ULN2004A
Product Overview
Category
The ULN2004A belongs to the category of high-voltage, high-current Darlington transistor arrays.
Use
It is commonly used as a driver for relays, lamps, LEDs, displays, and other medium to high current or high voltage devices.
Characteristics
- High-Voltage and High-Current Capability
- Darlington Transistor Array
- Suitable for Medium to High Current Applications
- Compatible with TTL and CMOS Logic
- Integral Suppression Diodes for Inductive Loads
Package
The ULN2004A is available in various package types including DIP (Dual Inline Package) and SOIC (Small Outline Integrated Circuit).
Essence
The essence of ULN2004A lies in its ability to provide a convenient solution for driving medium to high current loads with minimal external components.
Packaging/Quantity
The ULN2004A is typically available in reels or tubes containing multiple units, with quantities varying based on the supplier and customer requirements.
Specifications
- Input Voltage: 5V to 50V
- Output Voltage: 50V
- Continuous Collector Current: 500mA
- Maximum Collector-Emitter Voltage: 50V
- Number of Channels: 7
Detailed Pin Configuration
The ULN2004A features a 16-pin configuration with each pin serving specific functions related to input, output, and power supply connections.
| Pin No. | Name | Function | |---------|------|----------| | 1 | COM | Common Terminal | | 2 | IN1 | Input for Channel 1 | | 3 | OUT1 | Output for Channel 1 | | ... | ... | ... | | 16 | Vcc | Power Supply Voltage |
Functional Features
- High-Voltage and High-Current Amplification
- Built-in Clamp Diodes for Inductive Load Protection
- Compatible with Various Logic Levels
- Thermal Shutdown Protection
Advantages and Disadvantages
Advantages
- Simplifies Driving of High-Current Loads
- Reduced External Component Count
- Compatibility with TTL and CMOS Logic
- Built-in Diodes for Inductive Load Protection
Disadvantages
- Limited Maximum Collector Current
- Higher Power Dissipation in High-Current Applications
- Not Suitable for Low-Power Applications
Working Principles
The ULN2004A operates based on the principle of Darlington transistor pairs which provide high current gain and high voltage capability. When an input signal is applied, the corresponding output channel drives the connected load with amplified current and voltage levels.
Detailed Application Field Plans
Industrial Automation
- Control of Solenoids and Relays
- Driving of Stepper Motors
- Actuation of High-Current Loads in Machinery
Automotive Electronics
- Control of Automotive Lighting Systems
- Actuation of Power Windows and Door Locks
Consumer Electronics
- Driving of LED Displays
- Control of Home Appliances
Detailed and Complete Alternative Models
- ULN2003A
- ULN2803A
- TIP120/TIP122 Darlington Transistors
In conclusion, the ULN2004A serves as a versatile and reliable solution for driving medium to high current loads in various applications, offering convenience and performance in a compact package.
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技術ソリューションにおける ULN2004A の適用に関連する 10 件の一般的な質問と回答をリストします。
What is ULN2004A?
- ULN2004A is a high-voltage, high-current Darlington transistor array. It consists of seven NPN Darlington pairs that feature high-voltage outputs with common-cathode clamp diodes for switching inductive loads.
What are the typical applications of ULN2004A?
- ULN2004A is commonly used in applications such as relay drivers, stepper motor drivers, LED and lamp drivers, and other high-current/high-voltage interfacing tasks.
How do I connect ULN2004A to drive a relay?
- To drive a relay using ULN2004A, you would typically connect the input signal to one of the input pins (IN1 to IN7) and connect the relay coil between the corresponding output pin and the supply voltage, while ensuring the diode is connected in parallel with the relay coil to protect against back EMF.
Can ULN2004A be used to drive a stepper motor?
- Yes, ULN2004A can be used to drive a unipolar or bipolar stepper motor by connecting the motor windings to the output pins and controlling the sequence of inputs to achieve the desired stepping motion.
What is the maximum current ULN2004A can handle?
- ULN2004A can handle a maximum continuous output current of 500 mA per channel and a peak output current of 600 mA per channel.
How should I protect ULN2004A from voltage spikes?
- To protect ULN2004A from voltage spikes, it is recommended to use external clamping diodes across the inductive loads (such as relays or motors) to suppress any voltage spikes generated during switching.
Can ULN2004A be used with microcontrollers like Arduino?
- Yes, ULN2004A can be easily interfaced with microcontrollers like Arduino to drive various loads such as relays, motors, and LEDs.
What is the maximum voltage ULN2004A can handle?
- ULN2004A can handle a maximum voltage of 50V.
How do I select the appropriate resistor for ULN2004A inputs?
- The input resistors for ULN2004A are typically chosen based on the input current required for the application, and they are often selected to limit the base current to a safe value for the driving device.
Can ULN2004A be used for PWM (Pulse Width Modulation) applications?
- While ULN2004A itself does not support PWM, it can be used in conjunction with PWM signals from a microcontroller to control the average current through loads such as LEDs or motors. However, care must be taken to ensure that the peak current ratings are not exceeded.