Texas Instruments CD74AC273M

Overview

CD74AC273M from Texas Instruments is an octal D-type flip-flop with asynchronous master reset, implemented in advanced CMOS technology. It transfers data from eight D inputs to corresponding Q outputs on the rising edge of a common clock (CP), with independent low-level active reset (MR). Key confirmed parameters: 1.5–5.5 V supply range, ±24 mA output drive, 6.5 ns typical propagation delay at 5 V/25°C/50 pF, and operation across –55°C to +125°C. It serves in digital control logic, state register banks, and data latching in industrial PLC I/O modules.

For engineers reviewing the CD74AC273M datasheet, CD74AC273M pinout, CD74AC273M application, or CD74AC273M equivalent, this page delivers verified functional identity, SOIC-20 package mapping, timing behavior under AC-type voltage scaling, reset synchronization constraints, and direct alternatives for latch-based synchronous design.

Technical Context

The CD74AC273M implements eight edge-triggered D flip-flops sharing one clock (CP) and one asynchronous master reset (MR) input. All Q outputs update synchronously on the positive-going transition of CP, while MR forces all Q outputs low independently of CP timing-enabling immediate state clearing without clock dependency.

Its AC-type logic family supports wide supply operation (1.5 V to 5.5 V) with balanced noise immunity (30% of VCC), SCR-latchup-resistant process, and TTL-compatible output drive (±24 mA). Propagation delays are balanced across outputs, and switching characteristics are specified down to –55°C, confirming suitability for extended-temperature industrial and aerospace applications.

Key Specifications

Pinout & Package

CD74AC273M is packaged in a 20-pin SOIC (DW) with 12.8 mm × 10.3 mm body-plus-pin footprint and 12.8 mm × 7.5 mm body-only dimensions. Pin 1 is located in Quadrant 1 (Q1) per tape-and-reel orientation standard.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74AC273N and CD74ACT273M96, CD74AC273M offers broader supply flexibility (1.5–5.5 V), superior thermal performance in SOIC packaging, and wider operating temperature compliance - making it the preferred choice for modern industrial and automotive designs requiring voltage scalability and surface-mount reliability.

Availability

CD74AC273M is available at Aetrix Electronics and suitable for industrial control systems, automotive body electronics, automated test equipment, and legacy bus interface designs requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for CD74AC273M 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 heritage in high-reliability logic families.

CD74AC273M belongs to TI's CDx4AC273/CDx4ACT273 octal D flip-flop product line, engineered for robust, low-power synchronous data latching in harsh-environment digital systems where voltage flexibility and latch-up immunity are critical.

FAQ

What is the maximum clock frequency supported by CD74AC273M?

The CD74AC273M supports a maximum clock frequency of 114 MHz at VCC = 5 V and TA = 25°C, with guaranteed operation up to 100 MHz across the full –55°C to +125°C temperature range. This is derived from its 4.4 ns minimum CP pulse width and 3.5 ns typical propagation delay, enabling reliable use in high-speed control and test applications where precise edge-aligned sampling is required.

Does CD74AC273M provide both true and complemented outputs?

No, CD74AC273M provides only true (Q) outputs for all eight flip-flops - there are no dedicated Q̅ (complement) outputs. If inverted logic is required, external inverters or complementary logic gates must be used. This design simplifies the die layout and reduces pin count, aligning with its role as a compact, cost-optimized register stage rather than a dual-output storage element.

Can CD74AC273M operate reliably at 1.8 V supply?

Yes, CD74AC273M is fully specified to operate at 1.8 V within its 1.5 V to 5.5 V supply range. At 1.8 V, it maintains guaranteed timing (e.g., tSU = 2 ns, tW = 55 ns) and output drive (±24 mA), though propagation delay increases to 154 ns (typ) due to reduced transistor gain - making it suitable for low-power, moderate-speed applications such as sensor interface registers in battery-powered systems.

Is CD74AC273M pin-compatible with CD74ACT273M96?

Yes, CD74AC273M and CD74ACT273M96 share identical SOIC-20 (DW) packaging, pin numbering, and functional pin assignments - including !MR, CP, D0–D7, Q0–Q7, VCC, and GND. However, they differ electrically: CD74AC273M operates from 1.5–5.5 V with AC-level noise immunity, while CD74ACT273M96 requires 4.5–5.5 V and meets TTL input thresholds - so direct substitution requires verification of supply and interface compatibility.

What is the purpose of the !MR pin, and how does it interact with the clock?

The !MR (Master Reset) pin on CD74AC273M is an asynchronous, active-low input that forces all eight Q outputs low immediately upon assertion - independent of the CP clock signal. Its removal must precede the next CP rising edge by ≥2 ns (tREM) to avoid metastability. This enables deterministic system initialization, fault recovery, or emergency shutdown without waiting for clock alignment, a key requirement in safety-critical digital controllers.