ULN2004A STMicroelectronics Integrated Circuit (Dual-In-Line Packages) In Stock
The ULN2004A is a 7-channel Darlington transistor array driver with open-collector outputs and integrated transient suppression diodes. Each channel sinks up to 500 mA at up to 50 V, making it ideal for driving relays, solenoids, and stepper motors from low-voltage logic. Available from stock with worldwide shipping.
- Manufacturer
- STMicroelectronics
- Package
- Dual-In-Line Packages
- Pin Count
- 16
- Lifecycle
- ACTIVE
- Datasheet
- ULN2004A Datasheet PDF
- Category
- Integrated Circuit
- Price
- From $0.1339(MOQ 1)
- Temp Range
- -40.0°C to 85.0°C
- RoHS
- Compliant
- Lead Time
- 3–7 business days
- Shipping
- DHL Express · Worldwide
Key Features
- 7 independent Darlington pair channels each sinking up to 500 mA at 50 V for high-current peripheral driving
- Built-in transient suppression diodes on every output protect against inductive load voltage spikes from relays and solenoids
- Open-collector outputs with input thresholds compatible with 5 V TTL and CMOS logic for direct microcontroller interfacing
Applications
The ULN2004A is a standard choice for driving 7 relay coils or solenoids directly from a microcontroller GPIO, eliminating the need for discrete transistors and flyback diodes. In stepper motor control, it buffers the phase outputs of a dedicated controller IC to deliver the higher current required by unipolar stepper windings. It is also used in industrial PLC output modules and home automation boards to switch 12 V or 24 V lamp, valve, and actuator loads from 5 V logic signals.
Specifications
| Factory Lead Time | 10Weeks |
| YTEOL | 5 |
| Built-in Protections | TRANSIENT |
| Driver Number of Bits | 7 |
| Interface IC Type | BUFFER OR INVERTER BASED PERIPHERAL DRIVER |
| JESD-30 Code | R-PDIP-T16 |
| JESD-609 Code | e3 |
| Number of Functions | 1 |
| Output Characteristics | OPEN-COLLECTOR |
| Output Current Flow Direction | SINK |
| Output Peak Current Limit-Nom | 0.5A |
| Package Body Material | PLASTIC/EPOXY |
| Package Equivalence Code | DIP16,.3 |
| Package Shape | RECTANGULAR |
| Package Style | IN-LINE |
| Supply Voltage-Max | 8V |
| Surface Mount | NO |
| Terminal Finish | Matte Tin (Sn) |
| Terminal Form | THROUGH-HOLE |
| Terminal Pitch | 2.54mm |
| Terminal Position | DUAL |
| Turn-off Time | 1 µs |
| Turn-on Time | 1 µs |
| Package | Dual-In-Line Packages |
Compliance & Regulatory
| RoHS Status | Compliant |
| Lead-Free | Yes (Pb-Free) |
| ECCN | EAR99 |
| HTS Code | 8542.39.00.60 |
| Country of Origin | Mainland China |
Alternate & Equivalent Parts
Compatible alternatives and drop-in replacements for ULN2004A:
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Frequently Asked Questions
How much current can each channel of ULN2004A sink and what load voltage does it support?
Each of the 7 Darlington channels in ULN2004A can sink up to 500 mA of continuous current with an output voltage up to 50 V. This means a single IC can simultaneously drive 7 relay coils rated at 12 V / 40 mA each, or drive lower-count higher-current loads such as 24 V solenoids drawing up to 500 mA per channel.
Do the integrated transient diodes in ULN2004A eliminate the need for external flyback diodes on relay coils?
Yes. The ULN2004A includes internal suppression diodes connected between each output and the common cathode pin (COM), which is tied to the relay supply rail. When a relay coil is de-energized, the collapsing magnetic field generates a voltage spike that the diode clamps to the supply plus one diode drop, typically below 55 V, protecting the output transistor and removing the need for 7 discrete 1N4148 or equivalent flyback diodes.
Is ULN2004A compatible with 3.3 V microcontroller outputs or does it require a 5 V input?
The ULN2004A input resistors are sized for 5 V TTL and CMOS logic levels. At 3.3 V input, the base current through the input resistor may be insufficient to fully saturate the Darlington pair, resulting in higher output saturation voltage and lower current capability. For reliable operation from 3.3 V logic at full 500 mA load, a variant with smaller input resistors or a logic-level translator is recommended instead.
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| Qty. | Unit Price | Ext. Price |
|---|---|---|
| 1+ | $0.2523 | $0.25 |
| 10+ | $0.1585 | $1.58 |
| 100+ | $0.1339 | $13.39 |
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