Texas Instruments SN74HC273PWT

Overview

SN74HC273PWT from Texas Instruments is an octal positive-edge-triggered D-type flip-flop with active-low asynchronous clear, operating across 2 V to 6 V. It delivers 12 ns typical propagation delay at 5 V, ±4 mA output drive, and 80 µA maximum supply current-enabling reliable data latching in digital control registers and synchronous logic interfaces.

For engineers reviewing the SN74HC273PWT datasheet, SN74HC273PWT pinout, SN74HC273PWT application, or SN74HC273PWT equivalent, this page provides verified functional identity, TSSOP-20 package mapping, timing-critical parameters (t_su, t_pd, f_max), and validated alternatives for register-level signal synchronization in industrial and embedded systems.

Technical Context

The SN74HC273PWT implements eight independent D flip-flops sharing a common clock and global active-low CLR input. Each stage samples D-input data on the rising edge of CLK and holds state until next clock or clear assertion-supporting synchronous register behavior without internal feedback paths.

Its CMOS design ensures rail-to-rail input thresholds (VIH = 3.15 V, VIL = 1.35 V at VCC = 4.5 V), low input leakage (<1 µA), and compatibility with LSTTL loads (up to 10 units). Timing is voltage-dependent: max clock frequency reaches 25 MHz at 6 V and 4 MHz at 2 V over –40°C to +85°C.

Key Specifications

Pinout & Package

TSSOP-20 (PW) package: 6.50 mm × 4.40 mm body, 0.65 mm lead pitch, surface-mount, RoHS-compliant with NiPdAu lead finish and MSL Level-1 rating.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74HC273PWT, SN74HC374PWR adds output enable for bus isolation but increases pin count complexity, while 74HC273D offers identical logic functionality in a larger, more serviceable package-making SN74HC273PWT optimal for space-constrained, high-density surface-mount production.

Availability

SN74HC273PWT is available at Aetrix Electronics and suitable for industrial PLC I/O expansion, motor control state registers, digital audio buffering, and LED matrix driver interfaces requiring stable component supply and long-term lifecycle support.

Supply support for SN74HC273PWT 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 ICs, with decades of experience in industrial, automotive, and communications markets.

The SN74HC273PWT belongs to TI's HC logic family-designed for robust, low-power, pin-compatible replacements of legacy TTL devices in synchronous digital systems where timing predictability and voltage flexibility are essential.

FAQ

What is the function of the CLR pin on the SN74HC273PWT?

The CLR (pin 1) is an active-low asynchronous clear input. When pulled low, it forces all eight Q outputs to logic low immediately-regardless of clock state or data inputs. This function is critical for system initialization and fault recovery in the SN74HC273PWT, and its minimum pulse width is 20 ns at 4.5 V supply.

Does the SN74HC273PWT support 3.3 V operation?

Yes, the SN74HC273PWT operates reliably from 2 V to 6 V, including standard 3.3 V supply rails. At VCC = 3.3 V, VIH is 2.31 V and VIL is 0.99 V per TI's recommended conditions, ensuring clean interfacing with 3.3 V microcontrollers and FPGAs without level translation.

What is the maximum clock frequency for SN74HC273PWT at 5 V?

At VCC = 5 V and TA = 25°C, the SN74HC273PWT supports up to 50 MHz typical f_max (per switching characteristics), though the guaranteed minimum over temperature is 21 MHz. For production designs across –40°C to +85°C, 21 MHz is the safe maximum clock rate per TI's SN74HC273PWT specification table.

Can unused inputs on the SN74HC273PWT be left floating?

No. All unused D inputs on the SN74HC273PWT must be tied to VCC or GND to prevent undefined logic states and excessive power consumption. TI explicitly warns against floating CMOS inputs due to potential oscillation and increased ICC-this applies equally to D, CLK, and CLR lines not in active use.

Is SN74HC273PWT RoHS compliant and what is its moisture sensitivity level?

Yes, SN74HC273PWT is RoHS compliant with NiPdAu lead finish and carries MSL Level-1 (unlimited floor life at ≤30°C/60% RH), per TI's packaging addendum. Its TSSOP-20 package requires no baking prior to reflow, simplifying manufacturing for high-reliability electronics production.