參數(shù)資料
型號(hào): LM231
廠商: National Semiconductor Corporation
英文描述: Precision Voltage-to-Frequency Converters
中文描述: 精密電壓到頻率轉(zhuǎn)換器
文件頁數(shù): 9/15頁
文件大?。?/td> 368K
代理商: LM231
Typical Applications
(Continued)
DETAILS OF OPERATION, FREQUENCY-TO-
VOLTAGE CONVERTERS (
Figure 6
and
Figure 7
)
In these applications, a pulse input at f
is differentiated by
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
AVERAGE
= i x (1.1 R
t
C
t
) x f.
In the simple circuit of Figure 6 this current is filtered in the
network R
=100 k
and 1 μF. The ripple will be less than 10
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.
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
*
Use stable components with low temperature coefficients.
See Typical Applications section.
**
This resistor can be 5 k
or 10 k
for V
S
=8V to 22V, but must be 10 k
for V
S
=4.5V to 8V.
***
Use low offset voltage and low offset current op amps for A1: recommended types LF411A or LF356.
FIGURE 5. Precision Voltage-to-Frequency Converter,
100 kHz Full-Scale,
±
0.03% Non-Linearity
www.national.com
9
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參數(shù)描述
LM231A 制造商:NSC 制造商全稱:National Semiconductor 功能描述:Precision Voltage-to-Frequency Converters
LM231AN 功能描述:電壓頻率轉(zhuǎn)換及頻率電壓轉(zhuǎn)換 RoHS:否 制造商:Texas Instruments 全標(biāo)度頻率:4000 KHz 線性誤差:+/- 1 % FSR 電源電壓-最大: 電源電壓-最小: 最大工作溫度:+ 85 C 最小工作溫度:- 25 C 安裝風(fēng)格:Through Hole 封裝 / 箱體:PDIP-14 封裝:Tube
LM231AN/A+ 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Voltage-to-Frequency Converter
LM231AN/B+ 制造商:未知廠家 制造商全稱:未知廠家 功能描述:Voltage-to-Frequency Converter
LM231AN/NOPB 功能描述:電壓頻率轉(zhuǎn)換及頻率電壓轉(zhuǎn)換 RoHS:否 制造商:Texas Instruments 全標(biāo)度頻率:4000 KHz 線性誤差:+/- 1 % FSR 電源電壓-最大: 電源電壓-最小: 最大工作溫度:+ 85 C 最小工作溫度:- 25 C 安裝風(fēng)格:Through Hole 封裝 / 箱體:PDIP-14 封裝:Tube