ACTIVE
Part Number
UM821
Status
ACTIVE
Watchdog
No
Output driver type/Reset outpt
Push-pull, Active-low
Manual Reset Input
Yes
PFI Option
No
Typical Threshold Voltage (V)
2.32, 2.63, 2.93, 3.08, 4, 4.38, 4.63
VCC Range (V)
1 to 5.5
Iq(typ) (mA)
0.002
Time delay (ms)
240
Features
Long Manual Reset Setup Period
Operating Temperature Range (℃)
-40 to 85
Package
SOT143
The UM821 is low-power microprocessor (μP) supervisory circuit used to monitor power supplies in μP and digital systems. The device provides excellent circuit reliability and low cost by eliminating external components and adjustments when used with 5V-powered or 3V-powered circuits. The UM821 also provides a debounced manual reset input with long setup period.
The reset output asserts when the VCC supply voltage drops below its specified threshold. The reset output remains asserted for the reset timeout period (240ms typ) after VCC rises above the reset threshold. The reset output is one-shot pulse asserted for the reset timeout period (140ms min) when manual reset input is held low for a fixed setup timeout period. The device ignores manual reset transitions of less than the fixed setup timeout period.
The UM821 has an active-low /RESET with push-pull output.
The device, offered in small SOT143 package, is fully guaranteed over the extended temperature range (-40°C to +85°C).
- No External Components
- VCC Transient Immunity
- Guaranteed Reset Valid 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
- Available in 3 Manual Reset Setup Periods (tMR):
-- A: 10.08s
-- B: 6.72s
-- C: 1.68s
- Available in One Output Configuration: Push-Pull Active-Low /RESET Output
- 4-Pin SOT143 Package
- Wide Operation Temperature: -40°C to +85°C
- Set-Top Boxes
- Consumer Electronics
- DVD Players
- Cable/DSL Modems
- MP3 Players
- Industrial Equipments
- Automotive
- Medical Devices
| Part Number | Packaging Type | Marking Code | Shipping Qty |
|---|---|---|---|
| UM821xAE | SOT143 | 1xA | 3000pcs/7Inch Tape & Reel |
| UM821xBE | SOT143 | 1xB | 3000pcs/7Inch Tape & Reel |
| UM821xCE | SOT143 | 1xC | 3000pcs/7Inch Tape & Reel |
