Texas Instruments TLC320AD545PT

Overview

TLC320AD545PT from Texas Instruments is a single-channel mixed-signal data/fax codec integrating sigma-delta ADC/DAC, analog hybrid circuitry, 8-Ω differential speaker driver (AT41), programmable gain amplifier, and serial port interface. It supports 16-bit 2s-complement data format, up to 11.025 kHz sample rate, and operates with 5 V or 3.3 V analog/digital/monitor supplies. Used in fax modems and voice-band data communication systems requiring transformer-coupled line interface.

For engineers reviewing the TLC320AD545PT datasheet, TLC320AD545PT pinout, TLC320AD545PT application, or TLC320AD545PT equivalent, key selection considerations include its dual-supply flexibility (5 V/3.3 V mixing), integrated 600-Ω data output PGA and 8-Ω speaker driver, software power-down mode, FS high/low serial interface modes, and flash write enable circuit for external EEPROM programming.

Technical Context

The TLC320AD545PT implements oversampling sigma-delta architecture: ADC uses decimation filter (512× oversampling) to produce 16-bit output at fs = DT_MCLK/512; DAC employs interpolation filter and sigma-delta modulation for reconstruction. Internal clocking derives DT_SCLK = DT_MCLK/2 and DT_FS = DT_MCLK/512.

Hybrid functionality is externally configurable via resistors/capacitors on DTRX_FB, DTRXP/DTRXM, and DTTX_INP/DTTX_INM nodes. The device supports analog loopback (DAC→ADC path) and digital loopback (ADC→DAC path) via control register bits, and provides transformer reference (DT_REF = 2.5 V @ 5 V DAVDD, 1.5 V @ 3.3 V DAVDD) with ±2.5 mA drive capability.

Key Specifications

Pinout & Package

Package: 48-pin PT (TQFP), RoHS-compliant, rated for –40°C to +85°C operation.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar data/fax codec applications.

Compared with TLV320AIC10IPFB and CS44600-CQZ, the TLC320AD545PT uniquely combines single-channel data/fax codec, transformer-referenced hybrid, AT41 speaker driver, and flash write enable in one TQFP-48 package - making it irreplaceable in cost-sensitive, space-constrained fax modem designs requiring all these functions.

Availability

TLC320AD545PT is available at Aetrix Electronics and suitable for fax modems, voice-band data communication systems, PC dial-up modems, and legacy telephony equipment requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for TLC320AD545PT 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 digital signal technologies, with decades of leadership in data converter and communications IC design.

The TLC320AD545PT belongs to TI's legacy mixed-signal broadband connectivity product line, engineered specifically for PSTN-based data/fax modem applications requiring integrated codec, hybrid, speaker driver, and serial interface in a single chip.

FAQ

What power supply configurations does the TLC320AD545PT support?

The TLC320AD545PT supports three verified power supply configurations: (1) 5 V for analog (DAVDD), digital (DVDD), and monitor (MVDD) supplies; (2) 3.3 V for all three supplies; and (3) mixed 5 V analog/monitor with 3.3 V digital. These options are explicitly defined in Section 3.11 of the SLAS206C datasheet and validated across the full –40°C to +85°C operating range. Each configuration maintains full functionality of the ADC, DAC, speaker driver, and serial interface in the TLC320AD545PT.

How does the TLC320AD545PT implement analog and digital loopback testing?

The TLC320AD545PT implements analog loopback by routing the DAC output back into the ADC input path (enabled via bit D4 in control register 1), and digital loopback by feeding the ADC output data directly to the DAC input (enabled via bit D5 in control register 1). Both functions operate independently of the hybrid amplifier stage and are fully documented in Section 3.8 of the SLAS206C datasheet. These capabilities allow in-circuit validation of the core codec signal chain without external test equipment in the TLC320AD545PT.

What is the purpose and electrical specification of the DT_REF pin on the TLC320AD545PT?

The DT_REF pin on the TLC320AD545PT provides a stable reference voltage (2.5 V when DAVDD = 5 V; 1.5 V when DAVDD = 3.3 V) for transformer-coupled hybrid circuits, enabling single-supply operation of analog amplifiers. It sources or sinks up to ±2.5 mA and must remain unconnected in differential hybrid configurations. This specification is confirmed in Sections 1.6 and 2.3 of the SLAS206C datasheet and is critical for proper biasing of the DTRXP/DTRXM and DTTX_INP/DTTX_INM amplifier stages in the TLC320AD545PT.

Can the TLC320AD545PT drive an 8-Ω speaker directly, and how is gain controlled?

Yes, the TLC320AD545PT integrates an 8-Ω differential speaker driver (AT41) with MONOUTP and MONOUTM outputs. Gain is fixed at 0 dB or can be muted entirely via control register 2 (bit D0), as specified in Section 1.1 and Appendix A of the SLAS206C datasheet. The driver input source is selectable between amplified DAC output (Data_Out PGA) or ADC input signal using control register 1 (bit D7), enabling flexible call-progress tone generation directly from the TLC320AD545PT without external amplification.

What is the function of the FLSH_OUT and FLSH_IN pins on the TLC320AD545PT?

The FLSH_IN pin (input) enables the FLSH_OUT pin (output) when pulled low, causing FLSH_OUT to supply up to 45 mA at 5 V to power external flash memory devices such as Intel 28F400B or AMD Am29F400 during write/erase operations. This circuit is powered from the DVDD rail and is detailed in Sections 1.1, 1.6, and 2.4 of the SLAS206C datasheet. It provides dedicated, isolated current delivery so the TLC320AD545PT can support field-upgradable firmware without loading the main power rails.