2

Pinout

ISL3685

(MLF)

TOP VIEW

44

43

42

41 40 39

38

37

36

35 34

12 13

14 15

16 17

18

19

20

21

22

1

2

3

4

5

6

7

8

9

10

11

LNA_VCC1

GND

RX_IN

BIAS1_VCC1

TX_VCC1

GND

PE2

PE1

GND

TXA_OUT

H/L

33

32

31

30

29

28

27

26

25

24

23

RX_MX_OUT-

TX_MX_IN-

GND

RX_LO_DRIVER_VCC1

LO_VCC1

LO_IN-

LO_IN+

TX_LO_DRIVER_VCC1

TX_MX_VCC1

TX_MX_OUT

TX_MX_VCC1

Pin Description

PIN

NAME

DESCRIPTION

1

LNA_VCC1

Low Noise Amplifier Positive Power Supply.

3

RX_IN

Low Noise Amplifier RF Input, internally DC coupled and requires an external blocking capacitor. A shunt capacitor to

ground matches the input for return loss and optimum NF.

4

BIAS1_VCC1

Bias Positive Power Supply for the LNA and Preamplifier.

5

H/L

High or Low Gain Select, controls the LNA high and low gain modes.

6

PE2

This pin along with pin PE1 and bit M(0) of PLL_PE determine which of various operational modes will be active. Please

refer to the Power Enable Truth Table.

7

PE1

This pin along with pin PE2 and bit M(0) of PLL_PE determine which of various operational modes will be active. Please

refer to the Power Enable Truth Table.

8

TX_VCC1

Transmit Amplifier Positive Power Supply, requires a high quality decoupling capacitor and a short return path.

10

TXA_OUT

Transmit Amplifier Output, internally matched to 50

Ω, requires an external DC blocking capacitor.

12

TX_VCC1

Transmit Amplifier Positive Power Supply.

13

TXA_IN

Transmit Amplifier Input, internally AC coupled.

15

LE

Synthesizer Latch Enable, the serial interface is active when LE is low and the serial data is latched into defined

registers on the rising edge of LE.

16

DATA

Synthesizer Serial Data Input, clocked in on the rising edge of the serial clock, MSB first.

17

CLK

Synthesizer Clock, DATA is clocked in on the rising edge of the serial clock, MSB first.

18

REF_BY

Synthesizer Reference Frequency Input Bypass, internally DC coupled and requires an external bypass to ground

when REF_IN is used as a Single Ended input, requires an external AC coupling capacitor when used as a differential

input.

ISL3685