PCM4202 QuestionsQ1

Rin of Analog-input is 3Kohm from the PCM4202 data sheet p4, and customer

measured the Rin(between Vin+/Vin-) by Tester* as Fig1-(c) , result shows 6Kohm ( 3Kohm x 2)

and customer says that data sheet description is confirmed…..

Is this reasonable? If No, would you please let us know the measuring method of

Rin in the data sheet?

* Note that power is ON (Vcc=5V/VDD=3.3V) when measuring the Rin by Tester

Q2

When Customer had directly insert 5V or 0V as Fig1-(a)(b), customer seen 5V or 0V

in the portion of VIN+ and also VIN- .

Is this reasonable?

In the data sheet p13, there are description that “The PCM4202 analog inputs are internally

biased to approximately VCC/2.”,,, but Cusomer’s test result does not show that.

In case of Fig-1-(a)(b), Vcom is Hi-Z ?? ( Fig2-(b) switch is OFF? )

5V10K

5V is seen

VCC=5VVDD=3.3V

VIN+

VIN-

PCM42020V(GND) 10K

0V is seen

VCC=5VVDD=3.3V

VIN+

VIN-

PCM4202

VCC=5VVDD=3.3V

VIN+

VIN-

PCM4202Tester shows“6kohm”

Tester

Fig1-(a)Fig1-(b)

Fig1-(c)

OpenOpen

VINR+

VINR-

Delta-SigmaModulator

VCOM=Vcc/2

3Kohm

3Kohm

?

Fig2-(a)Block Diagram(PCM4202D/S)

Fig2-(b)Block Diagram(Customer’s Guess)

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