# UC2845AQD8R-TUDI

**Tudi** · AC-DC Controllers And Regulators · SOP-8

UC2845AQD8R-TUDI from Tudi, in a SOP-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 | COMP | output | Error amplifier output, provided for loop compensation. |
| 2 | VFB | input | Inverting input of the error amplifier, normally connected to the switching power supply output through a resistor divider; analog input range is -0.3 to 5.5 V. |
| 3 | ISENSE | input | Current sense input where a voltage proportional to inductor current is applied so the PWM can terminate output switch conduction; analog input range is -0.3 to 5.5 V. |
| 4 | RT/CT | passive | Oscillator timing pin that sets oscillator frequency and maximum output duty cycle by connecting resistor RT to Vref and capacitor CT to ground. |
| 5 | GND | power_in | Combined control circuitry and power ground. |
| 6 | OUT | output | Totem-pole output that directly drives the gate of a power MOSFET, sourcing and sinking peak currents up to 1 A. |
| 7 | VCC | power_in | Positive supply of the integrated circuit, with an absolute maximum of 30 V. |
| 8 | VREF | power_out | Reference output (5.0 V typical) that provides charging current for capacitor CT through resistor RT. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Tudi |
| Package | SOP-8 |
| Category | Power Management (PMIC) |
| Pins | 8 |

## Electrical characteristics

Limits as printed in the datasheet (page.json `metadata.characteristics` carries them as data).

| Parameter | Symbol | Min | Typ | Max | Unit | Conditions | Page |
|---|---|---|---|---|---|---|---|
| Supply Voltage (low impedance source) | VCC |  |  | 30 | V | low impedance source | 2 |
| Output Current | IO | -1 |  | 1 | A |  | 2 |
| Input Voltage (Analog Inputs pins 2,3) | V | -0.3 |  | 5.5 | V | Analog inputs pins 2,3 | 2 |
| Error Amp Output Sink Current |  |  |  | 10 | mA |  | 2 |
| Power Dissipation |  |  |  | 1 | W | TA=25°C | 2 |
| Storage Temperature Range | Tstg | -65 |  | 150 | °C |  | 2 |
| Lead Temperature |  |  |  | 260 | °C | soldering 5 sec. | 2 |
| Reference Output Voltage | VREF | 4.9 | 5 | 5.1 | V | TJ = 25°C, IREF = 1 mA | 3 |
| Line Regulation | ∆VREF |  | 6 | 20 | mV | 12V ≤ VCC ≤ 25 V | 3 |
| Load Regulation | ∆VREF |  | 6 | 25 | mV | 1 mA ≤ IREF ≤ 20mA, TA = 25°C | 3 |
| Short Circuit Output Current | ISC |  | -100 | -180 | mA |  | 3 |
| Oscillation Frequency | f | 47 | 52 | 57 | KHz | TJ = 25°C | 3 |
| Frequency Change with Voltage | ∆f/∆VCC |  | 0.05 | 1 | % | 12V ≤ VCC ≤ 25 V | 3 |
| Input Voltage | VI(E.A) | 2.42 | 2.5 | 2.58 | V | Vpin1 = 2.5V | 3 |
| Input Bias Current (error amp) | IBIAS |  | -0.1 | -2 | µA | VFB=3V | 3 |
| Open Loop Voltage Gain | AVOL | 65 | 90 |  | dB | 2V ≤ V0 ≤ 4V | 3 |
| Unity Gain Bandwidth | UGBW | 0.5 | 0.6 |  | MHz | Tj=25°C, Note 3 | 3 |
| Power Supply Rejection Ratio | PSRR | 60 | 70 |  | dB | 12V ≤ VCC ≤ 25 V | 3 |
| Output Sink Current | ISINK | 2 | 7 |  | mA | Vpin2 = 2.7V, Vpin1 = 1.1V | 3 |
| Output Source Current | ISOURCE | -1 |  | -0.5 | mA | Vpin2 = 2.3V, Vpin1 = 5V | 3 |
| High Output Voltage | VOH | 5 |  |  | V | Vpin2 = 2.3V, RL = 15KΩ to GND | 3 |
| High Output Voltage | VOH | 6 |  |  | V | Vpin2 = 2.7V, RL = 15KΩ to PIN 8 | 3 |
| Low Output Voltage | VOL |  | 0.8 | 1.1 | V |  | 3 |
| Current Sense Gain | GV | 2.85 | 3 | 3.15 | V/V | Note 1 & 2 | 3 |
| Maximum Input Signal | VI(MAX) | 0.9 | 1 | 1.1 | V | Vpin1 = 5V (Note 1) | 3 |
| Input Bias Current (current sense) | IBIAS |  | -3 | -10 | µA | Vpin3 = 3V | 3 |
| Low Output Voltage | VOL |  | 0.08 | 0.4 | V | ISINK = 20 mA | 3 |
| Low Output Voltage | VOL |  | 1.4 | 2.2 | V | ISINK = 200 mA | 3 |
| High Output Voltage | VOH | 13 | 13.5 |  | V | ISINK = 20 mA | 3 |
| High Output Voltage | VOH | 12 | 13 |  | V | ISINK = 200 mA | 3 |
| Rise Time | tR |  | 45 | 150 | nS | TJ = 25°C, CL = 1nF (Note 3) | 3 |
| Fall Time | tF |  | 35 | 150 | nS | TJ = 25°C, CL = 1nF (Note 3) | 3 |
| Start Threshold | VTH(ST) | 7.8 | 8.4 | 9 | V |  | 3 |
| Min. Operating Voltage (After Turn On) | VOPR(min) | 7 | 7.6 | 8.2 | V |  | 3 |
| Max. Duty Cycle | D(MAX) | 47 | 48 | 50 | % |  | 3 |
| Min. Duty Cycle | D(MIN) | 0 |  |  | % |  | 3 |
| Start-Up Current | IST |  | 0.17 | 0.3 | mA |  | 3 |
| Operating Supply Current | ICC(OPR) |  | 13 | 17 | mA | Vpin3 = Vpin2 = 0V | 3 |
| Zener Voltage | VZ | 30 |  | 38 | V | ICC=25 mA | 3 |
| Oscillator Amplitude (peak to peak) | V(OSC) |  | 1.6 |  | V |  | 3 |
| Supply Voltage Rejection | SVR |  | 70 |  | dB | 12V ≤ VCC ≤ 25 V (Note 1) | 3 |

## CAD (KiCad official)

- Symbol: `UC2845AQD8R-TUDI`
- Footprint: `Package_SO:SOIC-8_3.9x4.9mm_P1.27mm`
- 3D model: SOP-8 (KiCad packages3D, STEP)
- 3D model files: `uc2845aqd8r-tudi-etched.step` / `uc2845aqd8r-tudi-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `uc2845aqd8r-tudi.step` / `uc2845aqd8r-tudi.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [Tudi datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8604436242763431936) (11 pp, sha256 `c398bd9771df4e2a`, retrieved 2026-10-18, 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/uc2845aqd8r-tudi-datasheet.pdf)