Texas Instruments CD74HC377E

Overview

CD74HC377E from Texas Instruments is an octal D-type flip-flop with buffered common clock and data enable, operating across 2V–6V supply. It features 14 ns typical propagation delay (CL = 15 pF, VCC = 5 V), ±25 mA output drive, and -55°C to +125°C industrial/military temperature range. Used in synchronous data latching for bus interface and control logic in embedded timing-critical systems.

For engineers reviewing the CD74HC377E datasheet, CD74HC377E pinout, CD74HC377E application, or CD74HC377E equivalent, this page delivers verified electrical specs, validated PDIP-20 pin mapping, real-world use scenarios, and two confirmed alternative parts with documented functional and application-level differences.

Technical Context

The CD74HC377E implements eight edge-triggered D flip-flops sharing a single buffered clock (CP) input and a common active-low Data Enable (E) control. All outputs update synchronously on the rising edge of CP when E is low - no asynchronous set/reset is provided.

Its HC-series CMOS architecture ensures high noise immunity (NIL/NIH = 30% of VCC at 5 V), rail-to-rail output swing, and fanout capability of 10 LSTTL loads. Propagation delay and transition times are balanced to minimize skew across all eight channels under load.

Key Specifications

Pinout & Package

CD74HC377E is supplied in a 20-pin plastic dual in-line package (PDIP-N), with 0.3-inch body width, 2.54 mm lead pitch, and JEDEC MS-001 compliant outline. Pin 1 is located at the top-left corner with notch or dot marking.

Key Features

Applications

Equivalent & Alternatives

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

Compared with CD74HC377E, SN74HC377N offers improved ESD robustness but sacrifices extended temperature support, while CD74HCT377E trades voltage flexibility for guaranteed TTL interoperability - making CD74HC377E the optimal choice for wide-supply, harsh-environment synchronous latching.

Availability

CD74HC377E is available at Aetrix Electronics and suitable for industrial control systems, avionics data interfaces, and automotive body electronics requiring stable component supply across extreme temperature ranges and long production lifecycles.

Supply support for CD74HC377E 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 with over 50 years of analog and logic IC innovation, serving industrial, automotive, and aerospace markets with high-reliability components.

CD74HC377E belongs to TI's CD74HC high-speed CMOS logic family, designed specifically for robust, low-power, wide-temperature synchronous data capture in mission-critical embedded systems.

FAQ

What is the maximum clock frequency supported by CD74HC377E at 5 V supply?

The CD74HC377E supports a maximum clock frequency of 60 MHz when loaded with CL = 15 pF and operated at VCC = 5 V and TA = 25°C. At full industrial temperature range (-55°C to +125°C), the guaranteed maximum is 23 MHz per datasheet Section 5 (Switching Specifications). This limit ensures setup/hold timing margins remain intact across process, voltage, and temperature corners.

Does CD74HC377E include asynchronous reset or preset functionality?

No, CD74HC377E does not provide asynchronous reset or preset inputs. It is a pure edge-triggered D-type flip-flop with synchronous update only on the rising edge of CP when E is low. Any reset functionality must be implemented externally using the E pin (to hold outputs) or by gating the CP signal - the device itself has no dedicated clear or set terminals.

Can CD74HC377E operate reliably at 3.3 V supply voltage?

Yes, CD74HC377E is fully specified for 2V–6V operation, including 3.3 V. At VCC = 3.3 V, VIH = 2.1 V (min), VIL = 0.99 V (max), and propagation delay increases to ~20 ns (typical, CL = 15 pF). All DC and AC parameters remain guaranteed across the full temperature range, making it suitable for mixed-voltage 3.3 V systems.

What is the purpose of the buffered clock (CP) input in CD74HC377E?

The buffered CP input in CD74HC377E reduces clock distribution skew and improves fanout capability by isolating the external clock source from internal capacitive loading of eight flip-flop clock inputs. This ensures uniform edge timing across all Q outputs and allows direct connection to moderate-strength clocks without external buffering - critical for deterministic multi-bit latching.

How does the Data Enable (E) pin affect output behavior in CD74HC377E?

The active-low E pin in CD74HC377E acts as a global latch enable: when E = low, all eight D inputs are captured on the next rising CP edge; when E = high, outputs retain their last latched values regardless of CP transitions. This enables precise control over data capture timing and eliminates spurious updates during clock glitches or initialization sequences.