STK672-400

No.A0751-11/19

[Vref (Sets the current that is used as the reference for setting the output current)]

(1) Pin circuit type: Analog input (differential amplifier). Input resistance: 200k

Ω

(2) Function: The input voltage must be in the voltage range from the control system power supply VDD to 2V. Note

that there is a resistance component (200k

Ω, typical) in this hybrid IC's input and that therefore an input

current occurs.

If the Vref voltage structure is formed as a resistor voltage divider, that circuit must be designed to take

that input current into account. The input current is 12.5

μA (typical). Note that this is the current when

Vref is 5V. The input current falls according to the formula shown below when the Vref voltage is below

that level.

Ios=Vref/(200k+200k) --------- (1)

• Input circuit structure

200k

Ω

2.5V

to DAC

Hybrid IC pin 19

200k

Ω : ±1%

Vref

STK672-400/410

200k

Ω

Ios=12.5

μA