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 | 具有手动复位输入的4引脚微处理器电压监测器 | 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 |