
Figure 6. Crystal-Controlled, Digitally Programmed Frequency Synthesizer—8kHz to 16MHz with 1kHz Resolution
N4
N3
N2
MC145151
N6
8.192MHz
MAX427
N5
OUT1
OUT2
RFB
VREF
VDD
GND1
MX7541
N7
N8
N9
T/R
N12
N13
N10
N11
OSC
OUT
OSC
IN
LD
N
N1
N0
FV
PDV
PDR
RA2
RA1
RA0
PD1
OUT
V
DD
V
SS
F
IN
35pF
20pF
15
14
28
1
GND
BIT1
BIT2
BIT3
BIT4
BIT5
BIT6
BIT12
BIT11
BIT10
BIT9
BIT8
BIT7
MAX038
A0
A1
COSC
GND1
DADJ
FADJ
OUT
GND
V+
DV+
DGND
SYNC
PDI
PDO
VREF
V-
GND1
IIN
GND1
3.3M
PDV
PDR
3.3M
33k
0.1
μ
F
0.1
μ
F
0.1
μ
F
0.1
μ
F
0.1
μ
F
0.1
μ
F
0.1
μ
F
0.1
μ
F
33k
7.5k
Ω
10k
Ω
2
3
7
4
6
+2.5V
2.5V
35
pF
10
11
0.1
μ
F
50.0
Ω
100
Ω
1
20
50
Ω
,50MHz
LOWPASS
FILTER
220nH
56pF
110pF
56pF
50
Ω
SIGNAL
OUTPUT
SYNC
OUTPUT
+5V
-5V
9
10
1
18
3
2
1
0V
TO
2.5V
2N3904
3.33k
Ω
2.7M
1k
Ω
1k
Ω
5
6
8
4
7
2N3906
1N914
2μ
A
to
750
μ
A
MAX412
8.192MHz
4.096MHz
2.048MHz
1.024MHz
512kHz
256kHz
128kHz
64kHz
32kHz
16kHz
8kHz
4kHz
2kHz
1kHz
WAVEFORM
SELECT
FREQUENCY
SYNTHESIZER
1kHz
RESOLUTION;
8kHz
TO
16.383MHz
Maxim Integrated
15
High-Frequency Waveform Generator
MAX038