SA2400A Datasheet, PDF (16/34 Pages) NXP Semiconductors – Single chip transceiver for 2.45 GHz ISM band

Philips Semiconductors
Single chip transceiver for 2.45 GHz ISM band
Product data
SA2400A
12.3 Phase detector (see Figure 6)
The reference and main divider outputs are connected to a
phase/frequency detector that controls the charge pump. The pump
current is set by the control bit CP (Synthesizer Register C). The
dead zone (caused by finite time taken to switch the current sources
on or off) is cancelled by forcing the pumps ON for a minimum time
(τ) at every cycle (backlash time) providing improved linearity.
1
D
Q
f_REF
REF DIVIDER
CLK
R
R
τ
1
D
R
f_RF
MAIN
DIVIDER
CLK
M
Q
V_CC
P
P–TYPE
CHARGE PUMP
I_PH
N–TYPE
CHARGE PUMP
N
GND
f_REF
R
M
τ
P
τ
N
I_PH
Figure 6. Phase Detector Structure with Timing
SR02355
2002 Nov 04
16