# BL0940

**BL(Shanghai Belling)** · Energy Metering ICs · TSSOP-14

BL0940 from BL(Shanghai Belling), in a TSSOP-14. 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 | VDD | power_in | Chip supply pin at +3.3V, with the datasheet specifying a supply range of 3.0 V to 3.6 V and absolute maximum of -0.3 V to +4 V. |
| 2 | VT | input | External temperature sensor signal input to the SAR ADC, whose maximum input is VDD/2 (full scale 1024 codes). |
| 3 | IP1 | input | Current channel analog input (differential with IN1), with a maximum differential voltage of ±50 mV (35 mV rms). |
| 4 | IN1 | input | Current channel analog input (differential with IP1), with a maximum differential voltage of ±50 mV (35 mV rms). |
| 5 | VP | input | Voltage signal input (differential with VN), with a maximum differential voltage of ±100 mV (70 mV rms). |
| 6 | VN | input | Voltage signal input (differential with VP), with a maximum differential voltage of ±100 mV (70 mV rms). |
| 7 | GND | power_in | Chip ground, referenced at 0 V for all supply and signal specifications. |
| 8 | ZX | output | Voltage zero-crossing indicator output, which goes low during the positive half-cycle and high during the negative half-cycle with a delay of about 570 µs relative to the input signal. |
| 9 | CF | output | Energy pulse output whose function is multiplexed by the MODE register (energy pulse, over-current/leakage alarm, or temperature alarm), with a 50% duty cycle for periods under 180 ms. |
| 10 | SEL | input | UART/SPI mode select (0 = UART, 1 = SPI) with an internal pull-down of 56.9 kΩ, so floating selects UART and tying directly to VDD selects SPI. |
| 11 | SCLK | input | SPI clock input (Mode 1, CPOL=0, CPHA=1, maximum 900 kHz); may be left floating in UART mode. |
| 12 | RX/SDI | input | Multiplexed pin serving as UART RX or SPI data input (DIN), with logic input high level at least 2.6 V and low level at most 0.8 V at VDD=3.3 V ±5%. |
| 13 | TX/SDO | output | Multiplexed pin serving as UART TX or SPI data output (DOUT), which requires an external pull-up resistor and outputs high level of at least VDD-0.5 V at 5 mA. |
| 14 | VPP | unconnected | Reserved pin that should be left floating (not connected). |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | BL(Shanghai Belling) |
| Package | TSSOP-14 |
| Category | Data Converters |
| Pins | 14 |

## 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 (supply voltage) | VDD | 3 |  | 3.6 | V | VDD | 11 |
| 快速有效值响应时间 (50Hz, 可设置为周波/半周波) |  | 10 |  | 40 | mS | 50Hz 可设置为周波/半周波 | 11 |
| 快速有效值响应时间 (60Hz) |  | 8.3 |  | 33 | mS | 60Hz | 11 |
| 逻辑输入高电平 |  | 2.6 |  |  | V | VDD=3.3V±5% | 12 |
| 逻辑输入低电平 |  |  |  | 0.8 | V | VDD=3.3V±5% | 12 |
| 逻辑输出低电平 |  |  |  | 0.5 | V | VDD=3.3V±5%, IOL=5mA | 12 |
| 电源电压 (absolute) | VDD | -0.3 |  | 4 | V | T = 25 ℃ | 12 |
| 模拟输入电压（相对于 GND）IP1、VP |  | -4 |  | 4 | V | T = 25 ℃ | 12 |
| 数字输入电压（相对于 GND）UART_SEL, RX/SDI |  | -0.3 |  |  | V | T = 25 ℃ | 12 |
| 数字输出电压（相对于 GND）CF, TX/SDO |  | -0.3 |  |  | V | T = 25 ℃ | 12 |
| 工作温度 | Topr | -40 |  | 85 | ℃ | T = 25 ℃ (table header) | 12 |
| 贮藏温度 | Tstr | -55 |  | 150 | ℃ | T = 25 ℃ (table header) | 12 |
| 功耗 | Iop |  | 3 |  | mA | VDD=3.3V | 11 |
| 有功电能测量精度（大信号） |  |  | 0.2 |  | % | 35A~100mA 输入@ 1mohm 采样电阻 | 11 |
| 有功电能测量精度（小信号） |  |  | 0.4 |  | % | 100mA~50mA 输入@ 1mohm 采样电阻 | 11 |
| 有功电能测量精度（微小信号） |  |  | 0.6 |  | % | 50mA~10mA 输入@ 1mohm 采样电阻 | 11 |
| 有效值测量精度（大信号） |  |  | 0.2 |  | % | 35A~100mA 输入@ 1mohm 采样电阻 | 11 |
| 有效值测量精度（小信号） |  |  | 2 |  | % | 100mA~50mA 输入@ 1mohm 采样电阻 | 11 |
| 有效值测量精度（微小信号） |  |  | 6 |  | % | 50mA~10mA 输入@ 1mohm 采样电阻 | 11 |
| 过零信号输出延时 |  |  | 571 |  | uS |  | 11 |
| 通道间相角引起测量误差（容性） | PF08err |  | 0.5 |  | % | 相位超前 37 （PF=0.8） | 11 |
| 通道间相角引起测量误差（感性） | PF05err |  | 0.5 |  | % | 相位滞后 60 （PF=0.5） | 11 |
| AC 电源抑制（输出频率幅度变化） | ACPSRR |  | 0.1 |  | % | IP/N=100mV | 11 |
| DC 电源抑制（输出频率幅度变化） | DCPSRR |  | 0.1 |  | % | VP/N=100mV | 11 |
| 模拟输入电平（电流） |  |  | 50 |  | mV | 电流差分输入（峰值） | 12 |
| 模拟输入电平（电压） |  |  | 200 |  | mV | 电压差分输入（峰值） | 12 |
| 模拟输入阻抗 |  |  | 370 |  | kΩ |  | 12 |
| SEL 下拉电阻 | SEL（下拉） |  | 56.9 |  | kΩ |  | 12 |
| 模拟输入带宽（-3dB） |  |  | 3.5 |  | kHz |  | 12 |
| 内部电压基准 | Vref |  | 1.218 |  | V |  | 12 |

## CAD (KiCad official)

- Symbol: `BL0940`
- Footprint: `Package_SO:TSSOP-14_4.4x5mm_P0.65mm`
- 3D model: TSSOP-14 (KiCad packages3D, STEP)
- 3D model files: `bl0940-etched.step` / `bl0940-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `bl0940.step` / `bl0940.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [BL(Shanghai Belling) datasheet](docs/bl0940-datasheet.pdf) (31 pp, sha256 `da8e25f05d4e5f65`, retrieved 2026-10-21, 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/bl0940-datasheet.pdf)