AK1575 Datasheet, PDF (3/35 Pages) Asahi Kasei Microsystems – Up Converter Mixer with Fractional-N Frequency Synthesizer and VCO

4. Block Diagram and Function
[AK1575]
VREF1
REFIN
CLK
DATA
LE
PVDD
GND
MIXBIAS
MIXINP
MIXINN
Dig
LDO
R Counter
8bit
Register
24bit
ΔΣ
Modulator
N-Counter
Lock
Detect
Phase
Frequency
Detector
Charge
Pump
VIREFGEN
Fast Counter
VCO
Calibration
VCO
Divider
1/N
N=1,2,4,8
MUX
LD
GND
CP
VREF2
GND
VCOVDD
VCNT
LOP
LON
OAVDD
Mixer
MUX
Fig. 1 Block diagram
Block function description
Block
Function
Mixer
N divider
ΔΣ Modulator
R counter
PFD (Phase Frequency Detector)
Charge Pump
VCO
Frequency Mixer which converts RF signal to IF signal
Frequency divider which divides the signal of VCO and pass it to
phase frequency detector
Control the modulus of N divider and realize fractional dividing
Frequency divider which divides the signal of reference clock and
pass it to phase frequency detector
Detect a phase difference between the divided VCO signal and
comparison frequency, and then drive the charge pump
Output the electric charge according to the phase difference
detected by PFD
The voltage controlled oscillator divided into three bands
MS1552-E-00
3
2013/8