link to page 9 link to page 9 Data SheetADCMP350/ADCMP354/ADCMP356APPLICATIONS INFORMATION ADDING HYSTERESISVOLTAGE DETECTOR To prevent oscillations at the output caused by noise or slowly The ADCMP350/ADCMP354/ADCMP356 can be used to moving signals passing the switching threshold, positive feedback monitor voltages, such as battery monitoring or threshold can be used to add hysteresis to the noninverting parts detectors. Using a resistor divider at the input to select the (ADCMP354 and ADCMP356). appropriate trip voltage, the comparator can be configured For the noninverting configuration shown in Figure 20, two to give a logic output when the input passes that threshold. resistors are used to create different switching thresholds, Figure 21 shows the typical configuration of the ADCMP354 depending on whether the input signal is increasing or decreasing for monitoring a supply to indicate that the voltage is above a in magnitude. When the input voltage is increasing, the threshold is certain level. above VREF, and when it is decreasing, the threshold is below VREF. VCC = 5V The upper input threshold level is given by V (R1+ R2) ADCMP354 = RPULLUPV I V REF N_HI IN R2 R1OUT where VREF = 0.6 V, assuming RLOAD >> R2, RPULLUP R2VREF = 0.6V The lower input threshold level is given by V (R1+ R2 + R ) −V R1 023 = 12- 1 I V REF PULLUP CC N_LO R2 + 05 P R ULLUP Figure 21. Voltage Detector Application The hysteresis is the difference between these voltage levels and is given by + RE V F ( ) R1 R1( RE V F C V C ) = − HY V S R2 R2 + P R ULLUP VCC = 5VADCMP354RPULLUPOUTVINR1RLOADVREF = 0.6V 022 12- 1 R2 05 Figure 20. Noninverting Comparator Configuration with Added Hysteresis Rev. E | Page 9 of 10 Document Outline FEATURES APPLICATIONS FUNCTIONAL BLOCK DIAGRAMS GENERAL DESCRIPTION TABLE OF CONTENTS REVISION HISTORY SPECIFICATIONS ABSOLUTE MAXIMUM RATINGS ESD CAUTION PIN CONFIGURATION AND FUNCTION DESCRIPTIONS TYPICAL PERFORMANCE CHARACTERISTICS APPLICATIONS INFORMATION ADDING HYSTERESIS VOLTAGE DETECTOR OUTLINE DIMENSIONS ORDERING GUIDE