REV. B
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ADVFC32
One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: 781/329-4700 World Wide Web Site: http://www.analog.com
Fax: 781/326-8703 © Analog Devices, Inc., 2000
Voltage-to-Frequency and
Frequency-to-Voltage Converter
FEATURES
High Linearity
ⴞ0.01% Max at 10 kHz FS
ⴞ0.05% Max at 100 kHz FS
ⴞ0.2% Max at 500 kHz FS
Output TTL/CMOS-Compatible
V/F or F/V Conversion
6 Decade Dynamic Range
Voltage or Current Input
Reliable Monolithic Construction
MIL-STD-883-Compliant Versions Available
PIN CONFIGURATION
(TOP VIEW)
N-14 Package
H-10A Package
PRODUCT DESCRIPTION
The industry standard ADVFC32 is a low cost monolithic
voltage-to-frequency (V/F) converter or frequency-to-voltage
(F/V) converter with good linearity (0.01% max error at 10 kHz)
and operating frequency up to 0.5 MHz. In the V/F configuration,
positive or negative input voltages or currents can be converted
to a proportional frequency using only a few external compo-
nents. For F/V conversion, the same components are used with
a simple biasing network to accommodate a wide range of input
logic levels.
TTL or CMOS compatibility is achieved in the V/F operating
mode using an open collector frequency output. The pull-up
resistor can be connected to voltages up to 30 volts, or to 15 V
or 5 V for conventional CMOS or TTL logic levels. This resis-
tor should be chosen to limit current through the open collector
output to 8 mA. A larger resistance can be used if driving a high
impedance load.
Input offset drift is only 3 ppm of full scale per °C, and full-
scale calibration drift is held to a maximum of 100 ppm/°C
(ADVFC32BH) due to a low T.C. Zener diode.
The ADVFC32 is available in commercial, industrial, and
extended temperature grades. The commercial grade is pack-
aged in a 14-lead plastic DIP while the two wider temperature
range parts are packaged in hermetically sealed 10-lead cans.
PRODUCT HIGHLIGHTS
1. The ADVFC32 uses a charge balancing circuit technique
(see Functional Block Diagram) which is well suited to high
accuracy voltage-to-frequency conversion. The full-scale
operating frequency is determined by only one precision
resistor and capacitor. The tolerance of other support compo-
nents (including the integration capacitor) is not critical.
Inexpensive ±20% resistors and capacitors can be used with-
out affecting linearity or temperature drift.
2. The ADVFC32 is easily configured to satisfy a wide range of
system requirements. Input voltage scaling is set by selecting
the input resistor which sets the input current to 0.25 mA at
the maximum input voltage.
3. The same components used for V/F conversion can also be
used for F/V conversion by adding a simple logic biasing
network and reconfiguring the ADVFC32.
4. The ADVFC32 is intended as a pin-for-pin replacement for
VFC32 devices from other manufacturers.
5. The ADVFC32 is available in versions compliant with MIL-
STD-883. Refer to the Analog Devices Military Products
Databook or current ADVFC32/883B data sheet for detailed
specifications.
