TSM971/72/73/82/84 Ultra-Low-Power, Open-Drain Single/Dual-Supply Comparators FEATURES DESCRIPTION ♦ Alternate source for: MAX971/MAX972/MAX973/MAX982/MAX984 ♦ Ultra-Low Quiescent Current Over Temperature TSM971 Single+Reference: 4μA (max) TSM972: Dual Comparator Only: 4μA (max) TSM973/TSM982 Dual+Reference: 6μA (max) TSM984 Quad+Reference: 8.5μA (max) ♦ Single or Dual Power Supplies: Single: +2.5V to +11V Dual: ±1.25V to ±5.5V ♦ Input Voltage Range Includes Negative Supply ♦ 12μs Propagation Delay at 10mV Overdrive ♦ Open-drain Output Stages for Wired-OR Applications ♦ Internal 1.182V±1% Reference: TSM971/TSM973 ♦ Internal 1.182V±2% Reference: TSM982/TSM984 ♦ Adjustable Hysteresis: TSM971/TSM973/TSM982 ♦ Separate Output GND Pin: TSM971/TSM984 The TSM971/972/973/982/984 family of single/dual/quad, low-voltage, micropower analog comparators is electrically and form-factor identical to the MAX971/972/973/982/984 family of analog comparators. Ideal for 3V or 5V single-supply applications, this comparator family can operate from single +2.5V to +11V supplies or from ±1.25V to ±5.5V dual supplies. The single TSM971 and the dual TSM972 draw less than 4μA (max) supply current over temperature. The TSM973/TSM982 duals and the quad TSM984 draw less than 3μA per comparator over temperature. APPLICATIONS Threshold Detectors Window Comparator Level Translators Oscillator Circuits Battery-Powered Systems All comparators in this family exhibit an input voltage range from the negative supply rail to within 1.3V of the positive supply. Wired-OR applications are enabled as the comparators’ output stages are opendrain. A 1.182V reference is internal to the TSM971/TSM973 (±1%) and the TSM982/TSM984 (±2%). Without complicated feedback configurations and only requiring two additional resistors, adding external hysteresis is available on the TSM971, TSM973, and the TSM982. TYPICAL APPLICATION CIRCUIT A 5V, Low-Parts-Count Window Detector PART TSM971 TSM972 TSM973 TSM982 TSM984 INTERNAL COMPARATORS INTERNAL REFERENCE PER PACKAGE HYSTERESIS Yes, ±1% 1 Yes No 2 No Yes, ±1% 2 Yes Yes, ±2% 2 Yes Yes, ±2% 4 No PART TSM971C TSM971E TSM972C TSM972E TSM973C TSM973E TSM982C TSM982E TSM984C TSM984E TEMPERATURE RANGE 0ºC to 70ºC -40ºC to 85ºC 0ºC to 70ºC -40ºC to 85ºC 0ºC to 70ºC -40ºC to 85ºC 0ºC to 70ºC -40ºC to 85ºC 0ºC to 70ºC -40ºC to 85ºC PACKAGE 8-Pin MSOP/SOIC 8-Pin MSOP/SOIC 8-Pin MSOP/SOIC 8-Pin MSOP/SOIC 16-Pin SOIC Page 1 © 2014 Silicon Laboratories, Inc. All rights reserved. TSM971/72/73/82/84 ABSOLUTE MAXIMUM RATINGS Supply Voltage (V+ to V-, V+ to GND, GND to V-)......-0.3V, +12V Voltage Inputs (IN+, IN-)..............................................(V+ + 0.3V) to (V- - 0.3V) HYST…………………………………….(REF + 5V) to (V- - 0.3V) Output Voltage REF..................................................... (V+ + 0.3V) to (V- - 0.3V) OUT (TSM971, TSM984).................(V+ + 0.3V) to (GND - 0.3V) OUT (TSM972/73, TSM982/84).... ......(V+ + 0.3V) to (V- - 0.3V) Input Current (IN+, IN-, HYST)..............................................20mA Output Current REF…………………………………………………………….20mA OUT…………………………………………………………….50mA Output Short-Circuit Duration (V+ ≤ 5.5V) ...................Continuous Continuous Power Dissipation (TA = +70°C) 8-Pin MSOP (derate 4.1mW/°C above +70°C) .................330mW 8-Pin SOIC (derate 5.88mW/°C above +70°C)..................471mW 16-Pin SOIC (8.7mW/°C above +70°C) ............................696mW Operating Temperature Range TSM97xC..................................................................0°C to +70°C TSM98xE...............................................................-40°C to +85°C Storage Temperature Range .................................-65°C to +150°C Lead Temperature (soldering, 10s) ......................................+300°C Electrical and thermal stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only and functional operation of the device at these or any other condition beyond those indicated in the operational sections of the specifications is not implied. Exposure to any absolute maximum rating conditions for extended periods may affect device reliability and lifetime. PACKAGE/ORDERING INFORMATION ORDER NUMBER PART CARRIER QUANTITY MARKING TSM971CUA+ Tube 50 TAAZ TSM971CUA+T Page 2 Tape & Reel ORDER NUMBER PART CARRIER QUANTITY MARKING TSM971CSA+ Tube 97 Tape & Reel 2500 Tube 97 Tape & Reel 2500 TSM971CSA+T TS971 TSM971ESA+ 2500 TSM971ESA+T TS971E TSM971/72/73/82/84 Rev. 1.0 TSM971/72/73/82/84 PACKAGE/ORDERING INFORMATION ORDER NUMBER PART CARRIER QUANTITY MARKING TSM972CUA+ Tube ORDER NUMBER PART CARRIER QUANTITY MARKING TSM972CSA+ Tube 97 Tape & Reel 2500 Tube 97 TSM972ESA+T Tape & Reel 2500 ORDER NUMBER PART CARRIER QUANTITY MARKING 50 TS972 TSM972CSA+T TABJ Tape & Reel TSM972CUA+T TSM972ESA+ 2500 ORDER NUMBER PART CARRIER QUANTITY MARKING TSM973CUA+ Tube 50 Tape & Reel 2500 TS972E TSM973CSA+ TABE TSM973CUA+T TSM971/72/73/82/84 Rev. 1.0 TSM973CSA+T TS973 TSM973ESA+ TSM973ESA+T TS973E Tube 97 Tape & Reel 2500 Tube 97 Tape & Reel 2500 Page 3 TSM971/72/73/82/84 PACKAGE/ORDERING INFORMATION ORDER NUMBER PART CARRIER QUANTITY MARKING ORDER NUMBER PART CARRIER QUANTITY MARKING TSM982CSA+ TSM982CUA+ Tube 50 Tape & Reel 2500 TABK TSM982CUA+T TSM982CSA+T TS982 TSM982ESA+ TSM982ESA+T TS982E Tube 97 Tape & Reel 2500 Tube 97 Tape & Reel 2500 ORDER NUMBER PART CARRIER QUANTITY MARKING ORDER NUMBER PART CARRIER QUANTITY MARKING TSM984CSE+ Tube 48 TSM984ESE+ Tube 48 Tape & Reel 2500 TSM984ESE+T Tape & Reel 2500 TSM984CSE+T TS984 TS984E Lead-free Program: Silicon Labs supplies only lead-free packaging. Consult Silicon Labs for products specified with wider operating temperature ranges. Page 4 TSM971/72/73/82/84 Rev. 1.0 TSM971/72/73/82/84 ELECTRICAL CHARACTERISTICS – 5V OPERATION V+ = 5V, V- = GND = 0V; TA = -40ºC to +85ºC, unless otherwise noted. Typical values are at TA = +25ºC. See Note 1. PARAMETER POWER REQUIREMENTS Supply Voltage Range Output Voltage Range CONDITIONS MIN See Note 2 2.5 0 TSM971; HYST = REF TSM972 Supply Current IN+ = IN- + 100mV TSM973 TSM982; HYST = REF Output Low Voltage Output Leakage Current REFERENCE 2.5 3.1 TA = -40°C to +85°C 5.5 ±0.01 ±0.02 V- V- to (V+ – 1.3V) V+ = 2.5V to 11V 100Hz to 100kHz TSM971, TSM973, TSM982 Overdrive = 10 mV TA = +25°C; 100pF load; 1MΩ Pullup to V+ Overdrive = 100 mV 0.1 0.1 20 REF- 0.05V TA = +25°C; 100pF load; 1MΩ Pullup to V+. See Note 3 TSM9x2, TSM973 TSM971, TSM984 VOUT = 11V TSM971, TSM973 TSM982, TSM984 Source Current Sink Current 100Hz to 100kHz TSM971/72/73/82/84 Rev. 1.0 UNITS 11 11 3.2 4 3.2 4 4.5 V V μA 1.170 1.158 1.158 1.147 15 6 8 4 6.5 8.5 ±10 ±5 V+ – 1.3V 1.0 1.0 REF mV nA nA V mV/V mV/V μVRMS V 12 4 μs 300 μs IOUT = 1.8mA IOUT = 1.8mA TA = 0°C to +70°C, 1% TA = -40°C to +85°C, 2% TA = 0°C to +70°C, 2% TA = -40°C to +85°C, 3% TA = +25°C TA = -40°C to +85°C TA = +25°C TA = -40°C to +85°C TSM 6 VCM = 2.5V IN+ = IN- = 2.5V C/E temp ranges TSM971, TSM973, TSM982 Reference Voltage Voltage Noise 2.5 TA = +25°C TA = -40°C to +85°C TSM984 COMPARATOR Input Offset Voltage Input Leakage Current (IN-, IN+) Input Leakage Current (at HYST Pin) Input Common-Mode Voltage Range Common-Mode Rejection Ratio Power-Supply Rejection Ratio Voltage Noise Hysteresis Input Voltage Range Response Time (High-to-Low Transition) Response Time (Low-to-High Transition) TA = +25°C TA = -40°C to +85°C TA = +25°C TA = -40°C to +85°C TA = +25°C TYP 1.182 1.182 V- + 0.4 GND + 0.4 100 nA 1.194 1.206 1.206 1.217 V V V V V 25 μA 15 μA 100 μVRMS Page 5 TSM971/72/73/82/84 ELECTRICAL CHARACTERISTICS – 3V OPERATION V+ = 3V, V- = GND = 0V; TA = -40ºC to +85ºC, unless otherwise noted. Typical values are at TA = +25ºC. See Note 1. PARAMETER POWER REQUIREMENTS CONDITIONS MIN TSM971; HYST = REF TSM972 Supply Current IN+ = IN- + 100mV TSM973 TSM982; HYST = REF Output Low Voltage Output Leakage Current REFERENCE 2.4 3.0 3.8 3.0 3.8 4.3 μA 3.4 5.8 5.2 ±0.01 ±0.02 V- V- to (V+ – 1.3V) V+ = 2.5V to 11V 100Hz to 100kHz TSM971, TSM973, TSM982 Overdrive = 10 mV TA = +25°C; 100pF load; 1MΩ Pullup to V+ Overdrive = 100 mV 0.2 0.1 20 REF- 0.05V TA = +25°C; 100pF load; 1MΩ Pullup to V+. See Note 3 TSM9x2, TSM973 TSM971, TSM984 VOUT = 11V TSM971, TSM973 TSM982, TSM984 Sink Current UNITS TA = -40°C to +85°C VCM = 1.5V IN+ = IN- = 1.5V C/E temp ranges TSM971, TSM973, TSM982 Reference Voltage Source Current TSM 2.4 TA = +25°C TA = -40°C to +85°C TSM984 COMPARATOR Input Offset Voltage Input Leakage Current (IN-, IN+) Input Leakage Current (at HYST Pin) Input Common-Mode Voltage Range Common-Mode Rejection Ratio Power-Supply Rejection Ratio Voltage Noise Hysteresis Input Voltage Range Response Time (High-to-Low Transition) Response Time (Low-to-High Transition) TA = +25°C TA = -40°C to +85°C TA = +25°C TA = -40°C to +85°C TA = +25°C TYP 1.170 1.158 1.158 1.147 15 6 8 4 ±10 ±5 V+ – 1.3V 1.0 1.0 REF mV nA nA V mV/V mV/V μVRMS V 12 4 μs 300 μs IOUT = 0.8mA IOUT = 0.8mA TA = 0°C to +70°C, 1% TA = -40°C to +85°C, 2% TA = 0°C to +70°C, 2% TA = -40°C to +85°C, 3% TA = +25°C TA = -40°C to +85°C TA = +25°C TA = -40°C to +85°C 6.2 8.0 1.182 1.182 V- + 0.4 GND + 0.4 100 nA 1.194 1.206 1.206 1.217 V V V V V 25 μA 15 μA Voltage Noise 100Hz to 100kHz 100 μVRMS Note 1: All specifications are 100% tested at TA = +25°C. Specification limits over temperature (TA = TMIN to TMAX) are guaranteed by device characterization, not production tested. Note 2: The TSM934 comparator operates below 2.5V. Refer to the “Low-Voltage Operation: V+ = 1.5V (TSM984 Only)” section. Note 3: Low-to-high response time is due to a 1MΩ pullup resistor and a 100pF capacitive load, based after three time constants. A smaller RC combination results in a faster response time. Page 6 TSM971/72/73/82/84 Rev. 1.0 TSM971/72/73/82/84 TYPICAL PERFORMANCE CHARACTERISTICS V+ = 5V; V- = GND; TA = +25°C, unless otherwise noted. Output Voltage Low vs Load Current Reference Output Voltage vs Output Load Current 1.190 2.5 V+ = 3V or 5V V+ = 5V SINK 1.185 REFERENCE VOLTAGE - V 2 VOL - V 1.5 V+ = 3V 1 0.5 1.180 1.175 1.170 SOURCE 1.165 1.160 1.155 0 0 4 8 12 16 20 24 0 28 5 LOAD CURRENT - mA 10 15 20 25 30 LOAD CURRENT - µA TSM971 Supply Current vs Temperature Reference Voltage vs Temperature 4.5 1.22 IN+ = IN- + 100mV 4 SUPPLY CURRENT - µA REFERENCE VOLTAGE - V 1.21 1.20 1.19 1.18 1.17 1.16 1.15 V+ = 5V, V- = -5V 3.5 3 V+ = 3V, V- = 0V 2.5 2 V+ = 5V, V- = 0V 1.5 1.14 -40 -15 10 35 60 -40 85 -15 10 35 60 85 TEMPERATURE - ºC TEMPERATURE - ºC TSM973/982 Supply Current vs Temperature TSM972 Supply Current vs Temperature 4.5 5 IN+ = IN- + 100mV 4.5 V+ = 10V, V- = 0V 3.5 V+ = 5V, V- = 0V 3 2.5 2 V+ = 3V, V- = 0V SUPPLY CURRENT - µA SUPPLY CURRENT - µA 4 4 V+ = 5V, V- = 0V 3.5 3 V+ = 3V, V- = 0V 2.5 2 1.5 -40 -15 10 35 TEMPERATURE - ºC TSM971/72/73/82/84 Rev. 1.0 60 85 -40 -15 10 35 60 85 TEMPERATURE - ºC Page 7 TSM971/72/73/82/84 TYPICAL PERFORMANCE CHARACTERISTICS V+ = 5V; V- = GND; TA = +25°C, unless otherwise noted. TSM984 Supply Current vs Low Supply Voltages TSM984 Supply Current vs Temperature 10 10 IN+ = IN- + 100mV SUPPLY CURRENT - µA SUPPLY CURRENT - µA 9 V+ = 5V, V- = -5V 8 7 V+ = 5V, V- = 0V 6 5 V+ = 3V, V- = 0V 4 0.1 3 -40 -15 10 35 60 85 1.5 2 SINGLE-SUPPLY VOLTAGE - V TSM971/973/982 Hysteresis Control TSM971/972/984 Transfer Function 5 60 OUTPUT HIGH 4 OUTPUT VOLTAGE - V 40 20 0 NO CHANGE -20 -40 OUTPUT LOW -60 -80 3 2 1 0 0 20 10 30 40 50 -0.4 -0.3 -0.2 -0.1 18 V- = 0V RESPONSE TIME - µs 16 14 VOHL 12 10 8 6 20 40 60 80 LOAD CAPACITANCE - nF 100 INPUT VOLTAGE - mV OUTPUT VOLTAGE - V Response Time vs Load Capacitance 0 0 0.1 0.2 0.3 0.4 IN+ INPUT VOLTAGE - mV VREF - VHYST - mV Page 8 2.5 TEMPERATURE - ºC 80 IN+ - IN- - mV 1 Response Time For Various Input Overdrives (High-to-Low) 5 50mV 4 10mV 3 2 1 20mV 100mV 0 100 0 -2 0 2 4 6 8 10 12 14 16 18 RESPONSE TIME - µs TSM971/72/73/82/84 Rev. 1.0 TSM971/72/73/82/84 TYPICAL PERFORMANCE CHARACTERISTICS V+ = 5V; V- = GND; TA = +25°C, unless otherwise noted. TSM984 Sink Current at Low Supply Voltages Response Time at Low Supply Voltages (Low-to-High) 10 100 SINK CURRENT AT VOUT = 0.4V CURRENT - mA RESPONSE TIME - µs RPULLUP = 10kΩ ±20mV OVERDRIVE 10 ±100mV OVERDRIVE 1 1 1.5 2 1.5 2.5 SINGLE-SUPPLY VOLTAGE - V 2 2.5 SINGLE-SUPPLY VOLTAGE - V Short-Circuit Sink Current vs Supply Voltage 24 SINK CURRENT - mA OUT CONNECTED TO V+ GND CONNECTED TO V22 20 18 16 2 TSM971/72/73/82/84 Rev. 1.0 4 6 8 10 Page 9 TSM971/72/73/82/84 PIN FUNCTIONS TSM971 1 PIN TSM972 TSM973 — — NAME FUNCTION TSM982 — GND Ground. Connect to V- for single-supply operation. Negative Supply. Connect to ground for single-supply operation (TSM971). Comparator Noninverting Input Comparator Inverting Input Hysteresis Input. Connect to REF if not used. Input voltage range is from VREF to (VREF - 50mV). Reference Output. 1.182V with respect to V-. Positive Supply Voltage Comparator Output. Sinks current to GND. Comparator A Output. Sinks current to V-. Comparator A Noninverting Input Comparator A Inverting Input Comparator B Inverting Input Comparator B Noninverting Input Comparator B Output. Sinks current to V-. 2 2 2 2 V- 3 4 — — — — — — IN+ IN- 5 — 5 5 HYST 6 7 8 — — — — — — — 7 — 1 3 4 5 6 8 6 7 — 1 3 — 4 — 8 6 7 — 1 3 — — 4 8 REF V+ OUT OUTA INA+ INAINBINB+ OUTB PIN TSM984 1 2 3 4 5 6 7 8 Page 10 NAME FUNCTION OUTB OUTA V+ INAINA+ INBINB+ REF Comparator B Output. Sinks current to GND. Comparator A Output. Sinks current to GND. Positive Supply Voltage Comparator A Inverting Input Comparator A Noninverting Input Comparator B Inverting Input Comparator B Noninverting Input 1.182V Reference Output with respect to V-. Negative Supply Voltage. Connect to ground for single-supply operation. Comparator C Inverting Input Comparator C Noninverting Input Comparator D Inverting Input Comparator D Noninverting Input Ground. Connect to V- for single-supply operation. Comparator D Output. Sinks current to GND. Comparator C Output. Sinks current to GND. 9 V- 10 11 12 13 14 15 16 INCINC+ INDIND+ GND OUTD OUTC TSM971/72/73/82/84 Rev. 1.0 TSM971/72/73/82/84 BLOCK DIAGRAMS TSM971/72/73/82/84 Rev. 1.0 Page 11 TSM971/72/73/82/84 THEORY OF OPERATION The TSM971/972/973/982/984 family of single/dual/quad, low-voltage, micropower analog comparators provide excellent flexibility and performance while sourcing continuously up to 40mA of current. The TSM971, TSM973, TSM982, and the TSM984 provide an on-board 1.182V reference voltage. To minimize current consumption while providing flexibility, the TSM971, TSM973, and the TSM982 have an on-board HYST pin in order to add additional hysteresis. Power-Supply and Input Signal Ranges The TSM971/972/973/982/984 can operate from a single supply voltage range of +2.5V to +11V, provide a wide common mode input voltage range of V- to V+-1.3V, and accept input signals ranging from V- to V+ - 1V. The inputs can accept an input as much as 300mV above the below the power supply rails without damage to the part. While the TSM971 and the TSM984 are able to operate from a single supply voltage range, a GND pin is available that allows for a dual supply operation with a range of ±1.25V to ±5.5V. If a single supply operation is desired, the GND pin needs to be tied to V-. In a dual supply mode, the TSM971 and the TSM984 are compatible with TTL/CMOS with a ±5V voltage and the TSM972, TSM973, and TSM982 are compatible with TTL with a single +5V supply. Low-Voltage Operation: V+ = 1.5V (TSM984 Only) Due to a decrease in propagation delay and a reduction in output drive, the TSM971/972/973/982 cannot be used with a supply voltage much lower than 2.5V. However, the TSM984 can operate down to a supply voltage of 2V; furthermore, as the supply voltage reduces, the TSM984 supply current drops and the performance is degraded. When the supply voltage drops to 2.2V, the reference voltage will no longer function; however, the comparators will function down to a 1.5V supply voltage. Furthermore, the input voltage range is extended to just below 1V the positive supply rail. For applications with a sub-2.5V power supply, it is recommended to evaluate the circuit over the entire power supply range and temperature. Comparator Output The TSM971 and the TSM984 have a GND pin that allows the output to swing from V+ to GND while the Page 12 V- pin can be set to a voltage below GND as long as the voltage difference between V+ and V- is within 11V. The TSM971 and the TSM984 sink current to GND. By having open-drain outputs, the TSM971/972/973/982/984 can be used in wireOREd and level-shifting applications. On the other hand, the TSM972, TSM973, and the TSM982 do not have a GND pin so the outputs sink current to V. With a 100mV input overdrive, the propagation delay of the TSM971/972/973/982/984 is 4μs. Voltage Reference The TSM971/972/973 have an on-board 1.182V reference voltage with an accuracy of ±1% while the TSM982/984 have an on-board 1.182V reference voltage with an accuracy of ±2% across a temperature range of 0°C to +70°C. The REF pin is able to source and sink 25μA and 15μA of current, respectively. The REF pin is referenced to V- and it should not be bypassed. Noise Considerations Noise can play a role in the overall performance of the TSM971/972/973/982/984. Despite having a large gain, if the input voltage is near or equal to the input offset voltage, the output will randomly switch HIGH and LOW. As a result, the TSM971/972/973/982/984 produces a peak-to-peak noise of about 0.3mV while the reference voltage produces a peak-to-peak noise of about 1mV. Furthermore, it is important to design a layout that minimizes capacitive coupling from a given output to the reference pin as crosstalk can add noise and as a result, degrade performance. APPLICATIONS INFORMATION Hysteresis As a result of circuit noise or unintended parasitic feedback, many analog comparators often break into oscillation within their linear region of operation especially when the applied differential input voltage approaches 0V (zero volt). Externally-introduced hysteresis is a well-established technique to stabilizing analog comparator behavior and requires external components. As shown in Figure 1, adding comparator hysteresis creates two trip points: VTHR (for the rising input voltage) and VTHF (for the falling input voltage). The hysteresis band (VHB) is defined as the voltage difference between the two trip points. When a comparator’s input voltages are equal, TSM971/72/73/82/84 Rev. 1.0 TSM971/72/73/82/84 hysteresis effectively forces one comparator input to move quickly past the other input, moving the input Figure 2. Programming the HYST Pin Figure 1. Threshold Hysteresis Band out of the region where oscillation occurs. Figure 1 illustrates the case in which an IN- input is a fixed voltage and an IN+ is varied. If the input signals were reversed, the figure would be the same with an inverted output. typically in the range of 0.1μA and 4μA. It is also important to ensure that the current from reference is much larger than the HYST pin input current. Given R2 = 2.4MΩ, the current sourced by the reference is 0.5μA. This allows the hysteresis band and R1 to be approximated as follows: R1(kΩ) = VHB(mv) Hysteresis (TSM971/973 and TSM982) Hysteresis can be generated with two external resistors using positive feedback as shown in Figure 2. Resistor R1 is connected between REF and HYST and R2 is connected between HYST and V-. This will increase the trip point for the rising input voltage, VTHR, and decrease the trip point for the falling input voltage, VTHF, by the same amount. If no hysteresis is required, connect HYST to REF. The hysteresis band, VHB, is voltage across the REF and HYST pin multiplied by a factor of 2. The HYST pin can accept a voltage between REF and REF-50mV, where a voltage of REF-50mV generates the maximum voltage across R1 and thus, the maximum hysteresis and hysteresis band of 50mV and 100mV, respectively. To design the circuit for a desired hysteresis band, consider the equations below to acquire the values for resistors R1 and R2: R1 = Hysteresis (TSM972 and TSM984) Relative to adding hysteresis with the HYST pin as was done for the TSM971, TSM973, and the TSM982, the circuit in Figure 3 uses positive feedback along with two external resistors to set the desired hysteresis. The circuit consumes more VHB ሺ2 x IREF ሻ 1.182 R2 = For the TSM973 and TSM982, the hysteresis is the same for both comparators. VHB 2 IREF where IREF is the primary source of current out of the reference pin and should be maintained within the maximum current the reference can source. This is TSM971/72/73/82/84 Rev. 1.0 Figure 3. External Hysteresis current and it slows down the hysteresis effect due to the high impedance on the feedback. Due to the pull-up resistor on the output and its inability to Page 13 TSM971/72/73/82/84 source current, upper threshold variations will depend on the value of the pull-up resistor. Board Layout and Bypassing While power-supply bypass capacitors are not typically required, it is good engineering practice to use 0.1μF bypass capacitors close to the device’s power supply pins when the power supply impedance is high, the power supply leads are long, or there is excessive noise on the power supply traces. To reduce stray capacitance, it is also good engineering practice to make signal trace lengths as short as possible. Also recommended are a ground plane and surface mount resistors and capacitors. TYPICAL APPLICATION CIRCUITS voltage VIN will appear larger due to the input resistor divider. 2. Selecting R1. As the leakage current at the INB- pin is less than 1nA, the current through R1 should be at least 100nA to minimize offset voltage errors caused by the input leakage current. Values within 100kΩ and 1MΩ are recommended. In this example, a 294kΩ, 1% standard value resistor is selected for R1. 3. Calculating R2 + R3. As the input voltage VIN rises, the overvoltage threshold should be 5.5V. Choose R2 + R3 as follows: R2 + R3 = R1 x ൬ Window Detector The schematic shown in Figure 4 is for a 4.5V undervoltage threshold detector and a 5.5V overvoltage threshold detector using the TSM973. Resistor components R1, R2, and R3 can be selected based on the threshold voltage desired while resistors R4 and R5 can be selected based on the hysteresis desired. Adding hysteresis to the circuit will minimize chattering on the output when the input voltage is close to the trip point. OUTA and OUTB generate the active-low undervoltage indication and active-low overvoltage indication, respectively. If both OUTA and OUTB signals are Wired-ORed, the resulting output is an active-high, power-good signal. To design the circuit, the following procedure needs to be performed: 1. As described in the section “Hysteresis (TSM971/973 and TSM982)”, determine the desired hysteresis and select resistors R4 and R5 accordingly. This circuit has ±5mV of hysteresis at the input where the input = 294kΩ x ൬ VOTH - 1൰ VREF +VHYS 5.5V - 1൰ 1.182V +5mV = 1.068MΩ 4. Calculating R2. As the input voltage VIN falls, the undervoltage threshold should be 4.5V. Choose R2 as follows: R2 = (R1 + R2+ R3) x = (294kΩ + 1.068MΩ) x ሺVREF -VHYS ሻ - 294k VUTH ሺ1.182V-5mVሻ - 294k 4.5 = 62.2kΩ In this example, a 61.9kΩ, 1% standard value resistor is selected for R2. 5. Calculating R3. R3 = (R2 + R3) - R2 = 1.068MΩ – 61.9kΩ = 1.006MΩ In this example, a 1MΩ, 1% standard value resistor is selected for R3. 6. Using the equations below, verify all resistor values selected: VOTH = (VREF + VHYS ) x ሺR1 + R2 + R3ሻ R1 Figure 4. Window Detector Page 14 TSM971/72/73/82/84 Rev. 1.0 TSM971/72/73/82/84 = 5.474V VOTH = (VREF - VHYS ) x ሺR1 + R2 + R3ሻ (R1+R2) = 4.484V Where the hysteresis voltage is given by: VHYS = VREF R5 x R4 Battery Switchover Circuit Diodes are typically used in applications where power to a device switches from a line-powered DC to a backup battery. However, the voltage drop and power loss across the diodes is undesired. Figure 5 shows a different approach that replaces the diode with a P-channel MOSFET and uses the TSM973 to control the MOSFET. When the voltage from the line-powered DC drops below 4V, OUTA switches low, and then turns on Q1. When the battery drops below 3.6V, Comparator B generates a “low-battery” signal. Level Shifter Figure 6 provides a simple way to shift from bipolar ±5V inputs to TTL signals by using the TSM984. To protect the comparator inputs, 10kΩ resistors are placed in series and do not have an effect on the performance of the circuit. Figure 6. Level Shifter: ±5V Input to Single-Ended 3.3V Output Figure 5. Battery Switchover Circuit TSM971/72/73/82/84 Rev. 1.0 Page 15 TSM971/72/73/82/84 PACKAGE OUTLINE DRAWING 8-Pin SOIC Package Outline Drawing (N.B., Drawings are not to scale) 0.546 REF 0.33 - 0.51 5.80 – 6.20 1.27 TYP 4.80 - 5.00 LEADFARME THICKNESS 0.19 – 0.25 1 1.32 – 1.52 7' REF ALL SIDE 3.73 - 3.89 7' REF ALL SIDE 2 0.48 Max 0.28 Min 45' Angle 0.76 Max 0.66 Min 1.75 Max GAUGE PLANE 3.81 – 3.99 0.25 0.10 – 0.25 2 0 - 8° 0.406 – 0.863 0.10 Max Notes: Page 16 1 Does not include mold flash, protrusions or gate burns. Mold flash, protrusions or gate burrs shall not exceed 0.15 mm per side. 2 Does not include inter-lead flash or protrusions. Inter-lead flash or protrusions shall not exceed 0.25 mm per side. 3. Lead span/stand off height/coplanarity are considered as special characteristic (s). 4. Controlling dimensions are in mm. 5. This part is compliant with JEDEC specification MS-012 6. Lead span/stand off height/coplanarity are considered as Special characteristic. TSM971/72/73/82/84 Rev. 1.0 TSM971/72/73/82/84 PACKAGE OUTLINE DRAWING 8-Pin MSOP Package Outline Drawing (N.B., Drawings are not to scale) TSM971/72/73/82/84 Rev. 1.0 Page 17 TSM971/72/73/82/84 PACKAGE OUTLINE DRAWING 16-Pin SOIC Package Outline Drawing (N.B., Drawings are not to scale) Patent Notice Silicon Labs invests in research and development to help our customers differentiate in the market with innovative low-power, small size, analog-intensive mixed-signal solutions. Silicon Labs' extensive patent portfolio is a testament to our unique approach and world-class engineering team. The information in this document is believed to be accurate in all respects at the time of publication but is subject to change without notice. Silicon Laboratories assumes no responsibility for errors and omissions, and disclaims responsibility for any consequences resulting from the use of information included herein. Additionally, Silicon Laboratories assumes no responsibility for the functioning of undescribed features or parameters. Silicon Laboratories reserves the right to make changes without further notice. Silicon Laboratories makes no warranty, representation or guarantee regarding the suitability of its products for any particular purpose, nor does Silicon Laboratories assume any liability arising out of the application or use of any product or circuit, and specifically disclaims any and all liability, including without limitation consequential or incidental damages. Silicon Laboratories products are not designed, intended, or authorized for use in applications intended to support or sustain life, or for any other application in which the failure of the Silicon Laboratories product could create a situation where personal injury or death may occur. Should Buyer purchase or use Silicon Laboratories products for any such unintended or unauthorized application, Buyer shall indemnify and hold Silicon Laboratories harmless against all claims and damages. Silicon Laboratories and Silicon Labs are trademarks of Silicon Laboratories Inc. Other products or brandnames mentioned herein are trademarks or registered trademarks of their respective holders. Page 18 Silicon Laboratories, Inc. 400 West Cesar Chavez, Austin, TX 78701 +1 (512) 416-8500 ▪ www.silabs.com TSM971/72/73/82/84 Rev. 1.0 Smart. Connected. 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