Texas Instruments 74AC16652DLR

Overview

74AC16652DLR from Texas Instruments is a 16-bit bus transceiver and register IC with dual 8-bit or unified 16-bit operation, 3-state outputs, real-time/stored data multiplexing, and ±24 mA drive at 5 V. It features independent clock, select, and output-enable controls per A/B bus pair and operates from –40°C to 85°C. Used in high-density backplane and memory interface applications requiring latch-controlled bidirectional data flow.

For engineers reviewing the 74AC16652DLR datasheet, 74AC16652DLR pinout, 74AC16652DLR application, or 74AC16652DLR equivalent, key selection criteria include its flow-through vs. registered transfer modes, 95 MHz max clock frequency at 5 V, distributed V_CC/GND pinning for noise reduction, and SSOP-56 package compatibility with space-constrained PCB layouts.

Technical Context

The 74AC16652DLR implements two independent 8-bit D-type flip-flop banks (A and B), each with dedicated CLKAB/CLKBA, SAB/SBA, and OEAB/OEBA control inputs. Its multiplexed architecture supports four bus-management functions: real-time A↔B transfer, stored A↔B transfer, simultaneous storage of A and B data, and isolated hold modes - all without decoding glitches during mode transitions.

It uses TI's EPIC 1-µm CMOS process, delivers 500-mA latch-up immunity at 125°C, and employs distributed power/ground pins (12 total V_CC/GND) to minimize simultaneous switching noise. The device supports both 3.3 V (55 MHz) and 5 V (95 MHz) operation with defined timing parameters including t_su = 4.5 ns and t_PLH/t_PHL ≤ 10.7 ns at 5 V.

Key Specifications

Pinout & Package

74AC16652DLR is housed in a 56-pin Shrink Small-Outline Package (SSOP-DL), measuring 14.24 mm × 7.87 mm × 1.95 mm, with 0.635 mm (25-mil) lead pitch and moisture sensitivity level 1 (260°C peak reflow).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar bus transceiver and register applications.

Compared with SN74AC16652DGGR and 74ACT16652DLR, the 74AC16652DLR offers optimal balance of industrial temperature range, SSOP-56 manufacturability, and low ICC - making it preferred for cost-sensitive, high-reliability industrial backplane designs where board real estate is less constrained than in portable electronics.

Availability

74AC16652DLR is available at Aetrix Electronics and suitable for memory interface buffers, FPGA I/O expansion, backplane data routing, and industrial PLC bus coupling requiring stable component supply and long-term industrial lifecycle support.

Supply support for 74AC16652DLR 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 decades of experience in high-reliability industrial and automotive IC design.

The 74AC16652DLR belongs to TI's Widebus™ family of advanced bus-interface devices, engineered specifically for high-speed, low-noise bidirectional data transfer in dense PCB environments such as telecom infrastructure, industrial automation, and test equipment.

FAQ

What is the maximum operating frequency of the 74AC16652DLR at 5 V supply?

The 74AC16652DLR supports a maximum clock frequency of 95 MHz at V_CC = 5 V ± 0.5 V, as specified in the timing requirements table. This applies to both CLKAB and CLKBA inputs under recommended operating conditions (TA = –40°C to 85°C). Real-time data transfer latency remains below 11 ns, enabling use in high-speed memory and FPGA interface applications where cycle-accurate timing is critical. The 74AC16652DLR achieves this performance using TI's EPIC CMOS process and distributed power pinning.

Does the 74AC16652DLR support 3.3 V operation, and what are the timing implications?

Yes, the 74AC16652DLR is fully specified for 3.3 V ± 0.3 V operation, with a maximum clock frequency of 55 MHz and propagation delays up to 17.1 ns (t_PLH). Input thresholds remain compatible with 3.3 V CMOS logic (VIH = 2.1 V min, VIL = 0.9 V max), allowing direct interfacing with 3.3 V microcontrollers and FPGAs. The 74AC16652DLR maintains full functionality-including registered storage, real-time transfer, and 3-state control-at 3.3 V, making it suitable for mixed-voltage system designs without level shifters.

How does the select-control logic (SAB/SBA) prevent glitches during mode transitions in the 74AC16652DLR?

The 74AC16652DLR implements internal synchronous select logic that decouples SAB/SBA evaluation from clock edges, eliminating metastability during real-time ↔ stored data transitions. Unlike conventional multiplexers, the 74AC16652DLR holds output states until the next valid clock edge after select change - ensuring glitch-free bus handoff. This behavior is confirmed in the FUNCTION TABLE and Figure 1, and removes the need for external synchronizers or delay circuits when dynamically reconfiguring data paths in the 74AC16652DLR.

What is the purpose of the distributed V_CC and GND pins in the 74AC16652DLR package?

The 74AC16652DLR features 12 dedicated V_CC and GND pins distributed across the SSOP-56 footprint to minimize simultaneous switching noise and voltage droop during 16-bit parallel transitions. This layout reduces ground bounce by shortening current return paths and improves power delivery stability - critical for maintaining signal integrity at 95 MHz operation. The distributed configuration is explicitly called out in the datasheet as a key enabler of high-speed performance and is integral to the 74AC16652DLR's noise-immune design.

Can the 74AC16652DLR be used as two independent 8-bit transceivers, and how is this configured?

Yes, the 74AC16652DLR can operate as two independent 8-bit transceivers using its dual-register architecture. Pins A1–A8 and B1–B8 form one 8-bit channel, while A9–A16 and B9–B16 (labeled 2A1–2A8 and 2B1–2B8 in the pin diagram) form the second. Each channel has dedicated control signals: 1CLKAB/1SAB/1OEAB for the first group, and 2CLKAB/2SAB/2OEAB for the second. This allows concurrent, asynchronous data transfer on both channels - a capability confirmed in the device description and FUNCTION TABLE of the 74AC16652DLR datasheet.