7

Peripheral Circuit in Handset

Figure 10. Peripheral circuit

Calibration

Calibration procedure is shown in Figure 11. Two

calibration tables, high mode and low mode respective-

ly, are required for Cool PAM, which is due to gain differ-

ence in each mode. For continuous output power at the

mode change points, the input power should be adjust-

ed according to gain step during the mode change.

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.

Average Current & Talk Time

Probability Distribution Function implies that what is

important for longer talk time is the efficiency of low

or medium power range rather than the efficiency at

full power. WS1103 idle current is 13 mA and operating

current at 16 dBm is 65 mA at nominal condition. This PA

with low current consumption prolongs talk time by no

less than 30 minutes compared to other PAs.

Figure 11. Calibration procedure

Figure 12. Setting of offset between rising and falling power

Figure 13. CDMA power distribution function

TX_AGC

Low Mode

High Mode

Min. PWR

Falling Rising

Max. PWR

Pout

GAIN

Low Mode

High Mode

Falling

Rising

Pout

5.00

4.50

4.00

3.50

3.00

2.50

2.00

1.50

1.00

0.50

0

700

600

CDG Urban

Conventional PAM

Digitally Controlled PAM

Cool PAM

CDG Suburban

500

400

300

200

100

0

-50

-40

-30

-20

-10

PA Out (dBm)

0

10

20

30

Vcc1

Vcc2

RF IN

RF OUT

Vcont

GND

GND

Vref

Duplexer

TX

FILTER

MSM

PA_RO

PA_ON

RF Out

Output Matching Circuit

RF In

WS1103

C1

C8

C7

C6

L1

C2

C5

C4

+2.85 V

C 3

NOTES:

• Recommended voltage for Vref is 2.85 V.

• Place C1 near to Vref pin.

• Place C3 and C4 close to pin 1 (Vcc1) and pin 10 (Vcc2). These capacitors can affect the RF performance.

• Use 50

Ω 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.

Notes:

•

Recommended voltage for Vref is 2.85 V.

•

Place C1 near to Vref pin.

•

Place C3 and C4 close to pin 1 (Vcc1) and pin 8 (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.