Regulator sustains up to 60V transient voltage

From Linear Technology Corp. comes the LT3695 fault-tolerant 1A, 36V input step-down switching regulator. Its burst mode operation keeps quiescent current under 75?A in no load standby conditions. The LT3695 operates from a 3.6V to 36V input voltage range and can safely sustain transient voltages up to 60V, making it suitable for load dump and cold-crank conditions commonly found in automotive applications. Its 1.45A internal switch can deliver up to 1A of continuous output current at voltages as low as 0.8V.

The LT3695's burst mode operation provides ultralow quiescent current, making the regulator suited for applications which demand always-on operation and optimum battery life. Switching frequency is user programmable from 250kHz to 2.2MHz, enabling the designer to optimize efficiency while avoiding critical noise-sensitive frequency bands. The combination of its thermally enhanced MSOP-16 package and high switching frequency, which keeps external inductors and capacitors small, provides a very compact, thermally efficient footprint.

The LT3695 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 theLT3695 or any downstream electronics, enhancing system reliability.

The device uses a high-efficiency 1.45A, 460mV switch, which can deliver efficiencies as high as 90 percent. Low ripple burst mode operation maintains high efficiency at low output currents while keeping output ripple below 15mV_PK-PK. Special design techniques and a new high voltage process enable high efficiency over a wide input voltage range, and the LT3695's current mode topology enables fast transient response and excellent loop stability. Other features include external synchronization (from 300kHz to 2.2MHz), a power good flag and short circuit protection.

Pricing for the LT3695EMSE starts at $3.25 each for 1,000-piece quantities. The LT3695IMSE is tested and guaranteed to operate from a -40°C to 125°C operating junction temperature and is priced at $3.61 each in 1,000-piece quantities. Finally, the LT3695HMSE is tested and guaranteed to operate from a -40°C to 150°C operating junction temperature and is priced at $3.86 each in 1,000-piece quantities. All versions are available from stock.

For application notes on switching regulators click here.