CX74001

Rx ASIC for CDMA, AMPS, and PCS Applications

6

Skyworks

101134A

Proprietary Information and Specifications are Subject to Change

March 5, 2002

Table 1. CX74001 Pin Assignments and Signal Descriptions (3 of 4)

Pin #

Name

Description

Equivalent Circuit

31

CDMA_MIX_OUT–

CDMA differential cellular mixer open collector output. VCC pull up inductor is required, and

the output impedance is set by an external matching network.

32

CDMA_MIX_OUT+

CDMA differential cellular mixer open collector output. VCC pull up inductor is required, and

the output impedance is set by an external matching network.

33

AMPS_MIX_OUT–

AMPS differential mixer open collector output. VCC pull up inductor is required, and the output

impedance is set by an external matching network.

34

AMPS_MIX_OUT+

AMPS differential mixer open collector output. VCC pull up inductor is required, and the output

impedance is set by an external matching network.

35

PCS_MIXER_OUT–

PCS differential mixer open collector output. VCC pull up inductor is required, and the output

impedance is set by an external matching network.

36

PCS_MIXER_OUT+

PCS differential mixer open collector output. VCC pull up inductor is required, and the output

impedance is set by an external matching network.

–

+

37

VCC_MIX

Voltage supply for the mixers. RF bypass capacitor should be close to pin with minimal trace

length.

38

PCS_LO

The local oscillator input for the PCS band mixer.

39

CELL_LO

The local oscillator input for the cellular band mixer.

40

PCSMIX_BYPASS

Low frequency bypass for the PCS mixer. Typically, a 47 nF is connected from pin to ground.

41

PCS_MIX_IN

PCS mixer input. Requires AC coupling capacitor

42

CELL_MIX_IN

Cellular mixer input

43

RF_BIAS_RES

This sets the RF bias current. Typically, a 15 k

Ω resistor is connected from the pin to ground.

44

CELL_LNA_BIAS_RES

This sets the cellular LNA bias current. Typically, 27 k

Ω is connected to ground.