# RS8905BXM

**Jiangsu RUNIC Tech** · Comparators · MSOP-8

RS8905BXM from Jiangsu RUNIC Tech, in a MSOP-8. Pinout and pin descriptions extracted from the manufacturer datasheet by ds2sf; symbol, footprint, and 3D from KiCad-official CAD.

## Pinout

| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | INA+ | input | Noninverting input of comparator A. Rail-to-rail CMOS input; common-mode range extends from (V-)-0.1V to (V+)+0.1V. Input bias current 1pA typ (10pA max). |
| 2 | INA- | input | Inverting input of comparator A. Rail-to-rail CMOS input; input signals that swing more than 0.5V beyond the supply rails must be current-limited to 10mA or less. |
| 3 | INB+ | input | Noninverting input of comparator B. Rail-to-rail CMOS input; common-mode range (V-)-0.1V to (V+)+0.1V. |
| 4 | INB- | input | Inverting input of comparator B. Rail-to-rail CMOS input; input bias current is essentially leakage of the input protection diodes (~1pA typ). |
| 5 | V- | power_in | Negative (lowest) power supply. Tie to GND for single-supply operation (Vs = 1.4V to 5.5V) or to the negative rail for dual-supply operation (±0.7V to ±2.75V). |
| 6 | OUTB | output | Comparator B push-pull rail-to-rail output. Can source up to 38mA and sink up to 42mA at Vs=5V; output must be current-limited to ±55mA. Output swing typ 140mV from V+ and 85mV from V- at Io=2.5mA, Vs=5V. |
| 7 | OUTA | output | Comparator A push-pull rail-to-rail output. Directly interfaces with TTL/CMOS logic; propagation delay ~9µs with 100mV overdrive at Vs=1.4V. |
| 8 | V+ | power_in | Positive (highest) power supply. Operating range 1.4V to 5.5V (single supply). Quiescent current 400nA typ per channel (1500nA max). Bypass with a local ceramic capacitor to V-. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | Jiangsu RUNIC Tech |
| Package | MSOP-8 |
| Category | Op-amp/Cmp |
| Pins | 8 |

## Ordering variants

Same part, different packaging or reel option.

- `RS8905BXM`
- `RS8905BXMXK`

## Electrical characteristics

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

| Parameter | Symbol | Min | Typ | Max | Unit | Conditions | Page |
|---|---|---|---|---|---|---|---|
| Single-supply operating voltage | Vs | 1.4 |  | 5.5 | V | Single-supply | 3 |
| Dual-supply operating voltage | Vs | 0.7 |  | 2.75 | V | Dual-supply, printed as ±0.7 to ±2.75 V | 3 |
| Supply voltage Vs=(V+)-(V-) | Vs |  |  | 7 | V |  | 3 |
| Input pin voltage (IN+, IN-) absolute maximum |  | -0.5 |  | 0.5 | V | Printed as (V-)-0.5 min and (V+)+0.5 max; values are offsets from the supply rails | 3 |
| Signal output pin voltage absolute maximum |  | -0.5 |  | 0.5 | V | Printed as (V-)-0.5 min and (V+)+0.5 max; values are offsets from the supply rails | 3 |
| Signal input pin current (IN+, IN-) |  | -10 |  | 10 | mA |  | 3 |
| Signal output pin current |  | -55 |  | 55 | mA |  | 3 |
| Operating range free-air temperature TA | TA | -40 |  | 125 | °C |  | 3 |
| Junction temperature TJ | TJ |  |  | 150 | °C |  | 3 |
| Storage temperature Tstg | Tstg | -65 |  | 150 | °C |  | 3 |
| Electrostatic discharge, human-body model | V(ESD) | -3000 |  | 3000 | V | Human-body model (HBM) | 3 |
| Electrostatic discharge, machine model | V(ESD) | -400 |  | 400 | V | Machine Model (MM) | 3 |
| Operating voltage range | Vs | 1.4 |  | 5.5 | V |  | 5 |
| Quiescent current per channel | IQ |  | 400 | 1500 | nA |  | 5 |
| Power-supply rejection ratio | PSRR | 70 |  |  | dB | Vs=1.4V to 5.5V, VCM=(V)+0.5V | 5 |
| Input offset voltage | Vos | -6 | 1 | 6 | mV | VCM =Vs/2, Vs =1.4V | 5 |
| Input offset voltage | Vos | -3 | 1 | 3 | mV | VCM =Vs/2, Vs =5.0V | 5 |
| Input offset voltage drift | ΔVos/ΔT |  | 2 |  | µV/°C | VCM =Vs/2, -40°C ≤ TA ≤125°C | 5 |
| Input bias current | IB |  | 1 | 10 | pA |  | 5 |
| Common-mode voltage range | VCM | -0.1 |  | 0.1 | V | TA = –40°C to 125°C; printed as (V-)-0.1 min and (V+)+0.1 max, offsets from the supply rails | 5 |
| Common-mode rejection ratio | CMRR | 70 |  |  | dB | Vs=5.5V, VCM =-0.1 to 5.6V | 5 |
| Output swing from upper rail | VOH |  | 70 | 75 | mV | Vs=1.4V, Io=0.1mA | 5 |
| Output swing from upper rail | VOH |  | 140 | 170 | mV | Vs=5.0V, Io=2.5mA | 5 |
| Output swing from lower rail | VOL |  | 35 | 40 | mV | Vs=1.4V, Io=-0.1mA | 5 |
| Output swing from lower rail | VOL |  | 85 | 115 | mV | Vs=5.0V, Io=-2.5mA | 5 |
| Short circuit sink current | ISC |  | 42 |  | mA | Vs=5.0V | 5 |
| Short circuit source current | ISC |  | 38 |  | mA | Vs=5.0V | 5 |
| Propagation delay high to low TPHL | TPHL |  | 13 |  | µs | Vs = 5.0 V, Overdrive = 10 mV | 5 |
| Propagation delay high to low TPHL | TPHL |  | 9 |  | µs | Vs = 5.0 V, Overdrive = 100 mV | 5 |
| Propagation delay high to low TPHL | TPHL |  | 12 |  | µs | Vs = 2.5 V, Overdrive = 10 mV | 5 |
| Propagation delay high to low TPHL | TPHL |  | 8 |  | µs | Vs = 2.5 V, Overdrive = 100 mV | 5 |
| Propagation delay low to high TPLH | TPLH |  | 30 |  | µs | Vs = 5.0 V, Overdrive = 10 mV | 5 |
| Propagation delay low to high TPLH | TPLH |  | 40 |  | µs | Vs = 5.0 V, Overdrive = 100 mV | 5 |
| Propagation delay low to high TPLH | TPLH |  | 22 |  | µs | Vs = 2.5 V, Overdrive = 10 mV | 5 |
| Propagation delay low to high TPLH | TPLH |  | 35 |  | µs | Vs = 2.5 V, Overdrive = 100 mV | 5 |
| Rise time TR | TR |  | 240 |  | ns | Overdrive = 100 mV | 5 |
| Fall time TF | TF |  | 260 |  | ns | Overdrive = 100 mV | 5 |
| Junction-to-ambient thermal resistance RθJA | RθJA |  | 165 |  | °C/W | MSOP-8 column | 3 |
| Junction-to-case (top) thermal resistance RθJC(top) | RθJC(top) |  | 53 |  | °C/W | MSOP-8 column | 3 |
| Junction-to-board thermal resistance RθJB | RθJB |  | 87 |  | °C/W | MSOP-8 column | 3 |
| Junction-to-top characterization parameter ΨJT | ΨJT |  | 4.9 |  | °C/W | MSOP-8 column | 3 |
| Junction-to-board characterization parameter ΨJB | ΨJB |  | 85 |  | °C/W | MSOP-8 column | 3 |

## CAD (KiCad official)

- Symbol: `RS8905BXM`
- Footprint: `Package_SO:MSOP-8_3x3mm_P0.65mm`
- 3D model: MSOP-8 (KiCad packages3D, STEP)
- 3D model files: `rs8905bxm-etched.step` / `rs8905bxm-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `rs8905bxm.step` / `rs8905bxm.glb` are the bare package body.

## 3D model downloads

Two STEP files. Same geometry, different body top:

| File | Size | Use it when |
|---|---|---|
| [`rs8905bxm.step`](rs8905bxm.step) | 123 KB | You want the bare part, or you mark your own boards. |
| [`rs8905bxm-etched.step`](rs8905bxm-etched.step) | 2.4 MB | You want the part with `RS8905BXM` already on it. |

The marking in the etched file is real recessed geometry cut into the solid, not a
texture or a decal: 576 faces against 147 in the bare model. It
survives export, section views, and rendering in any CAD tool, and it drops straight
into KiCad or Fusion with no extra setup.

## Provenance

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

- **Datasheet:** [Jiangsu RUNIC Tech datasheet](docs/rs8905bxm-datasheet.pdf) (11 pp, sha256 `93a9dcd2bb90565a`, retrieved 2026-08-17, tier: lcsc)
- **Extractor:** `ds2sf` (Claude). Every pin and dimension is cited to a datasheet page; it refuses to fabricate.
- **CAD:** KiCad official libraries (CC-BY-SA 4.0).

[Datasheet PDF](docs/rs8905bxm-datasheet.pdf)