Texas Instruments SN74ABT16657DLR

Overview

SN74ABT16657DLR from Texas Instruments is a 16-bit noninverting transceiver with dual 8-bit parity generator/checker circuits, 3-state outputs, ±32-mA high-drive capability, and operation over –40°C to 85°C. It supports bidirectional data flow per section (A↔B), selectable odd/even parity, and error detection via ERR outputs - used in high-reliability backplane and bus interface applications.

For engineers reviewing the SN74ABT16657DLR datasheet, SN74ABT16657DLR pinout, SN74ABT16657DLR application, or SN74ABT16657DLR equivalent, key selection criteria include its 56-pin SSOP (DL) package, 5-V supply compatibility, 3.9 ns typical enable-to-output delay, latch-up immunity >500 mA, and distributed V_CC/GND layout for noise suppression.

Technical Context

The SN74ABT16657DLR integrates two independent octal transceiver sections, each with dedicated T/R direction control, OE output enable, ODD/EVEN parity mode select, PARITY I/O, and ERR status output. Its EPIC-II^B BiCMOS process enables low power dissipation while maintaining TTL-compatible input thresholds and 5-V tolerant I/O.

Each section operates in transmit mode (data A→B, PARITY generated) or receive mode (data B→A, PARITY checked against ERR assertion). The flow-through pin architecture minimizes trace crossing on PCBs, and distributed power/ground pins reduce simultaneous switching noise at up to 100 MHz effective bus rates.

Key Specifications

Pinout & Package

SN74ABT16657DLR uses a 56-pin Shrink Small-Outline Package (SSOP-DL), 300-mil body width, 0.5-mm lead pitch, with exposed thermal pad not present. Pin 1 is located in Quadrant Q1 per tape-and-reel orientation standard.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar 16-bit parity transceiver applications.

Compared with SN74ABT16657DLR, SN74ABT162245DLR omits parity logic entirely but retains identical pinout and drive strength, while SN74LVTH1667DGGR offers voltage scalability at the cost of parity capability and reduced current drive - making SN74ABT16657DLR uniquely suited for legacy 5-V industrial systems requiring hardware parity assurance.

Availability

SN74ABT16657DLR is available at Aetrix Electronics and suitable for industrial backplane interfaces, telecom line card designs, memory subsystems, and test equipment requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.

Supply support for SN74ABT16657DLR 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 delivering analog, embedded processing, and connectivity solutions for industrial, automotive, and communications markets.

The SN74ABT16657DLR belongs to TI's Widebus™ family of high-speed bus interface ICs, designed specifically for robust, noise-immune data transfer in mission-critical industrial and telecom infrastructure.

FAQ

What is the operating temperature range for SN74ABT16657DLR?

The SN74ABT16657DLR is characterized for operation from –40°C to +85°C, meeting industrial-grade environmental requirements. This range is validated per JEDEC standards and applies to all electrical specifications in the datasheet, including propagation delay, drive strength, and parity functionality - ensuring reliable performance in factory automation, base station, and transportation control systems where ambient temperatures fluctuate widely.

Does SN74ABT16657DLR support both odd and even parity modes?

Yes, SN74ABT16657DLR supports configurable odd or even parity per section via the 1ODD/EVEN and 2ODD/EVEN inputs. A logic high selects odd parity; a logic low selects even parity. In transmit mode, SN74ABT16657DLR computes and outputs the correct parity bit on 1PARITY/2PARITY; in receive mode, it compares incoming 1B/2B data plus 1PARITY/2PARITY and asserts 1ERR/2ERR if mismatched - enabling full hardware-level data integrity enforcement.

What package type and dimensions does SN74ABT16657DLR use?

SN74ABT16657DLR uses a 56-pin Shrink Small-Outline Package (SSOP-DL) with 300-mil body width, 0.5-mm lead pitch, and 1.95-mm maximum height. Its reel packaging (1000 units per large tape-and-reel) follows EIA-481 standard with Q1 pin-1 quadrant orientation. The DL package features gull-wing leads and is RoHS-compliant with NiPdAu finish and MSL Level-1 rating - compatible with standard SMT reflow profiles up to 260°C peak.

How does SN74ABT16657DLR handle power-up and power-down sequencing?

To ensure high-impedance outputs during power transitions, SN74ABT16657DLR requires OE pins (1OE and 2OE) to be tied to V_CC through an external pull-up resistor. The minimum resistance value depends on the driver's current-sinking capability - typically 4.7 kΩ suffices for most applications. This prevents bus contention or undefined states when V_CC ramps, a design requirement explicitly stated in the datasheet for safe integration into systems with asynchronous power sequencing.

Can SN74ABT16657DLR be used in 3.3-V systems?

No, SN74ABT16657DLR is specified only for 4.5 V to 5.5 V operation and is not 3.3-V compatible. Its input thresholds, output drive, and internal BiCMOS circuitry are optimized for 5-V TTL logic levels. Attempting to operate SN74ABT16657DLR at 3.3 V may result in marginal VIH/VIL margins, degraded noise immunity, and unreliable parity checking. For 3.3-V applications, consider TI's LVTH or LVC families - but note none replicate the integrated parity function of SN74ABT16657DLR.