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Datasheet Reliability Report Package Information Order Sample  
Key Specifications
Part Number Description Status Reset Out treset (min) Watchdog Feature Watchdog Timeout Manual Reset Power Fail Comparator Reset Thresh. Accur. (@ +25°C) (%) Icc (max) (µA) RoHS Available Oper. Temp. (°C) Pin/Package EV Kit Available?
UM805xE 4-Pin μP Voltage Monitors with Manual Reset Input ACTIVE Open-drain, active LOW 140ms No Yes No 2.5 5 Yes -40 to 85 4/SOT143 Y
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Product Description
 
The UM805/811/812 are low-power microprocessor (μP) supervisory circuits used to monitor power supplies in μP and digital systems. They provide excellent circuit reliability and low cost by eliminating external components and adjustments when used with 5V-powered or 3V-powered circuits. The UM805/811/812 also provide a debounced manual reset input.
These devices perform a single function: They assert a reset signal whenever the VCC supply voltage falls below a preset threshold, keeping it asserted for at least 140ms after VCC has risen above the reset threshold. Reset thresholds are available for operation with a variety of supply voltages.
The UM805 has an open-drain output stage, while the UM811/812 have push-pull outputs. The UM805’s open-drain RESET(_______________) output requires a pull-up resistor that can be connected to a voltage higher than VCC. The UM805/811 have an active-low RESET(_______________) output, while the UM812 has an active-high RESET output. The reset comparator is designed to ignore fast transients on VCC, and the outputs are guaranteed to be in the correct logic state for VCC down to 1V.
Low supply current makes the UM805/811/812 ideal for use in portable equipments. The devices come in a 4-pin SOT143 package.
 
Features
 
- No External Components
- VCC Transient Immunity
- Correct Logic Output Guaranteed to VCC=1.0V
- Precision VCC Monitoring of 3.0V, 3.3V and 5.0V Supplies
- 2μA Supply Current
- 140ms Minimum Power-On Reset Pulse Width
- Guaranteed Over Temperature
- Available in 3 Output Configurations:
  Open-Drain Active-Low RESET(_______________) Output(UM805)
  Push-Pull Active-Low RESET(_______________) Output(UM811)
  Push-Pull Active-High RESET Output(UM812)
- 4-Pin SOT143 Package
- Wide Operation Temperature: -40°C to +85°C
  
Typical Application Circuit

 
Applications
 
- Computers
- Controllers
- Portable/Battery-Powered Equipments
- Intelligent Instruments
- Critical μP and μC Power Monitoring
 
Pin Configurations

  

( ) are for UM812
 
Ordering Information
 
UM8 XX Z P
XX: Output Type
=05   Open-Drain Active Low
=11   Push-Pull Active Low
=12   Push-Pull Active High
Z: Reset Threshold (V)
=L     4.63
=M    4.38
=J     4.00
=T     3.08
=S    2.93
=R    2.63
=Z    2.32
P: Package Type
=E    SOT143
 
Selection Table

Part Number
RESET Threshold (V)
Timeout Period (ms)
Output Type
Marking Code
Package Type
Shipping Qty
UM805LE
4.63
240
Open-Drain,
Active Low
05L
SOT143
3000pcs/7Inch
Tape & Reel
UM805ME
4.38
240
Open-Drain,
Active Low
05M
UM805JE
4.00
240
Open-Drain,
Active Low
05J
UM805TE
3.08
240
Open-Drain,
Active Low
05T
UM805SE
2.93
240
Open-Drain,
Active Low
05S
UM805RE
2.63
240
Open-Drain,
Active Low
05R
UM805ZE
2.32
240
Open-Drain,
Active Low
05Z
UM811LE
4.63
240
Push-Pull,
Active Low
11L
UM811ME
4.38
240
Push-Pull,
Active Low
11M
UM811JE
4.00
240
Push-Pull,
Active Low
11J
UM811TE
3.08
240
Push-Pull,
Active Low
11T
UM811SE
2.93
240
Push-Pull,
Active Low
11S
UM811RE
2.63
240
Push-Pull,
Active Low
11R
UM811ZE
2.32
240
Push-Pull,
Active Low
11Z
UM812LE
4.63
240
Push-Pull,
Active High
12L
UM812ME
4.38
240
Push-Pull,
Active High
12M
UM812JE
4.00
240
Push-Pull,
Active High
12J
UM812TE
3.08
240
Push-Pull,
Active High
12T
UM812SE
2.93
240
Push-Pull,
Active High
12S
UM812RE
2.63
240
Push-Pull,
Active High
12R
UM812ZE
2.32
240
Push-Pull,
Active High
12Z
 
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