www.fairchildsemi.com LM331 V-F Converter Features 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. 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 8-DIP 1 Internal Block Diagram Rev. 1.0.0 (c)2001 Fairchild Semiconductor Corporation LM331 Absolute Maximum Ratings (TA = 25C) Parameter Symbol Supply Voltage Input Voltage Operating Temperature Range Power Dissipation Value Unit VCC 40 V VI -0.2 ~ + VCC V TOPR 0 ~ +70 C PD 500 mW Electrical Characteristics Symbol Conditions VFC Non-Linearity Parameter VFCNL 4.5 VCC 20V Conversion Accuracy Scale Factor ACCUR VI = -10V, RS = 14K 0.90 1.00 1.10 KHz/V 4.5V VCC 10V - 0.01 0.1 %/V 10V VCC 40V - 0.006 0.06 10.0 - - KHz - 3 10 mV Chang Of Gain With VCC Rated Full - Scale Frequency VCCG/VCC f VI = -10V Min. - Typ. Max. Unit 0.003 0.01 % Full-Scale INPUT COMPARATOR Offset Voltage Bias Current Offset Current Common-Mode Range VIO 0C TA +70C IBIAS - - -80 -300 nA IIO - - 8 100 nA -0.2 - VCC2.0 V 0.701 xVCC 10 100 nA VCM 0C TA +70C TIMER (PIN 5) - 0.63 0.667 Timer Threshold Voltage VTH Input Bias Current IBIAS VCC = 15V, 0V V5 9.9V V5 = 10V - 200 1000 nA Saturation Voltage VSAT I = 5mA - 0.22 0.5 V 116 136 156 A - CURRENT SOURCE (PIN 1) Output Current IO RS = 14K, V1= 0V - 0.2 1.0 A ILKG - - 0.02 10.0 nA VREF - 1.70 1.89 2.08 VDC Stability vs Temperature STT - - 60 - ppm/C Stability vs Time, 1000Hours STT - - 0.1 - % I = 5mA - 0.15 0.50 I = 3.2mA - 0.10 0.40 - 0.05 1.0 Change with Voltage Current Source Off Leakage IO/V1 0V V1 10V REFERENCE VOLTAGE (PIN 2) Reference Voltage LOGIC OUTPUT (Pin 3) Saturation Voltage VSAT Off Leakage ILKG - V A SUPPLY CURRENT Supply Current 2 ICC VCC = 5V 1.5 3.0 6.0 VCC = 40V 2.0 4.0 8.0 mA 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 LM331 Mechanical Dimensions Package Dimensions in millimeters 1.524 0.10 #5 2.54 0.100 5.08 MAX 0.200 7.62 0.300 3.40 0.20 0.134 0.008 +0.10 0.25 -0.05 +0.004 0~15 4 0.010 -0.002 3.30 0.30 0.130 0.012 0.33 MIN 0.013 0.060 0.004 #4 0.018 0.004 #8 9.60 MAX 0.378 #1 9.20 0.20 0.362 0.008 ( 6.40 0.20 0.252 0.008 0.46 0.10 0.79 ) 0.031 8-DIP LM331 Ordering Information Product Number Package Operating Temperature LM331N 8-DIP 0 ~ + 70C 5 LM331 DISCLAIMER FAIRCHILD SEMICONDUCTOR RESERVES THE RIGHT TO MAKE CHANGES WITHOUT FURTHER NOTICE TO ANY PRODUCTS HEREIN TO IMPROVE RELIABILITY, FUNCTION OR DESIGN. FAIRCHILD DOES NOT ASSUME ANY LIABILITY ARISING OUT OF THE APPLICATION OR USE OF ANY PRODUCT OR CIRCUIT DESCRIBED HEREIN; NEITHER DOES IT CONVEY ANY LICENSE UNDER ITS PATENT RIGHTS, NOR THE RIGHTS OF OTHERS. LIFE SUPPORT POLICY FAIRCHILD'S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT OF FAIRCHILD SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant into the body, or (b) support or sustain life, and (c) whose failure to perform when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury of the user. 2. A critical component in any component of a life support device or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system, or to affect its safety or effectiveness. www.fairchildsemi.com 5/22/01 0.0m 001 Stock#DSxxxxxxxx 2001 Fairchild Semiconductor Corporation