UM706SS
Public Unreviewedby Ray
Union Semiconductor Supervisor and Reset ICs, SOP-8. Datasheet-verified pinout, KiCad symbol/footprint/3D.
3D Model
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Symbol & Footprint
Schematic Symbol
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README
markdownUM706SS
Union Semiconductor · Supervisor and Reset ICs · SOP-8
UM706SS from Union Semiconductor, in a SOP-8. Pinout and pin descriptions extracted from the manufacturer datasheet by ds2sf; symbol, footprint, and 3D from KiCad-official CAD.
Pinout
| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | MR | input | Active-low Manual Reset input. Triggers a reset pulse when pulled below 0.8 V. Has an internal ~250 µA pull-up to VCC; can be driven by TTL/CMOS logic or shorted to GND with a pushbutton. MR pulse width ≥150 ns; MR-to-reset delay ≤250 ns. |
| 2 | VCC | power_in | Supply input, 1.0 V to 5.5 V operating range. Typical supply current 80 µA (150 µA max). Absolute maximum -0.3 V to +6.0 V. |
| 3 | GND | power_in | Ground reference for all signals. |
| 4 | PFI | input | Power-Fail voltage-monitor comparator input. Threshold 1.25 V (typ, range 1.20-1.30 V). When PFI < 1.25 V, PFO is driven low. Input current ±25 nA. Tie to GND or VCC when unused. |
| 5 | PFO | output | Power-Fail Output. Open drive that goes low and sinks current (up to 3.2 mA at 0.4 V) when PFI is below the 1.25 V threshold; otherwise stays high (VOH ≥ 0.7·VCC at 800 µA source). |
| 6 | WDI | input | Watchdog Input. If WDI stays high or low for 1.6 s (typ; 1.0-2.25 s) the internal watchdog times out and WDO is driven low. Rising or falling edges, three-stating WDI, or asserting RESET all clear the timer. Floating WDI or driving with a high-impedance three-state buffer disables the watchdog. Input thresholds VIL ≤0.8 V, VIH ≥3.5 V at VCC=5 V. |
| 7 | RESET | output | Active-Low Reset Output. Pulses low for 200 ms (140-280 ms) when triggered, and stays low whenever VCC is below the 2.93 V reset threshold. Remains low for 200 ms after VCC rises above threshold or MR returns high. Guaranteed valid down to VCC=1.0 V. VOL ≤0.3 V at 1.2 mA sink. |
| 8 | WDO | output | Watchdog Output. Pulls low when the 1.6 s watchdog timer expires and stays low until the watchdog is cleared. Also driven low whenever VCC is below the reset threshold, but (unlike RESET) has no minimum pulse width and goes high immediately once VCC recovers. VOL ≤0.4 V at 1.2 mA sink; VOH ≥0.7·VCC at 800 µA source. |
Key specifications
| Parameter | Value |
|---|---|
| Manufacturer | Union Semiconductor |
| Package | SOP-8 |
| Category | PMIC |
| Pins | 8 |
Ordering variants
Same part, different packaging or reel option.
UM706SSUM708SSUM706SSUM813SS
CAD (KiCad official)
- Symbol:
UM706SS - Footprint:
Package_SO:SOIC-8_3.9x4.9mm_P1.27mm - 3D model: SOP-8 (KiCad packages3D, STEP)
3D model downloads
Two STEP files. Same geometry, different body top:
| File | Size | Use it when |
|---|---|---|
um706ss.step |
122 KB | You want the bare part, or you mark your own boards. |
um706ss-etched.step |
1.9 MB | You want the part with UM706SS already on it. |
The marking in the etched file is real recessed geometry cut into the solid, not a texture or a decal: 451 faces against 147 in the bare model. It survives export, section views, and rendering in any CAD tool, and it drops straight into KiCad or Fusion with no extra setup.
Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- Datasheet: Union Semiconductor datasheet (17 pp, sha256
5e756f3e9ddc319d, retrieved 2026-08-17, tier: manufacturer) - Extractor:
ds2sf(Claude). Every pin and dimension is cited to a datasheet page; it refuses to fabricate. - CAD: KiCad official libraries (CC-BY-SA 4.0).