F6921 Datasheet

X0010170

Rev.1.0

Apr 8, 2021

Page 8

3.

Typical Application Circuit

Figure 3 shows two typical application circuits for biasing the F6921.

The top circuit uses a voltage source Vref to supply the bias reference current Iref through an external resistor

Rref. Vref should be set to achieve the recommended Iref bias currents per the indicated formula. Refer to

Figure 13 for the typical relationship between Viref and Iref.

The bottom circuit uses the programmable IDAC of the Renesas F61XX beamforming IC to provide the

reference current directly to the F6921.

Figure 3. Typical Application Circuits

CH1

CH2

VDD2

VDD1

F6921

VDD

VDD

Vref

IREF

Rref

Viref

CH1

CH2

VDD2

VDD1

IREF

F6921

VDD

VDD

F61xx

IB

Bias

Gen

IDAC

Iref

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