LT1638/LT1639 1.2MHz, 0.4V/μs Over-The-Top Micropower Rail-to-Rail Input and Output Op Amps DESCRIPTIO U FEATURES ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ ■ Operates with Inputs Above V + Rail-to-Rail Input and Output Low Power: 230μA per Amplifier Max Gain Bandwidth Product: 1.2MHz Slew Rate: 0.4V/μs High Output Current: 25mA Min Specified on 3V, 5V and ±15V Supplies Reverse Battery Protection to 18V No Supply Sequencing Problems High Voltage Gain: 1500V/mV Single Supply Input Range: – 0.4V to 44V High CMRR: 98dB No Phase Reversal Available in 14-Lead SO, 8-Lead MSOP and DFN Packages The LT ®1638 is a low power dual rail-to-rail input and output operational amplifier available in the standard 8-pin PDIP and SO packages as well as the 8-lead MSOP package. The LT1639 is a low power quad rail-to-rail input and output operational amplifier offered in the standard 14-pin PDIP and surface mount packages. For space limited applications the LT1638 is available in a 3mm x 3mm x 0.8mm dual fine pitch leadless package (DFN). The LT1638/LT1639 op amps operate on all single and split supplies with a total voltage of 2.5V to 44V drawing only 170μA of quiescent current per amplifier. These amplifiers are reverse battery protected and draw no current for reverse supply up to 18V. The input range of the LT1638/LT1639 includes both supplies, and a unique feature of this device is its capability to operate over the top with either or both of its inputs above V +. The inputs handle 44V, both differential and common mode, independent of supply voltage. The input stage incorporates phase reversal protection to prevent false outputs from occurring when the inputs are below the negative supply. Protective resistors are included in the input leads so that current does not become excessive when the inputs are forced below the negative supply. The LT1638/LT1639 can drive loads up to 25mA and still maintain rail-to-rail capability. The op amps are unity-gain stable and drive all capacitive loads up to 1000pF when optional output compensation is used. U APPLICATIO S ■ ■ ■ ■ ■ Battery- or Solar-Powered Systems Portable Instrumentation Sensor Conditioning Supply Current Sensing Battery Monitoring Micropower Active Filters 4mA to 20mA Transmitters , LT, LTC and LTM are registered trademarks of Linear Technology Corporation. Over-The-Top is a registered trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. U TYPICAL APPLICATIO Output Voltage vs Input Voltage Over-The-Top® Comparator with 100mV Hysteresis Centered at 0mV 10k 1M VCC VCC 1M + + A 1/2 LT1638 B 1/2 LT1638 – 5V VCC V1 1M V0 – 0V 10k 1M 1638/39 TA01 V2 VCC = 5V, VCM = 0V TO 44V, tPD = 27μs 20mV/DIV 1638/39 TA02 16389fd 1 LT1638/LT1639 U W W W ABSOLUTE MAXIMUM RATINGS (Note 1) Total Supply Voltage (V + to V –) .............................. 44V Input Differential Voltage ......................................... 44V Input Current ...................................................... ±25mA Output Short-Circuit Duration (Note 2) .........Continuous Operating Temperature Range (Note 3) LT1638C/LT1639C ............................. – 40°C to 85°C LT1638I/LT1639I ................................ – 40°C to 85°C LT1638H/LT1639H ........................... – 40°C to 125°C Specified Temperature Range (Note 4) LT1638C/LT1639C ............................. – 40°C to 85°C LT1638I/LT1639I ................................ – 40°C to 85°C LT1638H/LT1639H ........................... – 40°C to 125°C Junction Temperature ........................................... 150°C DD Package ...................................................... 125°C Storage Temperature Range ................. – 65°C to 150°C DD Package ...................................... – 65°C to 125°C Lead Temperature (Soldering, 10 sec).................. 300°C U W U PACKAGE/ORDER INFORMATION ORDER PART NUMBER ORDER PART NUMBER TOP VIEW TOP VIEW OUT A –IN A +IN A V– 1 2 3 4 8 7 6 5 A B V+ OUT B –IN B +IN B MS8 PACKAGE 8-LEAD PLASTIC MSOP TJMAX = 150°C, θJA = 300°C/W (MS8) LT1638CMS8 LT1638IMS8 MS8 PART MARKING* ORDER PART NUMBER TOP VIEW 1 –IN A 2 +IN A 3 V– 4 A B 1 –IN A 2 LT1638CDD LT1638IDD +IN A 3 V– 4 V+ 7 OUT B 6 –IN B 5 +IN B B N8 PACKAGE 8-LEAD PDIP TOP VIEW OUT A 1 –IN A 2 +IN A 3 V+ 7 OUT B V+ 4 6 –IN B +IN B 5 5 +IN B DD PART MARKING* LAAL S8 PACKAGE 8-LEAD PLASTIC SO TJMAX = 150°C, θJA = 150°C/W (N8) TJMAX = 150°C, θJA = 190°C/W (S8) 8 DD PACKAGE 8-LEAD (3mm × 3mm) PLASTIC DFN TJMAX = 125°C, θJA = 160°C/W (NOTE 10) UNDERSIDE METAL INTERNALLY CONNECTED TO V – 8 A LTCY OUT A OUT A –IN B 6 OUT B 7 14 OUT D A D 13 –IN D 12 +IN D 11 V – 10 +IN C B N PACKAGE 14-LEAD PDIP C 9 – IN C 8 OUT C LT1638CN8 LT1638IN8 LT1638CS8 LT1638IS8 LT1638HS8 S8 PART MARKING 1638 1638I 1638H ORDER PART NUMBER LT1639CN LT1639IN LT1639CS LT1639IS LT1639HS S PACKAGE 14-LEAD PLASTIC SO TJMAX = 150°C, θJA = 130°C/W (N) TJMAX = 150°C, θJA = 160°C/W (S) Order Options Tape and Reel: Add #TR Lead Free: Add #PBF Lead Free Tape and Reel: Add #TRPBF Lead Free Part Marking: http://www.linear.com/leadfree/ *The temperature grades are identified by a label on the shipping container. Consult LTC Marketing for parts specified with wider operating temperature ranges. 16389fd 2 LT1638/LT1639 ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the specified temperature range, otherwise specifications are at TA = 25°C. VS = 3V, 0V; VS = 5V, 0V; VCM = VOUT = half supply, unless otherwise noted. (Note 4) SYMBOL VOS PARAMETER Input Offset Voltage CONDITIONS LT1638 N, S Packages 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C LT1639 N, S Packages 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C LT1638 MS8 Package 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C LT1638 DD Package 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C Input Offset Voltage Drift (Note 9) IOS IB 1 6 2.5 nA μA ● ● 20 8 0.1 1 50 30 nA μA nA Input Noise Voltage Density Input Noise Current Density f = 1kHz f = 1kHz RIN Input Resistance Differential Common Mode, VCM = 0V to 44V CIN Input Capacitance Input Voltage Range 1 1.4 6 7 μVP-P 20 0.3 nV/√Hz pA/√Hz 2.5 5.5 MΩ MΩ 5 CMRR Common Mode Rejection Ratio VCM = 0V to VCC – 1V VCM = 0V to 44V (Note 8) AVOL Large-Signal Voltage Gain VS = 3V, VO = 500mV to 2.5V, RL = 10k 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C VS = 5V, VO = 500mV to 4.5V, RL = 10k 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C Short-Circuit Current (Note 2) μV/°C μV/°C ● ● Input Noise Voltage ISC μV μV μV μV μV μV VCM = 44V (Note 5) Input Bias Current Output Voltage Swing High 400 ● ● 900 1150 1450 1100 1350 1450 2 2.5 en in VOH 350 ● ● ● ● Input Offset Current Output Voltage Swing Low ● ● UNITS μV μV μV μV μV μV LT1638/LT1639 N, S Packages LT1638MS8, LT1638DD VCM = 44V (Note 5) VS = 0V 0.1Hz to 10Hz VOL ● ● LT1638C/LT1639C, LT1638I/LT1639I MIN TYP MAX 200 600 850 950 300 700 950 1050 ● 0 ● ● 88 80 98 88 200 133 100 400 250 200 1500 ● ● ● ● 44 pF V dB dB V/mV V/mV V/mV V/mV V/mV V/mV 1500 VS = 3V, No Load VS = 3V, ISINK = 5mA ● ● 3 250 8 450 mV mV VS = 5V, No Load VS = 5V, ISINK = 10mA ● ● 3 500 8 700 mV mV VS = 3V, No Load VS = 3V, ISOURCE = 5mA ● ● 2.94 2.25 2.98 2.40 V V VS = 5V, No Load VS = 5V, ISOURCE = 10mA ● ● 4.94 3.8 4.98 4.0 V V VS = 3V, Short to GND VS = 3V, Short to VCC 10 15 15 25 mA mA VS = 5V, Short to GND VS = 5V, Short to VCC 15 15 20 25 mA mA 16389fd 3 LT1638/LT1639 ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the specified temperature range, otherwise specifications are at TA = 25°C. VS = 3V, 0V; VS = 5V, 0V; VCM = VOUT = half supply, unless otherwise noted. (Note 4) SYMBOL PSRR PARAMETER Power Supply Rejection Ratio CONDITIONS VS = 3V to 12.5V, VCM = VO = 1V LT1638C/LT1639C, LT1638I/LT1639I MIN TYP MAX ● 90 100 Reverse Supply Voltage Minimum Operating Supply Voltage IS = – 100μA per Amplifier ● IS Supply Current per Amplifier (Note 6) GBW Gain Bandwidth Product (Note 5) SR Slew Rate (Note 7) 18 ● 27 2.4 170 ● f = 5kHz 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C AV = – 1, RL = ∞ 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C ● ● ● ● 650 550 500 0.210 0.185 0.170 UNITS dB 2.7 V V 230 275 μA μA 1075 kHz kHz kHz V/μs V/μs V/μs 0.38 The ● denotes the specifications which apply over the specified temperature range, otherwise specifications are at TA = 25°C. VS = ±15V, VCM = 0V, VOUT = 0V, unless otherwise noted. (Note 4) LT1638C/LT1639C, LT1638I/LT1639I SYMBOL VOS PARAMETER Input Offset Voltage CONDITIONS LT1638 N, S Packages 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C LT1639 N, S Packages 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C LT1638 MS8 Package 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C LT1638 DDPackage 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C Input Offset Voltage Drift (Note 9) LT1638/LT1639 N, S Packages LT1638MS8, LT1638DD MIN TYP 250 ● ● 350 ● ● 400 ● ● 450 ● ● MAX 800 1000 1100 900 1100 1200 UNITS μV μV μV μV μV μV 1050 1250 1550 1250 1450 1550 μV μV μV μV μV μV ● ● 2 2.5 6 7 μV/°C μV/°C ● 1 20 6 50 nA nA IOS IB Input Offset Current Input Bias Current en Input Noise Voltage Input Noise Voltage Density 0.1Hz to 10Hz f = 1kHz 1 20 μVP-P nV/√Hz in RIN Input Noise Current Density Input Resistance f = 1kHz Differential Common Mode, VCM = – 15V to 14V CIN Input Capacitance 0.3 2.5 500 4.5 pA/√Hz MΩ MΩ pF CMRR Input Voltage Range Common Mode Rejection Ratio AVOL Large-Signal Voltage Gain VO Output Voltage Swing ● 1 ● VCM = –15V to 29V VO = ±14V, RL = 10k 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C No Load IOUT = ±10mA ● ● ● ● ● – 15 80 200 125 100 ±14.9 ±13.7 29 88 500 ±14.95 ±14.0 V dB V/mV V/mV V/mV V V 16389fd 4 LT1638/LT1639 ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the specified temperature range, otherwise specifications are at TA = 25°C. VS = ±15V, VCM = 0V, VOUT = 0V, unless otherwise noted. (Note 4) LT1638C/LT1639C, LT1638I/LT1639I SYMBOL PARAMETER CONDITIONS ISC Short-Circuit Current (Note 2) Short to GND 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C VS = ±1.5V to ±22V PSRR Power Supply Rejection Ratio IS Supply Current per Amplifier MIN TYP 40 ● ● 25 20 15 mA mA mA ● 90 100 dB 205 ● GBW SR Gain Bandwidth Product Slew Rate MAX 280 350 UNITS μA μA f = 5kHz 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C 750 650 600 1200 ● ● kHz kHz kHz AV = – 1, RL = ∞, VO = ±10V, 0°C ≤ TA ≤ 70°C – 40°C ≤ TA ≤ 85°C 0.225 0.2 0.18 0.4 ● ● V/μs V/μs V/μs The ● denotes the specifications which apply over the full operating temperature range of –40°C ≤ TA ≤ 125°C. VS = 3V, 0V; VS = 5V, 0V; VCM = VOUT = Half Supply unless otherwise specified. (Note 4) SYMBOL VOS PARAMETER Input Offset Voltage CONDITIONS LT1638S8 ● LT1639S ● ● Input Offset Voltage Drift (Note 9) IOS IB ● ● 15 10 nA μA VCM = 44V (Note 5) ● ● 150 100 nA μA 44 V dB dB V/mV V/mV V/mV V/mV mV mV Input Bias Current Input Voltage Range Common Mode Rejection Ratio AVOL Large-Signal Voltage Gain ● VCM = 0.3V to VCC – 1V VCM = 0.3V to 44V VS = 3V, VO = 500mV to 2.5V, RL = 10k VS = 5V, VO = 500mV to 4.5V, RL = 10k VOL VOH PSRR IS GBW SR UNITS μV mV μV mV μV/°C VCM = 44V (Note 5) Input Offset Current CMRR LT1638H/LT1639H MIN TYP MAX 200 650 3 300 750 3.2 15 ● ● ● ● 0.3 76 72 200 20 400 35 1500 1500 No Load ISINK = 5mA VS = 5V, ISINK = 10mA ● ● ● VS = 3V, No Load VS = 3V, ISOURCE = 5mA ● ● 2.9 2 V V VS = 5V, No Load VS = 5V, ISOURCE = 10mA ● ● 4.9 3.5 V V Power Supply Rejection Ratio Minimum Supply Voltage VS = 3V to 12.5V, VCM = VO = 1V ● ● 80 2.7 dB V Reverse Supply Voltage Supply Current (Note 6) Gain Bandwidth Product (Note 5) Slew Rate (Note 7) IS = – 100μA ● 18 Output Voltage Swing Low Output Voltage Swing High 15 900 1500 170 ● f = 5kHz ● AV = – 1, RL = ∞ ● 650 350 0.21 0.1 1075 0.38 230 450 mV V μA μA kHz kHz V/μs V/μs 16389fd 5 LT1638/LT1639 ELECTRICAL CHARACTERISTICS The ● denotes the specifications which apply over the full operating temperature range of –40°C ≤ TA ≤ 125°C, otherwise specifications are at TA = 25°C. VS = ±15V, VCM = 0V, VOUT = 0V, VSHDN = V – unless otherwise specified. (Note 4) SYMBOL VOS PARAMETER Input Offset Voltage CONDITIONS LT1638S8 ● LT1638H/LT1639H MIN TYP MAX 250 850 3.4 LT1639S 350 ● ● IOS Input Offset Voltage Drift (Note 9) Input Offset Current IB CMRR Input Bias Current Common Mode Rejection Ratio VCM = –14.7V to 29V AVOL Large-Signal Voltage Gain VO = ±14V, RL = 10k VO Output Voltage Swing PSRR Power Supply Rejection Ratio IS Minimum Supply Voltage Supply Current GBW Gain Bandwidth Product ● ● ● 72 ● 200 15 ● ±14.8 ±14 ±13.4 84 ● ±1.35 ● ● ● No Load IOUT = ± 5mA IOUT = ±10mA VS = ±1.5V to ±22V SR Slew Rate AV = – 1, RL = ∞, VO = ±10V, Measure at VO = ±5V 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: A heat sink may be required to keep the junction temperature below absolute maximum. This depends on the power supply voltage and how many amplifiers are shorted. Note 3: The LT1638C/LT1639C and LT1638I/LT1639I are guaranteed functional over the operating temperature range of –40°C to 85°C. The LT1638H/LT1639H are guaranteed functional over the operating temperature range of – 40°C to 125°C. Note 4: The LT1638C/LT1639C are guaranteed to meet specified performance from 0°C to 70°C and are designed, characterized and expected to meet specified performance from –40°C to 85°C but not tested or QA sampled at these temperatures. The LT1638I/LT1639I are guaranteed to meet specified performance from –40°C to 85°C. The LT1638H/LT1639H are guaranteed to meet specified performance from –40°C to 125°C. ● 750 400 0.225 0.1 μV mV 15 25 μV/°C nA 250 nA dB V/mV V/mV V V V dB 205 ● 950 3.6 500 ● f = 5kHz UNITS μV mV 1200 0.4 280 550 V μA μA kHz kHz V/μs V/μs Note 5: VS = 5V limits are guaranteed by correlation to VS = 3V and VS = ±15V or VS = ±22V tests. Note 6: VS = 3V limits are guaranteed by correlation to VS = 5V and VS = ±15V or VS = ±22V tests. Note 7: Guaranteed by correlation to slew rate at VS = ±15V, and GBW at VS = 3V and VS = ±15V tests. Note 8: This specification implies a typical input offset voltage of 2mV at VCM = 44V and a maximum input offset voltage of 5mV at VCM = 44V. Note 9: This parameter is not 100% tested. Note 10: The θJA specified for the DD package is with minimal PCB heat spreading metal. Using expanded metal area on all layers of a board reduces this value. 16389fd 6 LT1638/LT1639 U W TYPICAL PERFORMANCE CHARACTERISTICS Supply Current vs Supply Voltage 260 TA = 125°C 240 220 TA = 25°C 200 180 TA = –55°C 160 140 120 400 10000 300 8000 200 100 0 5 0 10 15 20 25 30 35 SUPPLY VOLTAGE (V) 40 TA = 25°C –100 TA = 125°C TA = –55°C –200 –300 – 400 100 INPUT BIAS CURRENT (nA) CHANGE IN INPUT OFFSET VOLTAGE (μV) SUPPLY CURRENT PER AMPLIFIER (μA) 300 280 Input Bias Current vs Common Mode Voltage Minimum Supply Voltage 45 0 1 3 4 2 TOTAL SUPPLY VOLTAGE (V) TA = –55°C 0.01 0.1 1 SOURCING LOAD CURRENT (mA) 10 TA = 125°C TA = 25°C 0.01 TA = –55°C 0.001 0.001 0.01 0.1 1 SINKING LOAD CURRENT (mA) 7 8 10 OUTPUT LOW 9 10 1638/39 G07 0 10 20 30 40 50 60 70 80 90 100 INPUT OVERDRIVE (mV) 1638/39 G05 1638/39 G06 Input Noise Current Density vs Frequency 4.5 INPUT NOISE CURRENT DENSITY (pA/√Hz) INPUT NOISE VOLTAGE DENSITY (nV/√Hz) 4 5 6 TIME (SEC) OUTPUT HIGH 1 10 70 3 44 VS = ±2.5V NO LOAD Noise Voltage Density vs Frequency VS = ±2.5 4.4 5.2 5.6 4.8 COMMON MODE VOLTAGE (V) 100 0.1 0.1Hz to 10Hz Noise Voltage 2 TA = 25°C Output Saturation Voltage vs Input Overdrive VS = ±2.5V VOD = 30mV 1638/39 G04 1 TA = 125°C 0 1638/39 G03 OUTPUT SATURATION VOLTAGE (mV) OUTPUT SATURATION VOLTAGE (V) TA = 25°C 0 20 –40 4.0 5 1 NOISE VOLTAGE (400nV/DIV) OUTPUT SATURATION VOLTAGE (V) 1 0.01 0.001 40 Output Saturation Voltage vs Load Current (Output Low) TA = 125°C TA = –55°C 60 1638/39 G02 Output Saturation Voltage vs Load Current (Output High) 0.1 6000 –20 1638/39 G01 VS = ±2.5V VOD = 30mV VS = 5V, 0V 60 50 40 30 20 10 0 4.0 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0 1 10 100 FREQUENCY (Hz) 1k 1638/39 G09 1 10 100 FREQUENCY (Hz) 1k 1638/39 G08 16389fd 7 LT1638/LT1639 U W TYPICAL PERFORMANCE CHARACTERISTICS Gain and Phase Shift vs Frequency Gain Bandwidth Product vs Temperature 100 80 PHASE 50 70 40 60 50 GAIN 20 40 10 30 0 20 10 –10 0 1000 –20 10 100 FREQUENCY (kHz) 1 1400 0.55 1300 VS = ±15V 1200 1100 1000 VS = ±2.5V 900 800 –50 –25 50 25 0 75 TEMPERATURE (°C) 1638/39 G12 GAIN BANDWIDTH 30 20 1100 5 10 15 20 25 30 35 40 TOTAL SUPPLY VOLTAGE (V) GAIN BANDWIDTH PRODUCT (kHz) 40 1300 0 VS = ± 2.5V AV = –1 RF = RG = 100k f = 1kHz 1400 1300 FALLING, VS = ±15V 50 25 0 75 TEMPERATURE (°C) 1100 20 GAIN BANDWIDTH PRODUCT 10 45 90 50 30 1000 10 900 0 800 –10 100 1 10 LOAD RESISTANCE (kΩ) 70 60 POSITIVE SUPPLY 50 40 30 NEGATIVE SUPPLY 20 10 0 –10 1 10 100 FREQUENCY (kHz) 1000 1638/39 G16 Output Impedance vs Frequency Channel Separation vs Frequency VS = ±15V 125 VS = ±2.5V 80 1638/39 G17 130 100 PSRR vs Frequency 1200 10k VS = ±15V VS = ± 2.5V 100 90 80 70 60 50 40 OUTPUT IMPEDANCE (Ω) 120 CHANNEL SEPARATION (dB) COMMON MODE REJECTION RATIO (dB) FALLING, VS = ±2.5V 0.35 1638/39 G14 60 PHASE MARGIN CMRR vs Frequency 110 0.40 0.25 –50 –25 125 40 1638/39 G15 120 100 PHASE MARGIN (DEG) PHASE MARGIN PHASE MARGIN (DEG) GAIN BANDWIDTH PRODUCT (kHz) 1500 50 1400 1000 RISING, VS = ±2.5V 0.45 Gain Bandwidth Product and Phase Margin vs Load Resistance 60 1200 0.50 1638/39 G13 Gain Bandwidth Product and Phase Margin vs Supply Voltage 1500 RISING, VS = ±15V 0.30 POWER SUPPLY REJECTION RATIO (dB) 30 PHASE SHIFT (DEG) GAIN (dB) f = 1kHz 90 60 0.60 SLEW RATE (V/μs) VS = ±2.5V 70 Slew Rate vs Temperature 1500 GAIN BANDWIDTH PRODUCT (kHz) 80 110 100 90 80 1k 100 AV = 10 AV = 100 10 AV = 1 1 70 30 20 1 10 100 FREQUENCY (kHz) 1000 1638/39 G18 60 0.1 1 10 FREQUENCY (kHz) 100 1638/39 G19 0.1 0.1 1 10 100 FREQUENCY (kHz) 1000 1638/39 G20 16389fd 8 LT1638/LT1639 U W TYPICAL PERFORMANCE CHARACTERISTICS Settling Time to 0.1% vs Output Step 100 VS = ±15V 8 80 AV = –1 4 OVERSHOOT (%) 2 0 –2 –4 AV = –1 –6 60 AV = 5 AV = 1 40 30 AV = 10 5 20 15 10 25 SETTLING TIME (μs) 35 30 10 100 1000 CAPACITIVE LOAD (pF) Total Harmonic Distortion + Noise vs Frequency THD + NOISE (%) VS = ±1.5V VIN = ±1V 0.1 VS = 3V, 0V VIN = 0.5V TO 2.5V 0.01 100 0.001 0.1 Open-Loop Gain 0.001 1 10 LOAD RESISTANCE TO GROUND (kΩ) 1638/39 G24 0.1 0.01 VS = 3V, 0V VIN = 0.2V TO 2.2V 1 10 FREQUENCY (Hz) RL = 10k, f = 1kHz VCM = HALF SUPPLY AV = –1, VS = ±1.5V AV = –1, VS = 3V, 0V AV = 1, VS = ±1.5V AV = 1, VS = 3V, 0V 1 AV = 1 0.1 100 10 1 AV = –1 1 10 FREQUENCY (kHz) Total Harmonic Distortion + Noise vs Output Voltage VS = 3V TOTAL AV = 1 VIN = 2VP-P AT 1kHz 0.1 0.001 0.01 VS = ± 2.5V 1638/39 G23 10 VS = 3V, 0V VOUT = 2VP-P VCM = 1.2V RL = 20k CHANGE IN INPUT OFFSET VOLTAGE (50μV/DIV) THD + NOISE (%) 10000 Total Harmonic Distortion + Noise vs Load Resistance 10 0.01 10 1638/39 G22 1638/39 G21 1 15 0 0.1 0 –10 0 20 5 10 DISTORTION ≤ 1% RL = 20k 25 20 AV = 1 –8 70 50 VS = ±15V 30 THD + NOISE (%) OUTPUT STEP (V) 90 AV = 1 6 35 VS = 5V, 0V VCM = 2.5V ISOURCE = 150μA OUTPUT SWING (VP-P) 10 Undistorted Output Swing vs Frequency Capacitive Load Handling, Overshoot vs Capacitive Load 100 0 2 1 OUTPUT VOLTAGE (VP-P) 1638/39 G26 1638/39 G25 Large-Signal Response 3 Small-Signal Response VS = ±15V RL = 2k RL = 10k RL = 50k VS = ±15V AV = 1 –20V –10V 10V 0V OUTPUT VOLTAGE (5V/DIV) 1638/39 G28 VS = ±15V AV = 1 CL = 15pF 1638/39 G29 20V 1638/39 G27 16389fd 9 LT1638/LT1639 U W U U APPLICATIONS INFORMATION Supply Voltage The positive supply pin of the LT1638/LT1639 should be bypassed with a small capacitor (typically 0.1μF) within an inch of the pin. When driving heavy loads an additional 4.7μF electrolytic capacitor should be used. When using split supplies, the same is true for the negative supply pin. The LT1638/LT1639 are protected against reverse battery voltages up to 18V. In the event a reverse battery condition occurs, the supply current is less than 1nA. The LT1638/LT1639 can be shut down by removing V +. In this condition the input bias current is less than 0.1nA, even if the inputs are 44V above the negative supply. At temperatures greater than 70°C, when operating the LT1638/LT1639 on total supplies of 10V or more, the supply must not be brought up faster than 1V/μs. Increasing the bypass capacitor and/or adding a small resistor in series with the supply will limit the rise time. Inputs The LT1638/LT1639 have two input stages, NPN and PNP (see the Simplified Schematic), resulting in three distinct operating regions as shown in the Input Bias Current vs Common Mode typical performance curve. For input voltages about 0.8V or more below V +, the PNP input stage is active and the input bias current is typically – 20nA. When the input common mode voltage is within 0.5V of the positive rail, the NPN stage is operating and the input bias current is typically 40nA. Increases in temperature will cause the voltage at which operation switches from the PNP input stage to the NPN input stage to move towards V +. The input offset voltage of the NPN stage is untrimmed and is typically 600μV. A Schottky diode in the collector of each NPN transistor allow the LT1638/LT1639 to operate over the top, with either or both of its inputs above V +. At about 0.3V above V + the NPN input transistor is fully saturated and the input bias current is typically 8μA at room temperature. The input offset voltage is typically 2mV when operating above V +. The LT1638/LT1639 will operate with its inputs 44V above V – regardless of V +. The inputs are protected against excursions of 2V below V – by an internal 1k resistor in series with each input and a diode from the input to the negative supply. If the inputs can go more than 2V below V –, an additional external resistor is required. A 10k resistor will protect the input against excursions as much as 10V below V –. The input stage of the LT1638/LT1639 incorporates phase reversal protection to prevent the output from phase reversing for inputs below V –. There are no clamping diodes between the inputs and the maximum differential input voltage is 44V. Output The output of the LT1638/LT1639 can swing within 20mV of the positive rail with no load, and within 3mV of the negative rail with no load. When monitoring voltages within 20mV of the positive rail or within 3mV of the negative rail, gain should be taken to keep the output from clipping. The LT1638/LT1639 are capable of sinking and sourcing over 40mA on ±15V supplies; sourcing current capability is reduced to 20mA at 5V total supplies as noted in the electrical characteristics. The LT1638/LT1639 are internally compensated to drive at least 200pF of capacitance under any output loading conditions. A 0.22μF capacitor in series with a 150Ω resistor between the output and ground will compensate these amplifiers for larger capacitive loads, up to 1000pF, at all output currents. Optional Output Compensation for Capacitive Loads Greater than 200pF VIN + LT1638 – 1000pF 0.22μF 150Ω Distortion There are two main contributors of distortion in op amps: output crossover distortion as the output transitions from sourcing to sinking current and distortion caused by 16389fd 10 LT1638/LT1639 U W U U APPLICATIONS INFORMATION nonlinear common mode rejection. If the op amp is operating inverting there is no common mode induced distortion. If the op amp is operating in the PNP input stage (input is not within 0.8V of V +), the CMRR is very good, typically 98dB. When the LT1638 switches between input stages there is significant nonlinearity in the CMRR. Lower load resistance increases the output crossover distortion, but has no effect on the input stage transition distortion. For lowest distortion the LT1638/LT1639 should be operated single supply, with the output always sourcing current and with the input voltage swing between ground and (V + – 0.8V). See the Typical Performance Characteristics curves. Gain The open-loop gain is almost independent of load when the output is sourcing current. This optimizes performance in single supply applications where the load is returned to ground. The typical performance curve of Open-Loop Gain for various loads shows the details. U TYPICAL APPLICATIONS VCC R5 100k With 1.2MHz bandwidth, Over-The-Top capability, reverse-battery protection and rail-to-rail input and output features, the LT1638/LT1639 are ideal candidates for general purpose applications. The lowpass slope limiting filter in Figure 1 limits the maximum dV/dT (not frequency) that it passes. When the input signal differs from the output by one forward diode drop, D1 or D2 will turn on. With a diode on, the voltage across R2 will be constant and a fixed current, VDIODE/R2, will flow through capacitor C1, charging it linearly instead of exponentially. The maximum slope that the circuit will pass is equal to VDIODE divided by (R2)(C1). No matter how fast the input changes the output will never change any faster than the dV/dT set by the diodes and (R2)(C). + 1/4 LT1639 D1 R3 100k – R1 1k D2 VOUT 1/4 LT1639 R2 + VIN C1 R4 100k D3 LT1634-1.2V D4 – 1/4 LT1639 FOR R2 = 50k, C1 = 500pF, MAXIMUM SLOPE = 0.048V/μs 1.2V d = V dt OUT (R2)(C1) D1 LT1634-1.2V – D2 + R6 100k 1638/39 F02 D1 TO D4 = IN4148 R1 VIN VD d V = dt OUT(MAX) (R2)(C1) FOR R1 = 10k, R2 = 100k, C1 = 1000pF d V = 0.006V/μs dt OUT(MAX) R2 VEE + C1 1/2 LT1638 Response of Slope Limiting Filter VOUT – 1638/39 F01 VOUT Figure 1. Lowpass Slope Limiting Filter A modification of this application is shown in Figure 2 using references instead of diodes to set the maximum slope. By using references, the slope is independent of temperature. A scope photo shows a 1VP-P, 2kHz input signal with a 2V pulse added to the sine wave; the circuit passes the 2kHz signal but limits the slope of the pulse. VIN 1638/39 TA02 Figure 2. Lowpass Slope Limiting Filter with 0 TC 16389fd 11 LT1638/LT1639 U TYPICAL APPLICATIONS The Figure 4 application uses the LT1638 in conjunction with the LT1634 micropower shunt reference. The supply current of the op amp also biases the reference. The drop across resistor R1 is fixed at 1.2V generating an output current equal to 1.2V/R1. The application in Figure 3 utilizes the Over-The-Top capabilities of the LT1638. The 0.2Ω resistor senses the load current while the op amp and NPN transistor form a closed loop making the collector current of Q1 proportional to the load current. As a convenient monitor, the 2k load resistor converts the current into a voltage. The positive supply rail, V +, is not limited to the 5V supply of the op amp and could be as high as 44V. V+ 200Ω VCC + Q1 2N3904 1/2 LT1638 200Ω LOAD R1 LT1634-1.2 5V 0.2Ω VCC – + 0V TO 4.3V IOUT = 1.2V R1 1/2 LT1638 2k ILOAD – IOUT 1638/39 F03 VOUT = (2Ω)(ILOAD) 1638/39 F04 Figure 3. Positive Supply Rail Current Sense Figure 4. Current Source W W SI PLIFIED SCHE ATIC V+ Q2 Q1 D1 R1 6k Q3 D2 Q22 D3 R2 1k Q4 Q19 – IN Q17 Q7 R3 1k + 10μA Q11 OUT +IN Q6 Q20 Q12 Q16 Q18 Q15 Q9 Q5 Q8 D4 D5 Q10 Q13 Q14 R4 8k Q21 R5 8k V– ONE AMPLIFIER 1638/39 SS 16389fd 12 LT1638/LT1639 U PACKAGE DESCRIPTION DD Package 8-Lead Plastic DFN (3mm × 3mm) (Reference LTC DWG # 05-08-1698) R = 0.115 TYP 5 0.38 ± 0.10 8 0.675 ±0.05 3.5 ±0.05 1.65 ±0.05 2.15 ±0.05 (2 SIDES) 3.00 ±0.10 (4 SIDES) PACKAGE OUTLINE 1.65 ± 0.10 (2 SIDES) PIN 1 TOP MARK (NOTE 6) (DD) DFN 1203 0.25 ± 0.05 4 0.25 ± 0.05 0.75 ±0.05 0.200 REF 0.50 BSC 2.38 ±0.05 (2 SIDES) 1 0.50 BSC 2.38 ±0.10 (2 SIDES) 0.00 – 0.05 BOTTOM VIEW—EXPOSED PAD NOTE: 1. DRAWING TO BE MADE A JEDEC PACKAGE OUTLINE M0-229 VARIATION OF (WEED-1) 2. DRAWING NOT TO SCALE 3. ALL DIMENSIONS ARE IN MILLIMETERS 4. DIMENSIONS OF EXPOSED PAD ON BOTTOM OF PACKAGE DO NOT INCLUDE MOLD FLASH. MOLD FLASH, IF PRESENT, SHALL NOT EXCEED 0.15mm ON ANY SIDE 5. EXPOSED PAD SHALL BE SOLDER PLATED 6. SHADED AREA IS ONLY A REFERENCE FOR PIN 1 LOCATION ON TOP AND BOTTOM OF PACKAGE RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS MS8 Package 8-Lead Plastic MSOP (Reference LTC DWG # 05-08-1660) 3.00 ± 0.102 (.118 ± .004) (NOTE 3) 0.889 ± 0.127 (.035 ± .005) 5.23 (.206) MIN 3.20 – 3.45 (.126 – .136) 0.254 (.010) 8 7 6 5 3.00 ± 0.102 (.118 ± .004) (NOTE 4) 4.90 ± 0.152 (.193 ± .006) DETAIL “A” 0.52 (.0205) REF 0° – 6° TYP GAUGE PLANE 0.42 ± 0.038 (.0165 ± .0015) TYP 0.65 (.0256) BSC 1 0.53 ± 0.152 (.021 ± .006) RECOMMENDED SOLDER PAD LAYOUT DETAIL “A” 1.10 (.043) MAX 2 3 4 0.86 (.034) REF 0.18 (.007) NOTE: 1. DIMENSIONS IN MILLIMETER/(INCH) 2. DRAWING NOT TO SCALE 3. DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS. MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.152mm (.006") PER SIDE 4. DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS. INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.152mm (.006") PER SIDE 5. LEAD COPLANARITY (BOTTOM OF LEADS AFTER FORMING) SHALL BE 0.102mm (.004") MAX SEATING PLANE 0.22 – 0.38 (.009 – .015) TYP 0.65 (.0256) BSC 0.127 ± 0.076 (.005 ± .003) MSOP (MS8) 0204 16389fd 13 LT1638/LT1639 U PACKAGE DESCRIPTION N8 Package 8-Lead PDIP (Narrow .300 Inch) (Reference LTC DWG # 05-08-1510) .400* (10.160) MAX .300 – .325 (7.620 – 8.255) .008 – .015 (0.203 – 0.381) ( +.035 .325 –.015 8.255 +0.889 –0.381 .130 ± .005 (3.302 ± 0.127) .045 – .065 (1.143 – 1.651) 7 6 5 1 2 3 4 .255 ± .015* (6.477 ± 0.381) .065 (1.651) TYP ) 8 .120 (3.048) .020 MIN (0.508) MIN .018 ± .003 (0.457 ± 0.076) .100 (2.54) BSC N8 1002 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) .189 – .197 (4.801 – 5.004) NOTE 3 .045 ±.005 .050 BSC 8 .245 MIN 5 .150 – .157 (3.810 – 3.988) NOTE 3 .228 – .244 (5.791 – 6.197) 1 RECOMMENDED SOLDER PAD LAYOUT INCHES (MILLIMETERS) 2. DRAWING NOT TO SCALE 3. THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .006" (0.15mm) 6 .160 ±.005 .030 ±.005 TYP NOTE: 1. DIMENSIONS IN 7 .010 – .020 × 45° (0.254 – 0.508) .008 – .010 (0.203 – 0.254) .053 – .069 (1.346 – 1.752) 0°– 8° TYP .016 – .050 (0.406 – 1.270) .014 – .019 (0.355 – 0.483) TYP 2 3 4 .004 – .010 (0.101 – 0.254) .050 (1.270) BSC SO8 0303 16389fd 14 LT1638/LT1639 U PACKAGE DESCRIPTION N Package 14-Lead PDIP (Narrow .300 Inch) (Reference LTC DWG # 05-08-1510) .770* (19.558) MAX 14 13 12 11 10 9 8 1 2 3 4 5 6 7 .255 ± .015* (6.477 ± 0.381) .300 – .325 (7.620 – 8.255) .130 ± .005 (3.302 ± 0.127) .045 – .065 (1.143 – 1.651) .020 (0.508) MIN .065 (1.651) TYP .008 – .015 (0.203 – 0.381) ( +.035 .325 –.015 +0.889 8.255 –0.381 .005 (0.127) .100 MIN (2.54) BSC .120 (3.048) MIN ) NOTE: 1. DIMENSIONS ARE .018 ± .003 (0.457 ± 0.076) N14 1103 INCHES MILLIMETERS *THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .010 INCH (0.254mm) S Package 14-Lead Plastic Small Outline (Narrow .150 Inch) (Reference LTC DWG # 05-08-1610) .337 – .344 (8.560 – 8.738) NOTE 3 .045 ±.005 .050 BSC 14 N 12 11 10 9 8 N .245 MIN .160 ±.005 .150 – .157 (3.810 – 3.988) NOTE 3 .228 – .244 (5.791 – 6.197) 1 .030 ±.005 TYP 13 2 3 N/2 N/2 RECOMMENDED SOLDER PAD LAYOUT 1 NOTE: 1. DIMENSIONS IN .010 – .020 × 45° (0.254 – 0.508) INCHES .008 – .010 (MILLIMETERS) (0.203 – 0.254) 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) 2 3 4 5 .053 – .069 (1.346 – 1.752) .014 – .019 (0.355 – 0.483) TYP 7 .004 – .010 (0.101 – 0.254) 0° – 8° TYP .016 – .050 (0.406 – 1.270) 6 .050 (1.270) BSC S14 0502 16389fd 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. 15 LT1638/LT1639 U TYPICAL APPLICATION The battery monitor in Figure 5 also demonstrates the LT1638’s ability to operate with its inputs above the positive rail. In this application, a conventional amplifier would be limited to a battery voltage between 5V and ground, but the LT1638 can handle battery voltages as high as 44V. When the battery is charging, Amp B senses the voltage drop across RS. The output of Amp B causes Q2 to drain sufficient current through RB to balance the input of Amp B. Likewise, Amp A and Q1 form a closed RS, 0.2Ω CHARGER VOLTAGE RA, 2k RA', 2k IBATT loop when the battery is discharging. The current through Q1 or Q2 is proportional to the current in RS and this current flows into RG and is converted into a voltage. Amp D buffers and amplifies the voltage across RG. Amp C compares the output of Amp A and Amp B to determine the polarity of current through RS. The scale factor for VOUT with S1 open is 1V/A. With S1 closed the scale factor is 1V/100mA and currents as low as 500μA can be measured. Q1 2N3904 + A 1/4 LT1639 + C 1/4 LT1639 – LOGIC – RB, 2k RB', 2k LOAD + + Q2 2N3904 LOGIC HIGH (5V) = CHARGING LOGIC LOW (0V) = DISCHARGING B 1/4 LT1639 + – RG 10k VBATT = 12V D 1/4 LT1639 VOUT – S1 10k 90.9k 1638/39 F05 IBATT = VOUT V = OUT AMPS (RS)(RG /RA)(GAIN) GAIN S1 = OPEN, GAIN = 1 S1 = CLOSED, GAIN = 10 RA = RB VS = 5V, 0V Figure 5. Battery Monitor RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LT1078/LT1079 LT2078/LT2079 Dual/Quad 55μA Max, Single Supply, Precision Op Amps Input/Output Common Mode Includes Ground, 70μV VOS(MAX) and 2.5μV/°C Drift (Max), 200kHz GBW, 0.07V/μs Slew Rate LT1178/LT1179 LT2178/LT2179 Dual/Quad 17μA Max, Single Supply, Precison Op Amps Input/Output Common Mode Includes Ground, 70μV VOS(MAX) and 4μV/°C Drift (Max), 85kHz GBW, 0.04V/μs Slew Rate LT1366/LT1367 Dual/Quad Precision, Rail-to-Rail Input and Output Op Amps 475μV VOS(MAX), 500V/mV AVOL(MIN), 400kHz GBW LT1490/LT1491 Dual/Quad Over-The-Top Micropower, Rail-to-Rail Input and Output Op Amps Single Supply Input Range: – 0.4V to 44V, Micropower 50μA per Amplifier, Rail-to-Rail Input and Output, 200kHz GBW LT1636 Single Over-The-Top Micropower Rail-to-Rail Input and Output Op Amp 55μA Supply Current, VCM Extends 44V above VEE, Independent of VCC; MSOP Package, Shutdown Function 16389fd 16 Linear Technology Corporation LT 0707 REV D • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com © LINEAR TECHNOLOGY CORPORATION 1998