11
Application on mobile phone board
The figure 3 shows an application example in mobile. C5 and C6 should be placed close to pin4 and pin11. Bypass cap
C1, C2, C3 and C4 should be also placed nearby from pin2, pin3, pin5 and pin6, respectively. The length of post-PA trans-
mission line should be minimized to reduce line loss.
Figure 3. Peripheral Circuits
PCB layout and part placement on phone board
Figure 4. PCB guideline on phone board
Notes:
1. To prevent voltage drop, make the bias lines as wide as
possible (Pink line).
2. Use many via holes to fence off PA RF input and output
traces for better isolation. Output signal of the PA should
be isolated from input signal and the receive signal. Output
signal should not be fed into PA input. (Green line)
3. Use via holes to connect outer ground plates to internal
ground planes. They help heat spread out more easily and
accordingly the board temperature can be lowered. They
also help to improve RF stability (Yellow square).
4. PA which has a ground slug requires many via holes which
go through all the layers (Red square).
C4
ACPM-7357
Low IN
Vmode
Vbp
Vcc1
Ven_L
Ven_H
High IN
C2
RF In High
C1
TX filter
C9
C7
V
BATT
C5
C6
output matching circuit
C13
C12
L2
Coupler
RF Out High
Low OUT
GND
GND
Vcc2
GND
GND
High OUT
TX filter
C8
RF In Low
C3
C11
C10
L1
Coupler
RF Out Low
PA_ON_Low Band
PA_R1
PA_R0
PA_ON _High Band
1
4
Via hole
3
2
