WS1403 Просмотр технического описания (PDF) - Avago Technologies

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WS1403

CDMA PCS 3x3 Power Amplifier Module (1850-1910 MHz)

Avago Technologies 

Peripheral Circuit in Handset

+2.85 V

C8

MSM PA_ON

PA_RO

C2

C1

RF In

TX

FILTER

C3

WS1403

Vref

Vcont

GND

GND

RF IN RF OUT

Vcc1

Vcc2

Output Matching Circuit

C6

RF Out

Duplexer

C7

L1

C4

C5

VBATT

Figure 10. Peripheral circuit

Notes:

• Recommended voltage for Vref is 2.85 V.

• Place C1 near to Vref pin.

• Place C3 and C4 close to pin 4 (Vcc1) and pin 5 (Vcc2). These capacitors can affect the RF performance.

• Use 50 W transmission line between PAM and Duplexer and make it as short as possible to reduce conduction loss.

• π-type circuit topology is good to use for matching circuit between PA and Duplexer.

Calibration

Calibration procedure is shown in Figure 11. Two

calibration tables, high mode and low mode respectively,

are required for Cool PAM, which is due to gain difference

in each mode. For continuous output power at the mode

change points, the input power should be adjusted

according to gain step during the mode change.

TX_AGC

Offset Value (Difference between Rising Point and Falling

Point)

Offset value, which is the difference between the rising

point (output power where PA mode changes from low

mode to high mode) and falling point (output power

where PA mode changes from high mode to low mode),

should be adopted to prevent system oscillation. 3 to 5

dB is recommended for hysteresis.

GAIN

Low Mode

High Mode

Falling Rising

Min. PWR

Pout

Max. PWR

Figure 11. Calibration procedure

Low Mode

High Mode

Pout

Falling

Rising

Figure 12. Setting of offset between rising and falling power



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