● Power Management and Control for Two SIM Cards 

   or Smart Cards

● Independent 1.8V/3V VCC Control for Both Cards

● Two LDOs Support up to 250mA Loading

● Supports Simultaneous Powering of Both Cards

● Fast Channel Switching

● Automatic Level Translation

● Fast Signal Rise Times

● Built-In Fault Protection Circuitry

● Automatic Activation/Deactivation Sequencing Circuitry

● Low Operating and Shutdown Current

● -40℃ to +85℃ Operating Temperature Range

● Available in Green TQFN-3×3-20L Package

The SGM4558 provides the power conversion and signal level translation needed for advanced cellular telephones to interface with 1.8V or 3V subscriber identity modules (SIMs). The device meets all requirements for 1.8V and 3V SIMs and contains two LDO regulators to power 1.8V or 3V SIM cards from a 2.7V to 5.5V input. The output voltages can be set using the two voltage selection pins and up to 250mA of load current can be supplied. A channel select pin determines which channel is open for communication. Separate enable pins for each channel allow both cards to be powered at once and allow for faster transition from one channel to the other.

Internal level translators allow controllers operating with supplies as low as 1.4V to interface with 1.8V or 3V smart cards. Battery life is maximized by a low operating current of 90μA and a shutdown current of less than 2μA when battery voltage is less than 3.3V.