General Introduction

The ULN2803ADWR, manufactured by Texas Instruments, is a Darlington transistor array. It is designed to meet the needs of various high-current and high-voltage driving applications.

Features

1. High-Voltage and High-Current Capability: With a maximum collector-emitter voltage (VCEO) of 50 V and a rated collector current (Ic) of 500 mA per channel, it can drive high-power loads such as relays, motors, and lamps.
2. Eight Independent Channels: The device contains eight NPN Darlington pairs, each of which can work independently, providing eight channels for driving different loads or signals.
3. Internal Clamp Diodes: Each Darlington pair is equipped with a common-cathode clamp diode. These diodes protect the device from the reverse electromotive force generated by inductive loads, improving the reliability and stability of the circuit.
4. Logic Input Compatibility: It has a 2.7kΩ series base resistor for each Darlington pair, enabling direct connection with TTL or 5V CMOS devices. The input is compatible with various logic levels, making it easy to interface with different control circuits.
5. Surface Mount Package: It adopts the SOIC-18 package, which has the advantages of small size and easy surface mount technology (SMT) installation, suitable for use in circuit boards with high integration requirements.
6. Wide Operating Temperature Range: The operating temperature range is from -40°C to +85°C, which allows the device to work stably in different environmental conditions

Technical Parameters

1. Collector-Emitter Voltage VCEO: 50 V
2. Collector Current Ic: 500 mA (per channel)
3. Saturation Voltage VCE(sat): 1.3 V at 350 mA collector current
4. Input Voltage: Compatible with TTL and 5V CMOS logic levels
5. Series Base Resistance: 2.7 kΩ
6. Operating Temperature Range: -40°C to +85°C

Applications

1. Relay Drive: It is widely used in relay drive circuits. The ULN2803ADWR can control the on and off of relays with low-voltage logic signals, and is commonly used in home appliances and industrial control systems.
2. Motor Control: In motor drive and control systems, such as those for DC motors and stepper motors in industrial automation equipment, it can provide the necessary driving current to control the start, stop, and speed of the motors.
3. Lighting Control: It can be used to control high-power LEDs and other lighting devices in lighting systems, achieving functions such as dimming and switching control.
4. Display Drive: It is suitable for driving display devices such as LED displays and gas discharge displays, providing the required driving signals to control the display content and brightness.
5. Logic Buffer: In digital circuits, it can be used as a logic buffer to isolate and amplify logic signals, improving the driving ability and anti-interference ability of the signals.
6. Printer and Office Equipment: In printers, copiers and other office equipment, it is used to drive various solenoid valves and mechanical components