Moteur de recherche de fiches techniques de composants électroniques
  French  ▼
ALLDATASHEET.FR

X  

LM331N Fiches technique(PDF) 7 Page - Texas Instruments

No de pièce LM331N
Description  LM231A/LM231/LM331A/LM331 Precision Voltage-to-Frequency Converters
Download  20 Pages
Scroll/Zoom Zoom In 100%  Zoom Out
Fabricant  TI [Texas Instruments]
Site Internet  http://www.ti.com
Logo TI - Texas Instruments

LM331N Fiches technique(HTML) 7 Page - Texas Instruments

Back Button LM331N Datasheet HTML 3Page - Texas Instruments LM331N Datasheet HTML 4Page - Texas Instruments LM331N Datasheet HTML 5Page - Texas Instruments LM331N Datasheet HTML 6Page - Texas Instruments LM331N Datasheet HTML 7Page - Texas Instruments LM331N Datasheet HTML 8Page - Texas Instruments LM331N Datasheet HTML 9Page - Texas Instruments LM331N Datasheet HTML 10Page - Texas Instruments LM331N Datasheet HTML 11Page - Texas Instruments Next Button
Zoom Inzoom in Zoom Outzoom out
 7 / 20 page
background image
LM231, LM331
www.ti.com
SNOSBI2B – JUNE 1999 – REVISED MARCH 2013
APPLICATIONS INFORMATION
PRINCIPLES OF OPERATION
The LM231/331 are monolithic circuits designed for accuracy and versatile operation when applied as voltage-to-
frequency (V-to-F) converters or as frequency-to-voltage (F-to-V) converters. A simplified block diagram of the
LM231/331 is shown in Figure 14 and consists of a switched current source, input comparator, and 1-shot timer.
Figure 14. Simplified Block Diagram of Stand-Alone
Voltage-to-Frequency Converter and
External Components
Simplified Voltage-to-Frequency Converter
The operation of these blocks is best understood by going through the operating cycle of the basic V-to-F
converter, Figure 14, which consists of the simplified block diagram of the LM231/331 and the various resistors
and capacitors connected to it.
The voltage comparator compares a positive input voltage, V1, at pin 7 to the voltage, Vx, at pin 6. If V1 is
greater, the comparator will trigger the 1-shot timer. The output of the timer will turn ON both the frequency
output transistor and the switched current source for a period t=1.1 RtCt. During this period, the current i will flow
out of the switched current source and provide a fixed amount of charge, Q = i × t, into the capacitor, CL. This will
normally charge Vx up to a higher level than V1. At the end of the timing period, the current i will turn OFF, and
the timer will reset itself.
Now there is no current flowing from pin 1, and the capacitor CL will be gradually discharged by RL until Vx falls
to the level of V1. Then the comparator will trigger the timer and start another cycle.
The current flowing into CL is exactly IAVE = i × (1.1×RtCt) × f, and the current flowing out of CL is exactly Vx/RL
VIN/RL. If VIN is doubled, the frequency will double to maintain this balance. Even a simple V-to-F converter can
provide a frequency precisely proportional to its input voltage over a wide range of frequencies.
Detail of Operation, Functional Block Diagram
The block diagram (FUNCTIONAL BLOCK DIAGRAM) shows a band gap reference which provides a stable 1.9
VDC output. This 1.9 VDC is well regulated over a VS range of 3.9V to 40V. It also has a flat, low temperature
coefficient, and typically changes less than ½% over a 100°C temperature change.
The current pump circuit forces the voltage at pin 2 to be at 1.9V, and causes a current i=1.90V/RS to flow. For
Rs=14k, i=135 μA. The precision current reflector provides a current equal to i to the current switch. The current
switch switches the current to pin 1 or to ground, depending upon the state of the RS flip-flop.
The timing function consists of an RS flip-flop and a timer comparator connected to the external RtCt network.
When the input comparator detects a voltage at pin 7 higher than pin 6, it sets the RS flip-flop which turns ON the
current switch and the output driver transistor. When the voltage at pin 5 rises to
⅔ VCC, the timer comparator
causes the RS flip-flop to reset. The reset transistor is then turned ON and the current switch is turned OFF.
Copyright © 1999–2013, Texas Instruments Incorporated
Submit Documentation Feedback
7
Product Folder Links: LM231 LM331


Numéro de pièce similaire - LM331N

FabricantNo de pièceFiches techniqueDescription
logo
National Semiconductor ...
LM331N NSC-LM331N Datasheet
280Kb / 16P
   Precision Voltage-to-Frequency Converters
LM331N NSC-LM331N Datasheet
368Kb / 15P
   Precision Voltage-to-Frequency Converters
logo
Fairchild Semiconductor
LM331N FAIRCHILD-LM331N Datasheet
49Kb / 6P
   V-F Converter
logo
Texas Instruments
LM331N/NOPB TI1-LM331N/NOPB Datasheet
952Kb / 23P
[Old version datasheet]   Precision Voltage-to-Frequency Converters
More results

Description similaire - LM331N

FabricantNo de pièceFiches techniqueDescription
logo
National Semiconductor ...
LM131A NSC-LM131A Datasheet
280Kb / 16P
   Precision Voltage-to-Frequency Converters
LM231A NSC-LM231A Datasheet
368Kb / 15P
   Precision Voltage-to-Frequency Converters
logo
Texas Instruments
LM231 TI1-LM231_15 Datasheet
952Kb / 23P
[Old version datasheet]   Precision Voltage-to-Frequency Converters
logo
Microchip Technology
TC9400 MICROCHIP-TC9400 Datasheet
504Kb / 20P
   Voltage-to-Frequency/Frequency-to-Voltage Converters
2002
logo
TelCom Semiconductor, I...
TC9400 TELCOM-TC9400 Datasheet
154Kb / 13P
   VOLTAGE-TO-FREQUENCY/FREQUENCY-TO-VOLTAGE CONVERTERS
logo
Microchip Technology
TC9400 MICROCHIP-TC9400_06 Datasheet
691Kb / 24P
   Voltage-to-Frequency/Frequency-to-Voltage Converters
2006
logo
Texas Instruments
LM2917P TI1-LM2917P Datasheet
96Kb / 7P
[Old version datasheet]   FREQUENCY-TO-VOLTAGE CONVERTERS
logo
Fairchild Semiconductor
RC4152 FAIRCHILD-RC4152 Datasheet
75Kb / 12P
   Voltage-to-Frequency Converters
logo
TelCom Semiconductor, I...
TC02 TELCOM-TC02 Datasheet
149Kb / 7P
   PRECISION TEMPERATURE-TO-VOLTAGE CONVERTERS
TC1023 TELCOM-TC1023 Datasheet
134Kb / 6P
   PRECISION TEMPERATURE-TO-VOLTAGE CONVERTERS WITH SHUTDOWN MODE
More results


Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20


Fiches technique Télécharger

Go To PDF Page


Lien URL




Politique de confidentialité
ALLDATASHEET.FR
ALLDATASHEET vous a-t-il été utile ?  [ DONATE ] 

À propos de Alldatasheet   |   Publicité   |   Contactez-nous   |   Politique de confidentialité   |   Echange de liens   |   Fabricants
All Rights Reserved©Alldatasheet.com


Mirror Sites
English : Alldatasheet.com  |   English : Alldatasheet.net  |   Chinese : Alldatasheetcn.com  |   German : Alldatasheetde.com  |   Japanese : Alldatasheet.jp
Russian : Alldatasheetru.com  |   Korean : Alldatasheet.co.kr  |   Spanish : Alldatasheet.es  |   French : Alldatasheet.fr  |   Italian : Alldatasheetit.com
Portuguese : Alldatasheetpt.com  |   Polish : Alldatasheet.pl  |   Vietnamese : Alldatasheet.vn
Indian : Alldatasheet.in  |   Mexican : Alldatasheet.com.mx  |   British : Alldatasheet.co.uk  |   New Zealand : Alldatasheet.co.nz
Family Site : ic2ic.com  |   icmetro.com