Description of the four-channel Darlington array IC ULN2402A:
The ULN2402A is a monolithic integrated high-voltage, high-current Darlington array, with four independent Darlington driver channels internally. It includes a freewheeling diode internally designed for driving inductive loads such as relays and stepper motors. Each Darlington transistor can output up to 500mA of current. Parallel connection of Darlington transistors achieves higher output current capability. This circuit is widely used in relay driving, lighting driving, display driving (LED), stepper motor driving, and logic buffers.
The ULN2402A features a Darlington pair per output, connected in series with a 2.7K base resistor. It can be directly interfaced with TTL/CMOS circuits at a 5V operating voltage, allowing for direct handling of data that previously required standard logic buffers.
Product Features of Four-Darlington Transistor Chip ULN2402A:
500mA Collector Output Current (Single Channel)
High-pressure resistant (50V)
Input compatible TTL/CMOS logic signals
Widely applied in relay drives
Electrostatic Discharge (ESD) Capability: 4000 (HBM)
Packaging: SOP-10, MSOP-10
Application Fields of the Four-Channel Darlington Transistor ULN2402A:
Relay Driver
LED Driver
Display driver
Four-channel Darlington transistor ULN2402A's maximum parameters:
TA25°C, unless otherwise specified
| Parameters | Symbol | Value | Unit |
| Collector-Emmitter Voltage (Pins 7-10) | VCE | -0.5~50 | V |
| COM terminal voltage (pin 6) | VCOM | 50 | V |
| Input Voltage (1~4 Pins) | VI | -0.5~30 | V |
| Collector Peak Current | ICP | 500 | mA/ch |
| Output Diode Forward Peak Current | IOK | 500 | mA |
| Total Emitter Peak Current (Max) | IET | -1.2 | A |
| Operating Temperature (Max) | TJ | 150 | ℃ |
| Welding Temperature | 260 | ℃，10S | |
| Storage temperature range | Tstg | -60~+150 | ℃ |
| Package Thermal Resistance (SOP10) | θJA | 123 | ℃/W |
| Packaged Thermal Resistance (MSOP10) | θJA | 125 | ℃/W |
Typical Application of Four-Darlington Transistor Chip ULN2402A:
