LM393A-SR

LM393A 36V Low Power Dual Differential Comparators Features  Wide Single-supply Voltage Range or Dual Supplies: +2.5 V to +36 V or ±1.25 V to ±18 V  Very Low Supply Current (150 μA/ch) Independent of Supply Voltage(0.75 mW/comparator at +5 V)  Low Input Bias Current：4 nA typ.  Low Offset Voltage： ± 3.0 mV Max  Input Common-mode Voltage Range Includes Ground  Internal Differential Input Voltage Range Equal to The Supply Voltage   TTL, DTL, ECL, MOS, CMOS compatible Outputs ESD Clamps on the Inputs Increase the Ruggedness of the Device Without Affecting Performance  Low Output Saturation  –40°C to 125°C Operation Range  ESD Rating： Robust 4KV – HBM, 2KV – CDM  High Performance Drop-In Compatible With 339, Description The devices in this series consist of dual/quad independent single or dual supply voltage comparators on a single monolithic substrate. The common mode input voltage range includes ground even when operated from a single supply, and the low power supply current drain makes these comparators suitable for battery operation. These types were designed to directly interface with TTL and CMOS, Current drain is independent of the supply voltage. The outputs can be connected to other open-collector outputs to achieve wired-AND relationships. The LM393A is dual channel version available in 8-pin SOP package. All devices are specified for the temperature range of –40°C to +125°C. 3PEAK and the 3PEAK logo are registered trademarks of 3PEAK INCORPORATED. All other trademarks are the property of their respective owners. 339, 393, 2901 Series Product Applications  High-speed Line or Digital Line Receivers  High Speed Sampling Circuits  Peak and Zero-crossing Detectors  Threshold Detectors/Discriminators  Sensing at Ground or Supply Line Pin Configuration (Top View) www.3peakic.com.cn 1 LM393A 36V Low Power Dual Differential Comparators Order Information Model Name Order Number Package MSL Level Transport Media, Quantity Marking Information LM393A LM393A-SR 8-Pin SOP 3 Tape and Reel, 4,000 393A LM393A LM393A-DFGR 8-Pin DFN 3 Tape and Reel, 3,000 93A LM393A LM393A-TSR 8-Pin TSSOP 3 Tape and Reel, 3,000 393A Thermal Information Package RθJA RθJC Unit 8-Pin SOP 112.40 64.12 ℃/W 8-Pin DFN 103 55 ℃/W 8-Pin TSSOP 152.5 51 ℃/W Absolute Maximum Ratings Note 1 Supply Voltage: V+ – V–......................................42V – + Input Voltage............................. V – 0.3 to V + 0.3 Operating Temperature Range.........–40°C to 125°C Maximum Junction Temperature................... 150°C Note 2...........................±20mA Storage Temperature Range.......... –65°C to 150°C Output Current: OUT..................................... ±20mA Lead Temperature (Soldering, 10 sec) ......... 260°C Input Current: +IN, –IN, Output Short-Circuit Duration Note 3….............. Infinite 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. Note 2: The inputs are protected by ESD protection diodes to each power supply. If the input extends more than 500mV beyond the power supply, the input current should be limited to less than 10mA. Note 3: A heat sink may be required to keep the junction temperature below the absolute maximum. This depends on the power supply voltage and how many amplifiers are shorted. Thermal resistance varies with the amount of PC board metal connected to the package. The specified values are for short traces connected to the leads. ESD, Electrostatic Discharge Protection Symbol www.3peakic.com.cn Parameter Condition Minimum Level Unit 2 LM393A 36V Low Power Dual Differential Comparators HBM Human Body Model ESD ANSI/ESDA/JEDEC JS-001 4 kV CDM Charged Device Model ESD ANSI/ESDA/JEDEC JS-002 2 kV www.3peakic.com.cn 3 LM393A 36V Low Power Dual Differential Comparators Electrical Characteristics The ● denotes the specifications which apply over the full operating temperature range(-40°C ~ +125°C), otherwise specifications are at TA = 27°C. VDD = +5V, VIN+ = VDD, VIN- = 1.4V, RPU=10kΩ, CL =15pF. SYMBOL PARAMETER VDD Supply Voltage VOS Input Offset Voltage Note 1 VCC = 5 V to MAX, VIC = VICR(min), VO = 1.4V, -40°C ~ +125°C IB Input Bias Current Vo=1.4V 4 nA Ios Input offset Current Vo=1.4V 1 nA CIN Input Capacitance Differential Common Mode 2.5 5 pF VCM Common-mode Input Voltage Range AVD Large-signal Differential-voltage Amplification CONDITIONS MIN ● 2.5 ● -6 25°C -40°C ~ +125°C ● VCC = 15 V, VO = 1.4 V to 11.4 V, V +6 mV 0 VDD-2 V 400 V/mV 200 nA 7 μA 400 mV 500 mV High-level Output Current ● 250 Low-Level Output Voltage IOL = 4mA, VID = −1V ● IOL Low-level Output Current IQ Quiescent Current per Comparator tRT 36 V 25 VOH = 36 V, VID = 1 V VOL UNITS VDD-1.5 VOH = 5 V, VID = 1 V IOH ±0.6 MAX 0 50 RL ≥ 15 kΩ to VCC TYP Response time VOL = 1.5 V, VID = −1 V 10 mA VCC = 5 V 150 300 μA VCC = 36 V 150 300 μA RL connected to 5 V through 5.1 kΩ, CL = 15 pF, See Note 3 100-mV input step with 5-mV overdrive 2 μs TTL-level input step 0.5 Note 1: The input offset voltage is the average of the input-referred trip points. www.3peakic.com.cn 4 LM393A 36V Low Power Dual Differential Comparators Typical Performance Characteristics VS = +5V, VCM = 0V, RL = Open, unless otherwise specified. Supply Current vs. Supply Voltage Response Time for Various Input Overdrives – Positive (Dual channel) Transition 6 240 5 180 4 150 3 Vout(V) Supply Current(uA) 210 120 90 1 ‐40°C 60 25°C 30 2 Vov=5mV Vov=20mV Vov=100mV 0 125°C -1 0 3 8 13 18 23 0 28 1 2 3 4 5 Time(us) Supply Voltage(V) Response Time For Various Input Overdrives Negative Output Swing vs. Sink Current - Negative Transition 6 6 5 5 Vov=5mV Vov=20mV Vov=100mV 4 Vdrop(V) Vout(V) 3 4 2 1 3 2 T=‐40°C T=25°C T=125°C 1 0 -1 0 1 2 3 Time(us) www.3peakic.com.cn 4 5 0 0 10 20 30 40 Isink(mA) 5 LM393A 36V Low Power Dual Differential Comparators Block Diagram Block Diagram Response Time Test Circuit Pin Functions –IN: Inverting Input of the Comparator. Voltage range of this pin can go from V– to V+ - 1.5V. +IN: Non-Inverting Input of Comparator. This pin has the same voltage range as –IN. V+ (VDD): Positive Power Supply. Typically the voltage is from 2.5V to 36V. Split supplies are possible as long as the voltage between V+ and V– is between 2.5V and 36V. A bypass capacitor of 0.1μF as close to the part as possible should be used between power supply pins or between supply pins and ground. V– (VSS): Negative Power Supply. It is normally tied to ground. It can also be tied to a voltage other than ground as long as the voltage between V+ and V– is from 2.5V to 36V. If it is not connected to ground, bypass it with a capacitor of 0.1μF as close to the part as possible. OUT: Comparator Output. The voltage range extends to within millivolts of each supply rail. Operation The LM393A family single-supply comparators feature high speed, and low power. Input signal range extends beyond the negative and positive power supplies. The output can even extend all the way to the negative supply. The input www.3peakic.com.cn 6 LM393A 36V Low Power Dual Differential Comparators stage is active over different ranges of common mode input voltage. Rail-to-rail input voltage range and low-voltage single-supply operation make these devices ideal for portable equipment. Applications Information Inputs The LM393A comparator family uses CMOS transistors at the input which prevent phase inversion when the input pins exceed the supply voltages. Figure 1 shows an input voltage exceeding both supplies with no resulting phase inversion. 6 Input Voltage Vout Voltage (mV) 4 2 0 VDD =5V Output Voltage -2 Time (100μs/div) Figure 1. Comparator Response to Input Voltage The electrostatic discharge (ESD) protection input structure of two back-to-back diodes and 1kΩ series resistors are used to limit the differential input voltage applied to the precision input of the comparator by clamping input voltages that exceed supply voltages, as shown in Figure 2. Large differential voltages exceeding the supply voltage should be avoided to prevent damage to the input stage. +In -In 1KΩ 1KΩ Core Chip Figure 2. Equivalent Input Structure External Hysteresis Greater flexibility in selecting hysteresis is achieved by using external resistors. Hysteresis reduces output chattering when one input is slowly moving past the other. It also helps in systems where it is best not to cycle between high and low states too frequently (e.g., air conditioner thermostatic control). Output chatter also increases the dynamic supply current. Non-Inverting Comparator with Hysteresis www.3peakic.com.cn 7 LM393A 36V Low Power Dual Differential Comparators A non-inverting comparator with hysteresis requires a two-resistor network, as shown in Figure 3 and a voltage reference (Vr) at the inverting input. Figure 3. Non-Inverting Configuration with Hysteresis When Vi is low, the output is also low. For the output to switch from low to high, Vi must rise up to Vtr. When Vi is high, the output is also high. In order for the comparator to switch back to a low state, Vi must equal Vtf before the non-inverting input V+ is again equal to Vr. Vr  R2 R1  R 2 Vtr Vr  (VDD  Vtf ) Vtr  Vtf  R1  R 2 R2 R1  R 2 R2 R1 R1  R 2  Vtf Vr R1 Vr  R2 R1 Vhyst  Vtr  Vtf  R2 VDD VDD Inverting Comparator with Hysteresis The inverting comparator with hysteresis requires a three-resistor network that is referenced to the comparator supply voltage (VDD), as shown in Figure 4. Figure 4. Inverting Configuration with Hysteresis When Vi is greater than V+, the output voltage is low. In this case, the three network resistors can be presented as paralleled resistor R2 || R3 in series with R1. When Vi at the inverting input is less than V+, the output voltage is high. The three network resistors can be represented as R1 ||R3 in series with R2. Vtr  Vtf  www.3peakic.com.cn R2 R1 || R3  R 2 R 2 || R3 R 2 || R3  R1 VDD VDD 8 LM393A 36V Low Power Dual Differential Comparators Vhyst  Vtr  Vtf  R1 || R 2 R1 || R 2  R3 VDD Low Input Bias Current The LM393A family is a CMOS comparator family and features very low input bias current in pA range. The low input bias current allows the comparators to be used in applications with high resistance sources. Care must be taken to minimize PCB Surface Leakage. See below section on “PCB Surface Leakage” for more details. PCB Surface Leakage In applications where low input bias current is critical, Printed Circuit Board (PCB) surface leakage effects need to be considered. Surface leakage is caused by humidity, dust or other contamination on the board. Under low humidity conditions, a typical resistance between nearby traces is 1012Ω. A 5V difference would cause 5pA of current to flow, which is greater than the LM393A’s input bias current at +27°C (±6pA, typical). It is recommended to use multi-layer PCB layout and route the comparator’s -IN and +IN signal under the PCB surface. The effective way to reduce surface leakage is to use a guard ring around sensitive pins (or traces). The guard ring is biased at the same voltage as the sensitive pin. An example of this type of layout is shown in Figure 5 for Inverting configuration application. 1. For Non-Inverting Configuration: a) Connect the non-inverting pin (VIN+) to the input with a wire that does not touch the PCB surface. b) Connect the guard ring to the inverting input pin (VIN–). This biases the guard ring to the same reference as the comparator. 2. For Inverting Configuration: a) Connect the guard ring to the non-inverting input pin (VIN+). This biases the guard ring to the same reference voltage as the comparator (e.g., VDD/2 or ground). b) Connect the inverting pin (VIN–) to the input with a wire that does not touch the PCB surface. Figure 5. Example Guard Ring Layout for Inverting Comparator Ground Sensing and Rail to Rail Output The LM393A family implements a rail-to-rail topology that is capable of swinging to within 10mV of either rail. Since the inputs can go 300mV beyond either rail, the comparator can easily perform ‘true ground’ sensing. The maximum output current is a function of total supply voltage. As the supply voltage of the comparator increases, the output current capability also increases. Attention must be paid to keep the junction temperature of the IC below 150°C when the output is in continuous short-circuit condition. The output of the amplifier has reverse-biased ESD diodes connected to each supply. The output should not be forced more than 0.5V beyond either supply, otherwise current will flow through these diodes. ESD The LM393A family has reverse-biased ESD protection diodes on all inputs and output. Input and output pins can not be biased more than 300mV beyond either supply rail. www.3peakic.com.cn 9 LM393A 36V Low Power Dual Differential Comparators Power Supply Layout and Bypass The LM393A family’s power supply pin should have a local bypass capacitor (i.e., 0.01μF to 0.1μF) within 2mm for good high frequency performance. It can also use a bulk capacitor (i.e., 1μF or larger) within 100mm to provide large, slow currents. This bulk capacitor can be shared with other analog parts. Good ground layout improves performance by decreasing the amount of stray capacitance and noise at the comparator’s inputs and outputs. To decrease stray capacitance, minimize PCB lengths and resistor leads, and place external components as close to the comparator’ pins as possible. Proper Board Layout The LM393A family is a series of fast-switching, high-speed comparator and requires high-speed layout considerations. For best results, the following layout guidelines should be followed: 1. Use a printed circuit board (PCB) with a good, unbroken low-inductance ground plane. 2. Place a decoupling capacitor (0.1μF ceramic, surface-mount capacitor) as close as possible to supply. 3. On the inputs and the output, keep lead lengths as short as possible to avoid unwanted parasitic feedback around the comparator. Keep inputs away from the output. 4. Solder the device directly to the PCB rather than using a socket. 5. For slow-moving input signals, take care to prevent parasitic feedback. A small capacitor (1000 pF or less) placed between the inputs can help eliminate oscillations in the transition region. This capacitor causes some degradation to propagation delay when the impedance is low. The topside ground plane should be placed between the output and inputs. 6. The ground pin ground trace should run under the device up to the bypass capacitor, thus shielding the inputs from the outputs. Typical Applications IR Receiver The LM393A is an ideal candidate to be used as an infrared receiver shown in Figure 6. The infrared photo diode creates a current relative to the amount of infrared light present. The current creates a voltage across RD. When this voltage level cross the voltage applied by the voltage divider to the inverting input, the output transitions. Optional Ro provides additional hysteresis for noise immunity. Figure 6. IR Receiver Relaxation Oscillator A relaxation oscillator using LM393A is shown in Figure 7. Resistors R1 and R2 set the bias point at the comparator's inverting input. The period of oscillator is set by the time constant of R4 and C1. The maximum frequency is limited by www.3peakic.com.cn 10 LM393A 36V Low Power Dual Differential Comparators the large signal propagation delay of the comparator. LM393A’s low propagation delay guarantees the high frequency oscillation. If the inverted input (VC1) is lower than the non-inverting input (VA), the output is high which charges C1 through R4 until VC1 is equal to VA. The value of VA at this point is VA1  VDD  R 2 R 1 || R 3  R 2 At this point the comparator switches pulling down the output to the negative rail. The value of VA at this point is VA2  VDD  R 2 || R 3 R 1  R 2 || R 3 If R1=R2=R3, then VA1=2VDD /3, and VA2= VDD/3 The capacitor C1 now discharges through R4, and the voltage VC decreases till it is equal to VA2, at which point the comparator switches again, bringing it back to the initial stage. The time period is equal to twice the time it takes to discharge C1 from 2VDD/3 to VDD/3. Hence the frequency is: Freq  1 2  ln2  R 4  C1 Figure 7. Relaxation Oscillator Windowed Comparator Figure 8 shows one approach to designing a windowed comparator using a single LM393A chip. Choose different thresholds by changing the values of R1, R2, and R3. OutA provides an active-low undervoltage indication, and OutB gives an active-low overvoltage indication. ANDing the two outputs provides an active-high, power-good signal. When input voltage Vi reaches the overvoltage threshold VOH, the OutB gets low. Once Vi falls to the undervoltage threshold VUH, the OutA gets low. When VUH