Comparator with 1.25% Reference and Adjustable Hysteresis

1 2017 Microchip Technology 1 MIC841/2 Features to Operating Range A Typical Supply Current Voltage Threshold Accuracy 10 nA Maximum Input Leakage Current Over Temperature 10 s Propagation Delay Externally Adjustable Hysteresis (MIC841) Internal 20 mV Hysteresis (MIC842) Output Options:- Push-Pull, Active-High- Push-Pull, Active-Low- Open-Drain, Active-Low Open-Drain Output can be Pulled to 6V Regardless of VDD Immune to Brief Input Transients Teeny 5-Pin SC-70 Package 6-Pin mm x mm TDFN (MIC841) 4-Pin mm x mm TDFN (MIC842)Applications Smartphones PDAs Precision Battery Monitoring Battery ChargersGeneral DescriptionThe MIC841 and MIC842 are micro-power,precision-voltage comparators with an on-chip devices are intended for voltage monitoringapplications.

2 External resistors are used to set thevoltage monitor threshold. When the threshold iscrossed, the outputs switch MIC842 incorporates a voltage Reference andcomparator with fixed internal Hysteresis ; two externalresistors are used to set the switching thresholdvoltage. The MIC841 provides a similar function withuser Adjustable Hysteresis ; this part requires threeexternal resistors to set the upper and lower thresholds(the difference between the threshold voltages beingthe Hysteresis voltage).Both the MIC841 and MIC842 are available withpush-pull or open-drain output stage. The push-pulloutput stage is configured either active-high oractive-low; the open-drain output stage is onlyconfigured current is extremely low ( A, typical),making it ideal for portable MIC841/2 is supplied in the Teeny 5-pin SC-70,6-pin mm mm Thin DFN (MIC841), and mm mm Thin DFN (MIC842) TypesMIC841SC-70-5 (C5)LTHGNDHTHOUTVDDYxx32145 MIC8416-Pin TDFN (MT)LTHGNDHTHOUTNCVDD123654 EPMIC842SC-70-5 (C5)NCGNDINPOUTVDDYxx32145 MIC8424-Pin TDFN (MT)

3 OUTGNDVDDINP1234 EPComparator with Reference and Adjustable HysteresisMIC841/2DS20005758A-page 2 2017 Microchip Technology Application CircuitsMIC841 Threshold Detection with Adjustable HysteresisHTHOUTVDDLTHGNDMIC841 VINR1R2R3 VOUTVDDVLTH > VHTHVREF = 9 9DD 9 MIC842 Threshold Detection with Internal Fixed HysteresisINPOUTVDDGNDVINR1 VOUTVDDVREF = 9 9DD 9 MIC842R2 2017 Microchip Technology 3 MIC841 BLOCK DIAGRAMSNote: Block diagrams show SC-70 package pin 1-1:MIC841H Block DiagramFIGURE 1-2:MIC841L Block DiagramFIGURE 1-3:MIC841N Block DiagramFIGURE 1-4:MIC842H Block DiagramFIGURE 1-5:MIC842L Block DiagramFIGURE 1-6:MIC842N Block 4 2017 Microchip Technology CHARACTERISTICSA bsolute Maximum Ratings Supply Voltage (VDD) .. to +7 VInput Voltage (VINP, VLTH,VHTH) ..+7 VOutput Current (IOUT) .. 20 mAESD Rating(1).

4 1 kVOperating Ratings Supply Voltage (VDD) .. + to + Voltage (VINP, VLTH,VHTH) .. 0V to +6 VVOUT ( H and L versions) .. VDDVOUT ( N version)..+6V Notice: Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the is a stress rating only and functional operation of the device at those or any other conditions above those indicatedin the operational sections of this specification is not intended. Exposure to maximum rating conditions for extendedperiods may affect device reliability. Notice: The device is not guaranteed to function outside its operating 1:Devices are ESD sensitive. Handling precautions are recommended. Human body model, k in serieswith 100 pF. 2017 Microchip Technology 5 MIC841/2 TABLE 2-1:ELECTRICAL CHARACTERISTICSE lectrical Characteristics: VDD ; TA = 25 C.

5 40 C TA +85 C, unless noted. (Note 1). Current (IDD) AOutput not assertedInput Leakage Current (IINP) Reference Voltage (VREF) C TA 85 40 C TA 85 CHysteresis Voltage (VHYST) (Note 2)82035mVMIC842 onlyPropagation Delay (tD) 1250 sVINP = to 8 50 VINP = to Voltage-Low (VOUT) (Note 3) = mA, VDD = 100 A, VDD Voltage-High (VOUT) (Note 3) ISOURCE = 500 A, VDD ISOURCE = 50 A, VDD 1:Specification for packaged product :VHTH = VREF + :VDD operating range is to Output is guaranteed to be de-asserted down to VDD = 6 2017 Microchip Technology RangesMaximum Junction Temperature TJ +150 CNote 1 Storage Temperature RangeTS 65 +150 C Ambient Temperature RangeTA 40 +85 C Lead Temperature +260 CSoldering, 10sPackage Thermal ResistancesSC-70-5 JA C/W 6-Pin mm x mm TDFN JA 92 C/W 4-Pin mm x mm TDFN JA 173 C/W Note 1:The maximum allowable power dissipation is a function of ambient temperature, the maximum allowable junction temperature and the thermal resistance from junction to air ( , TA, TJ, JA).

6 Exceeding the maximum allowable power dissipation will cause the device operating junction temperature to exceed the maximum +150 C rating. Sustained junction temperatures above +150 C can impact the device reliability. 2017 Microchip Technology 7 MIC841 DESCRIPTIONSThe descriptions of the pins are listed in Table 3-1 and Table 3-1:MIC841 PIN FUNCTION TABLEPin NumberSC-70 Pin NumberTDFNS ymbolDescription13 HTHHigh Threshold Input. HTH and LTH monitor external Threshold Input. LTH and HTH monitor external ( H Version) Active-Low Push-Pull Output. OUT asserts low when VLTH < VREF. OUT remains low until VHTH > ( L Version) Active-High Push-Pull Output. OUT asserts high when VLTH < VREF. OUT remains high until VHTH > ( N Version) Active-Low, Open-Drain Output. OUT asserts low when VLTH < VREF. OUT remains low until VHTH > Supply Input.

7 5 NCNo Connect. Not internally connected. EPePADH eatsink Pad. Connect to GND for best thermal 3-2:MIC842 PIN FUNCTION TABLEPin NumberSC-70 Pin NumberTDFNS ymbolDescription13 INPT hreshold Input. INP monitors an external NCNo Connect. Not internally ( H Version) Active-Low, Push-Pull Output. OUT asserts low when VINP < VREF. OUT remains low until VINP > (VREF + VHYST). OUT( L Version) Active-High, Push-Pull Output. OUT asserts high when VINP < VREF. OUT remains high until VINP > (VREF + VHYST).OUT( N Version) Active-Low, Open-Drain Output. OUT asserts low when VINP < VREF. OUT remains low until VINP > (VREF + VHYST).54 VDDP ower Supply Input. EPePADH eatsink Pad. Connect to GND for best thermal 8 2017 Microchip Technology MIC841N and MIC842N outputs are an open-drainMOSFET, so most applications will require a pull-upresistor.

8 The value of the resistor should not be toolarge or leakage effects may dominate. 470 k is themaximum recommended value. Note that the output ofthe N version may be pulled up as high as 6 Vregardless of the IC s supply voltage. The H and L versions of the MIC841 and MIC842 have a push-pulloutput stage with a diode clamped to VDD. Thus, themaximum output voltage of the H and L versions isVDD (see Ta b l e 2 - 1).When working with large resistors on the input to thedevices, a small amount of leakage current can causevoltage offsets that degrade system accuracy. Themaximum recommended total resistance from VIN toground is 3 M . The accuracy of the resistors can bechosen based upon the accuracy required by thesystem. The inputs may be subjected to voltages ashigh as 6V steady-state without adverse effects of anykind regardless of the IC s supply voltage.

9 This applieseven if the supply voltage is zero. This permits thesituation in which the IC s supply is turned off, butvoltage is still present on the inputs (see Ta b l e 2 - 1). the MIC841 ThresholdsThe low-voltage threshold is calculated usingEquation 4-1:The high-voltage threshold is calculated usingEquation 4-2:In order to provide the additional criteria needed tosolve for the resistor values, the resistors can beselected such that they have a given total value, that is,R1 + R2 + R3 = RTOTAL. A value such as 1 M forRTOTAL is a reasonable value because it drawsminimum current but has no significant effect 4-1:MIC841 Example CircuitOnce the desired trip points are determined, set theVIN(HI) threshold example, use a total of 1 M = R1 + R2 + R3.

10 Fora typical single-cell lithium ion battery, is a good high threshold because at the battery ismoderately charged. Solving for R3:EQUATION 4-3:Once R3 is determined, the equation for VIN(LO) can beused to determine R2. A single lithium-ion cell, forexample, should not be discharged below Manyapplications limit the drain to for the VIN(LO) threshold allows thecalculation of the two remaining resistor 4-4:The accuracy of the resistors can be chosen basedupon the accuracy required by the LO VREFR1R2R3++R2R3+----------------------- ---------- = HI VREFR1R2R3++R3-------------------------- ------- = 1%R256k 1%R3340k 1%VDDVDDLTHHTHOUTGND470kVOUTMIC841 NVIN HI R3------------- ==Solve:R3344 k VIN LO R2 344k +------------------------------ ==Solve:R256 k R11 M - R2 - R3R1600 k 2017 Microchip Technology 9 MIC841/2 FIGURE 4-2:Output Response and the MIC842 ThresholdsThe voltage threshold is calculated using Equation 4-5:FIGURE 4-3.