Synchronous micropower step-down regulator for automotive and industrial systems

Linear Technology's LT8631, available from Digi-Key, is a current-mode, PWM, step-down DC-DC converter with internal synchronous switches that provide current for output loads up to 1A. The wide input range of 3V to 100V makes the device suitable for regulating power from a wide variety of sources including automotive and industrial systems and 36V to 72V telecom supplies. Low ripple Burst Mode operation enables high-efficiency operation down to very-low output currents while keeping the output ripple below 10mVP-P. Resistor programmable 100 kHz to 1 MHz frequency range and synchronisation capability enable optimisation between efficiency and external component size. The soft-start feature controls the ramp rate of the output voltage, eliminating input current surge during start-up while also providing output tracking. A power good flag signals when the output voltage is within ±7.5% of the regulated output. Under-voltage lockout can be programmed using the EN/UV pin. Shutdown mode reduces the total quiescent current to less than 5 µA. The device is available in a 20-lead TSSOP package with exposed pad for low thermal resistance and high-voltage lead spacing.