www.fairchildsemi.com
LM331
V-F Converter
Features
•
•
•
•
•
Guaranteed linearity: 0.01% max.
Low power dissipation: 15mW at 5V
Wide range of full scale frequency: 1Hz to 100KHz
Pulse output compatible with all logic forms
Wide dynamic range: 100dB min at 10KHz full scale
frequency
Description
This voltage to frequency converter provides the output
pulse train at a frequency precisely proportional to the
applied input voltage. The LM331 can operate at power
supplies as low as 4.0V and be changed output frequency
from 1Hz to 100KHz. It is ideally suited for use in simple
low cost circuit for analog-to digital conversion, long term
integration, linear frequency modulation or demodulation,
frequency to voltage conversion, and many other functions.
8-DIP
1
Internal Block Diagram
Rev. 1.0.0
©2001 Fairchild Semiconductor Corporation
LM331
Absolute Maximum Ratings (T
A
= 25°C)
°
Parameter
Supply Voltage
Input Voltage
Operating Temperature Range
Power Dissipation
Symbol
V
CC
V
I
T
OPR
P
D
Value
40
-0.2 ~ + V
CC
0 ~ +70
500
Unit
V
V
°C
mW
Electrical Characteristics
Parameter
VFC Non-Linearity
Conversion Accuracy Scale Factor
Chang Of Gain With V
CC
Rated Full - Scale Frequency
INPUT COMPARATOR
Offset Voltage
Bias Current
Offset Current
Common-Mode Range
TIMER (PIN 5)
Timer Threshold Voltage
Input Bias Current
V
TH
I
BIAS
-
V
CC
= 15V,
0V
≤
V
5
≤
9.9V
V
5
= 10V
Saturation Voltage
CURRENT SOURCE (PIN 1)
Output Current
Change with Voltage
Current Source Off Leakage
REFERENCE VOLTAGE (PIN 2)
Reference Voltage
Stability vs Temperature
Stability vs Time, 1000Hours
LOGIC OUTPUT (Pin 3)
Saturation Voltage
Off Leakage
SUPPLY CURRENT
Supply Current
I
CC
V
CC
= 5V
V
CC
= 40V
1.5
2.0
3.0
4.0
6.0
8.0
mA
V
SAT
I
LKG
I = 5mA
I = 3.2mA
-
-
-
-
0.15
0.10
±0.05
0.50
0.40
1.0
V
µA
V
REF
ST
T
ST
T
-
-
-
1.70
-
-
1.89
±60
±0.1
2.08
-
-
V
DC
ppm/°C
%
I
O
∆I
O
/∆V
1
I
LKG
R
S
= 14KΩ, V
1
= 0V
0V
≤
V
1
≤
10V
-
116
-
-
136
0.2
0.02
156
1.0
10.0
µA
µA
nA
V
SAT
I = 5mA
0.63 0.667
-
-
-
±10
200
0.22
0.701
±100
1000
0.5
×V
CC
nA
nA
V
V
IO
I
BIAS
I
IO
V
CM
0°C
≤
T
A
≤
+70°C
-
-
0°C
≤
T
A
≤
+70°C
-
-
-
-0.2
±3
-80
±8
-
±10
-300
±100
V
CC
-
2.0
mV
nA
nA
V
Symbol
VFCNL
ACCUR
V
CC
∆G/V
CC
f
Conditions
4.5
≤
V
CC
≤
20V
4.5V
≤
V
CC
≤
10V
10V
≤
V
CC
≤
40V
V
I
= -10V
Min.
-
-
-
10.0
Typ.
1.00
0.01
0.006
-
Max.
1.10
0.1
0.06
-
KHz
Unit
KHz/V
%/V
±0.003 ±0.01
% Full-Scale
V
I
= -10V, R
S
= 14KΩ 0.90
2
LM331
Typical Applications
LM331
Figure 1. Precision Voltage-to-Frequency Converter, 100KHz Full-Scale
LM331
Figure 2. Simple Frequency-to-Voltage Converter, 10KHz Full-Scale
LM331
Figure 3. Light Intensity to Frequency Converter
3
京公网安备 11010802033920号
EEWORLD
