LM1578A / LM2578A / LM3578A Switching Regulator General Description
The LM1578A, LM2578A, and LM3578A are switching regulator controllers that support buck, boost, and inverting configurations. They feature separate inverting and non‑inverting comparator inputs with internal 1.0 V references, an on‑board oscillator, and a current‑limit terminal that can be referenced to ground or Vj.
Key features include operation from 2 V to 40 V supply voltage, up to 750 mA output current, a duty‑cycle limit of 90 %, and an oscillator frequency adjustable from <1 Hz to 100 kHz using a single external timing capacitor. The device also provides under‑voltage lockout, maximum duty‑cycle limiting, and detailed ordering information for various package types.
| Supply Voltage Range | 2 V to 40 V |
|---|---|
| Maximum Output Current | 750 mA |
| Oscillator Frequency (typical) | 20 kHz |
| Maximum Duty Cycle | 90 % |
The regulator can deliver up to 750 mA of output current.
It operates from 2 V up to 40 V.
The oscillator frequency is set by a single external timing capacitor, typically around 20 kHz (adjustable from <1 Hz to 100 kHz).
The device limits the duty cycle to a maximum of 90 %.