AD652JP Analog Devices Inc, AD652JP Datasheet - Page 14

• Manufacturer Part Number: AD652JP
• Description: IC V-F CONV SYNCH MONO 5V 20PLCC
• Manufacturer: Analog Devices Inc
• Type: Voltage to Frequencyr

Specifications of AD652JP

• Rohs Status: RoHS non-compliant
• Frequency - Max: 2MHz
• Full Scale: ±25ppm/°C
• Linearity: ±0.005%
• Mounting Type: Surface Mount
• Package / Case: 20-LCC (J-Lead)
• Converter Function: VFC
• Full Scale Frequency: 2000
• Power Supply Requirement: Single/Dual
• Single Supply Voltage (max): 36V
• Single Supply Voltage (min): 12V
• Dual Supply Voltage (typ): ±15V
• Dual Supply Voltage (min): ±6V
• Dual Supply Voltage (max): ±18V
• Operating Temperature (min): 0C
• Operating Temperature (max): 70C
• Operating Temperature Classification: Commercial
• Package Type: PLCC
• Lead Free Status / Rohs Status: Not Compliant

AD652
SINGLE-SUPPLY OPERATION
In addition to the Digital Ground being connected to –V
also possible to connect Analog Ground to –V
Thus, the device is truly operating from a single-supply voltage
that can range from 12 V to 36 V. This is shown in Figure 21 for
a positive voltage input, and in Figure 20 for a negative voltage
input.
In Figure 21, the comparator reference is used as a derived
ground; the input voltage is referred to this point as well as to
the op amp common mode (Pin 6 is tied to Pin 16). Since the
input signal source must drive 0.5 mA of full-scale signal
current into Pin 7, it must also draw the exact same current
from the input reference potential. This current is therefore
provided by the 5 V reference.
In single-supply operation, an external resistor, R
necessary between the power supply, +V
SOURCE
REFERENCE
SIGNAL
REFERENCE
SIGNAL
SOURCE
1V FULL SCALE
INPUT
INPUT
+
–
+
–
I
FULL SCALE
SIGNAL
I
0.5mA
SIGNAL
2kΩ
S
, and the 5 V reference
C
C
INT
INT
ANALOG
GND
+V
S
Figure 20. Single-Supply Mode Negative Voltage Input
+V
Figure 21. Single-Supply Mode Positive Voltage Input
of the AD652.
S
S
PULLUP
R
1
2
3
4
5
6
7
8
R
PULLUP
1
2
3
4
5
6
7
8
PULLUP
20kΩ
20kΩ
SYNCHRONOUS
VOLTAGE-TO-
SYNCHRONOUS
, is
FREQUENCY
CONVERTER
VOLTAGE-TO-
FREQUENCY
CONVERTER
AD652
1mA
S
AD652
, it is
1mA
Rev. C | Page 14 of 28
REFERENCE
AND
REFERENCE
AND
5V
output. This resistor should be selected such that a current of
approximately 500 µA flows during operation. For example,
with a power supply voltage of +15 V, a 20 kΩ resistor is selected
((15 V–5 V)/500 µA = 20 kΩ).
Figure 20 shows the negative voltage input configuration for
using the AD652 in single-supply mode. In this mode, the signal
source is driving the + input of the op amp, which requires only
20 nA (typical) compared to the 0.5 mA required in the positive
input voltage configuration. The voltage at Pin 6 may go as low
as 4 V above ground (−V
V above ground, this leaves a 1 V window for the input signal.
To drive the integrating capacitor with a 0.5 mA full-scale
current, it is necessary to provide an external 2 kΩ resistor. This
results in a 2 kΩ resistor and a 1 V input range. The external
2 kΩ resistor should be a low TC metal-film type for lowest
drift degradation.
5V
D
SHOT
ONE
D
Q
Q
SHOT
ONE
Q
Q
FLOP
"D"
FLOP
CK
"D"
CK
16
15
14
13
12
11
10
9
16
15
14
13
12
11
10
9
R
R
L
ANALOG
GND
L
ANALOG
GND
CLOCK
CLOCK
C
OS
5V
5V
C
S
OS
Pin 8). Since the input reference is 5.0
DIGITAL
GND
FREQ
OUT
DIGITAL
GND