®
VFC100
FPO
Synchronized
VOLTAGE-TO-FREQUENCY CONVERTER
FEATURES
DESCRIPTION
● FULL-SCALE FREQUENCY SET BY
The VFC100 voltage-to-frequency converter is an
important advance in VFCs. The well-proven charge
balance technique is used; however, the critical reset
integration period is derived from an external clock
frequency. The external clock accurately sets an out-
put full-scale frequency, eliminating error and drift
from the external timing components required for
other VFCs. A precision input resistor is provided
which accurately sets a 10V full-scale input voltage.
In many applications the required accuracy can be
achieved without external adjustment.
SYSTEM CLOCK; NO CRITICAL
EXTERNAL COMPONENTS REQUIRED
● PRECISION 10V FULL-SCALE INPUT,
0.5% max GAIN ERROR
● ACCURATE 5V REFERENCE VOLTAGE
● EXCELLENT LINEARITY:
0.02% max at 100kHz FS
0.1% max at 1MHz FS
● VERY LOW GAIN DRIFT: 50ppm/°C
The open collector active-low output provides fast fall
time on the important leading edge of output pulses,
and interfaces easily with TTL and CMOS circuitry.
An output one-shot circuit is particularly useful to
provide optimum output pulse widths for optical cou-
plers and transformers to achieve voltage isolation. An
accurate 5V reference is also provided which is useful
for applications such as offsetting for bipolar input
voltages, exciting bridges and sensors, and autocali-
bration schemes.
APPLICATIONS
● A/D CONVERSION
● PROCESS CONTROL
● DATA ACQUISITION
● VOLTAGE ISOLATION
– Comparator
Clock
Input
CINT
5
VOUT
+VCC
Input
1
14
10
4
11
12
fOUT
Integrator
Amplifier
Comparator
RIN
Clocked
Logic
Output
One-Shot
7
6
VIN
20kΩ
Digital
Common
Non-Inverting
Input
SW1
1mA
5V
Reference
–VCC
13
9
15
+ Comparator
16
8
Analog
VREF
COS
–VCC
Input
Common
International Airport Industrial Park
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Mailing Address: PO Box 11400, Tucson, AZ 85734
FAXLine: (800) 548-6133 (US/Canada Only)
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Street Address: 6730 S. Tucson Blvd., Tucson, AZ 85706
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Tel: (520) 746-1111 • Twx: 910-952-1111
Internet: http://www.burr-brown.com/
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Cable: BBRCORP
•
Telex: 066-6491
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FAX: (520) 889-1510
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Immediate Product Info: (800) 548-6132
© 1984 Burr-Brown Corporation
PDS-547H
Printed in U.S.A. June, 1995