# UC2845BNG-TUDI

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

UC2845BNG-TUDI from Tudi, in a DIP-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, made for loop compensation. |
| 2 | VFB | input | Inverting input of the error amplifier, normally connected to the switching power supply output through a resistor divider. |
| 3 | ISENSE | input | Input for a voltage proportional to inductor current, used by the PWM to terminate output switch conduction. |
| 4 | RT/CT | passive | Oscillator frequency and maximum output duty cycle are programmed by connecting resistor RT to Vref and capacitor CT to ground. |
| 5 | GND | power_in | Combined control circuitry and power ground. |
| 6 | OUT | output | Directly drives the gate of a power MOSFET, with peak currents up to 1A sourced and sunk. |
| 7 | VCC | power_in | Positive supply of the integrated circuit. |
| 8 | VREF | power_out | Reference output (5.0V typ at 1 mA) that provides charging current for capacitor CT through resistor RT. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Tudi |
| Package | DIP-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) |  |  |  | 30 | V | low impedance source | 3 |
| Output Current |  | -1 |  | 1 | A |  | 3 |
| Input Voltage (Analog Inputs pins 2,3) | V I | -0.3 |  | 5.5 | V | Analog inputs pins 2,3 | 3 |
| Error Amp Output Sink Current | ISINK (E.A) |  |  | 10 | mA |  | 3 |
| Power Dissipation | PO |  |  | 1 | W | TA=25°C | 3 |
| Storage Temperature Range | Tstg | -65 |  | 150 | °C |  | 3 |
| Lead Temperature | TL |  |  | 260 | °C | soldering 5 sec | 3 |
| Operating Ambient Temperature | TA | -40 |  | 85 | °C | UC2842/43/44/45 characterized range | 1 |
| Reference Output Voltage | VREF | 4.9 | 5 | 5.1 | V | TJ = 25°C, IREF = 1 mA | 3 |
| Line Regulation | ΔVREF | 6 |  | 20 | mV | 12V ≤ VCC ≤ 25 V | 3 |
| Load Regulation | ΔVREF | 6 |  | 25 |  | 1 mA ≤ IREF ≤ 20mA | 3 |
| Short Circuit Output Current | ISC | -100 |  | -180 | mA | TA = 25°C | 3 |
| Oscillation Frequency | f | 47 | 52 | 57 | KHz | TJ = 25°C | 3 |
| Frequency Change with Voltage | Δf/ΔVCC | 0.05 |  | 1 | % | 12V ≤ VCC ≤ 25 V | 3 |
| Oscillator Amplitude (peak to peak) | V(OSC) |  | 1.6 |  | V | peak to peak | 3 |
| Input Bias Current (error amp) | IBIAS | -0.1 |  | -2 | µA | VFB=3V | 3 |
| Input Voltage | VI(E.A) | 2.42 | 2.5 | 2.58 | V | Vpin1 = 2.5V | 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 | -0.5 |  | -1 | mA | Vpin2 = 2.3V, Vpin1 = 5V | 3 |
| High Output Voltage (error amp) | VOH | 5 |  | 6 | V | Vpin2 = 2.3V, RL = 15KΩ to GND | 3 |
| Low Output Voltage (error amp) | VOL | 0.8 |  | 1.1 | V | Vpin2 = 2.7V, RL = 15KΩ to PIN 8 | 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 |
| Supply Voltage Rejection | SVR |  | 70 |  | dB | 12V ≤ VCC ≤ 25 V, 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 (UVLO) | VTH(ST) | 7.8 | 8.4 | 9 | V | UC2843/45 variant | 3 |
| Min. Operating Voltage (after turn on) | VOPR(min) | 7 | 7.6 | 8.2 | V | UC2843/45 variant | 3 |
| Max. Duty Cycle | D(MAX) | 47 | 48 | 50 | % | UC2844/45 variant | 3 |
| Min. Duty Cycle | D(MAX) |  | 0 |  |  |  | 3 |
| Operating Supply Current | ICC (OPR) | 13 |  | 17 | mA | Vpin3 = Vpin2 = 0V | 3 |
| Zener Voltage | VZ | 30 |  | 38 | V | ICC = 25 mA | 3 |

## CAD (KiCad official)

- Symbol: `UC2845BNG-TUDI`
- Footprint: `Package_DIP:DIP-8_W7.62mm`
- 3D model: DIP-8 (KiCad packages3D, STEP)
- 3D model files: `uc2845bng-tudi-etched.step` / `uc2845bng-tudi-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `uc2845bng-tudi.step` / `uc2845bng-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/8604436123226173440) (11 pp, sha256 `fa001136cdaccd5a`, retrieved 2026-10-15, 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/uc2845bng-tudi-datasheet.pdf)