Texas Instruments SN74AHCT273DGVR

Overview

SN74AHCT273DGVR 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 industrial PLC I/O modules and embedded microcontroller peripheral interfaces.

For engineers reviewing the SN74AHCT273DGVR datasheet, SN74AHCT273DGVR pinout, SN74AHCT273DGVR application, or SN74AHCT273DGVR equivalent, key selection criteria include its direct-clear functionality, 8-bit parallel latch behavior, 120 MHz maximum clock frequency (CL = 15 pF), ±8 mA output drive, and VSSOP-20 package compatibility with space-constrained PCB 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, with no effect during high/low CLK states. The internal structure uses CMOS logic with TTL-voltage-level input thresholds, enabling direct interfacing with legacy 3.3 V logic while operating at 5 V.

It features low dynamic power consumption (ICC ≤ 40 µA at 25 °C), robust ESD protection (2000 V HBM), and guaranteed timing performance across –40 °C to +125 °C. Propagation delays are tightly specified: tPLH/tPHL ≤ 8.8 ns (CL = 15 pF), with setup time (tsu) of 5 ns and hold time (th) of 0 ns relative to CLK↑.

Key Specifications

Pinout & Package

VSSOP-20 (DGVR) package: 4.4 mm × 6.5 mm body size, 0.5 mm lead pitch, thin-profile surface-mount construction optimized for high-density routing and thermal dissipation in compact systems.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74AHCT273DGVR, SN74AHCT574PW adds output enable but removes dedicated clear, while 74LVX273M trades voltage flexibility for reduced speed and eliminates 5 V compatibility-making SN74AHCT273DGVR optimal for mixed-voltage, safety-critical latching.

Availability

SN74AHCT273DGVR is available at Aetrix Electronics and suitable for industrial automation, automotive body electronics, and test equipment requiring stable component supply with long-term manufacturability and full RoHS compliance.

Supply support for SN74AHCT273DGVR 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 SN74AHCT273DGVR belongs to TI's AHCT logic family, engineered for TTL-to-CMOS voltage translation and robust operation in harsh environments where reliability and interoperability across voltage domains are critical.

FAQ

What is the function of the CLR pin on the SN74AHCT273DGVR?

The CLR (clear) pin on the SN74AHCT273DGVR is an asynchronous active-low input that forces all eight Q outputs to logic low immediately, regardless of clock state. This function is essential for initializing registers at power-up or recovering from fault conditions. The SN74AHCT273DGVR guarantees CLR assertion within 6 ns (t_w) and maintains output stability during reset, making it suitable for safety-critical applications like automotive body controllers where deterministic startup behavior is required.

Can the SN74AHCT273DGVR interface directly with a 3.3 V microcontroller?

Yes, the SN74AHCT273DGVR accepts TTL-compatible input levels (VIH = 2 V, VIL = 0.8 V), allowing direct connection to 3.3 V microcontroller GPIOs without level-shifting circuitry. Its inputs tolerate voltages up to 5.5 V, providing margin against noise and overshoot. When operated at 5 V VCC, the SN74AHCT273DGVR delivers 5 V logic-high outputs compatible with downstream 5 V peripherals-enabling clean voltage translation in mixed-signal systems such as industrial HMI panels.

What is the maximum clock frequency supported by the SN74AHCT273DGVR?

The SN74AHCT273DGVR supports a maximum clock frequency of 120 MHz under CL = 15 pF load conditions at TA = 25 °C. At higher capacitive loads (e.g., CL = 50 pF), the maximum usable frequency drops to 75 MHz. These values are validated across the full operating temperature range (–40 °C to +125 °C), with timing parameters derated per datasheet specifications. Designers must verify actual system timing margins using the SN74AHCT273DGVR's published t_PLH/t_PHL and setup/hold requirements in their specific layout context.

Does the SN74AHCT273DGVR require external pull-up or pull-down resistors on unused inputs?

Yes, all unused inputs of the SN74AHCT273DGVR-including individual D inputs and the CLK and CLR pins-must be tied to either VCC or GND to prevent floating states that cause increased ICC, erratic switching, or ESD susceptibility. TI explicitly recommends this in Section 5.3 of the datasheet. Leaving inputs unconnected violates recommended operating conditions and may result in undefined output behavior or accelerated device degradation. The SN74AHCT273DGVR does not include internal termination resistors.

What package type does the SN74AHCT273DGVR use, and what are its key mechanical attributes?

The SN74AHCT273DGVR uses the VSSOP-20 (DGVR) package: a 20-pin, 0.5 mm pitch, thin shrink small-outline package with 4.4 mm × 6.5 mm body dimensions and 1.0 mm max height. Its lead finish is NiPdAu, moisture sensitivity level is Level-1 (unlimited floor life), and peak reflow temperature is 260 °C. This package enables high-density routing, improved thermal performance over SOIC, and compatibility with standard SMT assembly processes-making the SN74AHCT273DGVR ideal for space-constrained applications like portable test gear and automotive ECUs.