描述 Description

The MIC2172 and MIC3172 are complete 100kHz SMPS current-mode controllers with internal 65V 1.25A power switches. The MIC2172 features external frequency synchronization or frequency adjustment, while the MIC3172 features an enable/shutdown control input.Although primarily intended for voltage step-up applications, the floating switch architecture of the MIC2172/3172 makes it practical for step-down, inverting, and Cuk configurations as well as isolated topologies.Operating from 3V to 40V, the MIC2172/3172 draws only 7mA of quiescent current making it attractive for battery operated supplies.The MIC3172 is for applications that require on/off control of the regulator. The 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.The MIC2172 is for applications requiring two or more SMPS regulators that operate from the same input supply. The 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 oscillator frequencies of independent SMPS regulators.A reference signal can be supplied by one MIC2172 designated as a master. To insure locking of the slave's oscillators, the reference oscillator frequency must be higher than the slave's. The master MIC2172's oscillator frequency is increased up to 135kHz by connecting a resistor from SYNC to ground (see applications information).The MIC2172/3172 is available in an 8-pin plastic DIP or SOIC for -40°C to +85°C operation.

特性 Features

? 1.25A, 65V internal switch rating
? 3V to 40V input voltage range
? Current-mode operation
? Internal cycle-by-cycle current limit
? Thermal shutdown
? Low external parts count
? Operates in most switching topologies
? 7mA quiescent current (operating)
?

簡介

MIC2172屬于集成電路（IC）的穩(wěn)壓器-DC-DC開關(guān)穩(wěn)壓器。由制造生產(chǎn)的MIC2172穩(wěn)壓器 - DC-DC 開關(guān)穩(wěn)壓器DC-DC 開關(guān)穩(wěn)壓器 PMIC（電源管理集成電路）產(chǎn)品族中的產(chǎn)品是元器件級設(shè)備，用于需要穩(wěn)定 DC 輸入電壓和/或?qū)⑵滢D(zhuǎn)換為不同幅度的輸出電壓的應(yīng)用。這些器件與稱為“控制器”PMIC 的類似產(chǎn)品的區(qū)別在于集成了主開關(guān)元件，設(shè)備提供的電力會通過該元件。