Texas Instruments SN74HC595N-NG

Overview

SN74HC595N-NG from Texas Instruments is an 8-bit serial-in, parallel-out shift register with 3-state output registers, used for I/O expansion and LED multiplexing in microcontroller systems. It operates from 2 V to 6 V, delivers ±6 mA output drive at 5 V, features 13 ns typical propagation delay, and includes independent shift (SRCLK) and storage (RCLK) clocks plus direct clear (SRCLR) - enabling precise timing control in LED display drivers and industrial control interfaces.

For engineers reviewing the SN74HC595N-NG datasheet, SN74HC595N-NG pinout, SN74HC595N-NG application, or SN74HC595N-NG equivalent, key selection criteria include its 16-pin PDIP package, 3-state output enable (OE), QH′ serial cascade output, low 80 µA max ICC, and compatibility with 5 V TTL logic levels in embedded bus interface designs.

Technical Context

The SN74HC595N-NG integrates two synchronous clock domains: a serial shift register clocked by SRCLK (positive-edge triggered) and a parallel storage register clocked by RCLK (also positive-edge). Data shifts serially via SER input and cascades through QH′, while RCLK latches the 8-bit parallel output (QA–QH) into 3-state buffers controlled by OE.

Its functional modes are defined by SRCLR (active-low asynchronous reset), OE (active-low output enable), and clock sequencing - allowing independent data shifting and output updating without glitches. The device supports daisy-chaining via QH′ and maintains CMOS-level input thresholds across 2–6 V supply range.

Key Specifications

Pinout & Package

SN74HC595N-NG uses a 16-pin Plastic Dual In-line Package (PDIP) with 19.31 mm × 6.35 mm body size, through-hole mounting, and industry-standard pin spacing (0.1 inch).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar shift register applications.

Compared with SN74HC595N-NG, SN74HC165N serves input acquisition rather than output expansion, while 74LV595N offers enhanced performance in 3.3 V systems without layout changes - making it the preferred alternative when upgrading existing designs for speed or drive strength.

Availability

SN74HC595N-NG is available at Aetrix Electronics and suitable for LED display drivers, microcontroller I/O expansion, network switch status indication, and power infrastructure monitoring requiring stable component supply across industrial temperature ranges (–40°C to +85°C).

Supply support for SN74HC595N-NG 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 including the 74HC series.

The SN74HC595N-NG belongs to TI's HC (High-Speed CMOS) logic family, designed specifically for low-power, noise-immune serial-to-parallel data conversion in industrial, automotive, and consumer control systems.

FAQ

What is the maximum clock frequency supported by SN74HC595N-NG?

The SN74HC595N-NG supports up to 25 MHz maximum clock frequency at 5 V supply (per datasheet Section 6.6), with typical propagation delay of 13 ns. At 2 V, maximum frequency drops to 5 MHz due to slower switching characteristics - design must verify timing margins under worst-case VCC and temperature conditions for SN74HC595N-NG.

Can SN74HC595N-NG drive LEDs directly without current-limiting resistors?

No - SN74HC595N-NG must use external current-limiting resistors on each QA–QH output. Although it provides ±6 mA drive at 5 V, continuous output current per pin is rated to ±35 mA absolute maximum (Section 6.1), and sustained operation above 6 mA risks exceeding thermal limits or violating recommended operating conditions for SN74HC595N-NG.

How does the QH′ pin function in daisy-chained SN74HC595N-NG configurations?

QH′ is the non-inverted serial output of the QH stage, providing the shifted-out bit to feed SER of the next SN74HC595N-NG in chain. When cascading, SRCLK is shared across all devices, while individual RCLK signals allow synchronized latching - ensuring all SN74HC595N-NG devices update outputs simultaneously after full 8×N-bit shift.

Is SN74HC595N-NG compatible with 3.3 V microcontrollers?

Yes - SN74HC595N-NG operates from 2 V to 6 V and accepts 3.3 V logic levels as valid VIH/VIL (Section 6.3). Its 3-state outputs interface cleanly with 3.3 V systems when VCC = 3.3 V, and it tolerates 5 V-tolerant inputs even at lower supply voltages, making SN74HC595N-NG robust in mixed-voltage designs.

What is the purpose of the SRCLR pin on SN74HC595N-NG?

SRCLR is an asynchronous active-low input that clears the entire 8-bit shift register to zero, independent of SRCLK or RCLK states. It ensures deterministic initialization at power-up or fault recovery - unlike synchronous reset methods, SRCLR takes effect immediately, which is essential for reliable startup sequences in SN74HC595N-NG-based systems.