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2022-09-24 23:32:00
LTC1555-SIM Card Power and Level Shifter
The LTC®1555/LTC1556 provide power translation, level translation requires 3V for GSM mobile phones, 3V or 5V for the Subscriber Identity Module Interface (SIMS). These parts contain a charge pump DC/DCSIM converter that provides a 5V regulated power supply. The input voltage can range from 2.7V to 10V, allowing direct connection to the battery. The output voltage is programmable at 3V, 5V or directly connected to the VIN pin. A soft-start feature limits inrush current at turn-on, mitigating start-up problems that can cause when another low-power DC/DC converter input is supplied. The LTC1556 also includes an auxiliary LDO regulator/power switch that can be used for frequency synthesizers or other low-power circuits in the power supply. A shutdown current of 1mA is maximized by 60mA operating current and battery life. Minimized by miniature board area, the 16- and 20-pin narrow SSOP packages require only three small external capacitors.