Power Supply Switches Boost Integration

Highly integrated, the AAT4674 and AAT4674-1 dual-input, single-output power-supply selector switches, operate from any power source from 2.5V to 6V and integrate reverse blocking, current sensing, a programmable current limit, and single-control-pin switching in TSOPJW packages. Both devices connect the supply voltage on IN1 and IN2 to the output through power MOSFETs that minimize voltage drops and power dissipation. The enable and select pin voltages control the operational state of the MOSFET switches. A break-before-make switchover feature minimizes output voltage droop during the transition between the input supplies on IN1 and IN2 to the output. To power the output, both input supplies must be above the under-voltage lockout threshold. If both supplies are above the threshold and the device is enabled, both devices will connect the supply from IN1 to OUT when the SEL pin voltage is logic low and connect the supply from IN2 to OUT when the SEL pin voltage is logic high. If either input voltage is below the UVLO threshold on the AAT4674, then the output floats. When only one of the input voltages is above the UVLO threshold on the AAT4674-1, the device passes through the input that is above the UVLO threshold to the output. Price for either device is $0.73 each/1,000. ADVANCED ANALOGIC TECHNOLOGIES INC., Sunnyvale, CA. (408) 737-4600.