# UC2845BD

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

UC2845BD from lingxingic, 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 (比较端) that the datasheet specifies with a sink current capability of 2 to 12 mA and a limit of 10 mA for the error amplifier output sink current. |
| 2 | VFB | input | Negative feedback input (负反馈) of the error amplifier, with a 2.50 V reference (2.42 to 2.58 V) and an input bias current of -0.1 to -2 µA at VFB = 5 V. |
| 3 | ISENSE | input | Current sense input (电流灵敏度) with a current-sense gain of 3 V/V (2.85 to 3.15 V/V) and a maximum input signal of 0.9 to 1.1 V. |
| 4 | RT/CT | passive | Oscillator timing pin (振荡端); with RT = 10 kΩ and CT = 3.3 nF the datasheet gives an oscillator frequency of 49 to 55 kHz (52 kHz typical) at Tj = 25 ℃. |
| 5 | GROUND | power_in | Ground (地) reference pin for the controller. |
| 6 | OUTPUT | output | Push-pull output (输出) that can source or sink large currents to drive a MOSFET power device, with an output current rating of ±1 A. |
| 7 | Vi | power_in | Supply pin (电源) with a 30 V maximum rating from a low-impedance source; for the UC2845 the undervoltage lockout is 8.8 V turn-on and 7.6 V turn-off. |
| 8 | VREF | power_out | Reference voltage (参考电压) output of 5.00 V (4.90 to 5.10 V) at Io = 1 mA, with an output short-circuit current of -30 to -180 mA. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | lingxingic |
| 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 |
|---|---|---|---|---|---|---|---|
| 电源电压（低阻抗源） | Vi |  |  | 30 | V |  | 6 |
| 输出电流 | IO | -1 |  | 1 | A |  | 6 |
| 误差放大器输出端灌电流 | Isink(EA) |  |  | 10 | mA |  | 6 |
| 模拟输入范围 | Vin(EA) | -0.3 |  | 6.3 | V |  | 6 |
| 热阻 SOP8 | θJA |  |  | 160 | ℃/W | JEDEC 2S2P, SOP8 (single printed value) | 6 |
| 工作温度 | Tamb | -40 |  | 125 | ℃ |  | 6 |
| 存储温度 | Tstg | -65 |  | 150 | ℃ |  | 6 |
| 焊接温度 | TL |  |  | 260 | ℃ | 10 s, SOP8 | 6 |
| VREF 输出电压 | VREF | 4.9 | 5 | 5.1 | V | Io=1mA，Tj=25℃ | 6 |
| 线性调整率 | ∆VREF |  | 2 | 20 | mV | 12V≤Vi≤25V | 6 |
| 负载调整率 | ∆VREF |  | 3 | 25 | mV | 1≤Io≤20mA | 6 |
| 总输出变化率 |  | 4.7 |  | 5.3 | V | line, load, temperature | 6 |
| 输出短路电流 | ISC | -30 | -100 | -180 | mA | 注 4 | 6 |
| 振荡器频率 (Tj=25℃) | fOSC | 49 | 52 | 55 | kHz | Tj=25℃ | 6 |
| 振荡器频率 (Tamb=-40～125℃) | fOSC | 47 |  | 57 | kHz | Tamb=-40～125℃ | 6 |
| 振荡器频率 (RT/CT 测试条件) | fOSC | 225 | 250 | 275 | kHz | Tj=25℃ (RT=6.2kΩ，CT=1nF) | 6 |
| 频率的电压稳定性 | ∆fOSC/∆V |  | 0.2 | 1 | % | Vi=12V～25V | 6 |
| 放电电流 | Idischg | 7.6 | 8.3 | 9 | mA | VOSC=2V; Tj=25℃ | 6 |
| 误差放大器输入电压 | V2 | 2.42 | 2.5 | 2.58 | V | VPIN1=2.5V | 6 |
| 输入偏置电流 (误差放大器) | Ib |  | -0.1 | -2 | uA | VFB=5V | 6 |
| 开环电压增益 | AVOL | 65 | 90 |  | dB | 2V≤Vo≤4V | 6 |
| 单位增益带宽 | BW | 0.7 | 1 |  | MHz | Tj=25℃ 注 4 | 6 |
| 电源抑制比 (误差放大器) | PSRR | 60 | 70 |  | dB | 12V≤Vi≤25V | 7 |
| 输出灌电流 | IO | 2 | 12 |  | mA | VPIN2=2.7V，VPIN1=1.1V | 7 |
| 输出拉电流 | IO | -0.5 | -1 |  | mA | VPIN2=2.3V，VPIN1=5V | 7 |
| 输出高电平 | VOUT High | 5 | 6.2 |  | V | VPIN2=2.3V；RL=15KΩ to ground | 7 |
| 输出低电平 | VOUT Low |  | 0.8 | 1.1 | V | VPIN2=2.7V；RL=15KΩ to PIN 8 | 7 |
| 电流传感器增益 | GV | 2.85 | 3 | 3.15 | V/V | 注 5、6 | 7 |
| 最大输入信号 | V3 | 0.9 | 1 | 1.1 | V | VPIN1=5V（注 5） | 7 |
| 电流传感器电源抑制比 | SVR |  |  | 70 | dB | 12V≤Vi≤25V（注 5） | 7 |
| 输入偏置电流 (电流传感器) | Ib |  | -2 | -10 | uA |  | 7 |
| 传输延迟 |  |  | 150 | 300 | ns | 注 4 | 7 |
| 输出低电平 (Isink=20mA) | VOL |  | 0.1 | 0.4 | V | Isink=20mA | 7 |
| 输出低电平 (Isink=200mA) | VOL |  | 1.6 | 2.2 | V | Isink=200mA | 7 |
| 输出高电平 (Isource=20mA) | VOH | 13 | 13.5 |  | V | Isource=20mA | 7 |
| 输出高电平 (Isource=200mA) | VOH | 12 | 13.5 |  | V | Isource=200mA | 7 |
| 欠压锁存饱和压降 | VOLS |  | 0.1 | 1.1 | V | Vi=6V，ISINK=1mA | 7 |
| 上升时间 | tr |  | 50 | 150 | ns | CL=1nF（注 4） | 7 |
| 下降时间 | tf |  | 50 | 150 | ns | CL=1nF（注 4） | 7 |
| 开启阈值电压 (UC2843/UC2845 行) | VTH(ST) | 7.8 | 8.8 | 9.5 | V |  | 7 |
| 维持工作的最小电压 (UC2843/UC2845 行) | VOPR(MIN) | 7 | 7.6 | 8.4 | V |  | 7 |
| 最大占空比 (UC2844/UC2845 行) |  | 47 | 48 | 50 | % |  | 7 |
| 最小占空比 |  | 0 |  |  | % |  | 7 |
| 启动电流 | Ist |  | 0.3 | 1 | mA |  | 7 |
| 工作时电源电流 | Ii |  | 12 | 20 | mA | VPIN2=VPIN3=0V | 7 |
| 齐纳管电压 | Viz | 30 | 36 |  | V | Ii=25mA | 7 |
| 线性调整率温度系数 (VREF) | ∆VREF/∆T |  | 0.25 |  | mV/℃ | 注 4 | 6 |
| 频率的温度稳定性 | ∆fOSC/∆T |  | 0.55 |  | % | Tamb=-40～125℃（注 4） | 6 |
| 振荡幅度 (peak to peak) | VOSC |  | 1.6 |  | V |  | 6 |

## CAD (KiCad official)

- Symbol: `UC2845BD`
- Footprint: `Package_SO:SOIC-8_3.9x4.9mm_P1.27mm`
- 3D model: SOP-8 (KiCad packages3D, STEP)
- 3D model files: `uc2845bd-etched.step` / `uc2845bd-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `uc2845bd.step` / `uc2845bd.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [lingxingic datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8603345057739259904) (11 pp, sha256 `065498dc909cbc66`, retrieved 2026-10-18, 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-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/uc2845bd-datasheet.pdf)