LM331N National Semiconductor, LM331N Datasheet - Page 9

• Manufacturer Part Number: LM331N
• Description: IC, V/F CONVERTER, DIP8, 331
• Manufacturer: National Semiconductor

Specifications of LM331N

• Frequency: 10kHz
• Full Scale Range: 1Hz To 100kHz
• Linearity %: 0.01%
• Supply Voltage Range: 4V To 40V
• Digital Ic Case Style: DIP
• No. Of Pins: 8
• Svhc: No SVHC (15-Dec-2010)
• Operating Temperature Max: 70°C
• Converter Function: VFC
• Full Scale Frequency: 100
• Power Supply Requirement: Single
• Single Supply Voltage (typ): 5/9/12/15/18/24/28V
• Single Supply Voltage (max): 40V
• Single Supply Voltage (min): 4V
• Dual Supply Voltage (typ): Not RequiredV
• Dual Supply Voltage (min): Not RequiredV
• Dual Supply Voltage (max): Not RequiredV
• Operating Temperature (min): 0C
• Operating Temperature (max): 70C
• Operating Temperature Classification: Commercial
• Package Type: MDIP
• Bandwidth: 0.1MHz
• Rohs Compliant: Yes
• Converter Type: Voltage/Frequency
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Typical Applications
DETAILS OF OPERATION, FREQUENCY-TO-
VOLTAGE CONVERTERS ( Figure 6 and Figure 7 )
In these applications, a pulse input at f
a C-R network and the negative-going edge at pin 6 causes
the input comparator to trigger the timer circuit. Just as with
a V-to-F converter, the average current flowing out of pin 1 is
I
In the simple circuit of Figure 6 , this current is filtered in the
network R
mV peak, but the response will be slow, with a 0.1 second
time constant, and settling of 0.7 second to 0.1% accuracy.
*
See Typical Applications section.
**
***
AVERAGE
Use stable components with low temperature coefficients.
This resistor can be 5 k
Use low offset voltage and low offset current op amps for A1: recommended types LF411A or LF356.
= i x (1.1 R
L
= 100 k and 1 µF. The ripple will be less than 10
t
C
or 10 k
t
) x f.
for V
S
= 8V to 22V, but must be 10 k
FIGURE 5. Precision Voltage-to-Frequency Converter,
(Continued)
IN
is differentiated by
100 kHz Full-Scale,
for V
±
9
S
0.03% Non-Linearity
= 4.5V to 8V.
In the precision circuit, an operational amplifier provides a
buffered output and also acts as a 2-pole filter. The ripple will
be less than 5 mV peak for all frequencies above 1 kHz, and
the response time will be much quicker than in Figure 6 .
However, for input frequencies below 200 Hz, this circuit will
have worse ripple than Figure 6 . The engineering of the filter
time-constants to get adequate response and small enough
ripple simply requires a study of the compromises to be
made. Inherently, V-to-F converter response can be fast, but
F-to-V response can not.
DS005680-6
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