Analog Devices ADVFC32 Datasheet

Voltage-to-Frequency and

a

FEATURES
High Linearity

60.01% max at 10 kHz FS

60.05% max at 100 kHz FS

60.2% 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

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 components. 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 pullup 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 resis­tor 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 3ppm of full scale per °C, and full­scale 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 packaged
in a 14-pin plastic DIP while the two wider temperature range
parts are packaged in hermetically sealed TO-100 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 compo­nents (including the integration capacitor) is not critical.
Inexpensive ±20% resistors and capacitors can be used with­out affecting linearity or temperature drift.

Frequency-to-Voltage Converter

ADVFC32

PIN CONFIGURATION

(TOP VIEW)

“N” Package

“H” Package – TO-100

NC = NO CONNECT

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 MIL­STD-883. Refer to the Analog Devices Military Products
Databook or current ADVFC32/883B data sheet for detailed
specifications.

REV. A

Information furnished by Analog Devices is believed to be accurate and
reliable. However, no responsibility is assumed by Analog Devices for its
use, nor for any infringements of patents or other rights of third parties
which may result from its use. No license is granted by implication or
otherwise under any patent or patent rights of Analog Devices.

One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A.
Tel: [phone] Fax: [phone]

ADVFC32–SPECIFICA TIONS

(typical @ +258C with VS = 615 V unless otherwise noted)

ADVFC32K ADVFC32B ADVFC32S

Model Min Typ Max Min Typ Max Min Typ Max Units

DYNAMIC PERFORMANCE

Full Scale Frequency Range 0 500 0 500 0 500 kHz
Nonlinearity

f
f
f

Full-Scale Calibration Error

1

= 10 kHz –0.01 ±0.01 –0.01 +0.01 –0.01 +0.01 %

MAX

= 100 kHz –0.05 +0.05 –0.05 +0.05 –0.05 +0.05 %

MAX

= 0.5 MHz –0.20 ±0.05 +0.20 –0.20 ±0.05 +0.20 –0.20 ±0.05 +0.20 %

MAX

(Adjustable to Zero) ± 5 ± 5 ± 5%

vs. Supply

(Full Scale Frequency = 100 kHz)

–0.015 +0.015 –0.015 +0.015 –0.015 +0.015

% ofFSR%

vs. Temperature

(Full Scale Frequency = 10 kHz)

± 75 –100 +100 +150 +150

ppm/°C

DYNAMIC RESPONSE

Maximum Settling Time for Full Scale

Step Input 1 Pulse of New Frequency Plus 1 µs 1 Pulse of New Frequency Plus 1 µs 1 Pulse of New Frequency Plus 1 µs

Overload Recovery Time 1 Pulse of New Frequency Plus 1 µs 1 Pulse of New Frequency Plus 1 µs 1 Pulse of New Frequency Plus 1 µs

ANALOG INPUT AMPLIFIER

(V/F Conversion)

Current Input Range 0 +0.25 0 +0.25 0 +0.25 mA
Voltage Input Range 0 –10 0 –10 0 –10 V

0.25 0.25 0.25 mA

Differential Impedance

300 kΩ||10 pF

3

× R

2 MΩ||10 pF 300 kΩ||10 pF 2 MΩ||10 pF 300 kΩ||10 pF 2 MΩ||10 pF

IN

× R

3

IN

× R

2

3

IN

Common-Mode Impedance 300 MΩ||3 pF 750 MΩ||3 pF 300 MΩ||3 pF 750 MΩ||10 pF 300 MΩ||3 pF 750 MΩ||10 pF
Input Bias Current

Noninverting Input 40 250 40 250 40 250 nA
Inverting Input –100 ± 8 +100 –100 ± 8 +100 –100 ±8 +100 nA

Input Offset Voltage

(Trimmable to Zero)
vs. Temperature (T

Safe Input Voltage ± V

MIN

2, 3

MAX

S

± V

S

± V

S

to T

444mV

)30 30 30 µV/°C

COMPARATOR (F/V Conversion)

Logic “0” Level –V
Logic “1” Level +1 +V
Pulse Width Range

4

S

0.1 0.15/f

Input Impedance 50 kΩ||10 pF 250 kΩ 50 kΩ||10 pF 250 kΩ 50 kΩ||10 pF 250 kΩ

–0.6 –V

S

+1 +V

0.1 0.15/f

MAX

S

–0.6 –V

+1 +V

S

0.1

MAX

S

–0.6 V

S

0.15/f

MAX

V
µs

OPEN COLLECTOR OUTPUT

(V/F Conversion)

Output Voltage in Logic “0”

I

= 8 mA 0.4 0.4 0.4 V

SINK

Output Leakage Current in Logic “1”

111µA
Voltage Range 0 +30 0 +30 0 +30 V
Fall Times (Load = 500 pF and

I

= 5 mA) 400 400 400 ns

SINK

AMPLIFIER OUTPUT (F/V Conversion)

Voltage Range (0 mA≤IO≤7 mA) 0 +10 0 +10 0 +10 V
Source Current (0≤V
Capacitive Load (Without Oscillation) 100 100 100 pF

≤7 V) 10 10 10 mA

O

Closed Loop Output Impedance 1 1 1 Ω

POWER SUPPLY

Rated Voltage ± 15 ±15 ±15 V
Voltage Range ±9 ±18 ±9 ±18 ±9 ±18 V
Quiescent Current 6 8 6 8 6 8 mA

TEMPERATURE RANGE

Specified Range 0 +70 –25 +85 –55 +125 °C
Operating Range –25 +85 –55 +125 –55 +125 °C
Storage –25 +85 –65 +150 –65 +150 °C

PACKAGE OPTIONS

Plastic DIP (N-14) ADVFC32KN
TO–100 (H-10A)

NOTES

1

Nonlinearity defined as deviation from a straight line from zero to full scale, expressed as a percentage of full scale.

2

See Figure 3.

3

See Figure 1.

4

f

expressed in units of MHz.

MAX

Specifications subject to change without notice.
Specifications shown in boldface are tested on all production units at

final electrical test. Results from those tests are used to calculate
outgoing quality levels. All min and max specifications are guaranteed,
although only those shown in boldface are tested on all production units.

ADVFC32BH ADVFC32SH

–2–

REV. A