onsemi MC74ACT273DWR2G: Octal D-Type Flip-Flop with Clear

The onsemi MC74ACT273DWR2G is a high-performance, octal D-type flip-flop integrated circuit designed for bus-oriented applications. Fabricated with Advanced CMOS Technology, this device offers high noise immunity and low power consumption while maintaining a speed comparable to fast LSTTL logic. It is an essential component for digital systems requiring data storage, synchronization, or temporary data holding.

This octal flip-flop features eight edge-triggered D-type flip-flops with a common clock (CP) and a common asynchronous master reset (MR). A low level on the master reset (MR) pin clears all flip-flop outputs (Q) to a low state, regardless of the clock or data inputs. Data is transferred from the D inputs to the Q outputs on the low-to-high transition of the clock pulse. The high-impedance state of ACT outputs permits the direct connection to a bus-organized system without external pull-up resistors.

Key Features:

Octal D-Type Flip-Flop with Clear: Integrates eight flip-flops in a single 20-pin package.

Advanced CMOS Technology: Provides low static power dissipation and high speed.

High Noise Immunity: Characteristic of CMOS devices.

Bus-Driven Outputs: Outputs can drive up to 50 Ω transmission lines.

Latch-Up Performance: Exceeds 250 mA per JESD 17.

Pinout Configuration (DWG Package):

The MC74ACT273DWR2G is available in a 20-pin SOIC wide body package.

Pin 1 (MR): Master Reset (Active LOW)

Pin 2 (Q0): Output of Flip-Flop 0

Pin 3 (D0): Data Input for Flip-Flop 0

Pin 4 (D1): Data Input for Flip-Flop 1

Pin 5 (Q1): Output of Flip-Flop 1

... (Pins 6-11 and 13-18 follow the same pattern for Flip-Flops 2-7)

Pin 12 (GND): Ground

Pin 19 (CP): Clock Pulse Input (Positive Edge-Triggered)

Pin 20 (VCC): Supply Voltage

Application Circuit Guide: A Basic Data Latch

A typical application is an 8-bit data latch for a microprocessor data bus.

1. Connect the eight D0-D7 inputs to the microprocessor's data bus lines.

2. Connect the eight Q0-Q7 outputs to the input lines of the peripheral device.

3. Connect the clock (CP) pin to a control signal from the microprocessor (e.g., address latch enable ALE or a write pulse). This signal triggers the flip-flop to capture and hold the data present on the bus at the exact moment of the clock's rising edge.

4. Connect the master reset (MR) pin to a system-wide reset signal. Pulling this line LOW will asynchronously clear all outputs to zero.

5. Decoupling capacitors (e.g., 0.1 µF) should be placed between VCC (pin 20) and GND (pin 12) near the IC to suppress power supply noise.

ICGOODFIND: The onsemi MC74ACT273DWR2G is a robust and reliable solution for modern digital design. Its high-speed operation, excellent noise margin, and bus-driving capability make it an ideal choice for critical data registration tasks in computing, networking, and industrial control systems, ensuring stable and accurate data transfer across the bus.

Keywords: Octal D-Type Flip-Flop, Data Latch, Master Reset, Positive Edge-Triggered, Bus Interface