STMPE812A datasheet(16/53 Pages) STMICROELECTRONICS

Part #	STMPE812A

Description	Integrated 4-wire resistive touchscreen controller, pen-down/real-time mode, fullyautonomous

PDF	53 Pages

Scroll/Zoom	100%

Manufacturer	STMICROELECTRONICS [STMicroelectronics]

Direct Link	http://www.st.com

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16 / 53 page

Power modes

STMPE812A

16/53

Doc ID 18225 Rev 4

Figure 6.

Power modes state diagram

On power up reset, device goes to active state. However, as all the functional blocks are

clocked off by default, no touch/hotkey activity is possible. If there are no I2C activities,

device goes into auto-hibernate mode automatically.

The auto-hibernate feature of STMPE812A is always enabled. Whenever there is a period of

inactivity, the device enters this mode to reduce power consumption. On detection a touch,

correctly addressed I2C data, GPIO activity, the device wakes up immediately.

As the device is able to wake up very quickly, there is no loss of touch data.

AM04141V1

ACTIVE

AUTO -

HIBERNATE

I2C activity,

Touch, Hotkey

No activity

POR

Soft -Reset, Reset input

Reset Input

STMPE812A is in

active mode if PWM

is running

(about 33

μs)

STMPE812A Datasheet(PDF) 16 Page - STMicroelectronics