Texas Instruments TCM29C13DWR

Overview

TCM29C13DWR from Texas Instruments is a single-chip PCM codec and line filter for full-duplex voice telephony interfaces, supporting µ-law coding, 2.048 MHz fixed-data-rate operation, and 0°C to 70°C industrial temperature range. It integrates A/D and D/A conversion, transmit/receive filtering, and on-chip voltage references - requiring no external components for sample/hold or autozero functions. It serves in T1 carrier line interface and digital PABX systems.

For engineers reviewing the TCM29C13DWR datasheet, TCM29C13DWR pinout, TCM29C13DWR application, or TCM29C13DWR equivalent, key selection criteria include its 24-pin DW package, dual ±5 V supply operation, integrated analog front-end with 71 dB crosstalk attenuation, and direct replacement capability for Intel 2913 in legacy telecom designs.

Technical Context

The TCM29C13DWR implements a successive-approximation ADC and switched-capacitor DAC paired with analog band-pass filters optimized for 300–3400 Hz voiceband transmission. Its transmit section accepts differential analog input (ANLG IN±), processes via internal gain-setting network (GSR), and outputs filtered PCM data synchronized to CLKX/FSX timing.

Receive functionality decodes 8-bit µ-law PCM input (PCM IN) clocked by CLKR/FSR into analog output at PWRO±, with precision internal references ensuring ±0.08 dB gain stability over temperature and supply variation. Loopback test (ANLG LOOP) and 8th-bit signaling (SIGX/ASEL) support diagnostics and supervisory channel use.

Key Specifications

Pinout & Package

TCM29C13DWR uses a 24-pin SOIC (DW) package with exposed thermal pad, pin-compatible with TCM29C14 and TCM129C13 variants. Pin numbering follows standard top-view orientation with Pin 1 at bottom-left corner.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar PCM codec applications.

Compared with TCM129C13DWR, the TCM29C13DWR offers lower cost and sufficient performance for commercial indoor telecom gear, while TCM29C14DWR adds flexibility at the expense of pin count and design complexity - neither is pin-compatible with TCM29C13DWR due to differing pin assignments for SIGR and ANLG LOOP.

Availability

TCM29C13DWR is available at Aetrix Electronics and suitable for T1 carrier line interface, digital PABX subsystems, and telecom encryption modules requiring stable component supply across extended production lifecycles.

Supply support for TCM29C13DWR 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 technologies for industrial, automotive, and communications markets.

The TCM29C13DWR belongs to TI's legacy telecom codec family designed specifically for voiceband digitization in digital switching systems, emphasizing reliability, low power, and drop-in compatibility with Intel 2913-based infrastructure.

FAQ

What is the primary function of the TCM29C13DWR in a telecom system?

The TCM29C13DWR serves as a combined PCM codec and analog line filter that performs A/D and D/A conversion for voiceband signals, applies transmit/receive bandpass filtering (300–3400 Hz), and interfaces analog telephone lines to digital TDM networks. Its role in the TCM29C13DWR is to replace discrete encoder/decoder + filter combinations while maintaining CCITT G.711 µ-law compliance and enabling direct Intel 2913 replacement in legacy systems.

Does the TCM29C13DWR support A-law coding?

No, the TCM29C13DWR supports µ-law coding only. The SIGX/ASEL pin defaults to µ-law when tied to VCC or GND, and the device lacks internal A-law logic. For A-law capability, TI specifies TCM29C14DWR or TCM29C17DWR - the TCM29C13DWR datasheet explicitly states µ-law-only operation and does not list A-law in its feature table or electrical characteristics.

What are the supply voltage requirements for reliable operation of the TCM29C13DWR?

The TCM29C13DWR requires two supplies: VCC = +5 V ±5% and VBB = –5 V ±5%, both referenced to their respective ground planes (DGTL GND and ANLG GND). Operating outside these ranges risks exceeding absolute maximum ratings (–0.3 V to 15 V on any pin) and may cause latch-up or permanent damage. The TCM29C13DWR draws 80 mW typical in active mode and 5 mW in power-down mode under nominal conditions.

How does the TCM29C13DWR handle clocking in fixed versus variable data-rate modes?

In fixed-rate mode, the TCM29C13DWR uses CLKR and CLKX (internally connected) at 1.536/1.544/2.048 MHz, with DCLKR tied to VBB to select this mode. In variable-rate mode, DCLKR becomes the receiver data clock (64 kHz–2.048 MHz), and CLKSEL sets master clock frequency. Frame sync (FSR/FSX) remains essential in both modes, and the TCM29C13DWR maintains strict timing windows (e.g., td(FSR) = 100 ns to tc(CLK)–100 ns) to ensure PCM word alignment.

Can the TCM29C13DWR be used in new designs, or is it obsolete?

The TCM29C13DWR remains viable for new designs targeting legacy telecom infrastructure upgrades, especially where drop-in replacement of Intel 2913-based systems is required. Texas Instruments continues to list it in active production status with guaranteed long-term availability for industrial customers. While newer codecs offer higher integration, the TCM29C13DWR's proven reliability, documented performance, and backward compatibility make it suitable for maintenance and extension of existing T1/PABX platforms.