LT1011/LT1011A Voltage Comparator U FEATURES ■ ■ ■ ■ ■ ■ ■ ■ ■ DESCRIPTIO The LT ®1011 is a general purpose comparator with significantly better input characteristics than the LM111. Although pin compatible with the LM111, it offers four times lower bias current, six times lower offset voltage and five times higher voltage gain. Offset voltage drift, a previously unspecified parameter, is guaranteed at 15µV/°C. Additionally, the supply current is lower by a factor of two with no loss in speed. The LT1011 is several times faster than the LM111 when subjected to large overdrive conditions. It is also fully specified for DC parameters and response time when operating on a single 5V supply. These parametric improvements allow the LT1011 to be used in high accuracy (≥12-bit) systems without trimming. In a 12-bit A/D application, for instance, using a 2mA DAC, the offset error introduced by the LT1011 is less than 0.5LSB. The LT1011 retains all the versatile features of the LM111, including single 3V to ±18V supply operation, and a floating transistor output with 50mA source/sink capability. It can drive loads referenced to ground, negative supply or positive supply, and is specified up to 50V between V – and the collector output. A differential input voltage up to the full supply voltage is allowed, even with ±18V supplies, enabling the inputs to be clamped to the supplies with simple diode clamps. Pin Compatible with LM111 Series Devices Guaranteed Max 0.5mV Input Offset Voltage Guaranteed Max 25nA Input Bias Current Guaranteed Max 3nA Input Offset Current Guaranteed Max 250ns Response Time Guaranteed Min 200,000 Voltage Gain 50mA Output Current Source or Sink ±30V Differential Input Voltage Fully Specified for Single 5V Operation U APPLICATIO S ■ ■ ■ ■ ■ ■ ■ SAR A/D Converters Voltage-to-Frequency Converters Precision RC Oscillator Peak Detector Motor Speed Control Pulse Generator Relay/Lamp Driver , LTC and LT are registered trademarks of Linear Technology Corporation. U TYPICAL APPLICATIO 10µs 12-Bit A/D Converter 3.9k 15V LM329 7V R3 6.98k 450 16 17 INPUT 0V TO 10V 19 6012 12-BIT D/A CONVERTER 12 11 10 9 8 7 6 5 18 4 3 2 5V R4* 2.49k R6 820Ω 1 PARALLEL OUTPUTS 2 5 6 7 8 9 16 17 18 19 20 21 AM2504 SAR REGISTER 24 E S D 5V R5 1k + LT1011A 3 PARALLEL OUTPUTS 4 500 0.001µF 15 13 Response Time vs Overdrive *R2 AND R4 SHOULD TC TRACK –15V 7 – 400 RESPONSE TIME (ns) R1 1k FULL-SCALE TRIM R2* 6.49k 15V 20 14 350 300 250 200 150 FALLING OUTPUT RISING OUTPUT 100 50 SERIAL OUTPUT 0 0.1 7475 LATCH CC CP S 1 10 OVERDRIVE (mV) 100 1011 TA02 12 START CLOCK f = 1.4MHz 1011 TA01 1 LT1011/LT1011A W W U W ABSOLUTE MAXIMUM RATINGS (Note 1) Supply Voltage (Pin 8 to Pin 4) .............................. 36V Output to Negative Supply (Pin 7 to Pin 4) LT1011AC, LT1011C .......................................... 40V LT1011AI, LT1011I ............................................ 40V LT1011AM, LT1011M ........................................ 50V Ground to Negative Supply (Pin 1 to Pin 4) ............ 30V Differential Input Voltage ...................................... ±36V Voltage at STROBE Pin (Pin 6 to Pin 8) .................... 5V Input Voltage (Note 2) ....................... Equal to Supplies Output Short-Circuit Duration .............................. 10 sec Operating Temperature Range (Note 3) LT1011AC, LT1011C ............................... 0°C to 70°C LT1011AI, LT1011I ........................... – 40°C to 85°C LT1011AM, LT1011M ..................... – 55°C to 125°C Storage Temperature Range ................. – 65°C to 150°C Lead Temperature (Soldering, 10 sec).................. 300°C U W U PACKAGE/ORDER INFORMATION ORDER PART NUMBER TOP VIEW V + 8 7 OUTPUT GND 1 INPUT 2 + – 6 LT1011ACH LT1011CH LT1011AMH LT1011MH BALANCE/ STROBE ORDER PART NUMBER TOP VIEW GND 1 INPUT 2 INPUT 3 + – 5 BALANCE 4 V– H PACKAGE 8-LEAD TO-5 METAL CAN V+ 7 OUTPUT BALANCE/ STROBE BALANCE 6 V– 4 INPUT 3 8 5 J8 PACKAGE N8 PACKAGE 8-LEAD CERDIP 8-LEAD PDIP S8 PACKAGE 8-LEAD PLASTIC SO TJMAX = 150°C, θJA = 100°C/ W(J8) TJMAX = 150°C, θJA = 130°C/ W(N8) TJMAX = 150°C, θJA = 150°C/ W(S8) TJMAX = 150°C, θJA = 150°C/ W, θJC = 45°C/ W LT1011ACJ8 LT1011CJ8 LT1011ACN8 LT1011CN8 LT1011CS8 LT1011AIS8 LT1011IS8 LT1011AMJ8 LT1011MJ8 S8 PART MARKING 1011 1011AI 1011I ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the full operating temperature range, otherwide specifications are at TA = 25°C. VS = ±15V, VCM = 0V, RS = 0Ω, V1 = –15V, output at pin 7 unless otherwise noted. SYMBOL PARAMETER CONDITIONS VOS Input Offset Voltage (Note 4) *Input Offset Voltage IOS *Input Offset Current LT1011AC/AI/AM MIN TYP MAX LT1011C/I/M MIN TYP MAX 0.3 0.6 ● 0.5 1.0 ● 0.75 1.50 RS ≤ 50k (Note 5) (Note 5) 0.2 ● IB 3 5 1.5 3.0 mV mV 2.0 3.0 mV mV 4 6 nA nA Input Bias Current (Note 4) 15 25 20 50 nA *Input Bias Current (Note 5) 20 35 50 25 65 80 nA nA ● *Indicates parameters which are guaranteed for all supply voltages, including a single 5V supply. See Note 5. 2 0.2 UNITS LT1011/LT1011A ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the full operating temperature range, otherwide specifications are at TA = 25°C. VS = ±15V, VCM = 0V, RS = 0Ω, V1 = –15V, output at pin 7 unless otherwise noted. LT1011AC/AI/AM MIN TYP MAX LT1011C/I/M MIN TYP MAX UNITS 4 4 µV/°C SYMBOL PARAMETER CONDITIONS ∆VOS ∆T Input Offset Voltage Drift (Note 6) TMIN ≤ T ≤ TMAX AVOL *Large-Signal Voltage Gain RL = 1k to 15V, –10V ≤ VOUT ≤ 14.5V 200 500 200 500 V/mV RL = 500Ω to 5V, 0.5V ≤ VOUT ≤ 4.5V 50 300 50 300 V/mV 94 115 90 115 dB CMRR ● Common Mode Rejection Ratio *Input Voltage Range (Note 9) VS = ±15V VS = Single 5V tD *Response Time (Note 7) VOL *Output Saturation Voltage, V1 = 0 VIN = 5mV, ISINK = 8mA, TJ ≤ 100°C VIN = 5mV, ISINK = 8mA VIN = 5mV, ISINK = 50mA ● ● *Output Leakage Current VIN = 5mV, V1 = –15V, VOUT = 35V (25V for LT1011C/I) ● ● ● –14.5 0.5 *Positive Supply Current *Negative Supply Current *Strobe Current (Note 8) Minimum to Ensure Output Transistor is Off Input Capacitance 15 13 3 –14.5 0.5 25 13 3 V V 150 250 150 250 ns 0.25 0.25 0.70 0.40 0.45 1.50 0.25 0.25 0.70 0.40 0.45 1.50 V V V 0.2 10 500 0.2 10 500 nA nA 3.2 4.0 3.2 4.0 mA 1.7 2.5 1.7 2.5 mA 500 µA 500 6 6 pF *Indicates parameters which are guaranteed for all supply voltages, including a single 5V supply. See Note 5. Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: Inputs may be clamped to supplies with diodes so that maximum input voltage actually exceeds supply voltage by one diode drop. See Input Protection in the Applications Information section. Note 3: TJMAX = 150°C. Note 4: Output is sinking 1.5mA with VOUT = 0V. Note 5: These specifications apply for all supply voltages from a single 5V to ±15V, the entire input voltage range, and for both high and low output states. The high state is ISINK ≥ 100µA, VOUT ≥ (V + – 1V) and the low state is ISINK ≤ 8mA, VOUT ≤ 0.8V. Therefore, this specification defines a worst-case error band that includes effects due to common mode signals, voltage gain and output load. Note 6: Drift is calculated by dividing the offset voltage difference measured at min and max temperatures by the temperature difference. Note 7: Response time is measured with a 100mV step and 5mV overdrive. The output load is a 500Ω resistor tied to 5V. Time measurement is taken when the output crosses 1.4V. Note 8: Do not short the STROBE pin to ground. It should be current driven at 3mA to 5mA for the shortest strobe time. Currents as low as 500µA will strobe the LT1011A if speed is not important. External leakage on the STROBE pin in excess of 0.2µA when the strobe is “off” can cause offset voltage shifts. Note 9: See graph “Input Offset Voltage vs Common Mode Voltage.” 3 LT1011/LT1011A U W TYPICAL PERFOR A CE CHARACTERISTICS Input Bias Current Input Offset Current 45 IB FLOWS OUT OF INPUTS 35 0.7 30 0.6 25 20 15 0.5 0.4 0.3 10 0.2 5 0.1 0 – 50 – 25 0 EQUIVALENT OFFSET VOLTAGE (mV) 0.8 CURRENT (nA) 0 – 50 – 25 25 50 75 100 125 150 TEMPERATURE (°C) Input Characteristics* TA = 25°C – 25 – 30 –1.5 – 2.0 REFERRED TO SUPPLIES 0.4 0.3 NEGATIVE LIMIT 0.2 COLLECTOR OUTPUT RL = 1k 40 OUTPUT VOLTAGE (V) COMMON MODE VOLTAGE (V) INPUT CURRENT (nA) – 20 POSITIVE LIMIT –1.0 30 20 10 EMITTER OUTPUT RL = 600Ω 0.1 – 35 – 40 0 5 10 – 20 –15 –10 – 5 INPUT VOLTAGE (V) 15 20 V– – 50 – 25 0 1011 G05 Response Time—Collector Output Response Time—Collector Output 6 OVERDRIVE 20mV 5mV 2mV 4 3 2 5 15V VIN – 5V 500Ω 1 15V VIN OVERDRIVE 20mV 5mV 2mV 3 2 – –15V + 0 0 –15V 100mV 100mV INPUT = 100mV STEP 0 INPUT = 100mV STEP 0 PIN 1 GROUNDED 0.9 500Ω 1 0.5 Collector Output Saturation Voltage 5V + – 0.3 0.1 0.3 – 0.1 DIFFERENTIAL INPUT VOLTAGE (mV) 1011 G06 1.0 VS = ±15V 4 0 – 0.5 25 50 75 100 125 150 TEMPERATURE (°C) 1011 G04 VS = ±15V 1M Transfer Function (Gain) 50 – 0.5 –15 5 10k 100k SOURCE RESISTANCE (Ω) 1011 G03 Common Mode Limits *EITHER INPUT. REMAINING INPUT GROUNDED. CURRENT FLOWS OUT OF INPUT. VS = ± 15V LT1011AM LT1011AC 1 1k V+ –10 6 LT1011M LT1011C 1011 G01 5 –5 10 25 50 75 100 125 150 TEMPERATURE (°C) 1011 G01 0 LM311 (FOR COMPARISON) 0.1 0 SATURATION VOLTAGE (V) CURRENT (nA) 40 Worst-Case Offset Error 100 0.9 0.8 TA = 125°C 0.7 TA = 25°C 0.6 0.5 0.4 TA = – 55°C 0.3 0.2 0.1 0 0 50 100 150 200 250 300 350 400 450 TIME (ns) 1011 G07 4 0 50 100 150 200 250 300 350 400 450 TIME (ns) 1011 G08 0 5 10 15 20 25 30 35 40 45 50 SINK CURRENT (mA) 1011 G09 LT1011/LT1011A U W TYPICAL PERFOR A CE CHARACTERISTICS Response Time Using GND Pin as Output V+ 20mV 10 5mV 2mV V+ 5 VIN 0 –5 VOUT –10 2k –15 V 0 – – 50 VS = ±15V TA = 25°C –100 0 1 4 3 2 TIME (µs) INPUT VOLTAGE (mV) OUTPUT VOLTAGE (V) 15 VIN 10 5 VOUT 0 2k –5 V– –10 5mV 20mV –15 2mV 0 VS = ±15V TA = 25°C – 50 –100 0 1 2 TIME (µs) 1011 G10 Supply Current vs Supply Voltage 0.4 60 0.3 SHORT-CIRCUIT CURRENT 0.2 40 20 0.1 *MEASURED 3 MINUTES AFTER SHORT 10 5 OUTPUT VOLTAGE (V) 0 15 0 1011 G12 Output Leakage Current 10 –7 VS = ±15V 3 POSITIVE AND NEGATIVE SUPPLY COLLECTOR OUTPUT “HI” POSITIVE SUPPLY COLLECTOR OUTPUT “LO” 3 2 1 0 5 25 10 15 20 SUPPLY VOLTAGE (V) REFERRED TO V + 1 RL 4 V– 2 VOUT TJ = 25°C TJ = 125°C 1 TJ = 125°C 0.4 TJ = 25°C 0.3 0.2 TJ = – 55°C 0 10 30 40 20 OUTPUT CURRENT (mA) 50 1011 G16 65 85 TEMPERATURE (°C) 105 0 1 5 6 2 3 4 INPUT OVERDRIVE (mV) 125 Response Time vs Input Step Size 1000 0.1 0 45 1011 G15 0.5 7 LT1011 TJ = – 55°C 25 ISINK = 8mA V+ 8 SATURATION VOLTAGE (V) 2 3 3 125 Output Saturation Voltage 0.6 4 100 1011 G14 Output Saturation— Ground Output + 10 –10 10 –11 50 25 75 0 TEMPERATURE (˚C) 1011 G13 5 VOUT = 35V VGND = –15V 10 –9 POSITIVE AND NEGATIVE SUPPLY COLLECTOR OUTPUT “HI” 0 –50 –25 30 10 –8 PROPAGATION DELAY (ns) 2 4 LEAKAGE CURRENT (A) 5 POSITIVE SUPPLY COLLECTOR OUTPUT “LO” CURRENT (mA) CURRENT (mA) 0.5 80 Supply Current vs Temperature 1 V + TO GROUND PIN VOLTAGE (V) 100 6 4 0 0.6 POWER DISSIPATION 1011 G11 5 0 120 0 4 3 0.7 TA = 25°C POWER DISSIPATION (W) INPUT VOLTAGE (mV) OUTPUT VOLTAGE (V) 15 Output Limiting Characteristics* 140 SHORT-CIRCUIT CURRENT (mA) Response Time Using GND Pin as Output 7 8 1011 G17 VS = ± 15V RL = 500Ω TO 5V OVERDRIVE = 5mV 800 5V INPUT 600 3 – 2 + 500Ω 7 1 400 RISING INPUT FALLING INPUT 200 0 0 1 2 3 4 5 6 7 INPUT STEP (V) 8 9 10 1011 G18 5 LT1011/LT1011A U W TYPICAL PERFOR A CE CHARACTERISTICS Input Offset Voltage vs Common Mode Voltage INPUT OFFSET VOLTAGE (mV) 2.0 Offset Pin Characteristics CHANGE IN VOS (mV/µA) 2.5 TJ = 25°C 1.5 UPPER COMMON MODE + LIMIT = V – (1.5V) 1.0 0.5 0 0.8 0.6 0.4 0.2 0 – 0.5 –150mV –1.0 – 2.0 – 2.5 VOLTAGE ON PINS 5 AND 6 WITH RESPECT TO V + –100mV V – (OR GND WITH SINGLE SUPPLY) –1.5 CHANGE IN VOS FOR CURRENT INTO PINS 5 OR 6 – 50mV V – 0.1 0.2 0.3 0.4 0.5 0.6 0.7 COMMON MODE VOLTAGE (V) V+ 1011 G19 0 – 50 – 25 0 25 50 75 100 125 150 TEMPERATURE (°C) 1011 G20 U W U U APPLICATIONS INFORMATION Preventing Oscillation Problems Oscillation problems in comparators are nearly always caused by stray capacitance between the output and inputs or between the output and other sensitive pins on the comparator. This is especially true with high gain bandwidth comparators like the LT1011, which are designed for fast switching with millivolt input signals. The gain bandwidth product of the LT1011 is over 10GHz. Oscillation problems tend to occur at frequencies around 5MHz, where the LT1011 has a gain of ≈ 2000. This implies that attenuation of output signals must be at least 2000:1 at 5MHz as measured at the inputs. If the source impedance is 1kΩ, the effective stray capacitance between output and input must have a reactance of more than (2000)(1kΩ) = 2MΩ, or less than 0.02pF. The actual interlead capacitance between input and output pins on the LT1011 is less than 0.002pF when cut to printed circuit mount length. Additional stray capacitance due to printed circuit traces must be minimized by routing the output trace directly away from input lines and, if possible, running ground traces next to input traces to provide shielding. Additional steps to ensure oscillation-free operation are: 1. Bypass the STROBE/BALANCE pins with a 0.01µF capacitor connected from Pin 5 to Pin 6. This eliminates stray capacitive feedback from the output to the 6 BALANCE pins, which are nearly as sensitive as the inputs. 2. Bypass the negative supply (Pin 4) with a 0.1µF ceramic capacitor close to the comparator. 0.1µF can also be used for the positive supply (Pin 8) if the pullup load is tied to a separate supply. When the pull-up load is tied directly to Pin 8, use a 2µF solid tantalum bypass capacitor. 3. Bypass any slow moving or DC input with a capacitor (≥ 0.01µF) close to the comparator to reduce high frequency source impedance. 4. Keep resistive source impedance as low as possible. If a resistor is added in series with one input to balance source impedances for DC accuracy, bypass it with a capacitor. The low input bias current of the LT1011 usually eliminates any need for source resistance balancing. A 5kΩ imbalance, for instance, will create only 0.25mV DC offset. 5. Use hysteresis. This consists of shifting the input offset voltage of the comparator when the output changes state. Hysteresis forces the comparator to move quickly through its linear region, eliminating oscillations by “overdriving” the comparator under all input conditions. Hysteresis may be either AC or DC. AC techniques do not shift the apparent offset voltage LT1011/LT1011A U U W U APPLICATIONS INFORMATION 15V 2µF TANT + 8 C8 TO C6 = 0.003µF 7 INPUT OFFSET VOLTAGE (mV) of the comparator, but require a minimum input signal slew rate to be effective. DC hysteresis works for all input slew rates, but creates a shift in offset voltage dependent on the previous condition of the input signal. The circuit shown in Figure 1 is an excellent compromise between AC and DC hysteresis. 6 5 4 3 2 OUTPUT “LO” TO “HI” 1 0 OUTPUT “HI” TO “LO” –1 3 INPUTS 2 – + C1 0.003µF 8 6 LT1011 5 7 R2 15M RL (50kHz) –2 (5kHz) 10 100 TIME/FREQUENCY (µs) 1 1000 1011 F02 OUTPUT 1 Figure 2. Input Offset Voltage vs Time to Last Transition 4 –15V 0.1µF 1011 F01 Figure 1. Comparator with Hysteresis This circuit is especially useful for general purpose comparator applications because it does not force any signals directly back onto the input signal source. Instead, it takes advantage of the unique properties of the BALANCE pins to provide extremely fast, clean output switching even with low frequency input signals in the millivolt range. The 0.003µF capacitor from Pin 6 to Pin 8 generates AC hysteresis because the voltage on the BALANCE pins shifts slightly, depending on the state of the output. Both pins move about 4mV. If one pin (6) is bypassed, AC hysteresis is created. It is only a few millivolts referred to the inputs, but is sufficient to switch the output at nearly the maximum speed of which the comparator is capable. To prevent problems from low values of input slew rate, a slight amount of DC hysteresis is also used. The sensitivity of the BALANCE pins to current is about 0.5mV input referred offset for each microampere of BALANCE pin current. The 15M resistor tied from OUTPUT to Pin 5 generates 0.5mV DC hysteresis. The combination of AC and DC hysteresis creates clean oscillation-free switching with very small input errors. Figure 2 plots input referred error versus switching frequency for the circuit as shown. Note that at low frequencies, the error is simply the DC hysteresis, while at high frequencies, an additional error is created by the AC hysteresis. The high frequency error can be reduced by reducing CH, but lower values may not provide clean switching with very low slew rate input signals. Input Protection The inputs to the LT1011 are particularly suited to general purpose comparator applications because large differential and/or common mode voltages can be tolerated without damage to the comparator. Either or both inputs can be raised 40V above the negative supply, independent of the positive supply voltage. Internal forward biased diodes will conduct when the inputs are taken below the negative supply. In this condition, input current must be limited to 1mA. If very large (fault) input voltages must be accommodated, series resistors and clamp diodes should be used (see Figure 3). V+ R1** INPUTS D1 D2 R3* 300Ω 3 R4* 300Ω 2 R2** D3 – 8 LT1011 + 4 D4 D1 TO D4: 1N4148 *MAY BE ELIMINATED FOR IFAULT ≤ 1mA **SELECT ACCORDING TO ALLOWABLE FAULT CURRENT AND POWER DISSIPATION V– 1011 F03 Figure 3. Limiting Fault Input Currents 7 LT1011/LT1011A U W U U APPLICATIONS INFORMATION The input resistors should limit fault current to a reasonable value (0.1mA to 20mA). Power dissipation in the resistors must be considered for continuous faults, especially when the LT1011 supplies are off. One final caution: lightly loaded supplies may be forced to higher voltages by large fault currents flowing through D1-D4. 15V 5V 8 – RL 7 LT1011 6 4 TTL OR CMOS DRIVE (5V SUPPLY) –15 R3 and R4 limit input current to the LT1011 to less than 1mA when the input signals are held below V –. They may be eliminated if R1 and R2 are large enough to limit fault current to less than 1mA. OUTPUT 1 + 3k 1011 F04 Figure 4. Typical Strobe Circuit Input Slew Rate Limitations The response time of a comparator is typically measured with a 100mV step and a 5mV to 10mV overdrive. Unfortunately, this does not simulate many real world situations where the step size is typically much larger and overdrive can be significantly less. In the case of the LT1011, step size is important because the slew rate of internal nodes will limit response time for input step sizes larger than 1V. At 5V step size, for instance, response time increases from 150ns to 360ns. See the curve “Response Time vs Input Step Size for more detail. If response time is critical and large input signals are expected, clamp diodes across the inputs are recommended. The slew rate limitation can also affect performance when differential input voltage is low, but both inputs must slew quickly. Maximum suggested common mode slew rate is 10V/µs. level inputs. A 1pF capacitor between the output and Pin 5 will greatly reduce oscillation problems without reducing strobe speed. DC hysteresis can also be added by placing a resistor from output to Pin 5. See step 5 under “Preventing Oscillation Problems.” The pin (6) used for strobing is also one of the offset adjust pins. Current flow into or out of Pin 6 must be kept very low (< 0.2µA) when not strobing to prevent input offset voltage shifts. Output Transistor The LT1011 output transistor is truly floating in the sense that no current flows into or out of either the collector or emitter when the transistor is in the “off” state. The equivalent circuit is shown in Figure 5. Strobing The LT1011 can be strobed by pulling current out of the STROBE pin. The output transistor is forced to an “off” state, giving a “hi” output at the collector (Pin 7). Currents as low as 250µA will cause strobing, but at low strobe currents, strobe delay will be 200ns to 300ns. If strobe current is increased to 3mA, strobe delay drops to about 60ns. The voltage at the STROBE pin is about 150mV below V + at zero strobe current and about 2V below V + for 3mA strobe current. Do not ground the STROBE pin. It must be current driven. Figure 4 shows a typical strobe circuit. Note that there is no bypass capacitor between Pins 5 and 6. This maximizes strobe speed, but leaves the comparator more sensitive to oscillation problems for slow, low 8 V+ I1 0.5mA D1 D2 COLLECTOR (OUTPUT) Q1 R1 170Ω V– Q2 R2 470Ω OUTPUT TRANSISTOR EMITTER (GND PIN) Figure 5. Output Transistor Circuitry 1011 F05 LT1011/LT1011A U W U U APPLICATIONS INFORMATION In the “off” state, I1 is switched off and both Q1 and Q2 turn off. The collector of Q2 can be now held at any voltage above V – without conducting current, including voltages above the positive supply level. Maximum voltage above V – is 50V for the LT1011M and 40V for the LT1011C/I. The emitter can be held at any voltage between V + and V – as long as it is negative with respect to the collector. designations must be reversed. When the collector is tied to V +, the voltage at the emitter in the “on” state is about 2V below V + (see curves). Input Signal Range The common mode input voltage range of the LT1011 is about 300mV above the negative supply and 1.5V below the positive supply, independent of the actual supply voltages (see curve in the Typical Performance Characteristics). This is the voltage range over which the output will respond correctly when the common mode voltage is applied to one input and a higher or lower signal is applied to the remaining input. If one input is inside the common mode range and one is outside, the output will be correct. If the inputs are outside the common mode range in opposite directions, the output will still be correct. If both inputs are outside the common mode range in the same direction, the output will not respond to the differential input; it will remain unconditionally high (collector output) except at – 40 °C where it is undefined. In the “on” state, I1 is connected, turning on Q1 and Q2. Diodes D1 and D2 prevent deep saturation of Q2 to improve speed and also limit the drive current of Q1. The R1/R2 divider sets the saturation voltage of Q2 and provides turn-off drive. Either the collector or emitter pin can be held at a voltage between V + and V –. This allows the remaining pin to drive the load. In typical applications, the emitter is connected to V – or ground and the collector drives a load tied to V + or a separate positive supply. When the emitter is used as the output, the collector is typically tied to V + and the load is connected to ground or V –. Note that the emitter output is phase reversed with respect to the collector output so that the “+” and “–” input U TYPICAL APPLICATIONS Offset Balancing Driving Load Referenced to Positive Supply R2 3k V+ R1 20k V+ 5 2 + 8 – 2 8 7 V+ V ++ 7 LT1011 3 4 V 8 – INPUTS* 1 + 2 RLOAD 7 LT1011 6 LT1011 3 3 Driving Load Referenced to Negative Supply 1 + RLOAD 4 V – 1011 TA03 V OR GROUND V V ++ CAN BE GREATER OR LESS THAN V + 1011 TA05 1011 TA06 *INPUT POLARITY IS REVERSED WHEN USING PIN 1 AS OUTPUT 9 LT1011/LT1011A U TYPICAL APPLICATIONS Strobing Driving Ground Referred Load + 7 LT1011 3 V+ V ++** V+ 2 Window Detector – 2 INPUTS* 6 L1 4 V– 1k NOTE: DO NOT GROUND STROBE PIN – OUTPUT HIGH INSIDE “WINDOW” AND LOW ABOVE HIGH LIMIT OR BELOW LOW LIMIT 1 VIN 2 1011 TA07 *INPUT POLARITY IS REVERSED WHEN USING PIN 1 AS OUTPUT **V ++ MAY BE ANY VOLTAGE ABOVE V –. PIN 1 SWINGS TO WITHIN ≈ 2V OF V++ 1011 TA04 7 LT1011 3 1 + RL + 7 LT1011 3 TTL STROBE 2 HIGH LIMIT 8 – + 7 LT1011 3 LOW LIMIT – 1 1011 TA08 Crystal Oscillator Using Clamp Diodes to Improve Frequency Response* CURRENT MODE INPUT (DAC, ETC) 2 D1 + LT1011 D2 3 5V 10k 7 OUTPUT – 2 VOLTAGE INPUT 85kHz 100pF *SEE CURVE, “RESPONSE TIME vs INPUT STEP SIZE” OUT 4 – GROUND OR LOW IMPEDANCE REFERENCE 50k 7 LT1011 3 R1 1k 8 + 1 10k 1011 TA09 10k 1011 TA10 Noise Immune 60Hz Line Sync** High Efficiency** Motor Speed Controller 15V 5V R3 1k R2 75k 2VRMS TO 25VRMS 60Hz INPUT C1 50µF + R1 1k Q1 2N6667 5V R1* 330k 3 C1 0.22µF 8 – 1N4002 7 LT1011 2 1 + 4 MOTOR-TACH GLOBE 397A120-2 OUTPUT 60Hz R4 27k R2 470Ω R3* 10k MOTOR TACH R6 27k 15V 5V 1011 TA11 R5 10k *INCREASE R1 FOR LARGER INPUT VOLTAGES **LT1011 SELF OSCILLATES AT ≈ 60Hz CAUSING IT TO “LOCK” ONTO INCOMING LINE SIGNAL 8 + 7 2 LT1011 1 – 3 C2* 0.1µF R5 100k R6 2k C3 0.1µF R7 1k 1011 TA12 R4 1k 4 *R3/C2 DETERMINES OSCILLATION – 5V TO FREQUENCY OF CONTROLLER –15V 0V TO 10V **Q1 OPERATES IN SWITCH MODE INPUT 10 LT1011/LT1011A U TYPICAL APPLICATIONS Combining Offset Adjust and Strobe Combining Offset Adjustment and Hystersis V+ V+ 5k 10k RH* 2RH** 20k 5 – – TTL OR CMOS 5V 6 + LT1011 + 1k *HYSTERESIS IS ≈ 0.45mV/µA OF CURRENT CHANGE IN RH RL **THIS RESISTOR CAUSES HYSTERESIS TO BE CENTERED AROUND VOS 20k 6 5 7 LT1011 1011 TA15 1 1011 TA13 Direct Strobe Drive When CMOS* Logic Uses Same V + Supply as LT1011 Low Drift R/C Oscillator † V+ ** 8 – 6 + 15V 2 LT1011 C1 0.015µF 1011 TA14 15V 8 + 1k 7 LT1011 3 *NOT APPLICABLE FOR TTL LOGIC 74HC04 ×6 BUFFERED OUTPUT 4 – 1 Positive Peak Detector 15V 10k* 10k* 15V 2k INPUT 3 8 7 LT1011 2 2 1 4 10k 3 1M** *1% METAL FILM 10k* **TRW TYPE MTR-5/120ppm/°C, 25k ≤ RS ≤ 200k C1: 0.015µF = POLYSTYRENE, –120ppm/°C, 1011 TA16 ± 30ppm WESCO TYPE 32-P NOTE: COMPARATOR CONTRIBUTES ≤10ppm/°C DRIFT FOR FREQUENCIES BELOW 10kHz † LOW DRIFT AND ACCURATE FREQUENCY ARE OBTAINED BECAUSE THIS CONFIGURATION REJECTS EFFECTS DUE TO INPUT OFFSET VOLTAGE AND BIAS CURRENT OF THE COMPARATOR + C1* 2µF + 6 LT1008 – OUTPUT 8 100pF 1011 TA17 –15V *MYLAR **SELECT FOR REQUIRED RESET TIME CONSTANT Negative Peak Detector 15V 2 1M** 2k INPUT 3 – 1 + 4 –15V 10k 7 LT1011 2 – 8 + C1* 2µF 100pF LT1008 3 + 6 OUTPUT 8 1011 TA18 *MYLAR **SELECT FOR REQUIRED RESET TIME CONSTANT 11 LT1011/LT1011A U TYPICAL APPLICATIONS 4-Digit (10,000 Count) A/D Converter 15V ZERO TRIM R1 1k 1 3 R2 18k INPUT 0V TO 10V C4 0.01µF 7 R3 3.9k 8 4 D1 D2 6 C1* 0.1µF C2** 15pF R6 4.7K 7 OUTPUT = 1 COUNT PER mV, f = 1MHz CLOCK 1MHz 1 – R7 22Ω 5V C5 0.01µF + 3 6 5V 8 LT1011 2 5 LF398 15V R5 4.7k 2 4 –15V 15V –15V R4 5.6k R8 3k D3 15V D4 C3 0.1µF R11 6.8K R10 1k R9 FULL-SCALE 3.65k TRIM R12 6.8k 2N3904 C6 50pF LM329 ALL DIODES: 1N4148 *POLYSTYRENE **NPO 1011 TA19 START ≥12ms Capacitance to Pulse Width Converter TH ≥ [CMAX (pF)][1µs/pF] TL ≥ 10 • CMAX • (1µs/pF) D1 TTL OR CMOS (OPERATING ON 5V) R2 R1 100k 5k R3 86.6k + GAIN ADJ 5V 8 2 0.01µF + 10µF† 6 LT1011 3 C** 1 – ) OUTPUT 1µs/pF **TYPICAL 2 SECTIONS OF 365pF VARIABLE CAPACITOR WHEN USED AS SHAFT ANGLE INDICATION NEGATIVE SUPPLY IS AVAILABLE (–1V TO –15V) 10µF† + 1011 TA20 12 R5 4.7k †THESE COMPONENTS MAY BE ELIMINATED IF 4 D3† D2† 7 ( *PW = (R2 + R3)(C) R1 + R4 , INPUT CAPACITANCE OF R1 LT1011 IS ≈ 6pF. THIS IS AN OFFSET TERM. LT1011/LT1011A U TYPICAL APPLICATIONS Fast Settling* Filter 100pF 1M 15V 2 7 1M OUTPUT 8 3 VIN 1 4 4.7k –15V 15V 0.1µF 6 LT1008C 4.7k 1µF OFM-1A** –15V 100k 100pF 4 2 8 – 3 1.5k 7 1 LT1011 5 + 6 15V 15V 5k THRESHOLD 5k 6 + 5 1 LT1011 7 – 10k 8 4 –15V 15V 1011 TA21 100kHz Precision Rectifier 0.033µF 5V 100Ω AC INPUT 5k ZERO CROSS TRIM 2 8 + LT1011 3 5V – 1 5V 1k 7 5V 74C04 12k 820Ω HP5082-2800 ×4 RECTIFIED OUTPUT – 5V 4 5V – 5V 1k 820Ω 74C04 – 5V 12k – 5V 1011 TA23 13 LT1011/LT1011A W W SCHE ATIC DIAGRA OFFSET OFFSET/STROBE V+ 5 6 8 R8 800Ω Q6 R27 3k R4 300Ω R5 160Ω R1 1.3k R2 1.3k Q10 R3 300Ω R23 4k Q11 Q5 Q31 Q12 R6 3.2k D1 D2 Q30 INPUT (+) R7 3.2k Q13 Q29 R11 170Ω D5 R12 470Ω Q4 Q27 R16 Q24 800Ω Q2 Q26 Q25 Q15 Q9 Q19 Q28 3 7 Q20 R22 200Ω Q1 D7 OUTPUT Q14 Q3 INPUT (–) R10 4k Q7 Q8 D4 D6 2 R9 800Ω Q21 Q23 Q16 R17 200Ω R24 400Ω R20 940Ω R13 4Ω R15 700Ω Q22 1 Q18 GND R25 1.6k R26 1.6k R19 500Ω R21 960Ω R18 275Ω R14 4.8k D3 Q17 4 1011 SD V– U PACKAGE DESCRIPTION Dimensions in inches (millimeters) unless otherwise noted. H Package 8-Lead TO-5 Metal Can (0.230 PCD) (LTC DWG # 05-08-1321) 0.335 – 0.370 (8.509 – 9.398) DIA 0.305 – 0.335 (7.747 – 8.509) 0.040 (1.016) MAX 0.027 – 0.045 (0.686 – 1.143) 45°TYP 0.050 (1.270) MAX SEATING PLANE GAUGE PLANE 0.010 – 0.045* (0.254 – 1.143) 0.500 – 0.750 (12.700 – 19.050) *LEAD DIAMETER IS UNCONTROLLED BETWEEN THE REFERENCE PLANE AND 0.045" BELOW THE REFERENCE PLANE 0.016 – 0.024 **FOR SOLDER DIP LEAD FINISH, LEAD DIAMETER IS (0.406 – 0.610) PIN 1 0.230 (5.842) TYP REFERENCE PLANE 0.016 – 0.021** (0.406 – 0.533) 14 0.028 – 0.034 (0.711 – 0.864) 0.165 – 0.185 (4.191 – 4.699) 0.110 – 0.160 (2.794 – 4.064) INSULATING STANDOFF H8 (TO-5) 0.230 PCD 1197 LT1011/LT1011A U PACKAGE DESCRIPTION Dimensions in inches (millimeters) unless otherwise noted. J8 Package 8-Lead CERDIP (Narrow 0.300, Hermetic) (LTC DWG # 05-08-1110) CORNER LEADS OPTION (4 PLCS) 0.023 – 0.045 (0.584 – 1.143) HALF LEAD OPTION 0.045 – 0.068 (1.143 – 1.727) FULL LEAD OPTION 0.300 BSC (0.762 BSC) 0.015 – 0.060 (0.381 – 1.524) 0.008 – 0.018 (0.203 – 0.457) 0.005 (0.127) MIN 0.200 (5.080) MAX 0.405 (10.287) MAX 8 6 7 5 0.025 (0.635) RAD TYP 0.220 – 0.310 (5.588 – 7.874) 0° – 15° 1 0.045 – 0.068 (1.143 – 1.727) 0.125 3.175 0.100 ± 0.010 MIN (2.540 ± 0.254) 0.014 – 0.026 (0.360 – 0.660) 2 3 4 J8 1197 NOTE: LEAD DIMENSIONS APPLY TO SOLDER DIP/PLATE OR TIN PLATE LEADS N8 Package 8-Lead PDIP (Narrow 0.300) (LTC DWG # 05-08-1510) 0.300 – 0.325 (7.620 – 8.255) 0.009 – 0.015 (0.229 – 0.381) ( +0.035 0.325 –0.015 +0.889 8.255 –0.381 ) 0.045 – 0.065 (1.143 – 1.651) 0.400* (10.160) MAX 0.130 ± 0.005 (3.302 ± 0.127) 0.065 (1.651) TYP 8 7 6 5 1 2 3 4 0.255 ± 0.015* (6.477 ± 0.381) 0.125 (3.175) 0.020 MIN (0.508) MIN 0.018 ± 0.003 (0.457 ± 0.076) 0.100 ± 0.010 (2.540 ± 0.254) N8 1197 *THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.010 INCH (0.254mm) S8 Package 8-Lead Plastic Small Outline (Narrow 0.150) (LTC DWG # 05-08-1610) 0.189 – 0.197* (4.801 – 5.004) 0.010 – 0.020 × 45° (0.254 – 0.508) 0.008 – 0.010 (0.203 – 0.254) 0.053 – 0.069 (1.346 – 1.752) 0.004 – 0.010 (0.101 – 0.254) 8 7 6 5 0°– 8° TYP 0.016 – 0.050 0.406 – 1.270 0.014 – 0.019 (0.355 – 0.483) *DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE **DIMENSION DOES NOT INCLUDE INTERLEAD FLASH. INTERLEAD FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE 0.050 (1.270) TYP 0.150 – 0.157** (3.810 – 3.988) 0.228 – 0.244 (5.791 – 6.197) SO8 0996 1 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. 2 3 4 15 LT1011/LT1011A U TYPICAL APPLICATION 10Hz to 100kHz Voltage to Frequency Converter R7 4.7k R4 1M 15V 15V C1 0.002µF POLYSTYRENE R1 4.7k LT1009 2.5V 15V INPUT 0V TO 10V R2 5k FULL-SCALE R3 TRIM 8.06k R16 50k 10Hz TRIM 3 C2 0.68µF 15V R5 2k 15V R8 4.7k 7 1 + R17† 22M LINEARITY ≈ 0.01% 8 – LT1011 2 R6 2k –15V 4 1.5µs 6 4.4V –15V 0.002µF –15V 15V – 15V 15V R9 5k TTL OUTPUT 10HZ TO 100kHz R11 20k 10pF Q2 ALL DIODES 1N4148 TRANSISTORS 2N3904 *USED ONLY TO GUARANTEE START-UP † MAY BE INCREASED FOR BETTER 10Hz TRIM RESOLUTION R15 22k Q1* R14 1k 1.5µs R10 2.7k R12 100k 1011 TA22 + 2µF R13 620k –15V RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LT1016 UltraFastTM Precision Comparator Industry Standard 10ns Comparator LT1116 12ns Single Supply Ground-Sensing Comparator Single Supply Version of the LT1016 LT1394 UltraFast Single Supply Comparator 7ns, 6mA Single Supply Comparator LT1671 60ns, Low Power Comparator 450µA Single Supply Comparator UltraFast is a trademark of Linear Technology Corporation. 16 Linear Technology Corporation 1011fa LT/TP 0699 2K REV A • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408)432-1900 ● FAX: (408) 434-0507 ● www.linear-tech.com LINEAR TECHNOLOGY CORPORATION 1991