Step-down regulator

Linear Technology has announced the LT3695 fault-tolerant 1 A, 36 V input step-down switching regulator with burst mode operation to keep quiescent current under 75 µA at standby.

It operates from a 3.6 to 36 V input and can safely sustain transient voltages up to 60, making it suitable for load dump and cold-crank conditions commonly found in motor vehicle applications. Its 1.45 A internal switch can deliver up to 1 A of continuous output at 0.8 V.

Switching frequency is user programmable from 250 kHz to 2.2 MHz, enabling the designer to optimise efficiency while avoiding noise-sensitive frequency bands.

The device is designed to tolerate single fault conditions. Shorting two adjacent pins together or leaving one single pin floating does not raise V_OUT or cause damage to the device or any downstream electronics, enhancing system reliability.

It uses a 1.45 A, 460 mV switch with efficiencies up to 90%. Low ripple burst mode operation maintains efficiency at low output currents while keeping ripple below 15 mV_PK-PK.

Special design techniques and a new high-voltage process enable efficiency over a wide input voltage range and the device’s current mode topology enables fast transient response and loop stability.

Other features include external synchronisation (from 300 kHz to 2.2 MHz), a power good flag and short-circuit protection.