LT1116 12ns, Single Supply Ground-Sensing Comparator Features Description Ultra Fast (12ns Typ) nn Operates off Single 5V Supply or ± 5V nn Input Common Mode Extends to Negative Supply nn No Minimum Input Slew Rate Requirement nn Complementary TTL Output nn Inputs Can Exceed the Positive Supply Up to 15V without Damaging the Comparator nn Low Offset Voltage nn Pin-Compatible with LT1016 nn Output Latch Capability Available in 8-Lead PDIP and SO Packages The LT®1116 is an ultra fast (12ns) comparator designed for sensing signals near the negative supply. The input common mode range extends from 2.5V below the positive supply down to the negative supply rail. Like the LT1016, this comparator is specifically designed to interface directly to TTL logic with complementary outputs. The comparator may operate from either a single 5V supply or dual ±5V supplies. Tight offset voltage specifications and high gain allow the LT1116 to be used in precision applications. nn Applications High Speed A/D Converters Zero Crossing Detectors nn Current Sense for Switching Regulators nn Extended Range V to F Converters nn Fast Pulse Height/Width Discriminators nn High Speed Triggers nn Line Receivers nn High Speed Sampling Circuits nn nn L, LTC, LT, and LTM are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. The LT1116 is designed for improved speed and stability for a wide range of operating conditions. The output stage provides active drive in both directions for maximum speed into TTL logic or passive loads, yet it has minimal crossconduction current. Unlike other fast comparators, the LT1116 remains stable even for slow transitions through the active region, which eliminates the need to specify a minimum input slew rate. The LT1116 has an internal, TTL compatible latch for retaining data at the outputs. The latch holds data as long as the latch pin is held high. Device parameters such as gain, offset, and negative power supply current are not significantly affected by variations in negative supply voltage. Typical Application Fast Current Comparator for Current Mode Switching Regulator LOGIC DRIVER M1 VIN 100mV STEP 5mV OVERDRIVE Comparator Response Time THRESHOLD 12ns + LT1116 Q C1 – RSENSE OUTPUT VOLTAGE VOUT 1V/DIV 5V Q 12ns R1 BLANKING 0 CONTROL INPUT LT1116 • TA01 0 20 TIME (ns) 20 LT1116 • TA02 1116fc For more information www.linear.com/LT1116 1 LT1116 Absolute Maximum Ratings (Note 1) Supply Voltage (V +) to GND.........................................7V Negative Supply Voltage (V–)........................ –7V to GND Voltage Differential Input Voltage..................................... ±15V Inputs Voltage (Either Input)............(V–) –0.3V to 15V Latch Pin Voltage..............................Equal to Supplies Output Current (Continuous)................................ ± 20mA Operating Temperature Range...................... 0°C to 70°C Storage Temperature Range................... –65°C to 150°C Lead Temperature (Soldering, 10 sec).................... 300°C Pin Configuration TOP VIEW TOP VIEW V+ 1 +IN 2 –IN 3 V– 8 + – 4 V+ Q OUT 1 Q OUT +IN 2 6 GND –IN 3 5 LATCH ENABLE 7 V– 4 + – 8 Q OUT 7 Q OUT 6 GND 5 LATCH ENABLE S8 PACKAGE 8-LEAD PLASTIC SO TJMAX = 100°C, θJA = 160°C/W N8 PACKAGE 8-LEAD PDIP TJMAX = 100°C, θJA = 130°C/W Order Information TUBE TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION SPECIFIED TEMPERATURE RANGE LT1116CN8#PBF NA 1116 8-Lead PDIP 0°C to 70°C LT1116CS8#PBF LT1116CS8#TRPBF 1116 8-Lead Plastic SO 0°C to 70°C Consult LTC Marketing for parts specified with wider operating temperature ranges.*The temperature grade is identified by a label on the shipping container. Parts ending with PBF are RoHS and WEEE compliant. For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/. Some packages are available in 500 unit reels through designated sales channels with #TRMPBF suffix. 2 1116fc For more information www.linear.com/LT1116 LT1116 Electrical Characteristics The l denotes the specifications which apply over full operating temperature range, otherwise specifications are at TA = 25°C. V+ = 5V, V – = –5V, VOUT (Q) = 1.4V, LATCH = 0V. Specifications for VOS, IB, CMRR, and Voltage Gain are valid for single supply operation, V+ = 5V, V – = 0V, unless noted. SYMBOL PARAMETER VOS Input Offset Voltage CONDITIONS MIN RS ≤ 100Ω (Note 2) TYP MAX UNITS 1.0 ±3.0 3.5 mV mV l ΔVOS Input Offset Voltage Drift l 5 0.5 µV/°C ΔT IOS Input Offset Current (Note 2) l lB Input Bias Current, Sourcing (Note 3) l 10 V– 2 µA 20 µA (V+) –2.5 V V Input Voltage Range Arbitrary Supply Range Single 5V Supply l l CMRR Common Mode Rejection Ratio –5V ≤ VCM ≤ 2.5V, VS = ±5V 0V ≤ VCM ≤ 2.5V l l 75 65 90 90 dB dB PSRR Power Supply Rejection Ratio Positive Supply, 4.6V ≤ V+ ≤ 5.4V Negative Supply, –7 ≤ V– ≤ –2V l l 60 80 75 100 dB dB AV Small Signal Voltage Gain 1V ≤ VOUT ≤ 2V 1400 3000 V/V I+ Positive Supply Current l 27 38 mA I– Negative Supply Current l 5 7 mA VOH Output High Voltage ISOURCE = 1mA ISOURCE = 10mA l l VOL Output Low Voltage lSINK = 4mA lSINK = 10mA l VIH + Positive Latch Threshold l VIL – Latch Threshold l IIL Latch Input Current VLATCH = 0V tPD Propagation Delay ∆VIN = 100mV, OD = 5mV (Note 4) l 2.5 0 2.7 2.4 3.4 3.0 0.3 0.4 Propagation Delay ∆VIN = 100mV, OD = 20mV (Note 4) 0.5 2.0 V V V 0.8 V –20 –500 µA 12 16 18 ns ns 10 14 16 ns ns 3 ns l tPD V V l ∆tPD Differential Propagation Delay ∆VIN = 100mV, OD = 5mV (Note 4) tSU Latch Set-Up Time (Note 5) 2 ns tH Latch Hold Time (Note 5) 2 ns 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: Input offset voltage is defined as the average of two offset voltages measured by forcing first the Q output to 1.4V then forcing the Q output to 1.4V. Note 3: Input bias current is defined as the average of the two input currents. Note 4: tPD and ∆tPD cannot be measured in automatic handling equipment with low values of overdrive. The LT1116 is sample tested with a 1V step and 500mV overdrive. Correlation tests have shown that tPD and ∆tPD can be guaranteed with this test if additional DC tests are performed to verify internal bias conditions are correct. For low overdrive conditions VOS is added to the measured overdrive. Note 5: Input latch set-up time, tSU, is the interval in which the input signal must be stable prior to asserting the latch signal. The hold time, tH, is the interval after the latch is asserted in which the input signal must be stable. 1116fc For more information www.linear.com/LT1116 3 LT1116 Typical Performance Characteristics Gain Characteristics 5.0 TJ = 125°C 3.0 TJ = –55°C 2.0 16 15 tPDLH 10 tPDHL 1.5 – 1.5 1.5 – 0.5 0 0.5 DIFFERENTIAL INPUT VOLTAGE (mV) 0 2.5 0 10 30 40 20 OVERDRIVE VOLTAGE (mV) LT1116 • TPC01 80 0 50 Propagation Delay vs Temperature 25 30 STEP = 100mV OVERDRIVE = 5mV 25 CLOAD = 10pF VS = ±5V 70 20 400mV 40 200mV 30 20 STEP SIZE = 100mV 10 0.5 0 1.0 2.0 2.5 1.5 SOURCE RESISTANCE (kΩ) tPDLH FALLING OUTPUT 10 0 3.0 5 4.4 4.8 5.0 5.2 5.4 4.6 POWER SUPPLY VOLTAGE (V) LT1116 • TPC06 Latch Set-Up Time VIN = 2VP-P VS = ±5V TJ = 25°C 5.0 OUTPUT VOLTAGE (V) 2 TIME (ns) 70 0 –2 60 –4 50 100k 1M FREQUENCY (Hz) 10M LT1116 • TPC07 Output High Voltage (VOH) 4.5 4 100 40 10k 0 –50 –30 –10 10 30 50 70 90 110 130 JUNCTION TEMPERATURE (°C) 5.6 6 80 tPDLH LT1116 • TPC05 Common Mode Rejection 90 tPDHL 15 10 5 LT1116 • TPC04 REJECTION RATIO (dB) 20 tPDHL RISING OUTPUT 15 DELAY (ns) DELAY (ns) DELAY (ns) STEP SIZE = 800mV 50 50 LT1116 • TPC03 Propagation Delay vs Positive Supply VS = ±5V, OVERDRIVE = 20mV 60 10 30 40 20 OUTPUT LOAD CAPACITANCE (pF) 0 LT1116 • TPC02 Propagation Delay vs Source Resistance 4 8 2 0 – 2.5 110 tPDLH 12 10 4 0.5 120 tPDHL 6 5 1.0 0 STEP = 100mV, OVERDRIVE = 5mV 18 14 TJ = 25°C 2.5 20 TJ = 25°C STEP SIZE = 100mV 20 3.5 DELAY (ns) OUTPUT VOLTAGE (V) 4.0 25 VS = ±5V IOUT = 0 DELAY (ns) 4.5 Propagation Delay vs Load Capacitance Propagation Delay vs Overdrive TJ = 125°C 4.0 3.5 TJ = 25°C 3.0 TJ = –55°C 2.5 2.0 1.5 –6 50 100 –50 –25 25 75 0 JUNCTION TEMPERATURE (°C) 125 LT1116 • TPC08 1.0 0 2 4 6 8 10 12 14 16 18 20 OUTPUT SOURCE CURRENT (mA) LT1116 • TPC09 1116fc For more information www.linear.com/LT1116 LT1116 Typical Performance Characteristics Output Low Voltage (VOL) Supply Current vs Temperature VS = ±5V, VIN = 30mV 0.7 30 0.5 TJ = –55°C 0.4 TJ = 25°C 0.3 20 15 10 TJ = 125°C 0.2 NEGATIVE SUPPLY CURRENT 0 2 Positive Supply Current CURRENT (mA) 30 TJ = –55°C 25 20 15 10 6 2 4 POSITIVE SUPPLY VOLTAGE (V) 8 Positive Common Mode Limit 5 TJ = 25°C VS = ±5V 0 COMMON MODE VOLTAGE (V) TJ = 25°C INPUT BIAS CURRENT (µA) 40 0 LT1116 • TPC12 Input Bias Current 10 35 TJ = 25°C TJ = 125°C LT1116 • TPC11 50 TJ = 125°C 20 TJ = –55°C LT1116 • TPC10 45 30 0 0 –60 –40 –20 0 20 40 60 80 100 120 140 JUNCTION TEMPERATURE (°C) 4 6 8 10 12 14 16 18 20 OUTPUT SINK CURRENT (mA) 40 10 5 0.1 V– = 0 50 POSITIVE SUPPLY CURRENT 25 CURRENT (mA) VOLTAGE (V) 0.6 0 Positive Supply Current 60 35 CURRENT (mA) 0.8 –10 – 20 – 30 VS = ±5V 4 3 2 1 5 1 10 SWITCHING FREQUENCY (MHz) – 40 100 –6 –4 0 –2 INPUT VOLTAGE (V) LT1116 • TPC13 Negative Common Mode Limit LT1116 • TPC15 Latch Pin Threshold Latch Pin Current* 2.6 300 2.2 250 VS = 5V, OV –2 VOLTAGE (V) COMMON MODE VOLTAGE (V) 0 –60 –40 –20 0 20 40 60 80 100 120 140 JUNCTION TEMPERATURE (°C) 4 LT1116 • TPC14 0 –1 2 –3 –4 –5 1.8 OUTPUT LATCHED CURRENT (µA) 0 1.4 1.0 OUTPUT UNAFFECTED 0.6 VS = ±5V –6 – 60 –40 –20 0 20 40 60 80 100 120 140 JUNCTION TEMPERATURE (°C) LT1116 • TPC16 200 150 100 50 0.2 50 100 –50 –25 25 75 0 JUNCTION TEMPERATURE (°C) 125 LT1116 • TPC17 VS = ±5V *CURRENT COMES OUT OF LATCH PIN BELOW THRESHOLD 0 50 100 –50 –25 25 75 0 JUNCTION TEMPERATURE (°C) 125 LT1116 • TPC18 1116fc For more information www.linear.com/LT1116 5 LT1116 Timing Diagram VOD LATCH ENABLE tH tSU VIN ∆VIN VIN tPD tPD VOUT VOUT LT1116 • TD01 LT1116 • TD02 Applications Information Common Mode Considerations The LT1116 is specified for a common mode range of 0V to 2.5V with a single 5V supply, and –5V to 2.5V with ±5V supplies. The common mode range is defined as the DC input for which the output responds correctly to small changes in the input differential. Input signals can exceed the positive common mode limit up to the 15V absolute maximum rating without damaging the comparator. There will, however, be an increase in propagation delay of up to 10ns when the input signal switches back into the common mode range. When input signals fall below the negative common mode limit, the internal PN diode formed with the substrate can turn on (resulting in significant charge flow throughout the die). A Schottky clamp diode, between the input and the negative rail, speeds up recovery from negative overdrive by preventing the substrate diode from turning on. The zero crossing detector in Figure 1 demonstrates the use of a fast clamp diode. Recovery, from 500mV overdrive below V –, for this circuit is approximately 18ns. Fast Zero Crossing Detector VIN RS 50 5V CABLE + 1N5712 RT 50Ω Q LT1116 – Q LT1116 • AI01 Figure 1. The Zero Crossing Detector Terminates the Transmission Line at Its 50Ω Characteristic Impedance. Negative Inputs Should Not Fall Below –2V to Keep the Signal Current Within the Clamp Diode’s Maximum Forward Rating. Positive Inputs Should not Exceed the Device’s Absolute Maximum Ratings nor the Power Rating on the Terminating Resistor 6 1116fc For more information www.linear.com/LT1116 LT1116 Applications Information Input Characteristics Latch Pin Dynamics Each input to the LT1116 is buffered with a fast PNP follower—input bias current therefore does not vary significantly throughout the common mode range. When either input exceeds the positive common mode limit, the bias current drops to zero. Inputs that fall more than one diode and drop below V – will forward bias the substrate or clamp diode, causing large input current to flow. The internal latch uses local regenerative feedback to shorten set-up and hold times. Driving the latch pin high retains the output state. The latch pin floats to a high state when disconnected, so it must be driven low for flow-through operation. The set-up time required to guarantee detecting a given transition of the inputs is 2ns. The inputs must also remain stable for a 2ns hold time after latch is asserted. New data will appear at the output approximately 10ns to 12ns after the latch goes low. The latch pin has no built-in hysteresis, and is designed to be driven from TTL or CMOS logic gates. Single ended input resistance is about 5MΩ, and remains roughly constant over the input common mode range. The common mode resistance is about 2.5MΩ with zero differential input voltage, and does not change significantly with the absolute value of differential input. Effective input capacitance, typically 5pF, is determined by measuring the resulting change in propagation delay for a 1kΩ change in source resistance. Additional Information Linear Technology’s Application Note 13 provides an extensive discussion of design techniques for high speed comparators. Single Supply Crystal Oscillator 10MHz to 15MHz 5V 10 TO 15MHz AT CUT 1kΩ 5V Q + LT1116 1kΩ – Q OUTPUT 24pF 2kΩ LT1116 • AI02 Figure 2. This Single Supply Crystal Oscillator Utilizes Crystals From 10MHz To 15MHz Without Component Changes 1116fc For more information www.linear.com/LT1116 7 LT1116 Applications Information High Speed Adaptive Trigger Circuit Line receivers often require an adaptive trigger to compensate for variations in signal amplitude and DC offsets. The circuit in Figure 3 triggers on 2mV to 200mV signals from 100Hz to 10MHz from a single 5V rail. The trigger level is the average of the input signal’s positive and negative peaks stored on 0.005µF capacitors. Pairs of NPN and PNP transistors are used instead of diodes to temperature compensate the peak detector. 5pF 5V 3kΩ 1% 1kΩ VIN CABLE 200Ω 5V 1kΩ 4R 200Ω 5V 5V – A1 LT1191 + 0.005µF A2 LT1192 + – 47µF 1000pF To achieve single supply operation, the input signal must be shifted into the pre-amplifier’s common mode range. The input amplifier A1 adds a 1V level shift, while A2 provides a gain of 20 for high frequency signals. Capacitors C1 and C2 insure that low frequency signals see unity gain. Bandwidth limiting in A1 and A2 does not affect triggering because the adaptive trigger threshold varies ratiometrically to maintain circuit output. 500pF 0.005µF 3MΩ 3MΩ 5V + A3 LT1006 – R 100Ω 1kΩ 50Ω C1 100µF 3kΩ 1% C2 0.1µF NPN = 2N3904 PNP = 2N3906 500Ω 5V 0.1µF + Q LT1116 – Q TRIGGER OUT LT1116 • AI03 Figure 3. Fast Single Supply Adaptive Trigger 8 1116fc For more information www.linear.com/LT1116 LT1116 Revision History (Revision history begins at Rev C) REV DATE DESCRIPTION C 02/16 Addition of Web Links PAGE NUMBER 2 Reformat of Order Information All Correction to Electrical Characteristics Conditions, V– = –5V 3 1116fc 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. For more information www.linear.com/LT1116 9 LT1116 package description Please refer to http://www.linear.com/product/LT1116#packaging for the most recent package drawings. N Package 8-Lead PDIP (Narrow .300 Inch) (Reference LTC DWG # 05-08-1510 Rev I) .300 – .325 (7.620 – 8.255) ( +.035 .325 –.015 8.255 +0.889 –0.381 .130 ±.005 (3.302 ±0.127) .045 – .065 (1.143 – 1.651) .065 (1.651) TYP .008 – .015 (0.203 – 0.381) .400* (10.160) MAX 8 7 6 5 1 2 3 4 .255 ±.015* (6.477 ±0.381) .120 (3.048) .020 MIN (0.508) MIN .018 ±.003 .100 (2.54) BSC ) (0.457 ±0.076) N8 REV I 0711 NOTE: 1. DIMENSIONS ARE INCHES MILLIMETERS *THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .010 INCH (0.254mm) S8 Package 8-Lead Plastic Small Outline (Narrow .150 Inch) (Reference LTC DWG # 05-08-1610 Rev G) .010 – .020 × 45° (0.254 – 0.508) .050 BSC .189 – .197 (4.801 – 5.004) NOTE 3 .045 ±.005 8 .008 – .010 (0.203 – 0.254) 7 6 5 0°– 8° TYP .245 MIN .016 – .050 (0.406 – 1.270) .053 – .069 (1.346 – 1.752) .150 – .157 (3.810 – 3.988) NOTE 3 .228 – .244 (5.791 – 6.197) .004 – .010 (0.101 – 0.254) .050 (1.270) BSC .014 – .019 (0.355 – 0.483) TYP .160 ±.005 .030 ±.005 TYP RECOMMENDED SOLDER PAD LAYOUT NOTE: INCHES 1. DIMENSIONS IN (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) 4. PIN 1 CAN BE BEVEL EDGE OR A DIMPLE 1 2 3 4 SO8 REV G 0212 Related Parts PART NUMBER DESCRIPTION COMMENTS LT1016 10ns Precision Comparator Complementary Outputs with Latch, LT1116 Pinout LT1394 7ns Single Supply Comparator 6mA, 100MHz Toggle Rate, LT1116 Pinout LT1713/LT1714 7ns Single/Dual Comparator Rail-to-Rail Input and Output, 2.7V to + 5.5V Operation LT1715 4ns Dual Comparator Independent Input/Output Supplies, 150MHz Toggle Rate LT1719 4.5ns Single Supply Comparator Independent Input/Output Supplies, 3V/5V LT1720/LT1721 4.5ns Dual/Quad Comparator 4mA per Comparator, Input 100mV Below V –, 3V/5V LTC6752 2.9ns 280MHz CMOS Output Comparator Family 5 Options Offer a Broad Range of Features 10 Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7417 For more information www.linear.com/LT1116 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com/LT1116 1116fc LT 0216 REV C • PRINTED IN USA LINEAR TECHNOLOGY CORPORATION 2006