STK672-540

No. A0754-5/22

Precautions

[GND wiring]

• To reduce noise on the 5V system, be sure to place the GND of C01 in the circuit given above as close as possible to

Pin 1 of the hybrid IC. Also, the GND side of RO2 must be directly wired from P.GND terminal Pin 1 in order to

accurately set the current.

[Input pins]

• Insert resistor RO3 (47 to 100Ω) so that the discharge energy from capacitor CO2 is not directly applied to the CMOS

IC in this hybrid device. If the diode D1 has Vf characteristics with Vf less than or equal to 0.6V (when If = 0.1A),

this will be smaller than the CMOS IC input pin diode Vf. If this is the case RO3 may be replaced with a short without

problem.

• Apply 2.5V High level input to pins 8, 9, 10, 11, and 12.

• If VDD is being applied, use care that each input pin does not apply a negative voltage less than -0.3V to P.GND,

Pin 1, and do not apply a voltage greater than or equal to VDD voltage.

• Since the input pins do not have built-in pull-up resistors, when the open-collector type pins 8, 9, 10, 11, and 12 are

used as inputs, a 10 to 47k

Ω pull-up resistor (to VDD) must be used.

At this time, use a device for the open collector driver that has output current specifications that pull the voltage down

to less than 0.6V at Low level.

• To prevent malfunction due to chopping noise, we recommend that you mount a 1000pF capacitor between Pin 1 and

each of the input Pins 8, 9, 10, 11, and 12. Be sure to mount the capacitor as close as possible to the pins of hybrid IC.

If input is fixed Low, directly connect to Pin 1.

If input is fixed High, directly connect to the 5V power line.

[Current setting Vref]

• In consideration of the specifications of the Vref input bias current, IIB, a resistance from several kΩ to 100kΩ is

recommended for RO1.

• If the motor current is temporarily reduced, the circuit given below (STK672-540: IOH>0.25A) is recommended.

• Although the driver is equipped with a fixed current control function, it is not equipped with an overcurrent protection

function to ensure that the current does not exceed the maximum output current, IOH max. If Vref is mistakenly set to

a voltage that exceeds IOH max, the driver will be damaged by overcurrent.

5V

RO1

RO2

R3

5V

RO1

RO2

R3

Vref

Vref