FC5754

2014. 11. 04

4/21

Revision No : 0

Pin Functions

Name

E-SOP-8 SOT-23-5

Function

NC

1,6,8

NA

Not connected.

PROG

2

5

Charge Current Program, Charge Current Monitor and Shutdown Pin. The charge

in constant-current mode, this pin servos to 1V. In all modes, the voltage on this pin

can be used to measure the charge current using the following formula:

The PROG pin can also be used to shut down the charger. Disconnecting the program

resistor from ground allows a 0.4υA current to pull the PROG pin high. When it reaches

the 1.18V shutdown threshold voltage, the charger enters shutdown mode. This pin is

charger to normal operation. Connecting the PROG pin to a voltage between 0.2V

and 0.4V can force FC5754 into LDO mode.

The PROG pin must not be directly

shorted to ground at any condition.

GND

3

2

Ground

VIN

4

4

Positive Input Supply Voltage. Provides power to the charger. VIN can range from

VBAT+0.5V to 5.5V and should be bypassed with at least a 1υF capacitor. When VIN

drops to within 30mV above the BAT pin voltage, the FC5754 enters shutdown

BAT

5

3

Charge Current Output and battery voltage feedback. This pin provides charge

current to the battery and regulates the final float voltage to 4.2V/4.35V. An internal

precision resistor divider from this pin sets the float voltage which is disconnected in

standby, shutdown and sleep modes.

CHGB

7

1

Open-Drain Charge Status Output. An internal N-channel MOSFET connects CHGB pin

to ground when the battery is charging. After the charge cycle is completed, the

internal N-channel MOSFET is replaced by a weak pull-down of approximately 24υA,

indicating an “AC present” condition. When the FC5754 detects an under voltage

lockout condition, CHGB is forced high impedance.

GND

9

NA

Thermal ground area.