The NCN4555 is a level shifter analog circuit designed to translate the voltages between a SIM Card and an external microcontroller or MPU. A built-in LDO-type DC-DC converter makes the NCN4555 useable to drive 1.8 V and 3.0 V SIM card. The device fulfills the ISO7816-3 smart card interface standard as well as GSM 11.11 and related (11.12 and 11.18) and 3G mobile requirements (IMT-2000/3G TS 31.101). With the STOP pin a low current shutdown mode can be activated making the battery life longer. The Card power supply voltage (SIM_VCC) is selected using a single pin (MOD_VCC).