6/16/2003Edited by PETech Staff
Tiny LDO Power Management ICs
The MIC221x family from Micrel offers one of the highest performance, smallest size and most efficient power management solutions for the portable electronics market. It consists of two low-dropout (LDO) regulators, a power-on reset (POR) supervisor, and an open-drain driver. The MIC2213 and MIC2214 offer a dual LDO regulator with an integrated POR supervisor and an open-drain driver. The first regulator (LDO1) is capable of sourcing 150mA of current, while the second regulator (LDO2) can source 300mA and has a POR circuit that detects faults on the output. The MIC2213/4 allows the user to program the delay on the POR to alert the processor when the output of the LDO has reached and settled to its intended voltage. This feature allows for sequencing and fault detection for the processor's supply voltages. The MIC2213/4 also offers an open-drain, N-Channel MOSFET that can be used to drive external LEDs for backlighting applications in portable electronics.
The total current consumption of the MIC2213/4 is only 48uA, compared to existing discrete solutions that consume 200uA. The MIC2213 offers the additional benefit of sequencing between two LDO outputs. LDO1 must reach 90% of its final value prior to LDO2 turning on, ensuring LDO1 is on first.
The MIC2213 and MIC2214 are uCap regulators, stable with small ceramic output capacitors, eliminating the need for larger, less reliable tantalum capacitors.
For more information, visit www.micrel.com.