ULN2003 / µPA2003 seven Darlington driver pinout
DIP-16. Seven-channel Darlington driver (stepper and motor drive)
Seven open-collector Darlington sinks with flyback diodes to COM. On the 1541-II (schematic 355207) inputs 2-5 take the gate array stepper phases and outputs 15-12 drive stepper connector CN3; output 11 drives the spindle motor line on CN4; COM (pin 9) goes to +12 V through R43 (56 Ω). A bad one leaves the spindle stopped or always on, or the stepper dead (Ray Carlsen).
Open the interactive 2003 pinoutPins
| Pin | Name | Type | Signal |
|---|---|---|---|
| 1 | 1B | ctrl | Channel 1 input. |
| 2 | 2B | ctrl | Channel 2 input (TTL/CMOS level, 2.7 kΩ base resistor). |
| 3 | 3B | ctrl | Channel 3 input (TTL/CMOS level, 2.7 kΩ base resistor). |
| 4 | 4B | ctrl | Channel 4 input (TTL/CMOS level, 2.7 kΩ base resistor). |
| 5 | 5B | ctrl | Channel 5 input (TTL/CMOS level, 2.7 kΩ base resistor). |
| 6 | 6B | ctrl | Channel 6 input (TTL/CMOS level, 2.7 kΩ base resistor). |
| 7 | 7B | ctrl | Channel 7 input. |
| 8 | E | ground | Common emitter, ground. |
| 9 | COM | power | Flyback diode common; tie to the load supply when driving coils. |
| 10 | 7C | ctrl | Channel 7 open-collector output. |
| 11 | 6C | ctrl | Channel 6 open-collector output, sinks up to 500 mA. |
| 12 | 5C | ctrl | Channel 5 open-collector output, sinks up to 500 mA. |
| 13 | 4C | ctrl | Channel 4 open-collector output, sinks up to 500 mA. |
| 14 | 3C | ctrl | Channel 3 open-collector output, sinks up to 500 mA. |
| 15 | 2C | ctrl | Channel 2 open-collector output, sinks up to 500 mA. |
| 16 | 1C | ctrl | Channel 1 open-collector output. |
Fitted in
- Commodore 1541 disk drive U13 (1541-II only)
- Disk II D4 on the analog card (socketed, Apple 327-2003)