LTC6990
22
6990fc
For more information www.linear.com/LTC6990
TYPICAL APPLICATIONS
Full Range VCO with Any NDIV Setting (fMAX to fMIN for VIN = 0V to VSET)
6990 TA03
LTC6990
5V
OE
GND
SET
OUT
V+
DIV
C1
0.1F
R1
R2
RSET
826k
5V
D1
IN4148
–
+
LT1490
RVCO1
26.1k
VIN
0V TO 1V
RVCO2
26.1k
Full Range VCO with Any NDIV Setting (Positive Frequency Control, fMIN to fMAX for VIN = 0V to VSET
6990 TA04
LTC6990
5V
OE
GND
SET
OUT
V+
DIV
C1
0.1F
R1
R2
RSET2
412k
RSET1
412k
5V
–
+
LT1490
R3
10k
VIN
0V TO 1V
R4
10k
RVCO
53.6k
Programming NDIV Using an 8-Bit DAC
6990 TA02
LTC6990
OE
GND
SET
OUT
V+
DIV
C1
0.1F
RSET
619k
2.25V TO 5.5V
C2
0.1F
P
LTC2630-LZ8
SDI
SCK
CS/LD
VCC
GND
VOUT
DIVCODE
0
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
DAC CODE
0
24
40
56
72
88
104
120
136
152
168
184
200
216
232
255