Texas Instruments SN75477PE4

Overview

SN75477PE4 from Texas Instruments is a dual NAND peripheral driver IC designed for high-voltage, high-current switching in electromechanical interfaces. It delivers 300 mA continuous output per channel, supports 100 V typical output breakdown voltage, features integrated output clamp diodes (70 V, 300 mA), and operates across 0°C to 70°C - commonly used in relay and solenoid driver circuits.

For engineers reviewing the SN75477PE4 datasheet, SN75477PE4 pinout, SN75477PE4 application, or SN75477PE4 equivalent, key selection criteria include its dual-NAND logic function, TTL/MOS-compatible diode-clamped inputs, pnp-input architecture reducing input current, 5 V nominal supply operation, and plastic DIP-8 package with copper-lead frame for thermal reliability.

Technical Context

The SN75477PE4 implements two independent NAND gate drivers with pnp transistor inputs that minimize input current draw while maintaining TTL- and MOS-level compatibility via internal diode clamping. Each output includes a built-in clamp diode rated for 300 mA and 70 V reverse transient suppression.

Its logic behavior follows Y = A·S̅ (positive-logic NAND), where S serves as an enable/strobe input controlling both outputs simultaneously. The device is characterized for latch-up immunity at 55 V after conducting 300 mA, and supports fast switching with tPLH/tPHL ≤ 350 ns under 15 pF load conditions.

Key Specifications

Pinout & Package

SN75477PE4 uses an 8-pin plastic dual in-line package (PDIP-P) with copper-lead frame for enhanced thermal performance and reliability. Pin numbering follows standard DIP orientation with Pin 1 marked by a notch or dot.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar dual-NAND peripheral driver applications.

Compared with SN75477P, the SN75477PE4 offers identical functionality with RoHS-compliant NIPDAU lead finish and full traceability; versus ULN2003A, it provides integrated NAND logic and higher 100 V output breakdown but fewer channels - making it optimal for dual, logic-gated, high-voltage peripheral control.

Availability

SN75477PE4 is available at Aetrix Electronics and suitable for relay driver circuits, solenoid control modules, hammer-driver interfaces, and legacy printer head controllers requiring stable component supply and long-lifecycle support.

Supply support for SN75477PE4 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 founded in 1930, specializing in analog, embedded processing, and logic solutions for industrial, automotive, and communications markets.

The SN75477PE4 belongs to TI's legacy peripheral driver product line, engineered specifically for robust electromechanical interface applications requiring high-voltage isolation, inductive load handling, and TTL/MOS compatibility in commercial-temperature environments.

FAQ

What logic function does the SN75477PE4 implement?

The SN75477PE4 implements two independent positive-logic NAND gates (Y = A·S̅), where each channel has dedicated input A and shared strobe input S. When S is high, output Y follows NAND of A and S; when S is low, both outputs are forced high. This configuration enables synchronized enable/disable control across both drivers - a key feature distinguishing SN75477PE4 from simple inverters or buffers.

Does the SN75477PE4 require external flyback diodes when driving inductive loads?

No, the SN75477PE4 does not require external flyback diodes. It integrates clamp diodes on both outputs with a rated reverse voltage of 70 V and forward current capability of 300 mA. These diodes connect internally to the CLAMP pin (Pin 4), which must be tied to the positive rail of the inductive load (e.g., +55 V) to safely dissipate back-EMF energy - eliminating discrete components and saving board space.

What is the maximum continuous output current rating for the SN75477PE4?

The SN75477PE4 is characterized for 300 mA continuous output current per channel at 0°C to 70°C ambient temperature. Absolute maximum ratings allow 400 mA continuous and 500 mA peak (≤10 ms, 50% duty cycle), but design margins should respect the 300 mA specification to ensure reliability under worst-case thermal conditions in the PDIP-8 package.

How does the SN75477PE4 differ from the SN75476PE4 and SN75478PE4?

The SN75477PE4 is the NAND variant in the SN75476/SN75477/SN75478 family. SN75476PE4 implements AND logic (Y = A·S), while SN75478PE4 implements OR logic (Y = A+S). All three share identical pinouts, electrical specs (voltage ratings, current capability, thermal performance), and packaging - differing only in internal logic configuration. This allows functional substitution with minimal schematic changes when logic polarity permits.

Is the SN75477PE4 RoHS compliant?

Yes, the SN75477PE4 is RoHS compliant. Per TI's Package Option Addendum, it carries "Yes" for RoHS status and uses NIPDAU (nickel-palladium-gold) lead finish. The "E4" suffix denotes TI's green packaging standard, confirming compliance with EU Directive 2011/65/EU and associated exemptions applicable to legacy logic devices.