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www.pingjingsemi.com

Revision

:1.0 May-2019

Pin Distribution

Pin Function

CHRG(Pin1)

Output of open drain charging state. The CHRG pin is pulled to low level by an

internal N-channel MOSFET during battery charging. When the charging cycle

ends, CHRG pin is off and all lights are off. When PJ4057 detects an under

voltage blocking condition, the CHRG pin is forced to a high impedance state.

GND(Pin2)

GND

BAT(Pin3)

Charging current output.The pin provides charging current to the battery and

adjusts the final floating charging voltage to 4.2V. A precise internal resistance

voltage divider of the pin sets the floating charging voltage. In the shutdown mode,

the internal resistance voltage divider is disconnected.

VCC(Pin4)

Positive input power voltage.This pin supplies power to the charger.VCC shall vary

from 4.25V to 6.5V and shall be bypassed by at least one 1uF capacitor.When the

VCC drops to less than 30mV of BAT pin voltage,PJ4057 enters the stop mode,

and the Ibat falls below 2uA.

PROG(Pin6)

Charging current setting, charging current monitoring and stop pin.The charging

current can be set by connecting a 1% precision resistor Prog between the pin

and the ground.When charging in constant current mode, the voltage of this pin is

maintained at 1V. In all modes, the voltage on this pin can be used to calculate the

charging current. The formula is Ibat=(Vprog/Rprog)*1000.Short connect the set

resistor to the ground, and an internal 2uA current pulls the PROG pin to a high

level.When the voltage of this pin reaches the stop threshold voltage of 1.21V, the

charger enters the stop mode, the charging stops and the input power current

drops to 25uA.The clamping voltage of this port is about 2.4V.Supply this port with

a voltage in excess of the clipping voltage and a high current of 1.5 mA will be

obtained,Reconnecting the Rprog to the ground will restore the charger to normal

operation.

PJ4057

Linear Lithium-ion Battery Charger

1.CHRG

SOT-23-6

2.GND 3.BAT

4.VCC

5.STBY

6.PORG

STBY(Pin5)

The charging status indicates that when the battery is charged, STDBY is

pulled to a low level by an internal switch to indicate the end of charging. In

other states, STDBY pins are in a high impedance state