AD652AQ/+ Analog Devices Inc, AD652AQ/+ Datasheet - Page 13

• Manufacturer Part Number: AD652AQ/+
• Description: IC,Voltage-to-Frequency Converter,DIP,16PIN
• Manufacturer: Analog Devices Inc
• Type: Voltage to Frequencyr

Specifications of AD652AQ/+

• Rohs Status: RoHS non-compliant
• Frequency - Max: 2MHz
• Full Scale: ±50ppm/°C
• Linearity: ±0.02%
• Mounting Type: Through Hole
• Package / Case: 16-CDIP (0.300", 7.62mm)

The one-shot capacitor controls the pulse width of the
frequency output. The pulse is initiated by the rising edge of the
clock signal. The delay time between the rising edge of the clock
and the falling edge of the frequency output is typically 200 ns.
The width of the pulse is 5 ns/pF, and the minimum width is
about 200 ns with Pin 9 floating. If the one-shot period is
accidentally chosen longer than the clock period, the width of
the pulse defaults to equal the clock period. The one-shot can be
disabled by connecting Pin 9 to +V
pulse width is then equal to the clock period. The one-shot is
activated (Figure 18) by connecting a capacitor from Pin 9 to
+V
S
, −V
S,
or Digital Ground (+V
1
2
3
4
5
6
7
8
+V
S
20kΩ
SYNCHRONOUS
1
2
3
4
5
6
7
8
VOLTAGE-TO-
FREQUENCY
CONVERTER
20kΩ
AD652
1mA
SYNCHRONOUS
VOLTAGE-TO-
FREQUENCY
CONVERTER
Figure 17. One-Shot Disabled
Figure 18. One-Shot Enabled
AD652
1mA
REFERENCE
(+V
AND
S
S
5V
, –V
is preferred).
REFERENCE
AND
S
D
SHOT
S
(Figure 17); the output
ONE
Q
Q
, OR DIGITAL GND)
5V
FLOP
"D"
CK
D
SHOT
ONE
Q
Q
ANY AC GND
FLOP
"D"
CK
16
15
14
13
12
11
10
9
16
15
14
13
12
11
10
9
C
OS
Rev. C | Page 13 of 28
DIGITAL GROUND
Digital Ground can be at any potential between −V
(+V
grounds rather than stiff supplies. For example, in a small
isolated power circuit, often only a single supply is generated
and the ground is set by a divider tap. Such a ground cannot
handle the large currents associated with digital signals. With
the AD652 SVFC, it is possible to connect the Digital Ground to
–V
C
V
INT
–
+
IN
S
S
for a solid logic reference, as shown in Figure 19.
– 4 V). This can be very useful in systems with derived
+V
–V
S
S
1
2
3
4
5
6
7
8
20kΩ
SYNCHRONOUS
VOLTAGE-TO-
FREQUENCY
CONVERTER
AD652
1mA
Figure 19. Digital GND at −V
REFERENCE
AND
5V
D
SHOT
ONE
Q
Q
FLOP
"D"
CK
S
16
15
14
13
12
11
10
9
R
S
C
L
CLOCK
OS
and
AD652
5V
FREQ
OUT