ULN2804A STMicroelectronics Integrated Circuit (Dual-In-Line Packages) In Stock
STMicroelectronics ULN2804A is an 8-channel Darlington transistor array with open-collector outputs rated at 50 V and 500 mA per channel, housed in an 18-pin DIP package. It includes built-in transient suppression diodes on each output for direct relay, solenoid, and motor driver applications without external flyback diodes. Available in stock worldwide with fast shipping for industrial automation, consumer appliances, and LED matrix driving.
- Manufacturer
- STMicroelectronics
- Package
- Dual-In-Line Packages
- Pin Count
- 18
- Lifecycle
- ACTIVE
- Datasheet
- ULN2804A Datasheet PDF
- Category
- Integrated Circuit
- Price
- From $0.8750(MOQ 4)
- Temp Range
- -20.0°C to 85.0°C
- RoHS
- Compliant
- Lead Time
- 3–7 business days
- Shipping
- DHL Express · Worldwide
Key Features
- 8-channel open-collector Darlington array with 500 mA per channel and 50 V output rating for driving relays, solenoids, and stepper motors directly from logic signals
- Integrated transient suppression diodes on every output channel eliminate external flyback protection components, simplifying PCB design and reducing BOM
- CMOS and TTL-compatible inputs with input resistors allowing direct interfacing to 5 V logic without additional current-limiting resistors
Applications
The ULN2804A is extensively used in industrial PLC output modules, relay driver boards, and stepper motor controllers where up to 8 independent 500 mA sink channels are required from a single 18-pin DIP IC. Its integrated flyback diodes make it the go-to solution for driving inductive loads such as solenoids and latching relays in home automation and white goods appliances. LED matrix display driving and lamp switching circuits also leverage the ULN2804A open-collector outputs for multiplexed high-current display segments.
Specifications
| Factory Lead Time | 10Weeks |
| YTEOL | 5.5 |
| Built-in Protections | TRANSIENT |
| Driver Number of Bits | 8 |
| Interface IC Type | BUFFER OR INVERTER BASED PERIPHERAL DRIVER |
| JESD-30 Code | R-PDIP-T18 |
| Number of Functions | 1 |
| Output Characteristics | OPEN-COLLECTOR |
| Output Current Flow Direction | SINK |
| Package Body Material | PLASTIC/EPOXY |
| Package Equivalence Code | DIP18,.3 |
| Package Shape | RECTANGULAR |
| Package Style | IN-LINE |
| Surface Mount | NO |
| 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, Malaysia |
Alternate & Equivalent Parts
Compatible alternatives and drop-in replacements for ULN2804A:
Frequently Asked Questions
How many output channels does the ULN2804A provide and what is the maximum current per channel?
The ULN2804A integrates 8 independent Darlington transistor channels, each capable of sinking up to 500 mA at voltages up to 50 V, making it capable of driving 8 relay coils or solenoids simultaneously from a single 18-pin package.
Do I need external flyback diodes when driving inductive loads with the ULN2804A?
No; the ULN2804A includes built-in transient suppression diodes connected between each output and a common cathode pin (COM), which clamp inductive kickback spikes when switching relay coils, solenoids, or stepper motor windings rated up to 50 V.
Which logic families can directly interface to the ULN2804A inputs without additional components?
The ULN2804A accepts CMOS and TTL-level inputs; its input resistors are sized for 5 V logic, so outputs from standard 74HC, 74HCT, and 5 V microcontroller GPIO pins drive the Darlington bases without external current-limiting resistors, simplifying interface design.
How does the ULN2804A differ from ULN2803A and which should be chosen for a 5 V CMOS design?
The ULN2804A includes 10.5 kΩ input resistors optimized for CMOS logic at 5 V supply, while the ULN2803A uses 2.7 kΩ resistors suited for TTL; for a 5 V CMOS microcontroller driving relay coils at up to 500 mA, the ULN2804A is the preferred 8-channel choice.
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About STMicroelectronics
STMicroelectronics is a global semiconductor leader serving customers across the spectrum of electronics applications. ST's products are found in a wide range of applications including automotive, industrial, personal electronics, and communications.
| Qty. | Unit Price | Ext. Price |
|---|---|---|
| 4+ | $0.9169 | $3.67 |
| 8+ | $0.9002 | $7.20 |
| 16+ | $0.8842 | $14.15 |
| 2000+ | $0.8750 | $1750.00 |
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