LM231N ,Precision Voltage-to-Frequency ConverterGeneral Descriptionas low as 4.0V. The precision timer circuit has low bias cur-The LM231/LM331 fam ..
LM231WM ,Precision Voltage-to-Frequency Convertersapplications. Further, the LM131A/YSplit or single supply operationLM231A/LM331A attains a new high ..
LM234 ,3-Terminal Adjustable Current Sourceapplications.For the LM134/LM234/LM334, the voltage on thePackagePart Num- Temperatureocontrol pin ..
LM234 ,3-Terminal Adjustable Current SourceFEATURESThe sense voltage used to establish operating current2• Operates From 1V to 40Vin the LM134 ..
LM234D ,ADJUSTABLE CURRENT SOURCESELECTRICAL CHARACTERISTICSoT = +25 C with pulse testing so that junction temperature does not chang ..
LM234H ,3-Terminal Adjustable Current SourceGeneral DescriptionLM234-6 are specified as true temperature sensors withThe LM134/LM234/LM334 are ..
LM4040DIM3-10.0 ,Precision Micropower Shunt Voltage ReferenceGeneral Description2.500V,3.000V, 4.096V, 5.000V, 8.192V, and 10.000VIdeal for space critical
LM4040DIM3-2.0 ,Precision Micropower Shunt Voltage ReferenceLM4040 Precision Micropower Shunt Voltage ReferenceAugust 2002LM4040Precision Micropower Shunt Volt ..
LM4040DIM3-2.0/NOPB ,Precision Micropower Shunt Voltage Reference 3-SOT-23 Electrical Characteristics: 2-V LM4040-N VR6.23 Typical Characteristics...... 31Tolerance Grades 'C ..
LM4040DIM3-2.5 ,Improved Precision Micropower Shunt Voltage Reference with Multiple Reverse Breakdown VoltagesLM4040 Precision Micropower Shunt Voltage ReferenceAugust 2002LM4040Precision Micropower Shunt Volt ..
LM4040DIM3-2.5+T ,Improved Precision Micropower Shunt Voltage Reference with Multiple Reverse Breakdown VoltagesFeaturesThe LM4040 is a precision two-terminal shunt mode,♦ Ultra-Small 3-Pin SC70 Packagebandgap v ..
LM4040DIM3-3.0 ,Improved Precision Micropower Shunt Voltage Reference with Multiple Reverse Breakdown Voltagesapplications, the LM4040 precisionvoltagereferenceisavailableinthesub-miniatureSC70andKey Specifica ..
LM231AN-LM231N-LM331AN-LM331N
Precision Voltage-to-Frequency Converter
LM231A/LM231/LM331A/LM331
Precision Voltage-to-Frequency Converters
General DescriptionThe LM231/LM331 familyof voltage-to-frequencyconverters
are ideally suitedfor usein simple low-cost circuitsfor
analog-to-digital conversion, precision frequency-to-voltage
conversion, long-term integration, linear frequency modula-
tionor demodulation,and many other functions.The output
when usedasa voltage-to-frequency converterisa pulse
trainata frequency precisely proportionaltothe appliedin-
put voltage. Thus,it providesallthe inherent advantagesof
the voltage-to-frequency conversion techniques, andis easy applyinall standard voltage-to-frequency converter appli-
cations. Further,the LM231A/LM331A attaina new high
levelof accuracy versus temperature whichcould onlybeat-
tained with expensive voltage-to-frequency modules. Addi-
tionallythe LM231/331are ideally suitedforusein digital
systemsatlow power supply voltages and can provide
low-cost analog-to-digital conversion in
microprocessor-controlled systems. And,the frequency from battery powered voltage-to-frequency converter canbe
easily channeled througha simple photoisolatorto provide
isolation against high common mode levels.
The LM231/LM331 utilizea new temperature-compensated
band-gap reference circuit,to provide excellent accuracy
overthefull operating temperature range,at power supplieslowas 4.0V.The precision timer circuithaslow bias cur-
rents without degradingthe quick response necessaryfor
100 kHz voltage-to-frequency conversion. Andthe output
are capableof driving3TTL loads,ora high voltage outputto 40V,yetis short-circuit-proof against VCC.
Features Guaranteed linearity 0.01% max Improved performancein existing voltage-to-frequency
conversion applications Splitor single supply operation Operateson single5V supply Pulse output compatible withall logic forms Excellent temperature stability, ±50 ppm/˚C max Low power dissipation,15 mW typicalat5V Wide dynamic range,100dBminat10kHzfull scale
frequency Wide rangeoffull scale frequency,1Hzto100 kHz Low cost
Typical ApplicationsTeflon®isaregistered trademarkof DuPont
DS005680-1
*Use stable components withlow temperature coefficients.See Typical Applications section.
**0.1μF or1μF,See “Principlesof Operation.”
FIGURE1. Simple Stand-Alone Voltage-to-Frequency Converter
with ±0.03% Typical Linearity(f=10Hzto11 kHz)June 1999
LM231A/LM231/LM331A/LM331
Precision
oltage-to-Frequency
Converters©1999 National Semiconductor Corporation DS005680
