Texas Instruments TRF7961RHBTG4

Overview

TRF7961RHBTG4 from Texas Instruments is a fully integrated 13.56-MHz RFID analog front end and data-framing reader IC supporting ISO/IEC 14443 A/B, FeliCa, and ISO/IEC 15693 protocols. It delivers 200 mW RF output power (23 dBm), dual AM/PM receiver inputs with RSSI, and programmable ASK modulation depth (8–30%). Used in secure access control readers requiring robust near-field communication.

For engineers reviewing the TRF7961RHBTG4 datasheet, TRF7961RHBTG4 pinout, TRF7961RHBTG4 application, or TRF7961RHBTG4 equivalent, key selection criteria include its 32-pin VQFN package, SPI/parallel interface flexibility, ultra-low-power modes (<1 µA power-down), integrated 20-mA LDO for MCU supply, and dual-receiver architecture minimizing communication holes in noisy environments.

Technical Context

The TRF7961RHBTG4 implements a dual-input receiver with independent AM and PM demodulation paths, each with selectable gain and built-in band-pass filtering. Its framing engine handles SOF/EOF, CRC, and parity generation for ISO/IEC 14443 and ISO/IEC 15693 without MCU intervention.

It supports direct-mode operation for custom protocol implementation, providing raw subcarrier data or unframed ISO-formatted data with extracted clock. The transmitter offers OOK/ASK modulation with programmable output power (100 mW or 200 mW into 50 Ω) and adjustable modulation depth.

Key Specifications

Pinout & Package

TRF7961RHBTG4 is housed in a 32-pin VQFN package (5 mm × 5 mm) with exposed thermal pad connected to ground. Pin assignment follows TI's RHB footprint and supports both SPI and parallel host interfaces.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar RFID reader applications.

Compared with TRF7961RHBTG4, TRF7960RHB omits ISO/IEC 15693 capability but shares identical footprint and firmware compatibility, while ST25R3916B adds NFC certification at the expense of peak RF output - making TRF7961RHBTG4 optimal for multiprotocol, medium-range industrial readers requiring field-proven reliability.

Availability

TRF7961RHBTG4 is available at Aetrix Electronics and suitable for secure access control, public transport ticketing, and medical authentication systems requiring stable component supply across multi-year production cycles.

Supply support for TRF7961RHBTG4 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 leader specializing in analog, embedded processing, and connectivity solutions, with over 50 years of innovation in RF and mixed-signal design.

The TRF7961RHBTG4 belongs to TI's RFID reader analog front-end product line, engineered specifically for high-reliability, multi-standard contactless identification in industrial, transportation, and healthcare applications.

FAQ

What communication interfaces does the TRF7961RHBTG4 support?

The TRF7961RHBTG4 supports both an 8-bit parallel interface and a 4-pin SPI interface, with automatic mode detection. It uses a shared 12-byte FIFO for transmit/receive data buffering. The interface voltage is configurable from 1.8 V to 5.5 V via VDD_I/O, allowing direct connection to diverse MCUs including MSP430, ARM Cortex-M, and PIC families without level-shifting circuitry. TRF7961RHBTG4 also provides dedicated DATA_CLK and SYS_CLK outputs to synchronize host timing.

Does the TRF7961RHBTG4 support ISO/IEC 15693, and how is it enabled?

Yes, the TRF7961RHBTG4 explicitly supports ISO/IEC 15693 as confirmed in the device comparison table (Table 3-1) and Section 1.3. Protocol selection is performed via software configuration of control registers - no hardware changes are needed. The framing engine handles 1-out-of-4 coding, EOF/SOF insertion, and CRC-16 calculation per ISO/IEC 15693-2. TRF7961RHBTG4 also supports direct mode for custom 15693 extensions beyond standard command sets.

What is the maximum data rate supported by the TRF7961RHBTG4?

The TRF7961RHBTG4 supports data rates up to 848 kbps, as stated in Section 1.3 and verified in Table 6-13 (Receiver Output Data Rates). This applies to ISO/IEC 14443 high-bit-rate mode and is achieved using the internal framing engine and 12-byte FIFO. At 848 kbps, the device maintains full protocol compliance including bit-collision detection and CRC validation - TRF7961RHBTG4 achieves this without requiring external FPGA or high-speed logic.

How does the TRF7961RHBTG4 manage power in battery-operated devices?

The TRF7961RHBTG4 provides three ultra-low-power states: power-down (<1 µA), standby (120 µA), and active RX-only (10 mA). EN and EN2 pins control entry/exit; power-down retains VDD_X regulation to keep external MCU alive. Its wide 2.7–5.5 V input range allows direct use of single Li-ion or two-AA cells. TRF7961RHBTG4's internal LDOs maintain stable analog/digital rails across battery discharge curves - eliminating need for external buck/boost converters in portable readers.

Can the TRF7961RHBTG4 drive an antenna directly, or is external matching required?

The TRF7961RHBTG4 requires external impedance matching between TX_OUT and the antenna. Its TX_OUT pin drives a 50-Ω load at 200 mW (23 dBm), but real-world antennas rarely present pure 50 Ω - especially in compact or metal-near form factors. TI reference designs (e.g., TRF7960AEVM) use discrete LC networks or baluns to match typical 13.56-MHz loop antennas. TRF7961RHBTG4 does not integrate matching components; omitting them risks reduced range, overheating, or regulatory noncompliance.