# LS1240AG-SO8-R

**UTC Unisonic Tech** · Gate Drivers · SOP-8

LS1240AG-SO8-R from UTC Unisonic Tech, 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 | LINE | passive | Connecting pin to the B-wire of the telephone line. |
| 2 | GND | power_in | Ground. |
| 3 | Csw | passive | Sweep rate control capacitor; the datasheet specifies the sweep frequency test condition as C1=100nF with R1=14k. |
| 4 | Ra | passive | Output frequency control resistor; the datasheet gives a programming resistor range of 8 to 56 k. |
| 5 | OUT | output | Buzzer output that drives a piezo-ceramic converter directly or, with a decoupling capacitor, a dynamic loudspeaker. |
| 6 | NULL | unconnected | Not connected. |
| 7 | Cr | passive | Rectifier capacitor for the integrated rectifier bridge. |
| 8 | LINE | passive | Connecting pin to the A-wire of the telephone line. |

## Key specifications

| Parameter | Value |
|---|---|
| Manufacturer | UTC Unisonic Tech |
| Package | SOP-8 |
| Category | Motor Driver ICs |
| 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 | VS |  |  | 26 | V |  | 4 |
| Current Consumption without load | IB |  | 1.5 | 1.8 | mA | VS=9.3 to 25V | 4 |
| Activation Voltage | VON | 12 |  | 13.5 | V |  | 4 |
| Sustaining Voltage | VOFF | 7.8 |  | 9.3 | V |  | 4 |
| Differential Resistance in OFF Condition | RD |  | 6.4 |  | k |  | 4 |
| Short Circuit Current | IOUT |  | 70 |  | mA | VS=20V, RL=250 | 4 |
| Output Frequency 1 | fOUT1 | 1.55 |  | 2.53 | kHz | Vs=26V,R1=14k; V3=0V | 4 |
| Output Frequency 2 | fOUT2 | 1.08 |  | 1.9 | kHz | Vs=26V,R1=14k; V3=6V | 4 |
| Fout1/Fout2 ratio | Fout1/Fout2 | 1.33 |  | 1.43 |  | Vs=26V,R1=14k | 4 |
| Programming Resistor Range |  | 8 |  | 56 | k |  | 4 |
| Sweep Frequency |  | 5.25 | 7.5 | 9.75 | Hz | C1=100nF,R1=14k | 4 |
| Calling Voltage (f=50Hz) Continuous | VAB |  |  | 120 | VRMS | f=50Hz | 4 |
| Calling Voltage (f=50Hz) (5s ON/10s OFF) | VAB |  |  | 200 | VRMS | f=50Hz, 5s ON/10s OFF | 4 |
| Supply Current | IDC |  |  | 30 | mA |  | 4 |
| Operating Temperature | TOPR | -40 |  | 70 | C |  | 4 |
| Storage Temperature | TSTG | -65 |  | 150 | C |  | 4 |
| Junction to Ambient (SOP-8) | JA |  | 150 |  | ℃/W | SOP-8 | 4 |

## CAD (KiCad official)

- Symbol: `LS1240AG-SO8-R`
- Footprint: `Package_SO:SOIC-8_3.9x4.9mm_P1.27mm`
- 3D model: SOP-8 (KiCad packages3D, STEP)
- 3D model files: `ls1240ag-so8-r-etched.step` / `ls1240ag-so8-r-etched.glb` carry the MPN laser-etched on the die in a toggleable `Adom.LaserEtch` group (Fusion-ready); `ls1240ag-so8-r.step` / `ls1240ag-so8-r.glb` are the bare package body.

## Provenance

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

- **Datasheet:** [UTC Unisonic Tech datasheet](https://jlcpcb.com/api/file/downloadByFileSystemAccessId/8588881121890852864) (5 pp, sha256 `0d53d49022ed729a`, retrieved 2026-10-18, tier: lcsc)
- **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/ls1240ag-so8-r-datasheet.pdf)