AD831

REV. B

–11–

Single Supply Operation

Figure 26 is similar to the dual supply circuit in Figure 19. Sup-

plies may be as low as 9 V but should not be higher than

11 V due to power dissipation. As in Figure 19, both the RF

and LO ports are driven single-ended and terminated.

In single supply operation, the COM terminal is the “ground”

reference for the output amplifier and must be biased to 1/2 the

supply voltage, which is done by resistors R1 and R2. The OUT

pin must be ac-coupled to the load.

R1

110

Ω

IF

OUTPUT

NC

0.1µF

0.1µF

+9V

51.1

Ω

0.1µF

+9V

0.1µF

C2

L1

C1

RF

INPUT

82pF

82pF

0.1µF

+9V

LO INPUT

–10 dBm

5k

Ω

5k

Ω

+5V

R2

51.1

Ω

0.1µF

0.1µF

IFN

VP

IFP

AP

GND

VN

RFP

RFN

VN

VP

LON

LOP

VP

GND

BIAS

VN

AD831

Top View

50

Ω

50

Ω

6

7

8

4

5

9

10

11

12

13

AN

VFB

COM

OUT

14

15

16

17

18

1

2

3

19

20

Figure 26. Connections for +9 V Single-Supply Operation