STMicroelectronics ULQ2004A

Overview

ULQ2004A from STMicroelectronics is a 7-channel high-voltage, high-current Darlington array in DIP-16 package, designed for interfacing 6–15 V CMOS/PMOS logic to inductive loads. Each channel delivers 500 mA continuous (600 mA peak) output current at up to 50 V, with integrated clamp diodes and -40 to 105 °C operating range. It drives relays, solenoids, thermal print-heads, and LED displays in industrial control panels.

For engineers reviewing the ULQ2004A datasheet, ULQ2004A pinout, ULQ2004A application, or ULQ2004A equivalent, key selection criteria include input voltage compatibility (6–15 V), per-channel saturation voltage (≤1.6 V @ 350 mA), thermal resistance (70 °C/W), automotive-grade SO16 variant availability, and layout-optimized opposite-pin configuration for simplified PCB routing.

Technical Context

The ULQ2004A implements seven independent open-collector NPN Darlington pairs with common emitters and monolithically integrated flyback diodes across each output. Its input stage accepts 6–15 V logic levels without external resistors, enabling direct connection to PMOS and high-voltage CMOS families.

Each Darlington pair features a minimum DC current gain (h_FE) of 1000 at 350 mA collector current and 2 V V_CE, with guaranteed V_CE(SAT) ≤ 1.6 V under 350 mA load. The device supports parallel output operation for current sharing and includes thermal protection via 150 °C junction limit.

Key Specifications

Pinout & Package

ULQ2004A is supplied in a 16-pin plastic dual in-line package (DIP-16) with copper lead-frame for reduced thermal resistance. Pin numbering follows standard top-view orientation with inputs on one side and outputs on the opposite side to minimize trace crossovers.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ULN2004A and TD62004FG, ULQ2004A uniquely combines AEC-Q100 qualification, integrated clamping, and 105 °C operation-making it optimal for thermally demanding industrial controls where reliability and design simplicity are critical.

Availability

ULQ2004A is available at Aetrix Electronics and suitable for industrial relay control, thermal print-head driving, solenoid actuation systems, and LED display multiplexing requiring stable component supply across long production lifecycles.

Supply support for ULQ2004A 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

STMicroelectronics is a global semiconductor leader headquartered in Geneva, Switzerland, delivering intelligent power, analog, MEMS, and microcontroller solutions for industrial, automotive, and consumer markets.

The ULQ series belongs to ST's high-reliability Darlington array product line, engineered specifically for robust interfacing between logic controllers and rugged electromagnetic loads in harsh environments.

FAQ

What is the maximum safe continuous current per channel for ULQ2004A?

The ULQ2004A is rated for 500 mA continuous collector current per channel at T_A = 25 °C with proper heatsinking. At 105 °C ambient, derating applies: maximum continuous current drops to approximately 350 mA due to thermal limits and R_thJA = 70 °C/W. Peak current of 600 mA is allowed for ≤100 ms pulses with ≥1 s off-time.

Can ULQ2004A drive 12 V automotive relays directly from a 5 V microcontroller?

No-ULQ2004A requires 6–15 V input logic levels and is not compatible with 5 V TTL/CMOS. To interface with a 5 V MCU, use a level-shifting resistor network or select ULQ2003A (designed for 5 V TTL/CMOS). The ULQ2004A's VI(ON) threshold starts at 5 V, so 5 V logic may result in marginal or inconsistent turn-on.

Does ULQ2004A include internal flyback diodes for all seven channels?

Yes-each of the seven Darlington outputs includes a monolithically integrated clamp diode connected from the collector to the COM pin (pin 16). These diodes protect against inductive voltage spikes when switching relays, solenoids, or motors, eliminating the need for external diodes in standard configurations.

Is there an automotive-qualified version of ULQ2004A?

Yes-the ULQ2004D1013TR is the AEC-Q100 qualified SO16 variant, tested over -40 to 125 °C and subjected to PAT, SYL, and SBL statistical reliability tests. It shares identical electrical characteristics with the DIP-16 ULQ2004A but uses a surface-mount narrow SO16 package for automotive ECU and body-control module applications.