stm1818r STMicroelectronics, stm1818r Datasheet - Page 5

• Manufacturer Part Number: stm1818r
• Description: Low Power Reset Circuit
• Manufacturer: STMicroelectronics

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