Datasheet
The MIC2172/3172 is a complete 100kHz SMPS current-mode controller with an internal 65V 1.25A power switch. It operates from 3V to 40V input voltage range and features low external parts count, thermal shutdown, and can operate in most switching topologies. It is suitable for applications such as laptop/palmtop computers, toys, hand-held instruments, and off-line converters.
User Manual
The document introduces MIC2172 and MIC3172, two 100kHz 1.25A switching regulators. The features of these two products are internal 65V 1.25A power switches, external frequency synchronization or frequency adjustment, and enable/shutdown control input. Although these two products are mainly used for voltage step-up applications, their floating switch architecture makes them practical for step-down, inverting, and Cuk configurations as well as isolated topologies. MIC2172/3172 operates from 3V to 40V and draws only 7mA of quiescent current, making it attractive for battery operated supplies. MIC3172 is for applications that require on/off control of the regulator. MIC3172 is externally shutdown by applying a TTL low signal to EN (enable). When disabled, the MIC3172 draws only leakage current (typically less than 1µA). EN must be high for normal operation. For applications not requiring control, EN must be tied to VIN or TTL high. MIC2172 is for applications requiring two or more SMPS regulators that operate from the same input supply. MIC2172 features a SYNC input which allows locking of its internal oscillator to an external reference. This makes it possible to avoid the audible beat frequencies that result from the unequal input frequencies.
