MIC1232MY Micrel Inc, MIC1232MY Datasheet - Page 5

• Manufacturer Part Number: MIC1232MY
• Description: IC,Power Supply Supervisor,SOP,8PIN,PLASTIC
• Manufacturer: Micrel Inc
• Type: Simple Reset/Power-On Resetr

Specifications of MIC1232MY

• Number Of Voltages Monitored: 1
• Output: Open Drain or Open Collector
• Reset: Active Low
• Reset Timeout: 250 ms Minimum
• Voltage - Threshold: 4.37V, 4.62V
• Operating Temperature: -40°C ~ 85°C
• Mounting Type: Surface Mount
• Package / Case: 8-SOIC (3.9mm Width)
• Number Of Elements: 1
• Monitored Voltage 1 (typ): 4.5 to 5.5V
• Watchdog Timer: Yes
• Chip Enable Signals: No
• Reset Active Time: 1s
• Package Type: SOIC
• Operating Supply Voltage (min): 4.5V
• Operating Supply Voltage (max): 5.5V
• Reset Threshold Voltage (max): 4.74V
• Reset Threshold Voltage (min): 4.5V
• Operating Temp Range: -40C to 85C
• Operating Temperature Classification: Industrial
• Power Fail Detection: No
• Mounting: Surface Mount
• Pin Count: 8
• Battery Backup Switching: No
• Manual Reset: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

January 2006
MIC2755
Applications Information
Power Monitor
The /RST and RST pins are asserted whenever V
below the reset threshold voltage as determined by the TOL
pin. A 5% tolerance level (4.62V reset threshold voltage) can
be selected by connecting the TOL pin to ground and a 10%
tolerance can be selected by connecting the TOL pin to V
The reset pins will remain asserted for a period of 250ms
after V
reset function ensures the microprocessor is properly reset
and powers up into a known condition after a power failure.
/RST will remain valid with V
Watchdog Timer
The microprocessor can be mounted by connecting the /ST
pin (watchdog input) to a bus line or I/O line. If a high-to-low
does not occur on the/ST pin within the watchdog timeout
Block Diagram
CC
has risen above the reset threshold voltage. The
PBRST (1)
V CC (8)
TOL (3)
ST (7)
TD (2)
CC
as low as 1.4V.
TRIP POINT
SELECT
MANUAL RESET
DEBOUNCE
REF
TIMEOUT
SELECT
+
-
CC
falls
CC
.
5
period (determined by the TD pin, see Table 1.), the /RST and
the RST will remain asserted for 250ms when this occurs. A
minimum pulse of 75ns or any transition high-to-low on the
/ST pin will reset the watchdog timer. The watchdog timer
will be reset if /ST sees a valid transition within the watchdog
timeout period.
Pushbutton Reset Input
The /PBRST input can be driven with a manual pushbutton
switch or with external logic signals. the input is internally
debounced and requires an active low signal to force the
reset outputs into their active states. The /PBRST input will
recognize any pulse that is 20ms in duration or greater and
will ignore all pulses that are less than 1ms in duration.
WATCHDOG
TIMER
GENERATOR
RESET
RST (6)
RST (5)
GND (4)
Micrel, Inc.
MIC1232