# TPS3851G33SQDRBRQ1

**Texas Instruments** · Monitors & Reset Circuits · SON-8-EP(3x3)

TPS3851G33SQDRBRQ1 from Texas Instruments, in a SON-8-EP(3x3). Pinout and pin descriptions extracted from the manufacturer datasheet (extract_pins, cross-checked by a second model); symbol, footprint, and 3D from KiCad-official CAD.

## Pinout

| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | VDD | power_in | Power supply voltage pin; operating range VDD = 1.6V to 6.5V with recommended 0.1μF bypass capacitor for noisy systems |
| 2 | CWD | input | Programmable watchdog timeout input; connect capacitor between this pin and ground to set watchdog timeout, or connect 10kΩ resistor to VDD for preset watchdog timeout selection |
| 3 | MR | input | Manual reset input with internal pull-up; logic low level triggers RESET; RESET held low for fixed reset delay tRST after MR returns to logic high |
| 4 | GND | power_in | Ground reference pin; internally connects thermal pad to large ground plane |
| 5 | SET1 | input | Logic input to enable/disable watchdog timer; logic low disables watchdog, logic high enables normal watchdog operation with 150µs setup time after transition |
| 6 | WDI | input | Watchdog input triggered by falling edge; falling edge must occur before watchdog timeout (tWD) ends to prevent WDO trigger; must be driven to VDD or GND when watchdog disabled |
| 7 | WDO | output | Watchdog output (open-drain); driven low after watchdog timeout for duration tRST; high-impedance state when RESET is low; requires 1kΩ to 100kΩ pull-up resistor to VPU |
| 8 | RESET | output | Reset output (open-drain); driven low when VDD falls below undervoltage threshold VITN; held low for delay tRST after recovery to VITN + VHYST; requires 1kΩ to 100kΩ pull-up resistor to VPU |
| 9 | Thermal Pad | passive | Exposed pad (from the footprint; not named in the datasheet pin table). |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Texas Instruments |
| Package | SON-8-EP(3x3) |
| Category | Power Supply Chip |
| Pins | 9 |

## CAD (KiCad official)

- Symbol: `TPS3851G33SQDRBRQ1`
- Footprint: `Package_SON:WSON-8-1EP_3x3mm_P0.5mm_EP1.6x2.0mm`
- 3D model: SON-8-EP(3x3) (KiCad packages3D, STEP)
- 3D model files: `tps3851g33sqdrbrq1-etched.step` / `tps3851g33sqdrbrq1-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `tps3851g33sqdrbrq1.step` / `tps3851g33sqdrbrq1.glb` are the bare package body.

## Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

- **Datasheet:** [Texas Instruments datasheet](https://www.ti.com/cn/lit/gpn/tps3851-q1) (39 pp, sha256 `187a2d3c4a847f7d`, retrieved 2026-10-07, tier: lcsc)
- **Datasheet language:** Chinese. Pin names, descriptions, and specs on this page were extracted and translated to English by ds2sf; the linked PDF is the manufacturer original.
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-haiku-4-5-20251001` (text), consensus `claude-sonnet-5-5` (agreed), guards: pin_guards 0.1: passed. Pins are checked against the footprint pad set and their cited datasheet pages before publish.
- **CAD:** KiCad official libraries (CC-BY-SA 4.0).

[Datasheet PDF](docs/tps3851g33sqdrbrq1-datasheet.pdf)