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ULN2003A: Review Support and Questions

Part Number: ULN2003A

Hi expert,

Customer would like to use darlington transistor array ULN2003A for Pan/Tilt control in IP Camera. The stepper motor is 5V / 20ohm and 4phase/5wire. Each phase current would be 250mA and there might be two phases operate at the same time. 

Q1:  is ULN2003A a proper solution to fulfill their need? 

Q2:  do we need to connect 1Kohm in series at inputs?

Q3: what would be power dissipation of ULN2003A?



  • Hi Allan,

    Q1. Yes, it is.

    Q2. No, an input resistor is not needed as the device contains input resistors.

    Q3. Worst-case power dissipation would be during 0.5A (two phases on at once) at VCE,sat = 1.6V: 0.5 * 1.6 = 0.8W. Typical will be lower, around 0.55W when two phases are on.