Uln2003 application circuit

Photocoupler

Uln2003 application circuit

ULN2003 is a high-voltage, high-current Darlington display consisting of seven silicon NPN Darlington tubes.

The characteristics of this circuit are as follows:

Each pair of Darlington in ULN2003 is connected in series with a 2.7K base resistor, which can be used with TTL and CMOS circuits at 5V operating voltage.

Directly connected, you can directly process data that was originally processed using standard logic buffers.

ULN2003 has a high operating voltage, high operating current, sink current up to 500mA, and can withstand 50V in the off state, and the output is still

It can run in parallel at high load currents.

The ULN2003 is available in DIP-16 or SOP-16 plastic packages.

This design uses GALl6V8 as the ring pulse distributor. ULN2003 (domestic model 5G1413) is a seven-way Darlington driver array. It is an open collector with open collector (OC) output. The maximum drive current can reach 500mA. Usually used to connect one end of the load stepper motor to VDD (12V) and the other end to the output pin, such as pin 16. In order to prevent the program from entering an infinite loop, an external hardware watchdog timer MAX813L has been added, and its internal watchdog timer monitors the operation of UP/UC. If no operation is detected within 1.6s, the internal timer will cause the watchdog output WDO to be low and WDO will remain low until the WDI detects UP/UC operation. Connecting WR and WDO causes the watchdog timeout to generate a reset. Two pieces of ULN2003 are used to drive the stepping motors in the X and Y directions. The specific hardware circuit is shown in Figure 1.