STM6904 Description
Doc ID 14289 Rev 3 5/20
1 Description
The STM6904 supervisor is a low voltage/low supply current processor supervisor,
designed to monitor up to four system power supply voltages. This device is targeted at
applications such as “Set-Top Boxes” (STBs), portable, battery-powered systems,
networking and communication systems.
The device supports a push-button type manual reset input (MR
). Two of the four supply
monitors (V
CC
and V2IN) have fixed (customer-selectable, factory-trimmed) thresholds
(V
RST1
and V
RST2
). The other two voltage monitor inputs (V3IN and V4IN) are monitored
using externally adjustable threshold (0.600 V internal reference) to meet specific level
requirements.
If any of the four monitored voltages drops below its factory-trimmed or adjustable
thresholds, or if the MR
is asserted to logic low, the reset output RST is asserted (driven
low). Once asserted, RST is maintained low for a minimum delay period (t
REC
) after ALL
monitored supplies rise above their respective thresholds and MR returns to high. This
device is in the correct reset output logic state when V
CC
greater than 0.8 V.
The STM6904 is available in a standard 8-lead MSOP (TSSOP) package.
Figure 1. Logic diagram
Figure 2. MSOP/TSSOP-8 connections
V4IN
V
CC
STM6904
MR
RST
V
SS
TR
SEL
V2IN
V3IN
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1
V3IN
V
SS
V4IN
TR
SEL
V
CC
MR
RST
V2IN
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2
3
4
8
7
6
5