AN2407 datasheet(9/14 Pages) STMICROELECTRONICS

9 / 14 page

AN2407

CHRG and Power-on status output pins

9/14

CHRG and Power-on status output pins

The POWER ON pin (open drain) is a flag that indicates the presence of the VCC,

VUVLO<VCC<7.2V and VCC>VBAT. High impedance indicates that VCC< VUVLO, VCC>7.2V or

VCC<VBAT. In this case VCC is insufficient.

The CHRG pin (open drain) is a flag that indicates the status of the charge, if the pin is low

the device works and the charge is going, when the pin is high impedance the charge is

finished (constant Voltage and IPROG/10).

The values in Table 3 correspond to the following modes:

–

00 is Precharge mode (Trickle Charge mode) or Charge Mode. VCC is more than

VUVLO and RPROG is present on the PROG pin.

–

01 is Standby mode (completed charge) or Shutdown mode (RPROG not

connected).

–

11 is Supply (insufficient and unqualified.)

Figure 4.

Using a microprocessor to determine device state

Table 3.

LEDs status

CHRG

Low

High

Power-ON

Low

High

Not used

AN2407 Datasheet(PDF) 9 Page - STMicroelectronics