Texas Instruments SN74AHCT273DBRG4

Overview

SN74AHCT273DBRG4 from Texas Instruments is an octal positive-edge-triggered D-type flip-flop with asynchronous clear, TTL-compatible inputs (VIH = 2 V, VIL = 0.8 V), 5 V supply operation (4.5–5.5 V), and eight independent data-to-output paths. It functions as a synchronous storage register in digital control logic, supporting clocked data latching in PC motherboard I/O buffers and network switch timing control.

For engineers reviewing the SN74AHCT273DBRG4 datasheet, SN74AHCT273DBRG4 pinout, SN74AHCT273DBRG4 application, or SN74AHCT273DBRG4 equivalent, key selection criteria include its direct-clear functionality, 8-bit parallel latch behavior, 75 MHz maximum clock frequency at 15 pF load, ±8 mA output drive, and SSOP-20 package compatibility with space-constrained board layouts.

Technical Context

This device implements eight identical edge-triggered D flip-flops sharing a common clock (CLK) and global asynchronous clear (CLR) input. Each flip-flop transfers data from its dedicated D input to the corresponding Q output on the rising edge of CLK, provided CLR is high; when CLR is low, all Q outputs force low regardless of CLK or D states.

Its TTL-voltage-compatible inputs enable direct interfacing with legacy 3.3 V logic while operating from a 5 V supply-supporting voltage translation without level shifters. The design incorporates slow edge-rate control to minimize output ringing under light capacitive loads, and meets JESD 17 latch-up (>250 mA) and JESD 22 ESD specifications (2000 V HBM, 1000 V CDM).

Key Specifications

Pinout & Package

The SN74AHCT273DBRG4 is packaged in a 20-pin SSOP (Shrink Small Outline Package) with 0.65 mm lead pitch, body size 7.2 mm × 5.30 mm, and overall package size 7.2 mm × 7.8 mm. This surface-mount package supports fine-pitch PCB routing and reflow soldering per Level-1 MSL rating.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar octal D-type flip-flop applications.

Compared with SN74AHCT574PW and 74LVX273M, the SN74AHCT273DBRG4 uniquely combines 5 V operation, TTL input compatibility, edge-triggered behavior, and 75 MHz performance-making it irreplaceable in legacy 5 V control logic where timing determinism and mixed-voltage interfacing are mandatory.

Availability

SN74AHCT273DBRG4 is available at Aetrix Electronics and suitable for PC motherboard I/O buffers, network switch control registers, and industrial PLC input modules requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for SN74AHCT273DBRG4 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 U.S.-based semiconductor company specializing in analog, embedded processing, and logic solutions, with decades of leadership in industry-standard logic families.

The SN74AHCT273DBRG4 belongs to TI's AHCT logic series, designed specifically for 5 V systems requiring TTL-compatible inputs, high noise immunity, and robust operation in industrial and computing infrastructure applications.

FAQ

What is the function of the CLR pin on the SN74AHCT273DBRG4?

The CLR (clear) pin on the SN74AHCT273DBRG4 is an asynchronous active-low input that forces all eight Q outputs low immediately, regardless of the state of CLK or the D inputs. This function enables immediate system-wide reset without waiting for a clock edge, making it essential for fail-safe initialization in safety-critical control logic. The SN74AHCT273DBRG4 guarantees this behavior across its full –40 °C to +125 °C operating range.

Can the SN74AHCT273DBRG4 interface directly with 3.3 V microcontrollers?

Yes, the SN74AHCT273DBRG4 accepts TTL-compatible input voltages (VIH = 2 V min, VIL = 0.8 V max), allowing direct connection to 3.3 V logic outputs without level-shifting circuitry. Its inputs tolerate up to 5.5 V regardless of VCC, and it operates from a 5 V supply-enabling seamless voltage translation in mixed-signal systems. This capability is explicitly validated in the SN74AHCT273DBRG4 datasheet Section 7.1.

What is the maximum clock frequency supported by the SN74AHCT273DBRG4?

The SN74AHCT273DBRG4 supports a maximum clock frequency of 75 MHz when loaded with 15 pF, and 50 MHz at 50 pF, as specified in Section 5.7 of its datasheet. These values reflect guaranteed timing performance under recommended operating conditions (VCC = 5 V ± 0.5 V, TA = 25 °C). Real-world operation at 75 MHz requires careful PCB layout to minimize trace capacitance and maintain signal integrity.

Does the SN74AHCT273DBRG4 have 3-state outputs?

No, the SN74AHCT273DBRG4 does not feature 3-state outputs-it provides standard push-pull CMOS outputs capable of sourcing or sinking up to ±8 mA. Unlike latches such as the SN74AHCT574, this device lacks output-enable (OE) control. Its outputs are always active when powered, making it suitable for point-to-point register applications but not for shared bus architectures requiring tri-state contention management.

What package type is used for the SN74AHCT273DBRG4?

The SN74AHCT273DBRG4 uses a 20-pin SSOP (Shrink Small Outline Package) with package drawing DB, measuring 7.2 mm × 7.8 mm overall and 7.2 mm × 5.30 mm body size. It features a 0.65 mm lead pitch and is rated for moisture sensitivity Level-1 (unlimited floor life at ≤30 °C/60% RH), supporting standard reflow soldering processes without special baking requirements.