4

T0353

4559AS–CDMA–10/02

Operation

The various operating modes are controlled by the logic inputs Band_SEL, Gain, LIN,

LO/2 and BUFFEN. Table 1 shows the pin settings for the various operating modes.

Table 1. Mode Programming Truth Table (Continued)

Note:

1. The symbol X (“do not care”) means a logic input does not affect an operating mode.

15

CLO_OUT

Cellular LO buffer output. Internally matched to 100

W. Does not require a blocking capacitor.

16

GPSMix_IN

GPS mixer input.

17

Vcc_LO_Tx

Supply voltage for LO buffers.

18

GPSMix_OUT-

Negative GPS IF output.

19

GPSMix_OUT+

Positive GPS IF output.

20

AMPS_OUT-

Negative AMPS IF output.

21

AMPS_OUT+

Positive AMPS IF output.

22

Vcc_Mix

Supply voltage for all mixers.

23

CDMA_OUT-

Negative CDMA IF output.

24

CDMA_OUT+

Positive CDMA IF output.

25

BUFFEN

LO output buffer enable. Set BUFFEN pin HIGH to power up the LO buffer output corresponding to

the selected band.

26

CM_IN

Cell RF input to Cell CDMA mixer and Cell AMPS mixer.

27

PM_IN

PCS mixer RF input.

28

Vcc_DIG

Supply voltage for logic control circuits.

29

Band_SEL

Logic input for band select. Logic LOW selects PCS or GPS. Logic HIGH selects cellular (AMPS).

30

LIN

Logic input for high or low linearity. Logic HIGH selects High linearity.

31

PLNA_OUT

PCS LNA output. Requires a pull-up inductor to V

used as part of the output matching network.

32

Iset_PCS

Bias resistor for PCS LNA. For typical bias use a 560

W resistor to ground which sets the bias

current for HGHL mode.

–

Paddle

Device ground and heat sink, requires good thermal path; RF reference plane.

Pin Description (Continued)

Pin

Symbol

Function

Mode

Condition

Logic Inputs

(1)

Band SEL

Gain

LIN

LO/2

BUFFEN

Shut down

All circuits off

Low

Low

Low

X

X

PCS mode

High-gain, high-linearity

Low

High

High

X

X

High-gain, low-linearity

Low

High

Low

X

X

Activate PCS LO output buffer

Low

X

X

X

High

Cellular mode

High-gain, high-linearity

High

High

High

X

X

High-gain, low-linearity

High

High

Low

X

X

Low-gain

High

Low

High

X

X

AMPS mode

High

Low

Low

X

X

LO/2 On

High

X

X

High

X

Activate Cell LO output buffer

High

X

X

X

High

GPS mode

Low

Low

High

X

X