Diodes Incorporated ULN2004AD16-U

Overview

ULN2004AD16-U from Diodes Incorporated is a 7-channel high-voltage, high-current Darlington transistor array in SO-16 package, rated for 500mA per channel and 50V collector-emitter voltage, with integrated clamp diodes and 10.5kΩ input resistors optimized for 6V–15V CMOS/pMOS logic compatibility. It drives relays, solenoids, thermal print-heads, and LED displays in industrial control and automation interfaces.

For engineers reviewing the ULN2004AD16-U datasheet, ULN2004AD16-U pinout, ULN2004AD16-U application, or ULN2004AD16-U equivalent, key selection criteria include input resistor value (10.5kΩ), V_CE(SAT) ≤1.6V at 350mA, clamp diode integration, SO-16 thermal resistance (63°C/W), and -40°C to +105°C operating range.

Technical Context

The ULN2004AD16-U implements seven independent Darlington pairs with monolithic silicon construction, each featuring a 10.5kΩ series base resistor enabling direct interface with 6V–15V CMOS and pMOS logic without external biasing. The common cathode clamp diode network (pin 9, COM) suppresses inductive kickback from relay coils and solenoids.

Input-to-output pin opposition (e.g., pin 1B ↔ pin 16C) simplifies PCB routing in multi-load driver layouts. Its open-collector outputs support wired-OR logic and flexible pull-up configurations up to 50V, while thermal design relies on θ_JA = 63°C/W (SO-16) and maximum junction temperature of +150°C.

Key Specifications

Pinout & Package

ULN2004AD16-U is housed in a standard SO-16 (Small Outline, 150mil width) package with 1.26mm max thickness, RoHS-compliant matte tin plating, and moisture sensitivity level 1 per J-STD-020.

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar Darlington array applications.

Compared with ULN2003A, ULN2004AD16-U offers higher input impedance and lower static power draw for 6V–15V systems, while TD62003APG trades input convenience for added inversion logic and reduced protection integration.

Availability

ULN2004AD16-U is available at Aetrix Electronics and suitable for industrial relay control, thermal print-head driving, LED display multiplexing, and DC motor interface applications requiring stable component supply across extended temperature ranges and long production lifecycles.

Supply support for ULN2004AD16-U 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

Diodes Incorporated is a global manufacturer of discrete semiconductors and analog ICs, specializing in high-reliability power management, signal integrity, and interface solutions for industrial, computing, and consumer markets.

The ULN2004A belongs to Diodes' legacy Darlington array product line, engineered specifically for robust, cost-effective switching of inductive and resistive loads in non-automotive industrial control environments.

FAQ

What logic families is ULN2004AD16-U designed to interface with?

ULN2004AD16-U features a 10.5kΩ input resistor optimized for 6V–15V CMOS and pMOS logic families. It accepts input voltages up to 30V absolute maximum and delivers reliable turn-on with VI(ON) ≤8V at 350mA output current, making it ideal for industrial controllers using higher-voltage logic rails.

Can ULN2004AD16-U drive multiple channels simultaneously at full 500mA?

Yes - the device supports simultaneous conduction across all seven channels at 500mA each under derated conditions. At TA = +70°C, maximum continuous collector current per channel remains 500mA with N = 1–7 outputs active, provided θ_JA = 63°C/W and proper PCB copper area is used for thermal relief.

How is the COM pin used in inductive load applications?

The COM pin (pin 9) connects to the positive supply rail of the inductive load (e.g., relay coil). During turn-off, stored magnetic energy discharges through the internal clamp diodes into this rail, preventing voltage spikes >50V at the output pins and eliminating external flyback diodes.

Is ULN2004AD16-U suitable for automotive applications?

No - ULN2004AD16-U is not AEC-Q100 qualified and is intended for industrial, commercial, and consumer applications. Diodes Incorporated offers automotive-grade alternatives (e.g., ULN2004V) with PPAP support, IATF 16949 manufacturing, and extended qualification testing for under-hood use.