Texas Instruments ULQ2004ADR

Overview

ULQ2004ADR from Texas Instruments is a high-voltage, high-current Darlington transistor array comprising seven NPN Darlington pairs with integrated common-cathode clamp diodes, 10.5kΩ input base resistors, 50V collector-emitter rating, and 500mA per-channel sink capability - used for driving relays, stepper motors, and LED displays in industrial control systems.

For engineers reviewing the ULQ2004ADR datasheet, ULQ2004ADR pinout, ULQ2004ADR application, or ULQ2004ADR equivalent, key selection criteria include operating temperature range (–40°C to 85°C), input compatibility with 6V–15V CMOS logic, V_CE(sat) ≤1.6V at 350mA, flyback diode integration, and SOIC-16 package thermal performance (R_θJA = 88.6°C/W).

Technical Context

The ULQ2004ADR implements seven independent Darlington output stages, each with a dedicated 10.5kΩ series base resistor enabling direct interface with higher-voltage CMOS logic (6V–15V). Its internal clamp diodes are connected to the COM terminal, forming a common-cathode configuration optimized for inductive load suppression.

Unlike the ULN2003A (2.7kΩ resistor, TTL/5V CMOS compatible) or ULN2002A (Zener-limited input for 14V–25V PMOS), the ULQ2004ADR's higher input resistance reduces required drive current while maintaining full 500mA sink capability per channel and 50V output voltage rating.

Key Specifications

Pinout & Package

ULQ2004ADR is housed in a 16-pin SOIC (Small Outline Integrated Circuit) package measuring 9.90mm × 3.91mm, with standard JEDEC MS-012AC footprint and gull-wing leads. Thermal resistance is R_θJA = 88.6°C/W, supporting moderate-power continuous operation with adequate PCB copper area.

Key Features

Applications

Equivalent & Alternatives

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

Compared with ULN2004AD, ULQ2004ADR offers identical functionality at lower cost for applications staying within 85°C ambient, while ULQ2004ADWR provides identical performance in tape-and-reel format for automated manufacturing - neither requires PCB redesign.

Availability

ULQ2004ADR is available at Aetrix Electronics and suitable for relay control systems, stepper motor interfaces, lamp drivers, and industrial logic buffering requiring stable component supply across long-life industrial programs.

Supply support for ULQ2004ADR 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 connectivity technologies with over 50 years of industrial-grade component development.

The ULQ2004ADR belongs to TI's ULx200x Darlington array product line, engineered for robust, cost-effective interfacing between low-power logic and high-voltage/high-current industrial loads - emphasizing reliability, integrated protection, and wide supply compatibility.

FAQ

What is the maximum operating temperature for ULQ2004ADR?

The ULQ2004ADR is specified for operation from –40°C to +85°C ambient temperature. This range is validated per its absolute maximum ratings and recommended operating conditions in the official TI datasheet SLRS027T. Exceeding +85°C ambient may cause thermal shutdown or accelerated parametric drift; for higher-temperature environments, consider the ULN2004AD (–40°C to +105°C) instead of ULQ2004ADR.

Does ULQ2004ADR require external flyback diodes when driving relays?

No, ULQ2004ADR does not require external flyback diodes when driving relays. It integrates seven common-cathode clamp diodes connected to the COM pin, which safely dissipate inductive energy when the Darlington outputs switch off. To use this feature, connect the COM pin directly to the positive supply rail of the relay coil - ensuring the diode path is complete. ULQ2004ADR's internal diodes are rated for 500mA peak clamp current and 50V reverse voltage.

Can ULQ2004ADR drive a 12V DC brushed motor directly?

Yes, ULQ2004ADR can drive a small 12V DC brushed motor directly - provided the motor's stall current remains ≤500mA per channel and duty cycle is limited to prevent thermal overload. Its 50V collector rating and 500mA sink capacity suit low-power motors (e.g., <5W). For continuous full-load operation, derate based on SOIC-16 thermal resistance (88.6°C/W); ULQ2004ADR supports ≤3 channels active simultaneously at 350mA in still air per TI's Figure 5-4.

What logic families are compatible with ULQ2004ADR inputs?

ULQ2004ADR inputs are optimized for 6V–15V CMOS logic families due to its 10.5kΩ internal series base resistor. It accepts clean high-level signals from 74HC, CD4000, and other CMOS families operating in that range. It is not designed for TTL (which typically requires ~1.4V threshold) or 3.3V logic without additional level translation - unlike the ULN2003A (2.7kΩ, 5V-tolerant). Input current at 12V is ~1.14mA, well within typical CMOS drive capability.

How does ULQ2004ADR differ from ULN2004A?

ULQ2004ADR and ULN2004A share identical electrical specifications, pinout, and SOIC-16 package, but differ in temperature rating and ordering designation: ULQ2004ADR is rated for –40°C to +85°C and shipped in tubes, while ULN2004A is rated for –40°C to +105°C and available in tape-and-reel. Both belong to the same silicon die family and function identically within their respective temperature ranges; ULQ2004ADR is a cost-optimized variant for standard industrial applications.