STCF04 datasheet(17/43 Pages) STMICROELECTRONICS

17 / 43 page

STCF04

Detailed description

Doc ID 022927 Rev 3

17/43

8.1.7

READY pin

This pin can be used to monitor the voltage on the SuperCap by the microprocessor. The

status of this pin has different meanings according to the current mode of operation of the

STCF04.

- Idle, Monitoring, Torch mode with TCHV_H=1:

The READY pin goes LOW when the SuperCap voltage reaches the threshold voltage set

by the VDC register, otherwise the READY pin is HIGH when VSuperCap goes below VDC

voltage - 0.2 V of hysteresis. When READY is HIGH it means that it is necessary to recharge

the SuperCap in order to be able to make a flash.

- Torch mode with TCHV_H=0:

The READY pin goes LOW when the SuperCap reaches 4.2 V and is HIGH when the

SuperCap is below 4.2 V and Torch mode is not active.

- FLASH:

The READY pin goes LOW as soon as the SuperCap voltage reaches the threshold voltage

set by the VDC register. It stays LOW until the SuperCap voltage decreases below 4.2 V and

Flash mode is not active. This feature allows the user to perform multiple flashes.

See

Figure 4 below for details.

Figure 4.

Behavior of the READY pin in different modes

Table 7.

I²C address table

ADD pin

A7A6

A5A4

A3A2

A1A0

GND

R/W

VBAT

R/W

SDA

R/W

SCL

R/W

STCF04 Datasheet(PDF) 17 Page - STMicroelectronics