STM809_10 datasheet(8/21 Pages) STMICROELECTRONICS

Part #	STM809

Description	Reset circuit

PDF	21 Pages

Scroll/Zoom	100%

Manufacturer	STMICROELECTRONICS [STMicroelectronics]

Direct Link	http://www.st.com

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8 / 21 page

Operation

STM809/810/811/812

8/21

Doc ID 9873 Rev 5

2.4

Valid RST output down to VCC = 0 V

When VCC falls below 1 V, the RST (STM809/811) output no longer sinks current, but

becomes an open circuit. In most systems this is not a problem, as most MCUs do not

operate below 1 V. However, in applications where RST output must be valid down to 0 V, a

pull-down resistor may be added to hold the RST output low. This resistor must be large

enough to not load the RST output, and still be small enough to pull the output to ground. A

100 k

Ω resistor is recommended.

Note:

The same situation applies for the active-high RST of the STM810/812. A 100 k

Ω pull-up

resistor to VCC should be used if RST must remain valid for VCC < 1.0 V.

STM809 Datasheet(PDF) 8 Page - STMicroelectronics