Infinity PS212W Service Manual page 38

PS212W subwoofer
STM809/810/811/812
SUMMARY DESCRIPTION
The STM809/810/811/812 MICROPROCESSOR
RESET Circuits are low-power supervisory devic-
es used to monitor power supplies. They perform
a single function: asserting a reset signal whenev-
er the V supply voltage drops below a preset
CC
Figure 2. Logic Diagram (STM809/810)
Note: 1. For STM810
Figure 3. Logic Diagram (STM811/812)
MR
Note: 1. For STM812
Figure 6. Block Diagram
(1)
MR
Note: 1. STM811/812 only
2. RST for STM810/812
4/18
V
CC
STM809/810
RST (RST)
V
SS
V
CC
STM811/812
RST (RST)
V
SS
V
CC
V
RST
value and keeping it asserted until V
above the preset threshold for a minimum period
of time (t
rec
push-button reset input (MR).
Table 2. Signal Names
V
SS
RST
(1)
RST
V
(1)
CC
(2)
MR
Note: 1. STM810/812 only
2. STM811/812 only
Figure 4. SOT23-3 Connections
AI07832
RST (RST)
(For STM810)
Figure 5. SOT143-4 Connections
(1)
RST (RST)
(For STM812)
AI07831
COMPARE
DEBOUNCE
37
). The STM811/812 also provide a
Ground
Active-Low RESET Output
Active-High RESET Output
Supply Voltage
Manual Reset Input
V 1
SS
3 V
CC
2
AI07833
V
1 4 V
SS
CC
2 3
MR
AI07834
t
rec
RST
Generator
AI07835
has risen
CC
(2)