VFC101 Datasheet, PDF (1/10 Pages) Burr-Brown (TI) – Synchronized VOLTAGE-TO-FREQUENCY CONVERTER

®
VFC101
Synchronized
VOLTAGE-TO-FREQUENCY CONVERTER
FEATURES
q FULL-SCALE FREQUENCY SET BY
SYSTEM CLOCK
q MULTIPLE INPUT RANGES:
5V, 8V, 10V Full Scale
q ACCURATE 5V REFERENCE VOLTAGE
q LOW NONLINEARITY:
0.02% max at 100kHz FS
q LOW GAIN DRIFT: 40ppm/°C
APPLICATIONS
q INTEGRATING A/D CONVERTER
q MULTICHANNEL DATA ACQUISITION
q FREQUENCY-TO-VOLTAGE CONVERSION
q VOLTAGE ISOLATION
DESCRIPTION
The VFC101 voltage-to-frequency converter uses the
proven charge-balance technique with internal digital
logic to control the critical reference integration pe-
riod. Reference timing is derived from an external
clock signal which accurately sets the full-scale fre-
quency. This technique eliminates the errors and drift
from external timing components which are required
with other VFCs.
Internal resistors provide accurate full-scale input
ranges of 5V, 8V or 10V inputs without external
resistors or trimming. An accurate 5V reference volt-
age output is useful for bridge or sensor excitation.
With simple pin interconnections, it can provide half-
scale offset to allow bipolar input voltages.
The open-collector frequency output interfaces easily
to CMOS or TTL circuitry. Output one-shot circuitry
may be used to optimize the output pulse width for
optical couplers or transformers.
The VFC101 is packaged in a surface-mount 20-pin
PLCC (plastic leaded chip carrier) package.
8
10kΩ
7
10kΩ
9
16kΩ
4kΩ
10
6
5
4
Integrator
17
13
Comparator
Clocked
Logic
1mA
I₁
–V_CC
16
18
5V
Reference
20
+V_CC
2
14
Output
One-Shot
15
12
11
–V_CC
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© 1988 Burr-Brown Corporation
PDS-779B
Printed in U.S.A. October, 1993