The LM1949 is a low-voltage driver integrated circuit produced by National Semiconductor. The integrated circuit contains a high-voltage driver that can directly drive high-voltage solenoids, such as automobile injector solenoids. The integrated circuit has a working voltage range of 3V-5.5V and a working temperature range of -55˚C to 125˚C. The LM1949 integrated circuit has the characteristic of high output current, which can reach 22mA, which can meet the requirements of automobile injector solenoid current.
The LM1949 is a linear integrated circuit designed to control fuel injector drive circuitry in automotive systems. It senses the solenoid current, drives an external NPN Darlington transistor to a peak current four times the hold current, then reduces to the holding level for the duration of the input pulse, improving efficiency and reducing power consumption.
The document provides electrical characteristics, absolute maximum ratings, typical performance curves, application hints, physical dimensions, and packaging information. It also includes a life‑support policy disclaimer and ordering details for the mini‑DIP and dual‑in‑line packages.
| Operating Temperature Range | -55 °C to +125 °C |
|---|---|
| Peak Output Current (max) | 54 mA |
| Hold Output Current (max) | 26 mA |
| Package | 8‑pin plastic mini‑DIP (LM1949M) or dual‑in‑line (LM1949N) |
| Peak‑to‑Hold Current Ratio | 4 × hold current |
The IC senses the solenoid current, drives the external transistor to a peak current four times the hold current, then automatically reduces to the hold level for the pulse duration.
The peak output current can reach up to 54 mA as specified in the electrical characteristics.
It is offered in a plastic 8‑pin mini‑DIP (order LM1949M) and a molded dual‑in‑line package (order LM1949N).