Micrel recently launched a family of tiny dual ultra-low dropout voltage (ULDO) linear regulators. The MIC5320 and the MIC5321 offer ultra-low dropout voltages of 35 mV at 150 mA, more than 70 db of power-supply rejection ratio (PSRR) and ultra-low output noise, all in a compact form factor. The parts are offered in a 1.6- by 1.6-mm, 6-pin MLF package making them suitable for today's most advanced portable applications.
The MIC5321 is targeted for those applications requiring high PSRR because it provides a bypass pin for additional noise filtering. This coupled with the low dropout, enables significant advantages in applications where maintaining high PSRR under low input voltage-to-output voltage conditions is crucial. For general purpose, or digital applications requiring over 60 db PSRR, the MIC5320 eliminates the bypass capacitor and provides two enable pins for applications requiring sequenced start-up. Both devices provide exceptional thermal performance and high current capabilities delivering 117 mA/mm2 . The MIC5320 and MIC5321 integrate two, high performance LDOs that offer exceptional transient performance while requiring only small and inexpensive 1-μF ceramic capacitors. Both devices feature low quiescent current , a fast turn-on time of 30 μs, current limit and thermal shutdown protection, and can operate from -40°C to 125°C.
The MIC5320 and MIC5321 are currently available in volume, with pricing starting at $0.64 for lots of 1000. Additional family members will be introduced later in the year. More information is available at www.micrel.com.