Texas Instruments SN74ABT16821DGGR

Overview

SN74ABT16821DGGR from Texas Instruments is a 20-bit, edge-triggered D-type bus-interface flip-flop with 3-state outputs, designed for high-speed bidirectional bus driving in industrial and computing systems. It operates at 4.5–5.5 V, supports 150 MHz clock frequency, delivers ±32 mA/±64 mA output drive, and features distributed V_CC/GND pins to suppress switching noise.

For engineers reviewing the SN74ABT16821DGGR datasheet, SN74ABT16821DGGR pinout, SN74ABT16821DGGR application, or SN74ABT16821DGGR equivalent, key selection criteria include its 56-pin TSSOP (DGG) package, dual 10-bit configurable operation, true-edge-triggered logic, and high-drive 3-state outputs optimized for capacitive bus loading without external pullups.

Technical Context

This device implements two independent 10-bit D-type flip-flop banks, each with separate clock (CLK) and output-enable (OE) controls. All 20 flip-flops trigger on the positive edge of CLK, latching true input data (D) to Q outputs without inversion.

The 3-state outputs are fully decoupled from internal register operation: OE controls only output driver state (high/low/Z), allowing data retention or new sampling while outputs remain high-impedance. Distributed power/ground pinning and flow-through pin architecture minimize signal skew and PCB routing congestion.

Key Specifications

Pinout & Package

TSSOP-56 (DGG) package: 13.9 mm × 6.1 mm × 1.2 mm body, 0.5 mm pitch, lead-free NiPdAu finish, moisture sensitivity level 1.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar bus-interface flip-flop applications.

Compared with SN74ABT16821DGGR, SN74ABT16222ADGGR offers higher bit density in the same footprint but lacks 20-bit granularity, while SN74ALVCH16222ADGGR trades 5-V compatibility and drive strength for lower voltage operation and reduced static power - making it unsuitable as a drop-in replacement in industrial 5-V bus systems.

Availability

SN74ABT16821DGGR is available at Aetrix Electronics and suitable for industrial PLC backplanes, server memory buffer registers, automotive ADAS sensor hubs, and test equipment digital pattern generators requiring stable component supply across extended temperature ranges and high-volume production cycles.

Supply support for SN74ABT16821DGGR 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 logic solutions, with over 90 years of innovation in industrial, automotive, and communications markets.

The SN74ABT16821DGGR belongs to TI's Widebus™ family of high-speed bus-interface logic, engineered specifically for robust, noise-immune parallel data transfer in mission-critical industrial and computing infrastructure.

FAQ

What is the maximum clock frequency supported by the SN74ABT16821DGGR?

The SN74ABT16821DGGR supports a maximum clock frequency of 150 MHz across its full operating temperature range (–40°C to +85°C) and supply voltage range (4.5 V to 5.5 V). This rating is verified under CL = 50 pF load conditions and reflects guaranteed timing performance per the SCBS216B datasheet revision January 1997. The SN74ABT16821DGGR achieves this speed through its EPIC-II^B BiCMOS process and distributed power/ground architecture.

Does the SN74ABT16821DGGR support independent control of its two 10-bit sections?

Yes, the SN74ABT16821DGGR provides fully independent control of its two 10-bit sections via separate clock inputs (1CLK and 2CLK) and output-enable inputs (1OE and 2OE). Each section operates autonomously: data on 1D1–1D10 is latched on the rising edge of 1CLK and appears at 1Q1–1Q10, while 2D1–2D10 and 2Q1–2Q10 follow 2CLK and 2OE. This allows flexible partitioning - for example, using one section for address latching and the other for data strobing in the same SN74ABT16821DGGR device.

What is the recommended power-up sequence for the SN74ABT16821DGGR to ensure high-impedance outputs at startup?

To guarantee high-impedance outputs during power-up, OE inputs (1OE and 2OE) must be held high until V_CC stabilizes. TI recommends tying both OE pins to V_CC through a pullup resistor; the minimum resistance is determined by the current-sinking capability of the driving source, typically ≥10 kΩ for standard logic drivers. This prevents unintended output activation that could cause bus contention before system initialization completes. The SN74ABT16821DGGR itself does not include internal power-on reset circuitry.

Can the SN74ABT16821DGGR drive a 50-pF bus load at 150 MHz without signal integrity issues?

Yes, the SN74ABT16821DGGR is explicitly characterized for CL = 50 pF in its switching specifications and delivers guaranteed t_PLH/t_PHL ≤ 6.7 ns and t_PZH/t_PZL ≤ 5.8 ns under those conditions at 5 V and 25°C. Its high-drive capability (–32 mA/64 mA), distributed V_CC/GND pins, and flow-through architecture collectively minimize ground bounce (<1 V typical) and crosstalk, enabling clean 150 MHz signaling on properly terminated 50-pF nets. The SN74ABT16821DGGR datasheet confirms this performance in Figure 1 and Table 5.

Is the SN74ABT16821DGGR pin-compatible with other devices in the ABT16xxx series?

No, the SN74ABT16821DGGR is not pin-compatible with most other ABT16xxx devices due to its unique 56-pin TSSOP (DGG) pinout optimized for flow-through routing and distributed power. For example, SN74ABT16222ADGGR shares the same package but has different OE/CLK placement and additional I/O pins. Pin compatibility cannot be assumed across the ABT16xxx family; always verify against the specific device's top-view diagram - the SN74ABT16821DGGR pin map is defined in the SCBS216B datasheet Figure 1 (top view).