The LT3694/LT3694-1 is a monolithic 36V switching regulator and two low dropout linear regulators in a compact 4mm × 5mm QFN package or a thermally enhanced TSSOP. It has an internal power switch, cycle-by-cycle current limiting and track/soft-start control.
The document introduces the LT3694/LT3694-1, an integrated power solution designed to handle harsh automotive environments with input transients up to 70V. It combines a single switching regulator capable of delivering 2.6A with two low dropout linear regulators (LDOs) that can provide up to 500mA each.
The device features internal protection mechanisms, including overvoltage detection and foldback current limiting for the LDOs. Key design capabilities include adjustable frequency control from 250kHz to 2.5MHz, track/soft-start functions for multiple outputs, and an enable/undervoltage lockout function to protect against pulse stretching.
| Output Current (Switching) | 2.6A |
|---|---|
| Output Current (LDO) | 500mA |
| Input Voltage Range | 4V-36V |
| Overvoltage Protection Limit | 70V |
| Operating Temperature Range | -40°C to +125°C |
The device is available in a compact 4mm x 5mm QFN package or a thermally enhanced TSSOP.
It includes an internal overvoltage detector that shuts off the switching regulator when Vin exceeds 38V, allowing it to survive transients up to 70V.