# UC3853DTR

**Texas Instruments** · AC-DC Controllers And Regulators · SOIC-8

UC3853DTR from Texas Instruments, in a SOIC-8. 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 | IAC | input | AC waveform input to the multiplier, a low-impedance input nominally at 2V that accepts a current proportional to input voltage (resistor sized for 500mA at maximum line; absolute maximum input current 1mA). |
| 2 | VCC | power_in | Input supply voltage and RMS line-voltage signal to the squarer, operating range 12V to 40V, bypassed with at least a 0.1µF ceramic capacitor. |
| 3 | OUT | output | Gate driver output with 15V clamp for the external power MOSFET, use at least 5 ohm series gate resistor, 0.125A continuous and 0.5A peak drive current. |
| 4 | GND | power_in | Ground reference for all voltages, with the VCC bypass capacitor connected as close to this pin as possible. |
| 5 | FB | input | Voltage amplifier inverting input, overvoltage comparator input and sync input, regulated to a nominal 3V, trips OVP at 5% above nominal, maximum input voltage 5V. |
| 6 | VCOMP | output | Voltage loop transconductance error amplifier output, compensated with impedance to GND, multiplier output current is zero below 1.5V, maximum voltage 6.2V. |
| 7 | IMO | bidirectional | Multiplier output current and current amplifier inverting input summing node, avoid going below -0.5V, input resistance should be 3.9k, maximum output current -2mA. |
| 8 | ICOMP | output | Current loop error amplifier output with 150µA current source class A stage, compensated by impedance between ICOMP and IMO, sinks 20mA maximum and 7.2V maximum voltage. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Texas Instruments |
| Package | SOIC-8 |
| Category | Power Management (PMIC) |
| Pins | 8 |

## CAD (KiCad official)

- Symbol: `UC3853DTR`
- Footprint: `Package_SO:SOIC-8_3.9x4.9mm_P1.27mm`
- 3D model: SOIC-8 (KiCad packages3D, STEP)
- 3D model files: `uc3853dtr-etched.step` / `uc3853dtr-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `uc3853dtr.step` / `uc3853dtr.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/uc3853) (11 pp, sha256 `b2507c5b7940ba26`, retrieved 2026-10-11, tier: lcsc)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-sonnet-5-5` (text+vision), consensus `claude-opus-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/uc3853dtr-datasheet.pdf)