# UCC28C42DGKR

**Texas Instruments** · DC-DC Controllers · VSSOP-8-0.65mm

UCC28C42DGKR from Texas Instruments, in a VSSOP-8-0.65mm. 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 | COMP | output | Output of the error amplifier for loop compensation; the pin can both source and sink current, the error amplifier is internally current limited, and zero duty cycle can be commanded by externally forcing COMP to GND. |
| 2 | FB | input | Inverting input of the error amplifier used to control the voltage-feedback loop, with the noninverting input internally trimmed to 2.5V ±1%. |
| 3 | CS | input | Primary-side current sense input connected to the noninverting input of the PWM comparator, which terminates OUT conduction when the sensed voltage reaches the error amplifier-derived level. |
| 4 | RT/CT | bidirectional | Oscillator set point where timing resistor RRT connects to VREF and timing capacitor CCT connects to GND to set the switching frequency; for UCCx8C42 the gate drive frequency equals fOSC. |
| 5 | GND | power_in | Ground return pin for the output driver stage and the logic-level controller section. |
| 6 | OUT | output | Output of the on-chip totem-pole drive stage intended to directly drive a MOSFET, sourcing and sinking peak currents up to 1A; for UCCx8C42 it switches at the oscillator frequency, can operate near 100% duty cycle, and is held low when VDD is below the turn-on threshold. |
| 7 | VDD | power_in | Analog controller bias supply input with an absolute maximum of 20V, requiring a ceramic bypass capacitor (typically 0.1µF) connected directly to GND; total VDD current is the quiescent current plus the average OUT current. |
| 8 | VREF | power_out | 5V reference output with ±1% tolerance that requires a ceramic bypass of at least 0.1µF to GND placed as close to the pin as possible, and a short-circuit current of 55mA maximum. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Texas Instruments |
| Package | VSSOP-8-0.65mm |
| Category | Power Supply Chip |
| Pins | 8 |

## CAD (KiCad official)

- Symbol: `UCC28C42DGKR`
- Footprint: `Package_SO:VSSOP-8_2.3x2mm_P0.5mm`
- 3D model: VSSOP-8-0.65mm (KiCad packages3D, STEP)
- 3D model files: `ucc28c42dgkr-etched.step` / `ucc28c42dgkr-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `ucc28c42dgkr.step` / `ucc28c42dgkr.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/lit/ds/symlink/ucc28c42.pdf) (60 pp, sha256 `9fa55f996731c56b`, retrieved 2026-10-11, tier: manufacturer)
- **Extractor:** parts-factory `2.0.0` / `extract_pins 0.3`, primary `claude-haiku-5-5` (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/ucc28c42dgkr-datasheet.pdf)