LTC1442IN8

LTC1440/LTC1441/LTC1442 Ultralow Power Single/Dual Comparator with Reference FEATURES ■ ■ ■ ■ DESCRIPTIO ■ ■ ■ ■ ■ ■ ■ Ultralow Quiescent Current: 2.1µA Typ (LTC1440) Reference Output Drives 0.01µF Capacitor Adjustable Hysteresis (LTC1440/LTC1442) Wide Supply Range: Single: 2V to 11V Dual: ± 1V to ± 5.5V Input Voltage Range Includes the Negative Supply TTL/CMOS Compatible Outputs 12µs Propagation Delay with 10mV Overdrive No Crowbar Current 40mA Continuous Source Current Pin Compatible Upgrades for MAX921/922/923 3mm x 3mm x 0.75mm DFN Package (LTC1440) The LTC ®1440/LTC1441/LTC1442 are ultralow power single and dual comparators with built-in references. The comparators feature less than 3.7µA supply current over temperature (LTC1440), a 1.182V ± 1% reference, programmable hysteresis (LTC1440/LTC1442) and TTL/CMOS outputs that sink and source current. The reference output can drive a bypass capacitor of up to 0.01µF without oscillation. The comparators operate from a single 2V to 11V supply or a dual ± 1V to ± 5.5V supply (LTC1440). Comparator hysteresis is easily programmed by using two resistors and the HYST pin (LTC1440/LTC1442). Each comparator’s input operates from the negative supply to within 1.3V of the positive supply. The comparator output stage can continuously source up to 40mA. By eliminating the cross-conducting current that normally happens when the comparator changes logic states, the power supply glitches are eliminated. The LTC1440 is available in 8-pin PDIP, SO, MSOP and DFN packages. The LTC1441/LTC1442 are available in 8-pin PDIP and SO packages. APPLICATIO S ■ ■ ■ ■ Battery-Powered System Monitoring Threshold Detectors Window Comparators Oscillator Circuits , LTC and LT are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. TYPICAL APPLICATIO 3.3V Micropower 2.9V VCC Threshold Detector LTC1440 Supply Current vs Temperature 5.0 V + = 5V V – = GND = 0V SUPPLY CURRENT (µA) R1 1.65M 1% R2 1.13M 1% 7 V+ 3 IN + 4.5 4.0 3.5 3.0 2.5 2.0 + 8 OUT 4 IN– – 5 HYST LTC1440 6 REF 1.5 –40 –20 V– 2 GND 1 1440 TA01 U 40 20 60 0 TEMPERATURE (°C) 80 100 1440/1/2 TA02 U U 144012fc 1 LTC1440/LTC1441/LTC1442 ABSOLUTE MAXIMUM RATINGS (Note 1) Voltage V + to V –, V + to GND, GND to V – ...........12V to – 0.3V IN +, IN –, HYST ................. (V + + 0.3V) to (V – – 0.3V) REF ................................... (V + + 0.3V) to (V – – 0.3V) OUT (LTC1440) .............. (V + + 0.3V) to (GND – 0.3V) OUT (LTC1441/LTC1442) ... (V + + 0.3V) to (V – – 0.3V) Current IN +, IN –, HYST ................................................. 20mA REF ................................................................... 20mA OUT .................................................................. 50mA PACKAGE/ORDER INFORMATION TOP VIEW GND V– IN + IN – 1 2 3 4 8 7 6 5 OUT V+ REF HYST GND 1 V – 2 IN + 3 IN – 4 DD PACKAGE 8-LEAD (3mm × 3mm) PLASTIC DFN N8 PACKAGE 8-LEAD PDIP TJMAX = 125°C, θJA = 160°C/ W (DD) UNDERSIDE METAL CONNECTED TO V– (PCB CONNECTION OPTIONAL) TJMAX = 150°C, θJA = 130°C/ W (N8) TJMAX = 150°C, θJA = 175°C/ W (S8) ORDER PART NUMBER LTC1440CDD LTC1440IDD DD8 PART MARKING* LBTH TOP VIEW OUT A 1 V– 2 IN A + 3 IN A – 8 7 6 5 OUT B V+ IN B + IN B – 4 N8 PACKAGE 8-LEAD PDIP S8 PACKAGE 8-LEAD PLASTIC SO TJMAX = 150°C, θJA = 130°C/ W (N8) TJMAX = 150°C, θJA = 175°C/ W (S8) ORDER PART NUMBER LTC1440CN8 LTC1440CS8 LTC1440IN8 LTC1440IS8 ORDER PART NUMBER LTC1441CN8 LTC1441CS8 LTC1441IN8 LTC1441IS8 S8 PART MARKING 1441 1441I Order Options Tape and Reel: Add #TR Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF Lead Free Part Marking: http://www.linear.com/leadfree/ Consult LTC Marketing for parts specified with wider operating temperature ranges. * The temperature grade is identified by a label on the shipping container. 2 U U W WW U W OUT Short-Circuit Duration (V + ≤ 5.5V) .......Continuous Power Dissipation .............................................. 500mW Operating Temperature Range LTC144XC ............................................... 0°C to 70°C LTC144XI ........................................... – 40°C to 85°C Storage Temperature Range ................. – 65°C to 150°C Storage Temperature Range (DD Package) ................................... – 65°C to 125°C Junction Temperature ........................................... 150°C Junction Temperature (DD Package) .................... 125°C Lead Temperature (Soldering, 10 sec).................. 300°C TOP VIEW 8 7 6 5 OUT V + TOP VIEW GND V– IN + IN – 1 2 3 4 8 7 6 5 OUT V+ REF HYST REF HYST S8 PACKAGE 8-LEAD PLASTIC SO MS8 PACKAGE 8-LEAD PLASTIC MSOP TJMAX = 150°C, θJA = 250°C/ W S8 PART MARKING 1440 1440 1440I 1440I ORDER PART NUMBER LTC1440CMS8 LTC1440IMS8 MS8 PART MARKING* LTBX TOP VIEW OUT A 1 V– 2 IN A+ 3 IN B – 8 7 6 5 OUT B V+ REF HYST 4 N8 PACKAGE 8-LEAD PDIP S8 PACKAGE 8-LEAD PLASTIC SO TJMAX = 150°C, θJA = 130°C/ W (N8) TJMAX = 150°C, θJA = 175°C/ W (S8) ORDER PART NUMBER LTC1442CN8 LTC1442CS8 LTC1442IN8 LTC1442IS8 S8 PART MARKING 1442 1442I 144012fc LTC1440/LTC1441/LTC1442 The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. V + = 5V and V – = GND = 0V unless otherwise noted. SYMBOL PARAMETER Power Supply V+ Supply Voltage Range Supply Current ICC CONDITIONS ● ● ● ● ● ● ● ● ● ELECTRICAL CHARACTERISTICS MIN 2.0 TYP MAX 11.0 4.0 4.4 5.7 5.7 ± 10 ± 1.0 ± 1.0 V + – 1.3V 1 1 1 UNITS V µA µA µA µA mV nA nA V IN + = IN – + 80mV LTC1440 0°C ≤ TA ≤ 70°C HYST = REF (LTC1440/LTC1442) –40°C ≤ TA ≤ 85°C LTC1441 LTC1442 VCM = 2.5V VIN + = VIN – = 2.5V 2.1 3.5 3.5 ±3 ± 0.01 ± 0.02 V– 0.1 0.1 0.1 100 Comparator VOS Comparator Input Offset Voltage Input Leakage Current (IN +, IN –) IIN Input Leakage Current (HYST) Comparator Input Common VCM Mode Range CMRR Common Mode Rejection Ratio PSRR Power Supply Rejection Ratio NOISE VHYST tPD VOH VOL Voltage Noise Hysteresis Input Voltage Range Propagation Delay Output High Voltage Output Low Voltage V – to V + – 1.3V V + = 2V to 11V (LTC1441) V + = 2.5V to 11V (LTC1440/LTC1442) 100Hz to 100kHz LTC1440/LTC1442 COUT = 100pF Overdrive = 10mV Overdrive = 100mV IO = – 13mA IO = 1.8mA LTC1440 LTC1441/LTC1442 No Load LTC1440/LTC1442 0°C ≤ TA ≤ 70°C –40°C ≤ TA ≤ 85°C LTC1440 (MSOP, DFN) ● REF – 50mV 15 8 ● ● ● V + – 0.4V mV/V mV/V mV/V µVRMS REF V µs µs V GND + 0.4V V V – + 0.4V V Reference Reference Voltage VREF ISOURCE ISINK ∆VREF Reference Output Source Current Reference Output Sink Current Reference Source Current Reference Sink Current Voltage Noise ∆VREF ≤ 1mV (LTC1442) ∆VREF ≤ 2.5mV (LTC1442) 0 ≤ ISOURCE ≤ 2mA (LTC1440) 0 ≤ ISINK ≤ 10µA (LTC1440) 100Hz to 100kHz ● ● ● ● ● ● 1.170 1.164 1.164 100 10 1.194 1.200 1.200 20 0.8 0.5 100 5 1.5 5 V V V µA µA mV mV mV µVRMS NOISE 144012fc 3 LTC1440/LTC1441/LTC1442 The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. V + = 3V and V – = GND = 0V unless otherwise noted. SYMBOL PARAMETER Power Supply Supply Voltage Range V+ ICC Supply Current CONDITIONS ● ELECTRICAL CHARACTERISTICS MIN 2 TYP MAX 11 UNITS V µA µA µA µA mV nA nA V mV/V mV/V mV/V µVRMS V µs µs V V V + 80mV HYST = REF (LTC1440/LTC1442) IN + = IN – LTC1440 0°C ≤ TA ≤ 70°C –40°C ≤ TA ≤ 85°C LTC1441 LTC1442 ● ● ● ● ● ● ● ● 2 3.5 3.5 ±3 ± 0.01 ± 0.02 V– 0.1 0.1 0.1 100 3.9 4.3 5.7 5.7 ± 10 ±1 ±1 V + – 1.3V 1 1 1 REF Comparator VOS Comparator Input Offset Voltage Input Leakage Current (IN +, IN –) IIN Input Leakage Current (HYST) Comparator Input Common VCM Mode Range CMRR Common Mode Rejection Ratio PSRR Power Supply Rejection Ratio NOISE VHYST tPD Voltage Noise Hysteresis Input Voltage Range Propagation Delay VCM = 1.5V VIN + = VIN – = 1.5V VOH Output High Voltage Comparator Output Low Voltage VOL Reference Reference Voltage VREF V – to V + – 1.3V V + = 2V to 11V (LTC1441) V + = 2.5V to 11V (LTC1440/LTC1442) 100Hz to 100kHz LTC1440/LTC1442 COUT = 100pF Overdrive = 10mV Overdrive = 100mV IO = – 8mA IO = 0.8mA LTC1440 LTC1441/LTC1442 LTC1440/LTC1442 0°C ≤ TA ≤ 70°C –40°C ≤ TA ≤ 85°C LTC1440 (MSOP, DFN) ● REF – 50mV 14 5 ● ● ● V + – 0.4V GND + 0.4V V – + 0.4V No Load ISOURCE ISINK ∆VREF Reference Output Source Current Reference Output Sink Current Reference Source Current Reference Sink Current Voltage Noise ∆VREF ≤ 1mV (LTC1442) ∆VREF ≤ 2.5mV (LTC1442) 0 ≤ ISOURCE ≤ 1mA (LTC1440) 0 ≤ ISINK ≤ 10µA (LTC1440) 100Hz to 100kHz ● ● ● ● ● ● 1.170 1.164 1.164 60 10 1.182 1.194 1.200 1.200 120 20 0.8 0.5 100 5.5 1.5 5 V V V µA µA mV mV mV µVRMS NOISE Note 1: Stresses beyond those listed under Absolute Maximum Ratings may cause permanent damage to the device. Exposure to any Absolute Maximum Rating condition for extended periods may affect device reliability and lifetime. 144012fc 4 LTC1440/LTC1441/LTC1442 TYPICAL PERFOR A CE CHARACTERISTICS Comparator Response Time vs Input Overdrive OUTPUT VOLTAGE (V) 4 3 2 1 0 TA = 25°C OUTPUT VOLTAGE (V) 5 100mV 50mV INPUT VOLTAGE (mV) 0 100 –1 0 2 4 6 RESPONSE TIME (µs) 8 10 INPUT VOLTAGE (mV) Comparator Short-Circuit Sink Current vs Supply Voltage 200 180 160 140 120 100 80 60 40 20 0 0 1 2 345678 SUPPLY VOLTAGE (V) 9 10 20 0 OUT CONNECTED TO V + SOURCE CURRENT (mA) SINK CURRENT (mA) TA = 25°C UW Comparator Response Time vs Input Overdrive 5 4 3 2 1 0 TA = 25°C 100mV 50mV 20mV 10mV 10mV 20mV 100 0 –1 0 2 4 6 8 10 12 14 16 18 RESPONSE TIME (µs) 1440/1/2 G02 1440/1/2 G01 Comparator Short-Circuit Source Current vs Supply Voltage 160 140 120 100 80 60 40 OUT CONNECTED TO V – = GND = 0V 0 1 2 3 SUPPLY VOLTAGE (V) 4 5 1440/1/2 G04 1440/1/2 G03 144012fc 5 LTC1440/LTC1441/LTC1442 TYPICAL PERFOR A CE CHARACTERISTICS Comparator Response Time vs Load Capacitance with 100mV Input Overdrive 12 10000 10 RESPONSE TIME (µs) t PHL 8 RESPONSE TIME (µs) 6 t PLH 4 2 0 20 60 80 40 LOAD CAPACITANCE (nF) 100 1440/1/2 G05 OUTPUT VOLTAGE HIGH (V) 6 UW Comparator Response Time at Low Supply Voltage 1000 20mV OVERDRIVE 100 10 100mV OVERDRIVE 1 1.0 1.1 1.2 1.3 1.4 SUPPLY VOLTAGE (V) 1.5 1.6 1440/1/2 G06 Comparator Output Voltage High vs Load Current 5 V + = 5V TA = 25°C 4 3 V + = 3V 2 V + = 2V 1 0 10 20 30 40 LOAD CURRENT (mA) 50 60 1440/1/2 G07 144012fc LTC1440/LTC1441/LTC1442 TYPICAL PERFOR A CE CHARACTERISTICS Comparator Output Voltage Low vs Load Current TA = 25°C POSITIVE-TO-NEGATIVE INPUT VOLTAGE (mV) 2.5 OUTPUT VOLTAGE LOW (V) 2.0 V + = 2V V = 3V 1.5 + 1.0 0.5 0 0 10 50 60 20 30 40 LOAD CURRENT (mA) SUPPLY CURRENT (µA) UW LTC1440/LTC1442 Hysteresis Control 80 60 OUTPUT HIGH 40 20 0 –20 –40 –60 –80 0 10 20 30 VREF – VHYST (mV) 40 50 1440/1/2 G09 V + = 5V OUTPUT LOW 70 80 1440/1/2 G08 LTC1440 Supply Current vs Temperature 6 5 V + = 5V V – = – 5V 4 3 V + = 3V V – = GND = 0V 2 V + = 5V V – = GND = 0V 1 –60 –40 –20 0 20 40 60 80 100 120 140 TEMPERATURE (°C) 1440/1/2 G10 144012fc 7 LTC1440/LTC1441/LTC1442 TYPICAL PERFOR A CE CHARACTERISTICS Reference Output Voltage vs Output Load Current 1.190 VCC = 5V REFERENCE OUTPUT VOLTAGE (V) 1.185 SOURCE 1.180 1.175 1.170 1.165 1.160 1.155 0 0.5 1.0 1.5 2.0 2.5 3.0 OUTPUT LOAD CURRENT (mA) 3.5 REFERENCE OUTPUT VOLTAGE (V) REFERENCE VOLTAGE (V) 8 UW Reference Output Voltage vs Output Load Current (Sink) 1.200 V CC = 2V 1.195 V CC = 5V 1.190 1.185 SINK 1.180 1.175 1.170 0 25 10 15 20 5 OUTPUT LOAD CURRENT (µA) 30 1440/1/2 G11 1440/1/2 G12 Reference Voltage vs Temperature 1.186 1.184 1.182 1.180 1.178 1.176 1.174 1.172 1.170 –60 –40 –20 0 20 40 60 80 100 120 140 TEMPERATURE (°C) 1440/1/2 G13 144012fc LTC1440/LTC1441/LTC1442 PIN FUNCTIONS 1 GND LTC1440 OUT 8 7 1 2 OUT A LTC1441 OUT B 8 7 1 OUT A 2 LTC1442 OUT B 8 7 – 2V + 3 IN + – 4 IN– LTC1440 GND (Pin 1): Ground. Connect to V – for single supply operation. V – (Pin 2): Negative Supply. Connect to ground for single supply operation. Potential should be more negative than GND. IN + (Pin 3): Noninverting Comparator Input. Input common mode range from V – to V + –1.3V. Input current typically 10pA at 25°C. IN – (Pin 4): Inverting Comparator Input. Input common mode range from V – to V + –1.3V. Input current typically 10pA at 25°C. HYST (Pin 5): Hysteresis Input. Connect to REF if not used. Input voltage range is from VREF to VREF – 50mV. REF (Pin 6): Reference Output. 1.182V with respect to V –. Can source up to 200µA and sink 15µA at 25°C. Drive 0.01µF bypass capacitor without oscillation. V + (Pin 7): Positive Supply. 2V to 11V. OUT (Pin 8): Comparator CMOS Output. Swings from GND to V +. Output can source up to 40mA and sink 5mA. LTC1441 OUT A (Pin 1): Comparator A CMOS Output. Swings from V – to V +. Output can source up to 40mA and sink 5mA. V – (Pin 2): Negative Supply. IN A+ (Pin 3): Noninverting Input of Comparator A. Input common mode range from V – to V + –1.3V. Input current typically 10pA at 25°C. IN A– (Pin 4): Inverting Input of Comparator A. Input common mode range from V – to V + –1.3V. Input current typically 10pA at 25°C. U U U V+ V– V+ V– A B V+ + REF 6 5 3 IN A + A – – B + IN B + + 6 3 IN A+ – – + REF 6 HYST 5 HYST 4 IN A– IN B– 5 4 IN B– V– 1440/1/2 PD IN B – (Pin 5): Inverting Input of Comparator B. Input common mode range from V – to V + –1.3V. Input current typically 10pA at 25°C. IN B + (Pin 6): Noninverting Input of Comparator B. Input common mode range from V – to V + –1.3V. Input current typically 10pA at 25°C. V + (Pin 7): Positive Supply. 2V to 11V. OUT B (Pin 8): Comparator B CMOS Output. Swings from V – to V +. Output can source up to 40mA and sink 5mA. LTC1442 OUT A (Pin 1): Comparator A CMOS Output. Swings from V – to V +. Output can source up to 40mA and sink 5mA. V – (Pin 2): Negative Supply. IN A+ (Pin 3): Noninverting Input of Comparator A. Input common mode range from V – to V + –1.3V. Input current typically 10pA at 25°C. IN B– (Pin 4): Inverting Input of Comparator B. Input common mode range from V – to V + –1.3V. Input current typically 10pA at 25°C. HYST (Pin 5): Hysteresis Input. Connect to REF if not used. Input voltage range is from VREF to VREF – 50mV. REF (Pin 6): Reference Output. 1.182V with respect to V –. Can source up to 200µA and sink 15µA at 25°C. Drive 0.01µF bypass capacitor without oscillation. V + (Pin 7): Positive Supply. 2V to 11V. OUT B (Pin 8): Comparator B CMOS Output. Swings from V – to V +. Output can source up to 40mA and sink 5mA. 144012fc 9 LTC1440/LTC1441/LTC1442 APPLICATIONS INFORMATION LTC1440/LTC1441/LTC1442 are a family of micropower comparators with built-in 1.182V reference. Features include programmable hysteresis (LTC1440/LTC1442), wide supply voltage range (2V to 11V) and the ability of the reference to drive up to a 0.01µF capacitor without oscillation. The comparators’ CMOS outputs can source up to 40mA and the supply current glitches, that normally occur when switching logic states, have been eliminated. Power Supplies The comparator family operates from a single 2V to 11V supply. The LTC1440 includes a separate ground for the comparator output stage, allowing a split supply ranging from ± 1V to ± 5.5V. Connecting V – to GND on the LTC1440 will allow single supply operation. If the comparator output is required to source more than 1mA, or the supply source impedance is high, V + should be bypassed with a 0.1µF capacitor. Comparator Inputs The comparator inputs can swing from the negative supply V – to within 1.3V max of the positive supply V +. The inputs can be forced 300mV below V – or above V + without damage and the typical input leakage current is only ± 10pA. Comparator Outputs The LTC1440 comparator output swings between GND and V + to assure TTL compatibility with a split supply. The LTC1441 and LTC1442 outputs swing between V – and V +. The outputs are capable of sourcing up to 40mA and sinking up to 5mA while still maintaining microampere quiescent currents. The output stage does not generate crowbar switching currents during transitions which helps minimize parasitic feedback through the supply pins. Voltage Reference The internal bandgap reference has a voltage of 1.182V referenced to V –. The reference accuracy is 1.5% from – 40°C to 85°C. It can source up to 200µA and sink up to 20µA with a 5V supply. The reference can drive a bypass 1000 RESISTOR VALUE (kΩ) 10 U W U U capacitor of up to 0.01µF without oscillation and by inserting a series resistor, capacitance values up to 100µF can be used (Figure 1). Figure 2 shows the resistor value required for different capacitor values to achieve critical damping. Bypassing the reference can help prevent false tripping of the comparators by preventing glitches on V + or reference load transients from disturbing the reference output voltage. Figure 3 shows the bypassed reference output with a square wave applied to the V + pin. Resistors R2 and R3 set 10mV of hysteresis voltage band while R1 damps the reference response. Note that the comparator output doesn’t trip. REFERENCE OUTPUT REF R1 LTC144X C1 V– 1440/1/2 F01 Figure 1. Damping the Reference Output 100 10 1 0.1 0.001 0.01 0.1 1 CAPACITOR VALUE (µF) 10 1440/1/2 F02 Figure 2. Damping Resistance vs Bypass Capacitor Value 144012fc LTC1440/LTC1441/LTC1442 APPLICATIONS INFORMATION 7 V+ 3 IN + + 8 OUT 4 IN– 5V TO 8V – IREF 6 R1 5 HYST V– 2 1440/1/2 F04 5 HYST R2 10k R3 2.4M R1 430 Ω C1 1µF LTC1440 6 REF V– 2 GND 1 Figure 3a. Reference Transient Response Test Circuit 8V V+ 5V 2mV/DIV VREF OUT 2ms/DIV 1440/1/2 F03b Figure 3b. Reference and Comparator Output Transient Response Hysteresis Hysteresis can be added to the LTC1440 by connecting a resistor (R1) between the REF and HYST pins and a second resistor (R2) from HYST to V – (Figure 4). The difference between the upper and lower threshold voltages, or hysteresis voltage band (VHB), is equal to twice the voltage difference between the REF and HYST pins. When more hysteresis is added, the upper threshold increases the same amount as the low threshold decreases. The maximum voltage allowed between REF and HYST pins is 50mV, producing a maximum hysteresis voltage band of 100mV. The hysteresis band could vary by U W U U up to 15%. If hysteresis is not wanted, the HYST pin should be shorted to REF. Acceptable values for IREF range from 0.1µA to 5µA. If 2.4M is chosen for R2, then the value of R1 is equal to the value of VHB. R1 = LTC1440 R2 = VHB (2)(IREF) REF ( 1.182V – IREF VHB 2 ) R2 1440/1/2 F03a Figure 4. Programmable Hysteresis Level Detector The LTC1440 is ideal for use as a micropower level detector as shown in Figure 5. R1 and R2 form a voltage divider from VIN to the noninverting comparator input. R3 and R4 set the hysteresis voltage, and R5 and C1 bypass the reference output. The following design procedure can be used to select the component values: 1. Choose the VIN voltage trip level, in this example 4.65V. V IN R2 3.4M 1% R1 1.18M 1% 5V 7 V+ 3 IN + + 8 OUT 4 IN – – 5 HYST R3 15k 1% R4 2.4M 1% R5 430 Ω 5% C1 1µF LTC1440 6 REF V– 2 GND 1 1440/1/2 F05 Figure 5. Glitch-Free Level Detector with Hysteresis 144012fc 11 LTC1440/LTC1441/LTC1442 APPLICATIONS INFORMATION 2. Calculate the required resistive divider ratio. Ratio = VREF/ VIN Ratio = 1.182V/4.65V = 0.254 3. Choose the required hysteresis voltage band at the input VHBIN, in this example 60mV. Calculate the hysteresis voltage band referred to the comparator input VHB. VHB = (VHBIN)(Ratio) VHB = (60mV)(0.254) VHB = 15.24mV 4. Choose the values for R3 and R4 to set the hysteresis. R4 = 2.4M R3(kΩ) = VHB = 15k 5. Choose the values for R1 and R2 to set the trip point. V 1.182V = 1.18M R1 = REF = IBIAS 1µA ⎤ ⎡ ⎥ ⎢ VIN R2 = R1⎢ − 1⎥ VHB ⎥ ⎢ ⎥ ⎢ VREF + 2 ⎦ ⎣ 12 U W U U ⎤ ⎡ ⎥ ⎢ 4.65V − 1⎥ R2 = 1.18M ⎢ 15mV ⎥ ⎢ ⎥ ⎢ 1.182V + 2 ⎦ ⎣ R2 = 3.40M Low Voltage Operation The guaranteed minimum operating voltage is 2V or (± 1V). As the total supply voltage is reduced below 2V, the performance degrades and the supply current falls. Both the reference and the comparator are still functioning with supply voltage down to 1.5V. The reference will have slightly worse temperature coefficient. While the comparator would have less output drive and the propagation delay increases. The useful input voltage range extends from the negative supply to a little under 1V below the positive supply, which is slightly closer to the positive rail than the device operating from higher supply voltages. 144012fc LTC1440/LTC1441/LTC1442 TYPICAL APPLICATIONS 10-Bit 30µA A/D Converter 5V EIN 0V TO 3V LT 1034 1.2V ® 100k 10pF 365k* C1 1/2 LTC1441 + 2N3809 – VN2222LL 74C00 10M 74C00 *TRW-IRC MRT–5/+120ppm/°C CONV COMMAND Q 74C74 D CLK 1440/1/2 TA03 150k 0.033µF POLYSTYRENE 1N914 Low Battery Detect Operates Down to 1.5V 2-CELL NiCd 2.6M 3 IN + 1M + 8 OUT 4 IN– – 6 REF 20k 5 1.3M HYST GND 1 V– 2 1M U 1M 5V 470k 32.768kHz C2 1/2 LTC1441 + – 1.2M STATUS 74C00 74C00 DATA OUT Q 32.768kHz “Watch Crystal” Oscillator 7 V+ LTC1440 1M +V 470k 32.768kHz + 1/2 LTC1441 OUT – V+ 10pF 1440/1/2 TA05 1.2M 1440 TA06 144012fc 13 LTC1440/LTC1441/LTC1442 PACKAGE DESCRIPTIO 3.5 ± 0.05 1.65 ± 0.05 2.15 ± 0.05 (2 SIDES) PACKAGE OUTLINE 0.25 ± 0.05 0.50 BSC 2.38 ± 0.05 (2 SIDES) RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS PIN 1 TOP MARK (NOTE 6) 5.23 (.206) MIN 0.42 ± 0.038 (.0165 ± .0015) TYP RECOMMENDED SOLDER PAD LAYOUT 0.254 (.010) GAUGE PLANE 0.53 ± 0.152 (.021 ± .006) DETAIL “A” 0.18 (.007) SEATING PLANE 0.22 – 0.38 (.009 – .015) TYP 1 23 4 NOTE: 1. DIMENSIONS IN MILLIMETER/(INCH) 2. DRAWING NOT TO SCALE 3. DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS. MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.152mm (.006") PER SIDE 4. DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS. INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.152mm (.006") PER SIDE 5. LEAD COPLANARITY (BOTTOM OF LEADS AFTER FORMING) SHALL BE 0.102mm (.004") MAX 14 U DD Package 8-Lead Plastic DFN (3mm × 3mm) (Reference LTC DWG # 05-08-1698) R = 0.115 TYP 5 0.675 ± 0.05 0.38 ± 0.10 8 3.00 ± 0.10 (4 SIDES) 1.65 ± 0.10 (2 SIDES) (DD8) DFN 1203 0.200 REF 0.75 ± 0.05 4 0.25 ± 0.05 2.38 ± 0.10 (2 SIDES) 1 0.50 BSC 0.00 – 0.05 BOTTOM VIEW—EXPOSED PAD NOTE: 1. DRAWING TO BE MADE A JEDEC PACKAGE OUTLINE M0-229 VARIATION OF (WEED-1) 2. DRAWING NOT TO SCALE 3. ALL DIMENSIONS ARE IN MILLIMETERS 4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE 5. EXPOSED PAD SHALL BE SOLDER PLATED 6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION ON TOP AND BOTTOM OF PACKAGE MS8 Package 8-Lead Plastic MSOP (Reference LTC DWG # 05-08-1660) 0.889 ± 0.127 (.035 ± .005) 3.20 – 3.45 (.126 – .136) 3.00 ± 0.102 (.118 ± .004) (NOTE 3) 0.65 (.0256) BSC 8 7 65 0.52 (.0205) REF DETAIL “A” 0° – 6° TYP 4.90 ± 0.152 (.193 ± .006) 3.00 ± 0.102 (.118 ± .004) (NOTE 4) 1.10 (.043) MAX 0.86 (.034) REF 0.65 (.0256) BSC 0.127 ± 0.076 (.005 ± .003) MSOP (MS8) 0204 144012fc LTC1440/LTC1441/LTC1442 PACKAGE DESCRIPTION N8 Package 8-Lead PDIP (Narrow 0.300) (LTC DWG # 05-08-1510) .400* (10.160) MAX 8 7 6 5 .300 – .325 (7.620 – 8.255) .008 – .015 (0.203 – 0.381) ( +.035 .325 –.015 8.255 +0.889 –0.381 ) INCHES MILLIMETERS *THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .010 INCH (0.254mm) NOTE: 1. DIMENSIONS ARE .050 BSC 8 .245 MIN .030 ±.005 TYP RECOMMENDED SOLDER PAD LAYOUT .010 – .020 × 45° (0.254 – 0.508) .008 – .010 (0.203 – 0.254) NOTE: 1. DIMENSIONS IN INCHES (MILLIMETERS) 2. DRAWING NOT TO SCALE 3. THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .006" (0.15mm) Information furnished by Linear Technology Corporation is believed to be accurate and reliable. However, no responsibility is assumed for its use. Linear Technology Corporation makes no representation that the interconnection of its circuits as described herein will not infringe on existing patent rights. U .255 ± .015* (6.477 ± 0.381) 1 2 3 4 .130 ± .005 (3.302 ± 0.127) .045 – .065 (1.143 – 1.651) .065 (1.651) TYP .120 (3.048) .020 MIN (0.508) MIN .018 ± .003 (0.457 ± 0.076) N8 1002 .100 (2.54) BSC S8 Package 8-Lead Plastic Small Outline (Narrow 0.150) (LTC DWG # 05-08-1610) .045 ±.005 .189 – .197 (4.801 – 5.004) NOTE 3 7 6 5 .160 ±.005 .228 – .244 (5.791 – 6.197) .150 – .157 (3.810 – 3.988) NOTE 3 1 2 3 4 .053 – .069 (1.346 – 1.752) 0°– 8° TYP .004 – .010 (0.101 – 0.254) .016 – .050 (0.406 – 1.270) .014 – .019 (0.355 – 0.483) TYP .050 (1.270) BSC SO8 0303 144012fc 15 LTC1440/LTC1441/LTC1442 TYPICAL APPLICATION 10kHz V/F Converter +V 6.2V TO 12V INPUT 0V TO 5V 1.2M* 10kHz TRIM 200k 0.01µF = HP5082-2810 = 1N4148 = 2N2222 * = 1% METAL FILM ** = POLYSTYRENE Q6 Q5 15k Q7 RELATED PARTS PART NUMBER LTC1443 LTC1444/LTC1445 LTC1540 LTC1541 LTC1842/LTC1843 LTC1998 DESCRIPTION 1.182V Reference with Micropower Quad Comparators 1.2V Reference with Quad Comparator with Adjustable Hysteresis 1.182V Reference with Nanopower Comparator with Adjustable Hysteresis 1.2V Reference with Micropower Amplifier and Comparator 1.82V Reference with Dual Comparators with Adjustable Hysteresis 1.2 Reference with Comparator with Adjustable Thesholds COMMENTS 1% Accuracy, 8.5µA Maximum Current, Ref Output Drives 0.01µF 1% Accuracy, 8.5µA Maximum Current, Ref Output Drives 0.01µF DFN Package 0.3µA Quiescent Current (Typical), Reference Drives 0.01µF DFN Package 1.25% Accuracy, Rail-to-Rail Out, Low Offset Amplifier 1% Accuracy, Open-Drain Out, Reference Drives 0.01µF Li-Ion Low Battery Monitor, SOT23, 1% Accuracy SOT23, 1.4V to 18.5V Supply Range, ±2% Over Temperature LT6700-1 0.4 Reference with Low Voltage Dual Comparators LT6700-2/LT6700-3 16 Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● U LM334 2k* + – C1 1/2 LTC1441 Q1 2.2µF LT1034-1.2 LT1034-1.2 Q8 + 0.47µF + 50pF Q2 Q3 100k Q4 2M TYP 100Hz TRIM 100pF** fOUT 0kHz TO 10kHz 10M 74C14 2.7M 0.1µF – C2 1/2 LTC1441 + 1440/1/2 TA04 144012fc LT 0106 REV C • PRINTED IN USA www.linear.com © LINEAR TECHNOLOGY CORPORATION 1996