CX74005 Просмотр технического описания (PDF) - Skyworks Solutions

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CX74005

VGA + I/Q Demodulator Rx ASIC for Portable Phone Applications

Skyworks Solutions 

CX74005

Pin #

1

2

3

4

Name

GND

FM/CDMA

CELL/PCS

VCO_VCC

5

VCO_GND

6

CELL_TANK1–

7

CELL_TANK_1+

8

NC

9

PCS_TANK–

10 PCS_TANK+

11 DIV2/DIV4

12 PLL+

13 PLL–

14 GND

15 IF_GND

16 SLEEP

17 VGA_GC

18 IF_VCC

19 VGA_CDMA_IN–

20 VGA_CDMA_IN+

21 VGA_PCS_IN-

22 VGA_PCS_IN+

23 GND

24 VGA_AMPS

25 GND

26 GND

27 Q–

28 Q+

29 I–

30 I+

31 GND

32 GND

Rx ASIC

Table 2. CX74005 Pin Assignments and Signal Descriptions

Description

Ground

Cellular band mode select: 0 = AMPS, 1 = CDMA

Band select: 0 = Cellular; 1 = PCS

Voltage supply pin to the VCO buffers. A bypass capacitor should be placed close to the device from pin 4 to pin

5. The trace should be short and connected immediately to the ground plane for best performance.

Ground return from the VCO buffers.

Differential tank connection for the cellular band VCO. Care should be taken during the layout of the external tank

circuit to prevent parasitic oscillations.

Differential tank connection for the cellular band VCO. Care should be taken during the layout of the external tank

circuit to prevent parasitic oscillations.

No connection

Differential tank connection for the PCS band VCO. Care should be taken during the layout of the external tank

circuit to prevent parasitic oscillations.

Differential tank connection for the PCS band VCO. Care should be taken during the layout of the external tank

circuit to prevent parasitic oscillations.

Selects the divide ratio of the VCO to the LO port of the I/Q demodulator: 0 = divide by 2, 1 = divide by 4.

Differential buffered VCO output

Differential buffered VCO output

Ground

Ground

Activates sleep mode: 0 = Sleep, 1 = Enable

The VGA gain control signal. A DC control voltage should be applied to this pin to vary the gain of the VGA.

Voltage supply to VGA and I/Q demodulator stages. Supply should be well regulated and bypassed to prevent

modulation of the signal by the supply ripple.

CDMA differential VGA input

CDMA differential VGA input

PCS differential VGA input.

PCS differential VGA input.

Ground

AMPS VGA input

Ground

Ground

Q channel differential output

Q channel differential output

I channel differential output

I channel differential output

Ground

Ground

4

Conexant - Preliminary

101252A

Proprietary Information and Specifications Are Subject to Change

March 13, 2001

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