STM6904PWEDS6E STMICROELECTRONICS [STMicroelectronics], STM6904PWEDS6E Datasheet - Page 10

• Manufacturer Part Number: STM6904PWEDS6E
• Description: Quad, ultralow voltage supervisor with push-button reset
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

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3.1
3.2
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Operation
The STM6904 provides the ability to monitor critical voltages such as power-supply and
battery voltage levels, while interfacing easily to the system controllers/microprocessors.
Figure 4
(customer-selectable, factory-programmed ) and two adjustable monitor inputs. RST output
is open drain and requires a 10k ohms pull-up resistor tied to V
Setting the adjustable voltage levels for V3IN and V4IN inputs
The user can customize the minimum voltage levels for the two adjustable voltage inputs by
connecting an external resistor divider network to the V3IN and V4IN pins in order to set the
trip point at some voltage above the 600 mv (V
During normal operation, the STM6904 monitors the voltage levels at all four pins (V
V2IN, V3IN, and V4IN).
Power on reset (t
On power up, the STM6904 activates a power on reset circuit which asserts the reset pin
(i.e. RST goes low). The RST signal remains active until V
MR) rises above the minimum voltage level for the time period t
the supply voltage has stabilized to sufficient operating levels.
shows typical hardware hookup for monitoring four voltages; two fixed thresholds
REC
)
VTRIP
=
0
6 .
V
REF
×
) according to the following formula:
R
1
R
+
2
R
2
CC
(and V2IN, V3IN, V4IN and
CC
REC
.
thereby ensuring that
CC
,