STM1815R STMICROELECTRONICS [STMicroelectronics], STM1815R Datasheet - Page 4

• Manufacturer Part Number: STM1815R
• Description: Low Power Reset Circuit
• Manufacturer: STMICROELECTRONICS [STMicroelectronics]

STM1810/1811/1812/1813/1815/1816/1817/1818
SUMMARY DESCRIPTION
STM181x devices are low power reset devices
used to monitor power supplies for microcontrol-
lers. They perform a single function: asserting a
reset signal whenever V
below a preset value and keeping it asserted until
V
minimum period of time (t
lent circuit reliability without additional external
components
(STM1815–STM1818), and
STM1813) power supply systems.
A precision voltage reference and comparator
monitors the V
dition. When an invalid V
reset output (RST) is forced low (or high in the
case of RST) and remains asserted for t
V
STM1813/1818 also keep reset asserted for t
after the output is momentarily pulled to ground by
an external push-button switch.
The STM1812 and STM1817 have an active-high,
push-pull output. The STM1810 and STM1815
(push-pull) and STM1811, STM1813, STM1816,
Figure 2. Logic Diagram
Note: 1. For STM1812, STM1817
4/20
CC
CC
has risen above the preset threshold for a
rises above the reset threshold. The
V
V
STM181x
CC
SS
CC
when
input for an out-of-tolerance con-
used
CC
CC
rec
). They provide excel-
supply voltage drops
condition occurs, the
RST (RST)
with
+5V (STM1810–
AI09648
+3.0V/+3.3V
(1)
rec
after
rec
and STM1818 (open drain) have an active-low
RST output. The open drain devices (STM1811/
STM1813/STM1816/STM1818) also have an in-
ternal pull-up resistor to V
STM1818 feature a debounced manual reset fea-
ture that asserts a reset if the RST pin is pulled low
for more than 1.5µs. When used to initiate manual
reset, RST debounces signals from devices such
as mechanical switches. For devices with this fea-
ture, the release of the external switch triggers the
reset period.
The STM181x devices are guaranteed to output
the correct logic state for V
to +105°C). They also provide a reset comparator
designed to ignore fast transients on V
Reset thresholds are available between +2.55V
and +4.62V These small, low power devices are
ideal for use in portable equipment. All are avail-
able in the space-saving 3-pin SOT23 package,
and are specified from –40°C to +105°C.
4., page 5
STM181x devices to a Microcontroller.
Table 2. Signal Names
Note: 1. For STM1812, STM1817
Figure 3. SOT23-3 Connections
Note: RST for STM1812 and STM1817
V
RST
RST
V
SS
CC
(1)
RST (RST)
shows a typical hardware hookup for
Ground
Active-low Reset Output
Active-high Reset Output
Supply Voltage and Input for Reset
Threshold Monitor
V
CC
1
2
CC
3
CC
. The STM1813 and
down to 1.0V (0°C
AI09649
V
SS
CC
.
Figure