The ULN2804AG is a high-voltage, high-current Darlington transistor array manufactured by Toshiba Semiconductor and Storage. It is designed to interface between low-level logic circuitry and higher-current or higher-voltage loads. This device comprises eight NPN Darlington pairs, each including common-cathode suppression diodes to protect against inductive load switching transients.
Applications:
- Relay drivers
- Solenoid drivers
- Lamp drivers
- Stepper motor drivers
- LED display drivers
- Logic buffers
- Line drivers
Features:
- Eight Darlington pairs in one package
- High output voltage: 50 V
- High output current: 500 mA per driver
- Input compatible with TTL, DTL, CMOS logic levels
- Integrated free-wheeling diodes for inductive load handling
- DIP-18 package
Benefits:
- Simplified interface between logic circuits and high-power loads
- Reduced component count, saving board space
- Protection for driving circuitry against inductive kickback
- Increased system reliability
Additional Details:
Each of the eight Darlington pairs within the ULN2804AG offers significant current gain. The integrated common-cathode suppression diodes are specifically designed to handle inductive loads like relays, solenoids, and motors. These diodes clamp voltage spikes generated during switching, protecting the driver IC and other circuit components. The device's input structure is designed for direct compatibility with a broad range of logic families, including TTL, DTL, and CMOS. The device is available in a DIP-18 (Dual In-line Package) for through-hole mounting.
The ULN2804AG is widely used in industrial control systems, automotive electronics, and consumer electronics where microcontrollers or other logic devices need to control external devices requiring higher power levels. Its robust design and integrated features make it a reliable and cost-effective solution.