Texas Instruments TXS02326AMRGER

Overview

TXS02326AMRGER from Texas Instruments is a dual-supply 2:1 SIM card multiplexer/translator with integrated dual LDOs, supporting Class-B (2.95 V) and Class-C (1.8 V) smart card interfaces. It provides automatic SIM slot detection, I²C-based configuration (400 kb/s), 32-kHz clock input, and battery-removal–triggered shutdown. Used in dual-SIM mobile handsets to extend single baseband UICC interface.

For engineers reviewing the TXS02326AMRGER datasheet, TXS02326AMRGER pinout, TXS02326AMRGER application, or TXS02326AMRGER equivalent, key selection concerns include dual-LDO voltage selectability (1.8 V / 2.95 V), independent SIM1/SIM2 interface control via I²C registers, BSI/SDN debounce programmability, IRQ interrupt mapping, and QFN-24 thermal-pad grounding compliance.

Technical Context

The TXS02326AMRGER implements two independent voltage-level translation paths (SIM1 and SIM2), each referenced to its own LDO output (VSIM1/VSIM2), while interfacing to the baseband via VDDIO (1.7–3.3 V). Its internal logic decodes I²C commands to configure regulator enable/state, voltage selection, interface activation, and pull-down behavior per slot.

It integrates two 8-bit programmable debounce counters (BSI and SDN inputs), configurable detection thresholds (1.2 V / 1.65 V for BSI), and dual shutdown sequences-staged for active SIMs and instant for isolated/clock-stopped slots-triggered by debounced signals synchronized to the 32-kHz clock domain.

Key Specifications

Pinout & Package

24-pin QFN (RGE) package with 0.4-mm pitch and exposed thermal pad that must be soldered to ground plane for thermal management and EMI reduction.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar SIM card multiplexer applications.

Compared with MAX14749ETA+ and TPS65132ARSLR, the TXS02326AMRGER uniquely delivers integrated dual-SIM arbitration, programmable debounce, and I²C-configurable interface states - making it the only option among the three qualified for production dual-SIM handset designs requiring carrier-grade reliability and hot-swap compliance.

Availability

TXS02326AMRGER is available at Aetrix Electronics and suitable for mobile handset design, automotive telematics integration, and industrial M2M router development requiring stable component supply and long-term lifecycle support.

Supply support for TXS02326AMRGER includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor company specializing in analog, embedded processing, and connectivity solutions for industrial, automotive, and consumer markets.

The TXS02326AMRGER belongs to TI's Smart Card Interface product line, designed specifically to simplify dual-SIM integration in space-constrained wireless devices while meeting ISO/IEC 7816, GSM, and 3G timing and electrical compliance requirements.

FAQ

What is the primary function of the TXS02326AMRGER in a dual-SIM mobile handset?

The TXS02326AMRGER serves as a dual-supply SIM card multiplexer and level translator, enabling a single baseband processor UICC interface to drive two independent SIM cards operating at either 1.8 V (Class-C) or 2.95 V (Class-B). It manages power sequencing, interface arbitration, and automatic shutdown via BSI/SDN inputs - all critical for reliable dual-SIM operation in handheld devices. The TXS02326AMRGER integrates dual LDOs, I²C configuration, and 32-kHz timing to eliminate external components.

How does the TXS02326AMRGER handle SIM card voltage selection?

The TXS02326AMRGER provides independent 1.8-V or 2.95-V output selection for VSIM1 and VSIM2 via bits B1 and B5 in the SIM Interface Control Register (08h). Each LDO delivers up to 50 mA and accepts 2.3–5.5-V input from VBAT. This allows simultaneous support of mixed-voltage SIM cards - for example, a 1.8-V primary SIM and a 2.95-V backup SIM - without external regulators. The TXS02326AMRGER's voltage selection is fully software-configurable over I²C.

What role does the exposed thermal pad play in the TXS02326AMRGER QFN package?

The exposed thermal pad on the TXS02326AMRGER (RGE package) must be soldered to a PCB ground plane to ensure thermal stability, reduce junction temperature under load, and minimize EMI coupling into sensitive SIM signaling paths. TI documentation explicitly states this connection is mandatory - failure to do so risks thermal shutdown, signal integrity degradation, and non-compliance with ESD performance specifications. The TXS02326AMRGER's thermal pad is electrically connected to GND internally.

Can the TXS02326AMRGER support hot-swapping of SIM cards without system reset?

Yes, the TXS02326AMRGER supports hot-swapping through its programmable interface states (powered down, isolated, active) and auto-direction translation logic. When a SIM is removed, the BSI input detects battery disconnection and - if enabled - triggers a controlled shutdown sequence synchronized to the 32-kHz clock. The TXS02326AMRGER maintains baseband communication via IRQ and I²C during the event, allowing firmware to reinitialize the slot without resetting the entire system. This behavior is documented in the BSI debounce timing diagrams and status register definitions.

What is the purpose of the OE (Output Enable) pin on the TXS02326AMRGER?

The OE pin (Pin 19) on the TXS02326AMRGER controls data direction on the baseband-to-SIM I/O path. When OE is disabled (default), the device operates in auto-direction mode - detecting signal flow and enabling appropriate pull-ups/pull-downs dynamically. When enabled via bit B0 in the Device Control Register (0Eh), OE directly gates direction: logic level on OE determines whether data flows baseband→SIM or SIM→baseband. This gives firmware explicit control over bidirectional SIM I/O timing - critical for certain UICC protocol phases. The TXS02326AMRGER's OE function is configurable but not required for basic operation.