# MS2351M

**Hangzhou Ruimeng Tech** · Operational Amplifier · MSOP-8

MS2351M from Hangzhou Ruimeng Tech, in a MSOP-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 | RFIN | input | RF signal input with internal AC coupling, 95 kΩ DC resistance to ground and 3 kΩ in-band input resistance at 0.1 GHz; a 52.3 Ω shunt resistor to ground gives an equivalent 50 Ω input. |
| 2 | ENBL | input | Enable pin: tie to VPOS for normal operation and to ground to shut the chip down, with high-level input of at least 1.4 V and low-level of at most 0.1 V over -40℃ to 85℃. |
| 3 | VSET | input | Setpoint input with a voltage range of 0.15 V to 1.2 V; connect it to V_UP for measurement mode, otherwise drive it from an external control voltage for control mode. |
| 4 | FLTR | output | Filter pin where an external capacitor connected between FLTR and V_UP lengthens the output response time. |
| 5 | COMM | power_in | Reference ground for the device. |
| 6 | V_UP | output | Logarithmic RSSI output proportional to the input signal amplitude, with a range of 0.015 V to 1.23 V at RL≥10 kΩ. |
| 7 | V_DN | output | Inverted output of V_UP following V_DN = 2.25 - 2×V_UP, with a maximum output of 2.2 V to 2.3 V at VPOS≥3.3 V. |
| 8 | VPOS | power_in | Supply pin with a specified range of 2.7 V to 5.5 V, to be decoupled with a 0.1 µF low-inductance ceramic capacitor placed next to the pin. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Hangzhou Ruimeng Tech |
| Package | MSOP-8 |
| Category | Amplifiers |
| 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 | VPOS |  |  | 5.5 | V |  | 4 |
| Input voltage rms |  |  |  | 1.6 | V rms |  | 4 |
| Equivalent power |  |  |  | 17 | dBm |  | 4 |
| Maximum power dissipation | PD |  |  | 200 | mW |  | 4 |
| Operating ambient temperature | Topr | -40 |  | 85 | ℃ |  | 4 |
| Storage temperature | Tstg | -55 |  | 150 | ℃ |  | 4 |
| Die attach soldering temperature | TTOR |  |  | 260 | ℃ | 10 s | 4 |
| Overall frequency range |  | 0.1 |  | 2.5 | GHz | 满足所有规范 | 4 |
| Input voltage |  | 1.25 |  | 224 | mV rms | 内部 AC 耦合 | 4 |
| Equivalent power |  | -45 |  | 0 | dBm | 52.3Ω外部终端 | 4 |
| Voltage range V_UP with VSET connected | V_UP | 0.015 |  | 1.23 | V | V_UP 接 VSET | 4 |
| Minimum output voltage | V_UP | 0.013 | 0.015 | 0.016 | V | RFIN 端无信号输入，RL≥10k | 4 |
| Maximum output voltage | V_UP | 1.22 | 1.224 | 1.23 | V | RL≥10k | 4 |
| Source current capability |  | 17.8 | 18 | 18.7 | mA | V_UP 电流源 | 5 |
| Sink current capability |  | 1.5 | 2.2 | 2.4 | mA | V_UP 电流沉 | 5 |
| Minimum output voltage | V_DN | 0.03 | 0.036 | 0.05 | V | VPOS≥3.3V | 5 |
| Maximum output voltage | V_DN | 2.2 | 2.26 | 2.3 | V | VPOS≥3.3V | 5 |
| Source current capability V_DN |  | 35 | 37 | 39 | mA | 电流源 | 5 |
| Sink current capability V_DN |  | 1.4 | 2.1 | 2.4 | mA | 电流沉 | 5 |
| VSET voltage range | VSET | 0.15 |  | 1.2 | V | 对应中心 40dB | 5 |
| VSET input resistance |  | 8 | 10 | 12 | kΩ |  | 5 |
| Enable high-level input | ENBL | 1.4 |  |  | V | 高电平输入，-40℃~85℃ | 5 |
| Enable low-level output | ENBL | -0.5 | 0.1 |  | V | 低电平输出，-40℃~85℃ | 5 |
| Supply voltage | VPOS | 2.7 | 3.3 | 5.5 | V | 供电电压 | 5 |
| Quiescent current |  |  | 5.3 | 5.6 | mA | 静态电流 | 5 |
| Quiescent current over temperature |  | 4.2 | 5.7 | 6.3 | mA | 温度范围内 -40℃-85℃ | 5 |
| Enable-on input current |  |  | 20 | 300 | uA | ENBL=2.7V，-40℃~85℃ | 5 |
| Enable-off current |  |  | 1.2 | 6.3 | mA | 使能关时电流 | 5 |
| Enable-off current over temperature |  |  | 1.2 | 6.3 | mA | 温度范围内 -40℃-85℃ | 5 |
| Logarithmic slope V_UP |  |  | 22 |  | mV/dB | V_UP，100MHz | 4 |
| Logarithmic intercept V_UP |  |  | -63.5 |  | dBV | V_UP，100MHz | 4 |
| Equivalent power at intercept |  |  | -50.5 |  | dBm | 52.3Ω外部终端 | 4 |
| DC resistance to ground at RFIN |  |  | 95 |  | kΩ | 对地直流电阻 | 4 |
| In-band input resistance |  |  | 3 |  | kΩ | f=0.1GHz | 4 |
| Input capacitance |  |  | 2.3 |  | pF | f=0.1GHz | 4 |
| Response time 10%-90% |  |  | 83 |  | ns | 10%-90%，10dB 阶跃 | 5 |
| Residual RF signal worst case |  |  |  | 30 | uV | f=0.1GHz，最差情况 | 5 |
| V_DN gain relative to V_UP |  |  | -2 |  |  |  | 5 |
| Output referred noise |  |  | 0.16 |  | Hz V | RFIN=2GHz，-33dBV，fNOISE=10kHz | 5 |
| Full-scale settling time |  |  | 160 |  | ns | -40dBm 到 0dBm | 5 |
| Logarithmic slope at 0.9GHz |  |  | 22.2 |  | mV/dB | f=0.9GHz | 5 |
| Logarithmic slope at 1.9GHz |  |  | 21.9 |  | mV/dB | f=1.9GHz | 5 |

## CAD (KiCad official)

- Symbol: `MS2351M`
- Footprint: `Package_SO:MSOP-8_3x3mm_P0.65mm`
- 3D model: MSOP-8 (KiCad packages3D, STEP)
- 3D model files: `ms2351m-etched.step` / `ms2351m-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `ms2351m.step` / `ms2351m.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [Hangzhou Ruimeng Tech datasheet](docs/ms2351m-datasheet.pdf) (27 pp, sha256 `407ed168b9533fb6`, retrieved 2026-11-02, 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/ms2351m-datasheet.pdf)