FXLA2204: Dual-Mode, Dual-SIM-Card Level Translator

The FXLA2204 allows two hosts to simultaneously communicate with two Subscriber Identity Modules (SIMs) or two User Identity Modules (UIMs). Dual Mode refers to the mobile phones that are compatible with more than one form of data transmission or network (such as GSM, CDMA, WCDMA, TDSCDMA, or CDMA2000), resulting in a dual-baseband processor configuration. In a Dual-Mode application, the FXLA2204 host ports interface directly with the baseband processors.

The bi-directional I/O open-drain channel features auto-direction, which requires external pull-up resistors. RST and CLK provide uni-directional translation from host to card only.

Either host can swap SIM slots with the assertion of a single control pin: CH_Swap. The typical channel swap time is 130 ns.

The FXLA2204 does not contain internal Low Dropout Regulator (LDOs). Instead, the FXLA2204 architecture incorporates two low-RON internal power switches for routing existing Power Management Integrated Circuit (PMIC) LDOs to individual SIM slots. This reduces overall system power, leverages existing LDO system resources, and aligns with the philosophy that centralizing LDOs in the PMIC facilitates power management. Since the FXLA2204 does not block the LDO function to the SIM card, existing activation / deactivation timing transparency is maintained between Hosts, PMICs, and SIM cards.

The device allows voltage translation from as high as 3.6 V to as low as 1.65 V. Each port tracks its own port power supply.

Features

• Easy-to-Use “Single Pin” SIM Card Swap Control
• Channel Swap Time: 130 ns (Typical)
• Simultaneous Dual-Mode, Dual-SIM Communication
• Host Ports: 1.65 V to 3.6 V Voltage Translation
• Card Ports: 1.65 V to 3.6 V Voltage Translation
• Leverages the Presence of Existing PMIC LDOs
• ISO7816 Compliant
• Power Switch R_ON: 0.5 Ω (Typical)
• Supports Class B 3 V SIM / UIM Cards
• Supports Class C: 1.8 V SIM / UIM Cards
• Non-Preferential Host V_CC Power-Up Sequencing
• Activation / Deactivation Timing Compliant per ISO7816-03
• Requires External Pull-Up Resistors for Bi-Directional I/O Pins
• Outputs Switch to 3-State if Host V_CC at GND
• Power-Off Protection
• Packaged in 24-Terminal UMLP (2.5 mm x 3.4 mm)