Analog Devices Inc. LT8609/A/B Synchronous Step-Down Regulators

Analog Devices Inc. LT8609/A/B Synchronous Step-Down Regulators are compact, high efficiency, high speed and consume only 1.7µA of non-switching quiescent current. The LT8609/A/B Regulators deliver 3A of continuous current. The devices offer a Burst Mode operation enabling high efficiency down to very low output currents while keeping the output ripple below 10mVP-P.

The SYNC pin allows synchronization to an external clock, or spread spectrum modulation for low EMI operation. Internal compensation with peak current mode topology allows the use of small inductors and results in fast transient response and good loop stability. The devices feature an EN/UV pin that has an accurate 1V threshold and can be used to program V_IN UVLO or to shut down the part.

The TR/SS pins offer a capacitor that programs the output voltage ramp rate during start-up. This is while the PG flag signals when V_OUT is within ±8.5% of the programmed output voltage as well as fault conditions. The LT8609A has slower switch edges for lower EMI emissions. The LT8609B offers applications that operate in pulse-skipping mode only.

Features

Wide Input Voltage Range: 3.0V to 42V
Ultralow Quiescent Current Burst Mode^® Operation:
- <2.5µA IQ Regulating 12V_IN to 3.3V_OUT
- Output Ripple <10mVP-P
High Efficiency 2MHz Synchronous Operation:
- >93% Efficiency at 1A, 5V_OUT from 12V_IN
3A Maximum Continuous Output
Fast Minimum Switch-On Time: 45ns
Adjustable and Synchronizable: 200kHz to 2.2MHz