Texas Instruments AM26C31CDB

Overview

AM26C31CDB from Texas Instruments is a quadruple differential line driver IC compliant with TIA/EIA-422-B and ITU V.11 standards, operating from a single 5V supply with 7ns typical propagation delay, 0.5ns typical pulse skew, and 100μA typical quiescent current. It drives balanced transmission lines in industrial field transmitters and motor control systems.

For engineers reviewing the AM26C31CDB datasheet, AM26C31CDB pinout, AM26C31CDB application, or AM26C31CDB equivalent, key selection criteria include RS-422 compliance, low-power operation at 5V, high-speed timing (tPLH/tPHL ≤ 12ns), power-off high-impedance outputs, and dual enable logic (G and G) for flexible system-level control.

Technical Context

The AM26C31CDB implements four independent BiCMOS differential drivers with complementary Y/Z outputs per channel and shared active-high (G) and active-low (G) enable inputs. Each driver delivers ±20mA output current into 100Ω loads while maintaining 2–3.1V differential output voltage magnitude (VOD) and 3V common-mode output voltage (VOC).

It supports true 3-state operation with high-impedance outputs during power-off (IO(off) ≤ ±100μA) and operates across 0°C to 70°C. The device uses standard TTL-compatible input thresholds (VIH = 2V, VIL = 0.8V) and exhibits low input capacitance (6pF) and power dissipation capacitance (170pF per driver).

Key Specifications

Pinout & Package

AM26C31CDB is packaged in a 16-pin SSOP (Shrink Small Outline Package) with 0.65mm lead pitch, measuring 6.2mm × 5.3mm. This RoHS-compliant surface-mount package supports automated assembly and offers improved thermal performance over PDIP.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar differential line driver applications.

Compared with SN65LBC179D and THVD1550DR, AM26C31CDB provides superior timing precision (0.5ns skew), lower quiescent power (100μA vs. mA-range), and native quad-channel density - making it optimal for multi-signal synchronization in space-constrained industrial controllers.

Availability

AM26C31CDB is available at Aetrix Electronics and suitable for chemical sensor interfaces, field transmitter signal conditioning, and brushless DC motor control requiring stable component supply across extended production lifecycles.

Supply support for AM26C31CDB 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 headquartered in Dallas, Texas, delivering analog and embedded processing solutions for industrial, automotive, and communications markets.

The AM26C31 product line was designed specifically for high-reliability RS-422 differential signaling in electrically noisy industrial and military environments, emphasizing timing accuracy, power efficiency, and robustness over wide temperature ranges.

FAQ

What is the maximum data rate supported by the AM26C31CDB?

The AM26C31CDB supports data rates exceeding 100 Mbps, derived from its 7ns typical propagation delay and 0.5ns pulse skew-enabling clean signal edges and minimal jitter on properly terminated 100Ω twisted-pair lines. Actual achievable rate depends on cable length, termination, and receiver setup, but the AM26C31CDB datasheet confirms reliable operation up to 50 Mbps over 1200m and higher rates over shorter distances. AM26C31CDB's switching characteristics are validated per TIA/EIA-422-B test conditions.

Does the AM26C31CDB require external pull-up or pull-down resistors on its enable pins?

No, the AM26C31CDB does not require external pull-up or pull-down resistors on G or G pins. Its enable inputs have TTL-compatible thresholds (VIH = 2V, VIL = 0.8V) and low input current (±1μA), allowing direct connection to microcontroller GPIOs or logic gates. Internal design ensures defined states without external biasing-AM26C31CDB's functional table explicitly defines behavior for all valid logic combinations of G and G.

Can the AM26C31CDB be used with 3.3V logic systems?

The AM26C31CDB is specified for 4.5V–5.5V operation and is not 3.3V-tolerant on inputs or outputs. While its VIH threshold (2V) accepts 3.3V logic highs, the VCC must be 5V to guarantee VOH ≥ 2.4V and VOL ≤ 0.4V into 20mA loads. Using 3.3V VCC violates absolute maximum ratings and invalidates all AC/DC specs. For 3.3V systems, consider AM26LV31 or SN65LVDS31 instead-AM26C31CDB requires strict 5V supply.

How does the AM26C31CDB handle power sequencing when multiple supplies are present in a system?

The AM26C31CDB features inherent power-sequencing robustness: its outputs enter high-impedance state when VCC drops below ~1.5V, and IO(off) remains ≤ ±100μA even with VCC = 0V and output pins biased to 6V or –0.25V. This prevents back-driving of live buses during brown-out or hot-swap events. No external circuitry is needed-AM26C31CDB's datasheet characterizes this behavior across all temperature grades and confirms compatibility with common industrial power-rail sequencing schemes.

Is the AM26C31CDB pin-compatible with the older AM26LS31 device?

Yes, the AM26C31CDB is a drop-in replacement for AM26LS31 in SSOP-16 (DB) packaging, sharing identical pinout, footprint, and function table-including dual G/G enables and complementary Y/Z outputs. Key improvements include 10× lower ICC (100μA vs. 1mA), 2× faster tPLH/tPHL (7ns vs. 15ns), and enhanced ESD tolerance (±2000V HBM). All timing, voltage, and drive specs meet or exceed AM26LS31-AM26C31CDB maintains full backward compatibility while upgrading performance.