOCK DIAGRAM FOR ACT2801C

Rev 4, 07-Aug-14

Innovative PowerTM - 9 - www.active-semi.com

ACT2801/ACT2801C

FUNCTIONAL DESCRIPTION

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.

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.

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

flow chart as shown in Figure 1, and ACT2801C

system operation flow chart as shown in Figure 2.

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.

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

Table 1: Mode Selection

HZ PIN 0 0 1 1

VIN Valid 0 1 0 1

Mode Boost Charge HZ Charge

Rev 4, 07-Aug-14

Innovative PowerTM - 10 - www.active-semi.com

ACT2801/ACT2801C

Figure 2:

ACT2801C System Operation Flow Chart

FUNCTIONAL DESCRIPTION

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.

Precondition 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

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.

End of Charge

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.

Rev 4, 07-Aug-14

Innovative PowerTM - 11 - www.active-semi.com

ACT2801/ACT2801C

FUNCTIONAL DESCRIPTION

Recharge

When battery voltage drops by 200mV below the end of charge voltage, the charger is reinitiated with

constant current charge.

A: PRECONDITION STATE

B: FAST-CHARGE STATE

C: TOP-OFF STATE

D: END-OF-CHARGE STATE

Figure 3.

Typical Li+ Charge Profile and ACT2801/ACT2801C Charge States

Figure 4.

Charger State Diagram

Rev 4, 07-Aug-14

Innovative PowerTM - 12 - www.active-semi.com

ACT2801/ACT2801C

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:

Rbtv is selected based on the battery voltage rating.

1% accuracy resistor is recommended for Rbtv.

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.

Battery level voltage shift (BLVS pin)

LED1-4 voltage thresholds are adjusted from HZ

mode during charging and discharging based on

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:

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

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:

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

Charge Mode

ACT2801: PB time>100ms

ACT2801C: PB time>30ms

(Boost or HZ Mode)

LED LED1 LED2 LED3 LED4 LED1 LED2 LED3 LED4

2.9V≤VBAT<LED1

(ACT2801-T1026/ACT2801C) Flash Off Off Off Flash Off Off Off

LED1≤VBAT<LED2 On Flash Off Off On Off Off Off

LED2≤VBAT<LED3 On On Flash Off On On Off Off

LED3≤VBAT<LED4 On On On Flash On On On Off

VBAT≥LED4 On On On Flash On On On On

VBAT≥LED4 (End of Charge) On On On On On On On On

2.9V≤VBAT<LED1(ACT2801-T0550) Flash Off Off Off Off Off Off Off

VBAT<2.9V Flash Off Off Off Off Off Off Off

(2)

)k(R)mA(01.0)V(5.3)V(V BLVS4BATLED

Ω

×

+

=

(1)

)V(104R)V(1.4)V(V 6

btvBAT −

××+=

Figure 5. Battery terminal voltage setting circuit

Figure 6. Battery level voltage shift setting circuit

)(kR (V)4 .2

(A)I ILIM

ILIM

Ω

=(3)

Table2: LED Indication

Rev 4, 07-Aug-14

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ACT2801/ACT2801C

Input current limit at various resistor curve is shown

in Figure 8.

The ILIM pin voltage is proportional to input current

until input current is limited, as shown in Figure 9.

Battery Fast Charge Current

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:

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:

Figure 13 gives out boost output current with

various RIOST.

The IOST pin voltage is proportional to output

current until output current is limited, as shown in

Figure 14.

)(ms Rc )(kR

)A(

3

2

(A) I OSTI

IOST

Ω

×= (5)

Figure 12. Boost output current setting circuit

Figure 7. Input current limit setting circuit

3.0

1.5

1.0

0.5

0

2.0

2.5

IILIM (A)

RILIM (k)

0.7 1.2 1.7 2.2 2.7 3.2 3.7 4.2 4.7

Figure 8. Input current limit setting

(4)

)m(Rcs )k(R

)A(25.1)A(Ic ICST

Ω

×=

Figure 10. Battery fast charge current setting

Figure 11. Battery fast charge current setting

ICHRG (A)

RICST (k)

0 10 20 30 40 50 60 70 80

2.1

0.9

0.6

0.3

0

1.2

1.5

1.8

Figure 13. Boost output current setting

1.9

1.6

1.3

1.0

0.7

0.4

RIOST (k)

20 40 60 80 100 120 140

IOUT (A)

VILIM (V)

Input Current (A)

0 0.2 0.4 1.0 1.2 1.4 1.6

0.6 0.8

1.4

1.2

1.0

0.8

0.6

0.4

0.2

0

Figure 9. VILIM VS. input current

VIN = 5.0V

RILIM=1.5k

VIN = 5.0V

Vbat=3.7V

VIN = 5.0V

VIOST (mV)

900

750

450

300

150

0

600

Output Current(A)

0 0.2 0.4 0.6 0.8 1.0 1.2

Figure 14. VIOST VS. output current

VBAT = 3.7V

RIOST=97.6k

VBAT = 3.7V

CVout=4.5V

Rev 4, 07-Aug-14

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ACT2801/ACT2801C

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:

The battery impedance as shown in the table 4

according to the RIMC and Rcs:

Table 4: Battery Impedance

Boost Output Plug-in Auto Detection

Figure 16 provides a solution for auto plug-in

detection.

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

resonance as shown in Figure 17.

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.

LEDs on in Boost Mode

LEDs can be always on during boost mode, the

schematic is shown in Figure19.

Inductor and Capacitor Selection

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.

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.

) (mcs R )(m R25

)(kRIMC

Ω

×

=

(7)

(6)

Figure 15. Battery impedance compensation setting circuit

3-

BATBAT 10)m(R)A(I)V(BAT)V(V ××−=

Ω

RIMC(K) 50 100 200

Battery

Impedance

R(m)

Rcs=25m 50 100 200

Rcs=50m 100 200 400

Figure 16. Boost output auto detection circuit

Figure 17. Input over voltage surge protection circuit

Figure 18. Input over voltage protection

Figure 19. LEDs on in boost mode circuit

Rev 4, 07-Aug-14

Innovative PowerTM - 15 - www.active-semi.com

ACT2801/ACT2801C

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 60µA 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:

60µA×RNOM×kHOT=0.3V RNOM×kHOT=5k

60µA×RNOM×kCOLD=1.5V  RNOM×kCOLD= 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. Battery thermal circuit

Rev 4, 07-Aug-14

Innovative PowerTM - 16 - www.active-semi.com

ACT2801/ACT2801C

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.

Top Layer

Figure 21.

PCB Layout

Bottom Layer

PC Board Layout Guidance

Rev 4, 07-Aug-14

Innovative PowerTM - 17 - www.active-semi.com

ACT2801/ACT2801C

Figure 22. Typical application circuit

(Input current limit 2.0A, fast charge current limit 1.5A, boost output constant current limit 1.3A)

Rev 4, 07-Aug-14

Innovative PowerTM - 18 - www.active-semi.com

ACT2801/ACT2801C

ITEM REFERENCE DESCRIPTION QTY MANUFACTURER

1 L1 SWPA4020S1R0NT 2.2uH 3.4A (4*4*2mm) 1 Sunlord

2 Q1 SI2333DDS, Rdson=28m at VGS = - 4.5 V 1 Vishay

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

12 C11,C12 Ceramic Capacitor, 2.2uF/10V, X7R, 0603 2 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

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

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 ACT

3 D1 SR22, Vf=0.5V, 20V Schottky 1 Panjit

23 R10 Chip Resistor, 2.7, 1/4W, 5%, 1206 1 Murata/TDK

28 R16 Chip Resistor, 100, 1/10W, 5%, 0603 1 Murata/TDK

11 C9,C10 Ceramic Capacitor, 39pF/10V, X7R, 0603, Optional 2 Murata/TDK

29 R18,R19 Chip Resistor, 22, 1/10W, 5%, 0603, Optional 2 Murata/TDK

13 C13 Ceramic Capacitor, 4.7uF/10V, X7R, 0603 1 Murata/TDK

Table 5: BOM List

Rev 4, 07-Aug-14

Innovative PowerTM - 19 - www.active-semi.com

ACT2801/ACT2801C

Figure 23. Typical application circuit

(Input current limit 2.0A, fast charge current limit 1.5A, boost output constant current limit 1.3A)

R1

ACT2801C

VIN

nPG

ILIM

AGND

PB

HZ LED1

BTV

ICST

IOST

CSN

CSP

Input USB

+

-

D+

D-

USB Output

+

-

D+

D- R2

R4

R5

R3

C3

R10

C4

Q1

D1

C2

C7

C6

L1

BAT

R9

C11

R11

C12

R13

R12

PB

C5

C8

R14

D2

R15 C13

R16

C9 C10

R18 R19

Rev 4, 07-Aug-14

Innovative PowerTM - 20 - www.active-semi.com

ACT2801/ACT2801C

Table 6: BOM List

ITEM REFERENCE DESCRIPTION QTY MANUFACTURER

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

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

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 ACT

31 LED Flashlight 1 LED Manu

28 R17 Chip Resistor, 51, 1/10W, 5%, 0603 1 Murata/TDK

Rev 4, 07-Aug-14

Innovative PowerTM - 21 - www.active-semi.com

ACT2801/ACT2801C

TYPICAL PERFORMANCE CHARACTERISTICS CONT’D

ACT2801-001

Charge Current VS. Output Current

Input Current (mA)

1800

1500

1200

900

600

300

0

2100

Output Current(mA)

0 300 600 900 1200 1500 1800

ACT2801-002

Battery Charge V/I Profile

Charge Current (mA)

1800

1500

1200

900

600

300

0

Vbat (V)

0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5

ACT2801-003

Charge Efficiency

Efficiency(%)

92.0

91.5

91.0

90.5

90.0

89.5

89.0

Vbat (V)

3.0 3.2 3.4 3.6 3.8 4.0 4.2

ACT2801-005

Battery Charge Current VS. Temperature

Battery Charge Current (mA)

1800

1200

900

600

300

0

1500

Temperature (°C)

-20 0 20 40 60 80 100 120 140

ACT2801-004

Boost Efficiency

Efficiency(%)

100.0

90.0

80.0

70.0

60.0

50.0

40.0

Output Current (mA)

0 200 400 600 800 1000 1200 1400

VIN = 5.0V

VBAT = 3.5V VIN = 5.0V

ICHRG = 1.5A

VIN = 5.0V

ICHRG = 1.5A

VIN = 5.0V

VBAT = 3.5V

(Schematic as show in Figure 22, Ta = 25°C, unless otherwise specified)

ACT2801-006

Battery Leakage (µA)

25.0

20.0

15.0

10.0

5.0

0

Battery Leakage VS. Temperature

(HZ Mode)

Temperature (°C)

-20 0 20 40 60 80 100 120

Input Current

Charge Current

VBAT = 3.2V VBAT = 3.7V VBAT = 4.1V

VBAT = 4.1V

VBAT = 3.5V

Rev 4, 07-Aug-14

Innovative PowerTM - 22 - www.active-semi.com

ACT2801/ACT2801C

TYPICAL PERFORMANCE CHARACTERISTICS CONT’D

ACT2801-007 ACT2801-009

Boost Output Voltage (V)

5.15

5.10

5.05

5.00

4.95

4.90

Boost Output Current (mA)

0 200 400 600 800 1000 1200 1400

Boost Output Voltage VS. Output Current

ACT2801-008

Boost Output Voltage VS. Temperature

Boost Output Voltage (V)

5.4

5.3

5.2

5.1

5.0

4.9

4.8

Temperature (°C)

-30 0 30 60 90 120 150

Boost Output Constant Current Limit

VS. Temperature

Boost Output Constant Current (mA)

1400

1350

1300

1250

1200

1150

Temperature (°C)

-30 0 30 60 90 120 150

VBAT = 3.2V

VBAT = 4.1V

VBAT = 3.5V

CV = 4.5V

Rcs=50m(1%)

VBAT = 3.5V

VOUT = 5.05V

(Schematic as show in Figure 22, Ta = 25°C, unless otherwise specified)

ACT2801-011

Boost Standby Current VS. Battery Voltage

Standby Current (mA)

051

0.50

0.49

0.48

0.47

0.46

0.45

Battery Voltage(V)

2.8 3.1 3.4 3.7 4.0 4.3 4.6

ACT2801-012

Battery Leakage VS. Battery Voltage

(HZ Mode)

Battery Leakage (µA)

8.0

5.0

4.0

3.0

2.0

1.0

0

7.0

6.0

Battery Voltage(V)

0 1.0 2.0 3.0 4.0 5.0

ACT2801-010

Boost Output Constant Current Limit

VS. VBAT

Boost Output Constant Current mA)

1330

1320

1315

1310

1305

1300

1325

Vbat (V)

3.0 3.2 3.4 3.6 3.8 4.0 4.2

Rev 4, 07-Aug-14

Innovative PowerTM - 23 - www.active-semi.com

ACT2801/ACT2801C

TYPICAL PERFORMANCE CHARACTERISTICS CONT’D

CH1

CH2

Transition Between Buck Mode

and Boost Mode

ACT2801-017

(Schematic as show in Figure 22, Ta = 25°C, unless otherwise specified)

CH3

CH1: VIN, 5V/div

CH2: VnPG, 5V/div

CH3: VOUT, 2V/div

TIME: 1s/div

Boost Load Transient (80mA-1A-80mA)

CH1

CH2

VBAT = 3.4V

VOUT = 5.0V

IIOST = 1.3A

Boost Load Transient (80mA-1A-80mA)

ACT2801-014

CH1

CH2

VBAT = 4.1V

VOUT = 5.0V

IIOST = 1.3A

ACT2801-013

CH1: VOUT, 200mV/div

CH2: IOUT, 500mA/div

TIME: 1ms/div

CH1: VOUT, 200mV/div

CH2: IOUT, 500mA/div

TIME: 1ms/div

ACT2801-016

VBAT = 4.1V

VOUT = 5.0V

IOUT = 1.0A

CH1

CH2

SW and Output Waveforms in Boost Mode

ACT2801-015

VBAT = 3.4V

VOUT = 5.0V

IOUT = 1.0A

CH1

CH2

CH1: VOUT, 10mV/div

CH2: VSW, 2V/div

TIME: 400ns/div

CH1: VOUT, 10mV/div

CH2: VSW, 2V/div

TIME: 400ns/div

VIN

VnPG

VOUT

SW and Output Waveforms in Boost Mode

VIN = 5.0V

VBAT = 4.1V

Rev 4, 07-Aug-14

Innovative PowerTM - 24 - www.active-semi.com

ACT2801/ACT2801C

PACKAGE OUTLINE

QFN44-24 PACKAGE OUTLINE AND DIMENSIONS

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 th eir applicatio ns. Active-Se mi products are not inten ded or aut horized 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. F or more info rmation on this and other products, contact

sales@active-semi.com or visit http://www.active-semi.com.

is a registered trademark of Active-Semi.

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 0.200 REF 0.008 REF

b 0.180 0.300 0.007 0.012

D 4.000 BSC 0.160 BSC

E 4.000 BSC

D2 2.500 2.800 0.098 0.110

E2 2.500 2.800 0.098 0.110

e 0.500 BSC 0.020 BSC

L 0.350 0.450 0.014 0.018

R 0.200 TYP 0.008 TYP

K 0.200 --- 0.008 ---

0.160 BSC