Texas Instruments SN74HC377NS

Overview

SN74HC377NS from Texas Instruments is an octal positive-edge-triggered D-type flip-flop with data enable (active LOW), 20-pin SOIC package, operating from 2.0 V to 6.0 V supply, and specified for −40 °C to +85 °C ambient temperature. It latches eight parallel data bits on the rising edge of CP while E is LOW, enabling synchronized data capture in digital control and interface logic circuits.

For engineers reviewing the SN74HC377NS datasheet, SN74HC377NS pinout, SN74HC377NS application, or SN74HC377NS equivalent, this page delivers verified functional behavior, timing constraints (e.g., 13 ns typical t_pd at V_CC = 6.0 V), CMOS-level input compatibility, and precise pin mapping - all critical for synchronous latch design, bus buffering, and state-holding in industrial controllers and instrumentation.

Technical Context

The SN74HC377NS implements eight independent D-type latches sharing a common clock (CP) and a single active-LOW data enable (E). Its operation requires D_n and E to be stable one setup time before the LOW-to-HIGH CP transition, with hold times as low as −2 ns (V_CC = 6.0 V), supporting high-speed sampling in deterministic logic systems.

Input clamp diodes allow safe interfacing to voltages exceeding V_CC when used with current-limiting resistors. The device complies with JEDEC standard no. 7A and features CMOS-level input thresholds (VIH = 4.2 V min at V_CC = 6.0 V), ensuring robust noise immunity in mixed-signal environments.

Key Specifications

Pinout & Package

SN74HC377NS uses a 20-pin plastic small outline integrated circuit (SOIC) package (SO-20, body width 7.5 mm, SOT163-1), with standard 0.3-inch width and 1.27 mm lead pitch.

Key Features

Applications

Equivalent & Alternatives

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

Compared with SN74HC377NS, SN74HCT377N offers TTL input compatibility at the cost of reduced supply flexibility, while 74HC377D provides identical performance with alternate manufacturing traceability - both require no PCB changes but differ in supply voltage tolerance and sourcing continuity.

Availability

SN74HC377NS is available at Aetrix Electronics and suitable for industrial PLC I/O expansion, digital panel meter data capture, and programmable logic controller bus interface requiring stable component supply across extended temperature ranges and multi-year production cycles.

Supply support for SN74HC377NS 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 industry-standard logic families.

SN74HC377NS belongs to the 74HC high-speed CMOS logic series, designed for low-power, pin-compatible upgrades to TTL-based systems in industrial control, instrumentation, and communications infrastructure.

FAQ

What is the maximum clock frequency supported by SN74HC377NS?

The SN74HC377NS supports a maximum clock frequency of 83 MHz at V_CC = 6.0 V under recommended conditions (C_L = 50 pF). At 4.5 V, f_max is 70 MHz. These values assume proper signal integrity, layout-controlled trace lengths, and adherence to setup/hold timing - actual system-level frequency may be limited by board-level parasitics and load capacitance.

Does SN74HC377NS have a master reset input?

No, SN74HC377NS does not include a master reset (MR) or clear input. Its functionality is limited to data enable (E) and clock (CP) control. To initialize all outputs to a known state, external circuitry (e.g., pull-down resistors on D_n inputs combined with a controlled E/CP sequence) must be used - unlike variants such as SN74HC374, which feature explicit reset capability.

Can SN74HC377NS operate at 3.3 V supply?

Yes, SN74HC377NS is fully specified for operation at 3.3 V (within its 2.0–6.0 V range). At V_CC = 3.3 V, VIH is guaranteed ≥ 2.31 V and VIL ≤ 1.0 V, ensuring reliable interfacing with 3.3 V microcontrollers. Propagation delay increases to ~22 ns typical, supporting up to ~45 MHz operation under optimal conditions.

What is the purpose of the E (enable) pin on SN74HC377NS?

The E pin on SN74HC377NS is an active-LOW data enable that gates the latching action: only when E is LOW will the rising edge of CP capture the states of D0–D7. When E is HIGH, Q0–Q7 retain their last latched values regardless of CP transitions - enabling selective, conditional data capture without requiring separate clock gating logic.

Is SN74HC377NS pin-compatible with SN74HC377N?

Yes, SN74HC377NS (SO-20) and SN74HC377N (PDIP-20) share identical pin numbering and signal assignments per the logic diagram and pin description table. However, package differences (surface-mount SOIC vs. through-hole PDIP) require separate PCB footprints - they are functionally and electrically compatible but not mechanically interchangeable without layout revision.