LT6231IS8

LT6230/LT6230-10/ LT6231/LT6232 215MHz, Rail-to-Rail Output, 1.1nV/√Hz, 3.5mA Op Amp Family FEATURES s s s s DESCRIPTIO s s s s s s s s s Low Noise Voltage: 1.1nV/√Hz Low Supply Current: 3.5mA/Amp Max Low Offset Voltage: 350µV Max Gain Bandwidth Product: LT6230: 215MHz; AV ≥ 1 LT6230-10: 1450MHz; AV ≥ 10 Wide Supply Range: 3V to 12.6V Output Swings Rail-to-Rail Common Mode Rejection Ratio 115dB Typ Output Current: 30mA Operating Temperature Range – 40°C to 85°C LT6230 Shutdown to 10µA Maximum LT6230/LT6230-10 in SOT-23 Package Dual LT6231 in 8-Pin SO and Tiny DFN Packages LT6232 in 16-Pin SSOP Package The LT®6230/LT6231/LT6232 are single/dual/quad low noise, rail-to-rail output unity gain stable op amps that feature 1.1nV/√Hz noise voltage and draw only 3.5mA of supply current per amplifier. These amplifiers combine very low noise and supply current with a 215MHz gain bandwidth product, a 70V/µs slew rate and are optimized for low supply voltage signal conditioning systems. The LT6230-10 is a single amplifier optimized for higher gain applications resulting in higher gain bandwidth and slew rate. The LT6230 and LT6230-10 include an enable pin that can be used to reduce the supply current to less than 10µA. The amplifier family has an output that swings within 50mV of either supply rail to maximize the signal dynamic range in low supply applications and is specified on 3.3V, 5V and ±5V supplies. The en • √ISUPPLY product of 1.9 per amplifier is among the most noise efficient of any op amp. The LT6230/LT6230-10 is available in the 6-lead SOT-23 package and the LT6231 dual is available in the 8-pin SO package with standard pinouts. For compact layouts, the dual is also available in a tiny dual fine pitch leadless package (DFN). The LT6232 is available in the 16-pin SSOP package. APPLICATIO S s s s s s Ultrasound Amplifiers Low Noise, Low Power Signal Processing Active Filters Driving A/D Converters Rail-to-Rail Buffer Amplifiers , LTC and LT are registered trademarks of Linear Technology Corporation. TYPICAL APPLICATIO VS+ IN+ Low Noise Low Power Instrumentation Amplifier + 1/2 LT6231 R4 499Ω R2 196Ω VS+ R6 499Ω NOISE VOLTAGE (nV/√Hz) 6 5 4 3 Noise Voltage and Unbalanced Noise Current vs Frequency 6 VS = ±2.5V TA = 25°C VCM = 0V 5 4 3 NOISE CURRENT 2 1 0 2 1 – R1 10Ω + LT6202 VOUT – – IN– R3 196Ω R5 499Ω VS– R7 499Ω 1/2 LT6231 + VS– AV = 40 BW = 5.1MHz VS = ±1.5V to ±5V IS = 10mA EN = 5.8µVRMS INPUT REFERRED, MEASUREMENT BW = 8MHz 623012 TA01a 10 U UNBALANCED NOISE CURRENT (pA/√Hz) NOISE VOLTAGE 100 1k 10k FREQUENCY (Hz) 0 100k 623012 TA01b U U sn623012 623012fas 1 LT6230/LT6230-10/ LT6231/LT6232 ABSOLUTE AXI U RATI GS (Note 1) Junction Temperature ........................................... 150°C Junction Temperature (DD Package) ................... 125°C Storage Temperature Range ..................–65°C to 150°C Storage Temperature Range (DD Package) ...................................... – 65°C to 125°C Lead Temperature (Soldering, 10 sec).................. 300°C Total Supply Voltage (V+ to V–) ............................ 12.6V Input Current (Note 2) ........................................ ±40mA Output Short-Circuit Duration (Note 3) ............ Indefinite Operating Temperature Range (Note 4) ...–40°C to 85°C Specified Temperature Range (Note 5) ....–40°C to 85°C PACKAGE/ORDER I FOR ATIO ORDER PART NUMBER TOP VIEW OUT 1 V2 +IN 3 – 6 V+ 5 ENABLE 4 –IN LT6230CS6 LT6230IS6 LT6230CS6-10 LT6230IS6-10 S6 PART MARKING* LTAFJ LTAFK ORDER PART NUMBER S6 PACKAGE 6-LEAD PLASTIC TSOT-23 TJMAX = 150°C, θJA = 250°C/W TOP VIEW OUT A 1 –IN A 2 +IN A 3 V– 4 – + – + – + 8 7 6 5 +IN A 3 V + OUT B –IN B +IN B 4 B C– + – + +IN B 5 S8 PACKAGE 8-LEAD PLASTIC SO TJMAX = 150°C, θJA = 200°C/W S8 PART MARKING 6231 6231I –IN B 6 OUT B 7 NC 8 GN PACKAGE 16-LEAD NARROW PLASTIC SSOP TJMAX = 150°C, θJA = 135°C/W *The temperature grade is identified by a label on the shipping container.Consult LTC Marketing for parts specified with wider operating temperature ranges. 2 + V+ A D – LT6231CS8 LT6231IS8 U U W WW U W TOP VIEW OUT A –IN A +IN A V– 1 2 3 4 – + ORDER PART NUMBER 8 7 – + V+ OUT B –IN B +IN B LT6231CDD LT6231IDD 6 5 DD PACKAGE 8-LEAD (3mm × 3mm) PLASTIC DFN TJMAX = 125°C, θJA = 160°C/W UNDERSIDE METAL CONNECTED TO V– (PCB CONNECTION OPTIONAL) DD PART MARKING* LAEU ORDER PART NUMBER LT6232CGN LT6232IGN GN PART MARKING 6232 6232I TOP VIEW OUT A 1 –IN A 2 16 OUT D 15 –IN D 14 +IN D 13 V – 12 +IN C 11 –IN C 10 OUT C 9 NC sn623012 623012fas LT6230/LT6230-10/ LT6231/LT6232 ELECTRICAL CHARACTERISTICS ENABLE = 0V, unless otherwise noted. SYMBOL VOS PARAMETER Input Offset Voltage TA = 25°C, VS = 5V, 0V; VS = 3.3V, 0V; VCM = VOUT = half supply, CONDITIONS LT6230S6, LT6230S6-10 LT6231S8, LT6232GN LT6231DD MIN TYP 100 50 75 100 5 0.1 0.1 0.1Hz to 10Hz f = 10kHz, VS = 5V f = 10kHz, VS = 5V, RS = 10k f = 10kHz, VS = 5V, RS = 10k Common Mode Differential Mode Common Mode Differential Mode VS = 5V, VO = 0.5V to 4.5V, RL = 10k to VS/2 RL = 1k to VS/2 VO = 1V to 4V, RL = 100Ω to VS/2 VS = 3.3V, VO = 0.65V to 2.65V, RL = 10k to VS/2 RL = 1k to VS/2 105 21 5.4 90 16.5 1.5 1.15 90 90 84 90 84 3 No Load ISINK = 5mA VS = 5V, ISINK = 20mA VS = 3.3V, ISINK = 15mA No Load ISOURCE = 5mA VS = 5V, ISOURCE = 20mA VS = 3.3V, ISOURCE = 15mA V S = 5V VS = 3.3V ENABLE = V+ – 0.35V ±30 ±25 4 85 240 185 5 90 325 250 ±45 ±40 3.15 0.2 3.5 10 40 190 460 350 50 200 600 400 115 115 120 115 115 180 1.1 1 2.4 6.5 7.5 2.9 7.7 200 40 9 175 32 4 2.65 1.7 MAX 500 350 450 600 10 0.9 0.6 UNITS µV µV µV µV µA µA µA nVP-P nV/√Hz pA/√Hz pA/√Hz MΩ kΩ pF pF V/mV V/mV V/mV V/mV V/mV V V dB dB dB dB dB V mV mV mV mV mV mV mV mV mA mA mA µA Input Offset Voltage Match (Channel-to-Channel) (Note 6) IB IOS en in Input Bias Current IB Match (Channel-to-Channel) (Note 6) Input Offset Current Input Noise Voltage Input Noise Voltage Density Input Noise Current Density, Balanced Source Unbalanced Source Input Resistance CIN AVOL Input Capacitance Large-Signal Gain VCM CMRR Input Voltage Range Common Mode Rejection Ratio CMRR Match (Channel-to-Channel) (Note 6) Guaranteed by CMRR, VS = 5V, 0V VS = 3.3V, 0V VS = 5V, VCM = 1.5V to 4V VS = 3.3V, VCM = 1.15V to 2.65V VS = 5V, VCM = 1.5V to 4V VS = 3V to 10V VS = 3V to 10V PSRR Power Supply Rejection Ratio PSRR Match (Channel-to-Channel) (Note 6) Minimum Supply Voltage (Note 7) VOL Output Voltage Swing LOW (Note 8) VOH Output Voltage Swing HIGH (Note 8) ISC IS Short-Circuit Current Supply Current per Amplifier Disabled Supply Current per Amplifier sn623012 623012fas 3 LT6230/LT6230-10/ LT6231/LT6232 ELECTRICAL CHARACTERISTICS ENABLE = 0V, unless otherwise noted. SYMBOL IENABLE VL VH tON tOFF GBW SR PARAMETER ENABLE Pin Current ENABLE Pin Input Voltage LOW ENABLE Pin Input Voltage HIGH Output Leakage Current Turn-On Time Turn-Off Time Gain Bandwidth Product Slew Rate ENABLE = V+ – 0.35V, V O = 1.5V to 3.5V TA = 25°C, VS = 5V, 0V; VS = 3.3V, 0V; VCM = VOUT = half supply, MIN TYP –25 V+ – 0.35V 0.2 300 41 200 1300 42 60 250 4.8 6.3 11 55 10 MAX –75 0.3 UNITS µA V V µA ns µs MHz MHz V/µs V/µs MHz MHz ns CONDITIONS ENABLE = 0.3V ENABLE = 5V to 0V, RL = 1k, VS = 5V ENABLE = 0V to 5V, RL = 1k, VS = 5V Frequency = 1MHz, VS = 5V LT6230-10 VS = 5V, AV = – 1, RL = 1k, VO = 1.5V to 3.5V LT6230-10, VS = 5V, AV = – 10, RL = 1k, VO = 1.5V to 3.5V FPBW tS Full Power Bandwidth Settling Time (LT6230, LT6231, LT6232) VS = 5V, VOUT = 3VP-P (Note 9) LT6230-10, HD2 = HD3 = ≤ 1% 0.1%, VS = 5V, VSTEP = 2V, AV = –1, RL = 1k The q denotes the specifications which apply over 0°C < TA < 70°C temperature range. VS = 5V, 0V; VS = 3.3V, 0V; VCM = VOUT = half supply, ENABLE = 0V, unless otherwise noted. SYMBOL VOS PARAMETER Input Offset Voltage CONDITIONS LT6230S6, LT6230S6-10 LT6231S8, LT6232GN LT6231DD q q q q MIN TYP MAX 600 450 550 800 UNITS µV µV µV µV µV/°C µA µA µA V/mV V/mV V/mV V/mV V/mV Input Offset Voltage Match (Channel-to-Channel) (Note 6) VOS TC IB IOS AVOL Input Offset Voltage Drift (Note 10) Input Bias Current IB Match (Channel-to-Channel) (Note 6) Input Offset Current Large-Signal Gain VS = 5V, VO = 0.5V to 4.5V, RL = 10k to VS /2 RL = 1k to VS /2 RL = 100Ω to VS /2 VO = 1V to 4V, VS = 3.3V, VO = 0.65V to 2.65V, RL = 10k to VS /2 RL = 1k to VS /2 VCM CMRR Input Voltage Range Common Mode Rejection Ratio Guaranteed by CMRR, VS = 5V, 0V VS = 3.3V, 0V VS = 5V, VCM = 1.5V to 4V VS = 3.3V, VCM = 1.15V to 2.65V VCM = Half Supply q q q q q q q q q q q q q q q q q 0.5 3 11 1 0.7 78 17 4.1 66 13 1.5 1.15 90 85 84 85 79 3 50 200 500 380 4 2.65 V V dB dB dB dB dB V mV mV mV mV PSRR CMRR Match (Channel-to-Channel) (Note 6) VS = 5V, VCM = 1.5V to 4V Power Supply Rejection Ratio VS = 3V to 10V PSRR Match (Channel-to-Channel) (Note 6) Minimum Supply Voltage (Note 7) VS = 3V to 10V No Load ISINK = 5mA VS = 5V, ISINK = 20mA VS = 3.3V, ISINK = 15mA VOL Output Voltage Swing LOW (Note 8) q q q q sn623012 623012fas 4 LT6230/LT6230-10/ LT6231/LT6232 The q denotes the specifications which apply over 0°C < TA < 70°C temperature range. VS = 5V, 0V; VS = 3.3V, 0V; VCM = VOUT = half supply, ENABLE = 0V, unless otherwise noted. SYMBOL VOH PARAMETER Output Voltage Swing HIGH (Note 8) CONDITIONS No Load ISOURCE = 5mA VS = 5V, ISOURCE = 20mA VS = 3.3V, ISOURCE = 15mA V S = 5V VS = 3.3V ENABLE = V+ – 0.25V ENABLE = 0.3V q q q q q q q q q q q ELECTRICAL CHARACTERISTICS MIN TYP MAX 60 215 650 430 UNITS mV mV mV mV mA mA ISC IS IENABLE VL VH tON tOFF SR Short-Circuit Current Supply Current per Amplifier Disabled Supply Current per Amplifier ENABLE Pin Current ENABLE Pin Input Voltage LOW ENABLE Pin Input Voltage HIGH Output Leakage Current Turn-On Time Turn-Off Time Slew Rate ±25 ±20 4.2 1 –85 0.3 V+ – 0.25V 1 300 65 35 225 3.7 mA µA µA V V µA ns µs V/µs V/µs MHz ENABLE = V+ – 0.25V, VO = 1.5V to 3.5V ENABLE = 5V to 0V, RL = 1k, VS = 5V ENABLE = 0V to 5V, RL = 1k, VS = 5V VS = 5V, AV = – 1, RL = 1k, VO = 1.5V to 3.5V LT6230-10, AV = – 10, RL = 1k, VO = 1.5V to 3.5V q q q q q q FPBW Full Power Bandwidth (Note 9) VS = 5V, VOUT = 3VP-P LT6230, LT6231, LT6232 The q denotes the specifications which apply over – 40°C < TA < 85°C temperature range. VS = 5V, 0V; VS = 3.3V, 0V; VCM = VOUT = half supply, ENABLE = 0V, unless otherwise noted. (Note 5) SYMBOL VOS PARAMETER Input Offset Voltage CONDITIONS LT6230S6, LT6230S6-10 LT6231S8, LT6232GN LT6231DD q q q q MIN TYP MAX 700 550 650 1000 UNITS µV µV µV µV µV/°C µA µA µA V/mV V/mV V/mV V/mV V/mV Input Offset Voltage Match (Channel-to-Channel) (Note 6) VOS TC IB IOS AVOL Input Offset Voltage Drift (Note 10) Input Bias Current IB Match (Channel-to-Channel) (Note 6) Input Offset Current Large-Signal Gain VS = 5V, VO = 0.5V to 4.5V, RL = 10k to VS /2 RL = 1k to VS /2 RL = 100Ω to VS /2 VO = 1V to 4V, VCM = Half Supply q q q q q q q 0.5 3 12 1.1 0.8 72 16 3.6 60 12 1.5 1.15 90 85 84 85 4 2.65 VS = 3.3V, VO = 0.65V to 2.65V,RL = 10k to VS /2 q RL = 1k to VS /2 q VCM CMRR Input Voltage Range Common Mode Rejection Ratio CMRR Match (Channel-to-Channel) (Note 6) PSRR Power Supply Rejection Ratio Guaranteed by CMRR, VS = 5V, 0V VS = 3.3V, 0V VS = 5V, VCM = 1.5V to 4V VS = 3.3V, VCM = 1.15V to 2.65V VS = 5V, VCM = 1.5V to 4V VS = 3V to 10V q q q q q q V V dB dB dB dB sn623012 623012fas 5 LT6230/LT6230-10/ LT6231/LT6232 The q denotes the specifications which apply over – 40°C < TA < 85°C temperature range. VS = 5V, 0V; VS = 3.3V, 0V; VCM = VOUT = half supply, ENABLE = 0V, unless otherwise noted. (Note 5) SYMBOL PARAMETER PSRR Match (Channel-to-Channel) (Note 6) Minimum Supply Voltage (Note 7) VOL Output Voltage Swing LOW (Note 8) No Load ISINK = 5mA VS = 5V, ISINK = 15mA VS = 3.3V, ISINK = 15mA No Load ISOURCE = 5mA VS = 5V, ISOURCE = 20mA VS = 3.3V, ISOURCE = 15mA V S = 5V VS = 3.3V ENABLE = V+ – 0.2V ENABLE = 0.3V CONDITIONS VS = 3V to 10V q q q q q q q q q q q q q q q q q ELECTRICAL CHARACTERISTICS MIN 79 3 TYP MAX UNITS dB V 60 210 510 390 70 220 675 440 ±15 ±15 4.4 1 –100 0.3 V+ – 0.2V 1 300 72 31 185 3.3 mV mV mV mV mV mV mV mV mA mA mA µA µA V V µA ns µs V/µs V/µs MHz VOH Output Voltage Swing HIGH (Note 6) ISC IS IENABLE VL VH tON tOFF SR Short-Circuit Current Supply Current per Amplifier Disabled Supply Current per Amplifier ENABLE Pin Current ENABLE Pin Input Voltage LOW ENABLE Pin Input Voltage HIGH Output Leakage Current Turn-On Time Turn-Off Time Slew Rate ENABLE = V+ – 0.2V, VO = 1.5V to 3.5V ENABLE = 5V to 0V, RL = 1k, VS = 5V ENABLE = 0V to 5V, RL = 1k, VS = 5V VS = 5V, AV = – 1, RL = 1k, VO = 1.5V to 3.5V LT6230-10, AV = – 10, RL = 1k, VO = 1.5V to 3.5V q q q q q q FPBW Full Power Bandwidth (Note 9) VS = 5V, VOUT = 3VP-P LT6230, LT6231, LT6232 TA = 25°C, VS = ±5V, VCM = VOUT = 0V, ENABLE = 0V, unless otherwise noted. SYMBOL VOS PARAMETER Input Offset Voltage CONDITIONS LT6230, LT6230-10 LT6231S8, LT6232GN LT6231DD MIN TYP 100 50 75 100 5 0.1 0.1 0.1Hz to 10Hz f = 10kHz f = 10kHz, RS = 10k f = 10kHz, RS = 10k 180 1.1 1 2.4 1.7 MAX 500 350 450 600 10 0.9 0.6 UNITS µV µV µV µV µA µA µA nVP-P nV/√Hz pA/√Hz pA/√Hz Input Offset Voltage Match (Channel-to-Channel) (Note 6) IB IOS en in Input Bias Current IB Match (Channel-to-Channel) (Note 6) Input Offset Current Input Noise Voltage Input Noise Voltage Density Input Noise Current Density, Balanced Source Unbalanced Source sn623012 623012fas 6 LT6230/LT6230-10/ LT6231/LT6232 ELECTRICAL CHARACTERISTICS SYMBOL PARAMETER Input Resistance CIN AVOL Input Capacitance Large-Signal Gain TA = 25°C, VS = ±5V, VCM = VOUT = 0V, ENABLE = 0V, unless otherwise noted. CONDITIONS Common Mode Differential Mode Common Mode Differential Mode VO = ±4.5V, RL = 10k RL = 1k VO = ±2V, RL = 100Ω Guaranteed by CMRR VCM = –3V to 4V VCM = –3V to 4V VS = ±1.5V to ±5V VS = ±1.5V to ±5V No Load ISINK = 5mA ISINK = 20mA No Load ISOURCE = 5mA ISOURCE = 20mA ±30 ENABLE = 4.65V ENABLE = 0.3V 4.65 ENABLE = V+ – 4.65V, VO = ±1V ENABLE = 5V to 0V, RL = 1k ENABLE = 0V to 5V, RL = 1k Frequency = 1MHz LT6230-10 AV = – 1, RL = 1k, VO = –2V to 2V LT6230-10, AV = – 10, RL = 1k, VO = –2V to 2V FPBW tS Full Power Bandwidth Settling Time (LT6230, LT6231, LT6232) VOUT = 3VP-P (Note 9) LT6230-10, HD2 = HD3 ≤ 1% 0.1%, VSTEP = 2V, AV = –1, RL = 1k 5.3 150 1000 50 0.2 300 62 215 1450 70 320 7.4 11 50 10 3.3 0.2 –35 3.9 –85 0.3 140 35 8.5 –3 95 89 90 84 120 125 115 115 4 85 240 5 90 325 40 190 460 50 200 600 MIN TYP 6.5 7.5 2.4 6.5 260 65 16 4 MAX UNITS MΩ kΩ pF pF V/mV V/mV V/mV V dB dB dB dB mV mV mV mV mV mV mA mA µA µA V V µA ns µs MHz MHz V/µs V/µs MHz MHz ns VCM CMRR PSRR VOL Input Voltage Range Common Mode Rejection Ratio CMRR Match (Channel-to-Channel) (Note 6) Power Supply Rejection Ratio PSRR Match (Channel-to-Channel) (Note 6) Output Voltage Swing LOW (Note 8) VOH Output Voltage Swing HIGH (Note 8) ISC IS IENABLE VL VH tON tOFF GBW SR Short-Circuit Current Supply Current per Amplifier Disabled Supply Current per Amplifier ENABLE Pin Current ENABLE Pin Input Voltage LOW ENABLE Pin Input Voltage HIGH Output Leakage Current Turn-On Time Turn-Off Time Gain Bandwidth Product Slew Rate sn623012 623012fas 7 LT6230/LT6230-10/ LT6231/LT6232 The q denotes the specifications which apply over 0°C < TA < 70°C temperature range. VS = ±5V, VCM = VOUT = 0V, ENABLE = 0V, unless otherwise noted. SYMBOL VOS PARAMETER Input Offset Voltage CONDITIONS LT6230S6, LT6230S6-10 LT6231S8, LT6232GN LT6231DD q q q q q q q q ELECTRICAL CHARACTERISTICS MIN TYP MAX 600 450 550 800 UNITS µV µV µV µV µV/°C µA µA µA V/mV V/mV V/mV Input Offset Voltage Match (Channel-to-Channel) (Note 6) VOS TC IB IOS AVOL Input Offset Voltage Drift (Note 10) Input Bias Current IB Match (Channel-to-Channel) (Note 6) Input Offset Current Large-Signal Gain VO = ±4.5V, RL = 10k RL = 1k VO = ±2V, RL = 100Ω Guaranteed by CMRR VCM = –3V to 4V VCM = –3V to 4V VS = ±1.5V to ±5V VS = ±1.5V to ±5V No Load ISINK = 5mA ISINK = 20mA No Load ISOURCE = 5mA ISOURCE = 20mA 0.5 3 11 1 0.7 q q q q q q q q q q q q q q q 100 27 6 –3 95 89 85 79 50 200 500 60 215 650 ±25 4.6 1 –95 0.3 4.75 1 300 85 44 315 4.66 4 VCM CMRR PSRR VOL Input Voltage Range Common Mode Rejection Ratio CMRR Match (Channel-to-Channel) (Note 6) Power Supply Rejection Ratio PSRR Match (Channel-to-Channel) (Note 6) Output Voltage Swing LOW (Note 8) V dB dB dB dB mV mV mV mV mV mV mA mA µA µA V V µA ns µs V/µs V/µs MHz VOH Output Voltage Swing HIGH (Note 8) ISC IS IENABLE VL VH tON tOFF SR FPBW Short-Circuit Current Supply Current per Amplifier Disabled Supply Current per Amplifier ENABLE Pin Current ENABLE Pin Input Voltage LOW ENABLE Pin Input Voltage HIGH Output Leakage Current Turn-On Time Turn-Off Time Slew Rate Full Power Bandwidth ENABLE = 4.75V, VO = ±1V ENABLE = 5V to 0V, RL = 1k ENABLE = 0V to 5V, RL = 1k AV = – 1, RL = 1k, VO = –2V to 2V LT6230-10, AV = – 10, RL = 1k, VO = –2V to 2V VOUT = 3VP-P (Note 9) LT6230, LT6231, LT6232 ENABLE = 4.75V ENABLE = 0.3V q q q q q q q q q q q sn623012 623012fas 8 LT6230/LT6230-10/ LT6231/LT6232 The q denotes the specifications which apply over –40°C < TA < 85°C temperature range. VS = ±5V, VCM = VOUT = 0V, ENABLE = 0V, unless otherwise noted. (Note 5) SYMBOL VOS PARAMETER Input Offset Voltage CONDITIONS LT6230, LT6230-10 LT6231S8, LT6232GN LT6231DD q q q q q q q q ELECTRICAL CHARACTERISTICS MIN TYP MAX 700 550 650 1000 UNITS µV µV µV µV µV/°C µA µA µA V/mV V/mV V/mV Input Offset Voltage Match (Channel-to-Channel) (Note 6) VOS TC IB IOS AVOL Input Offset Voltage Drift (Note 10) Input Bias Current IB Match (Channel-to-Channel) (Note 6) Input Offset Current Large-Signal Gain VO = ±4.5V, RL = 10k RL = 1k VO = ±1.5V, RL = 100Ω Guaranteed by CMRR VCM = –3V to 4V VCM = –3V to 4V VS = ±1.5V to ±5V VS = ±1.5V to ±5V No Load ISINK = 5mA ISINK = 15mA No Load ISOURCE = 5mA ISOURCE = 20mA 0.5 3 12 1.1 0.8 q q q q q q q q q q q q q q q 93 25 4.8 –3 95 89 85 79 60 210 510 70 220 675 ±15 4.85 1 –110 0.3 4.8 1 300 72 37 260 3.9 4 VCM CMRR PSRR VOL Input Voltage Range Common Mode Rejection Ratio CMRR Match (Channel-to-Channel) (Note 6) Power Supply Rejection Ratio PSRR Match (Channel-to-Channel) (Note 6) Output Voltage Swing LOW (Note 8) V dB dB dB dB mV mV mV mV mV mV mA mA µA µA V V µA ns µs V/µs V/µs MHz VOH Output Voltage Swing HIGH (Note 8) ISC IS IENABLE VL VH tON tOFF SR FPBW Short-Circuit Current Supply Current per Amplifier Disabled Supply Current per Amplifier ENABLE Pin Current ENABLE Pin Input Voltage LOW ENABLE Pin Input Voltage HIGH Output Leakage Current Turn-On Time Turn-Off Time Slew Rate Full Power Bandwidth (Note 9) ENABLE = 4.8V, VO = ±1V ENABLE = 5V to 0V, RL = 1k ENABLE = 0V to 5V, RL = 1k AV = – 1, RL = 1k, VO = –2V to 2V LT6230-10, AV = – 10, RL = 1k, VO = –2V to 2V VOUT = 3VP-P LT6230, LT6231, LT6232 ENABLE = 4.8V ENABLE = 0.3V q q q q q q q q q q q sn623012 623012fas 9 LT6230/LT6230-10/ LT6231/LT6232 ELECTRICAL CHARACTERISTICS Note 1: Absolute maximum ratings are those values beyond which the life of the device may be impaired. Note 2: Inputs are protected by back-to-back diodes. If the differential input voltage exceeds 0.7V, the input current must be limited to less than 40mA. Note 3: A heat sink may be required to keep the junction temperature below the absolute maximum rating when the output is shorted indefinitely. Note 4: The LT6230C/LT6230I the LT6231C/LT6231I, and LT6232C/ LT6232I are guaranteed functional over the temperature range of –40°C and 85°C. Note 5: The LT6230C/LT6231C/LT6232C are guaranteed to meet specified performance from 0°C to 70°C. The LT6230C/LT6231C/LT6232C are designed, characterized and expected to meet specified performance from – 40°C to 85°C, but are not tested or QA sampled at these temperatures. The LT6230I/LT6231I/LT6232I are guaranteed to meet specified performance from –40°C to 85°C. Note 6: Matching parameters are the difference between the two amplifiers A and D and between B and C of the LT6232; between the two amplifiers of the LT6231. CMRR and PSRR match are defined as follows: CMRR and PSRR are measured in µV/V on the matched amplifiers. The difference is calculated between the matching sides in µV/V. The result is converted to dB. Note 7: Minimum supply voltage is guaranteed by power supply rejection ratio test. Note 8: Output voltage swings are measured between the output and power supply rails. Note 9: Full-power bandwidth is calculated from the slew rate: FPBW = SR/2πVP Note 10: This parameter is not 100% tested. TYPICAL PERFOR A CE CHARACTERISTICS (LT6230/LT6231/LT6232) VOS Distribution 100 VS = 5V, 0V + 90 VCM = V /2 S8 80 6 5 SUPPLY CURRENT (mA) NUMBER OF UNITS 70 60 50 40 30 20 10 0 50 100 150 200 –200 –150 –100 –50 0 INPUT OFFSET VOLTAGE (µV) 623012 GO1 4 3 2 1 0 TA = 125°C TA = 25°C TA = –55°C OFFSET VOLTAGE (mV) Input Bias Current vs Common Mode Voltage 14 12 VS = 5V, 0V INPUT BIAS CURRENT (µA) 9 8 7 6 5 4 3 –50 –25 VCM = 4V VCM = 1.5V OUTPUT SATURATION VOLTAGE (V) INPUT BIAS CURRENT (µA) 10 8 6 4 2 0 –2 –1 0 4 5 3 2 COMMON MODE VOLTAGE (V) 1 6 TA = 25°C TA = –55°C TA = 125°C 10 UW 623012 GO4 Supply Current vs Supply Voltage (Per Amplifier) 2.0 1.5 1.0 0.5 0 –0.5 –1.0 –1.5 0 2 10 12 4 8 6 TOTAL SUPPLY VOLTAGE (V) 14 –2.0 Offset Voltage vs Input Common Mode Voltage VS = 5V, 0V TA = –55°C TA = 25°C TA = 125°C 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 INPUT COMMON MODE VOLTAGE (V) 623012 GO3 623012 GO2 Input Bias Current vs Temperature 10 VS = 5V, 0V Output Saturation Voltage vs Load Current (Output Low) 10 VS = 5V, 0V 1 0.1 TA = 125°C TA = –55°C 0.01 TA = 25°C 0 75 50 25 TEMPERATURE (°C) 100 125 0.001 0.01 0.1 1 10 LOAD CURRENT (mA) 100 623012 GO6 623012 GO5 sn623012 623012fas LT6230/LT6230-10/ LT6231/LT6232 TYPICAL PERFOR A CE CHARACTERISTICS (LT6230/LT6231/LT6232) Output Saturation Voltage vs Load Current (Output High) 10 OUTPUT SATURATION VOLTAGE (V) 0.8 OFFSET VOLTAGE (mV) 1 TA = 125°C TA = –55°C TA = 25°C 0.6 0.4 0.2 0 –0.2 –0.4 –0.6 –0.8 0.1 1 10 LOAD CURRENT (mA) 100 623012 G07 0.1 TA = –55°C TA = 125°C TA = 25°C 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 TOTAL SUPPLY VOLTAGE (V) 623012 G08 0.01 0.001 0.01 –1.0 OUTPUT SHORT-CIRCUIT CURRENT (mA) VS = 5V, 0V Open Loop Gain 2.5 2.0 1.5 VS = 3V, 0V TA = 25°C INPUT VOLTAGE (mV) INPUT VOLTAGE (mV) 1.0 0.5 0 –0.5 –1.0 –1.5 –2.0 –2.5 0 0.5 1 1.5 2 OUTPUT VOLTAGE (V) 2.5 3 RL = 100Ω RL = 1k 1.0 0.5 0 –0.5 –1.0 –1.5 –2.0 –2.5 0 0.5 1 1.5 2 2.5 3 3.5 4 4.5 5 OUTPUT VOLTAGE (V) 623012 G11 INPUT VOLTAGE (mV) Offset Voltage vs Output Current 2.0 1.5 VS = ±5V CHANGE IN OFFSET VOLTAGE (µV) OFFSET VOLTAGE (mV) 24 22 20 18 16 14 12 10 VS = ±2.5V VS = ±1.5V 0.5 0 –0.5 –1.0 –1.5 –2.0 –75 –60 –45 –30 –15 0 15 30 45 60 75 OUTPUT CURRENT (mA) 623012 G13 TOTAL NOISE (nV/√Hz) 1.0 TA = –55°C TA = 125°C UW 623012 G10 Minimum Supply Voltage 1.0 VCM = VS/2 Output Short Circuit Current vs Power Supply Voltage 70 60 SINKING TA = 125°C 50 40 TA = 25°C 30 20 TA = –55°C 10 0 –10 SOURCING TA = 125°C –20 TA = –55°C –30 –40 –50 TA = 25°C –60 –70 4 4.5 5 2 2.5 3.5 3 1.5 POWER SUPPLY VOLTAGE (±V) 623012 GO9 Open Loop Gain 2.5 2.0 1.5 VS = 5V, 0V TA = 25°C 2.5 2.0 1.5 1.0 0.5 0 –0.5 –1.0 –1.5 –2.0 –2.5 Open Loop Gain VS = ±5V TA = 25°C RL = 1k RL = 100Ω RL = 1k RL = 100Ω –5 –4 –3 –2 –1 0 1 2 3 OUTPUT VOLTAGE (V) 4 5 623012 G12 Warm-Up Drift vs Time 30 28 26 VS = ±5V TA = 25°C 100 Total Noise vs Total Source Resistance VS = ±2.5V VCM = 0V f = 100kHz UNBALANCED SOURCE 10 RESISTORS TOTAL NOISE TA = 25°C RESISTOR NOISE 1 AMPLIFIER NOISE VOLTAGE 0.1 0 20 40 60 80 100 120 140 160 TIME AFTER POWER-UP (s) 623012 G14 10 100 1k 10k SOURCE RESISTANCE (Ω) 100k 623012 G15 sn623012 623012fas 11 LT6230/LT6230-10/ LT6231/LT6232 TYPICAL PERFOR A CE CHARACTERISTICS (LT6230/LT6231/LT6232) Noise Voltage and Unbalanced Noise Current vs Frequency 6 5 6 VS = ±2.5V TA = 25°C VCM = 0V 5 4 3 NOISE CURRENT 2 1 0 2 1 NOISE VOLTAGE (nV/√Hz) GAIN BANDWIDTH (MHz) 4 3 100nV/DIV NOISE VOLTAGE 10 100 1k 10k FREQUENCY (Hz) Open Loop Gain vs Frequency 80 70 60 50 GAIN (dB) 40 30 20 10 0 –10 –20 100k 1M VS = 3V, 0V 10M 100M FREQUENCY (Hz) 1G 623012 G19 PHASE GAIN BANDWIDTH (MHz) SLEW RATE (V/µs) VS = 3V, 0V VS = ±5V GAIN Output Impedance vs Frequency 1k COMMON MODE REJECTION RATIO (dB) VS = 5V, 0V CHANNEL SEPARATION (dB) 100 OUTPUT IMPEDANCE (Ω) 10 AV = 10 1 AV = 1 0.1 AV = 2 0.01 100k 1M 10M FREQUENCY (Hz) 12 UW 623012 G16 0.1Hz to 10Hz Output Voltage Noise VS = ±2.5V UNBALANCED NOISE CURRENT (pA/√Hz) PHASE (dB) Gain Bandwidth and Phase Margin vs Temperature CL = 5pF RL = 1k VCM = VS/2 70 PHASE MARGIN VS = ±5V 60 50 240 220 200 180 160 VS = 3V, 0V GAIN BANDWIDTH VS = 3V, 0V VS = ±5V 40 PHASE MARGIN (DEG) 100nV –100nV 0 100k 5s/DIV 623012 G17 140 –55 –25 65 35 5 TEMPERATURE (°C) 95 125 623012 G18 Gain Bandwidth and Phase Margin vs Supply Voltage TA = 25°C CL = 5pF RL = 1k PHASE MARGIN 240 220 200 180 160 140 0 2 10 12 8 6 TOTAL SUPPLY VOLTAGE (V) 4 14 GAIN BANDWIDTH 70 60 50 40 120 Slew Rate vs Temperature AV = –1 110 RF = RG = 1k 100 90 VS = ±5V FALLING 120 CL = 5pF RL = 1k 100 VCM = VS/2 80 VS = ±5V 60 40 20 0 –20 –40 –60 –80 PHASE MARGIN (DEG) 80 VS = ±5V RISING 70 60 50 40 30 20 –55 –35 –15 5 25 45 65 85 105 125 TEMPERATURE (°C) 623012 G21 VS = ±2.5V FALLING VS = ±2.5V RISING 623012 G20 Common Mode Rejection Ratio vs Frequency 120 100 80 60 40 20 0 10k VS = 5V, 0V VCM = VS/2 100k 1M 10M FREQUENCY (Hz) 100M 1G Channel Separation vs Frequency –40 AV = 1 –50 TA = 25°C VS = ±5V –60 –70 –80 –90 –100 –110 –120 –130 –140 100k 1M 10M FREQUENCY (Hz) 100M 623012 G24 100M 623012 G22 623012 G23 sn623012 623012fas LT6230/LT6230-10/ LT6231/LT6232 TYPICAL PERFOR A CE CHARACTERISTICS (LT6230/LT6231/LT6232) Power Supply Rejection Ratio vs Frequency 120 POWER SUPPLY REJECTION RATIO (dB) 100 80 60 NEGATIVE SUPPLY 40 20 0 1k 10k 1M 100k FREQUENCY (Hz) OVERSHOOT (%) POSITIVE SUPPLY 30 25 20 15 10 5 0 RS = 20Ω RS = 50Ω RL = 50Ω OVERSHOOT (%) Settling Time vs Output Step (Non-Inverting) 200 VS = ±5V TA = 25°C AV = 1 VOUT VIN SETTLING TIME (ns) SETTLING TIME (ns) 150 – + 500Ω 150 500Ω VIN OUTPUT VOLTAGE SWING (VP–P) 100 1mV 50 10mV 0 1mV 10mV –4 –3 –2 2 1 0 OUTPUT STEP (V) –1 Distortion vs Frequency –40 VS = ±2.5V AV = 1 –50 VOUT = 2V(P–P) DISTORTION (dBc) DISTORTION (dBc) –60 –70 RL = 1k, 2ND –80 –90 –60 RL = 100Ω, 2ND –70 RL = 1k, 2ND –80 –90 DISTORTION (dBc) RL = 100Ω, 3RD RL = 100Ω, 2ND RL = 1k, 3RD –100 10k 100k 1M FREQUENCY (Hz) 10M 623012 G31 UW VS = 5V, 0V TA = 25°C VCM = VS/2 10M 623012 G25 Series Output Resistance and Overshoot vs Capacitive Load 50 VS = 5V, 0V 45 AV = 1 40 35 RS = 10Ω 50 Series Output Resistance and Overshoot vs Capacitive Load VS = 5V, 0V 45 AV = 2 40 35 30 25 20 15 10 5 0 RS = 50Ω RL = 50Ω RS = 20Ω RS = 10Ω 100M 10 100 CAPACITIVE LOAD (pF) 1000 623012 G26 10 100 CAPACITIVE LOAD (pF) 1000 623012 G27 Settling Time vs Output Step (Inverting) 200 500Ω Maximum Undistorted Output Signal vs Frequency 10 9 8 7 6 5 4 V = ±5V 3 T S = 25°C A HD2, HD3 < –40dBc 2 100k 1M 10k FREQUENCY (Hz) AV = –1 AV = 2 VS = ±5V TA = 25°C AV = –1 VOUT – + 100 1mV 50 10mV 0 10mV 1mV 3 4 –4 –3 –2 2 –1 1 0 OUTPUT STEP (V) 3 4 10M 623012 G30 623012 G28 623012 G29 Distortion vs Frequency –40 VS = ±5V AV = 1 –50 VOUT = 2V(P–P) RL = 100Ω, 3RD –60 –70 –80 –90 RL = 1k, 3RD –100 10k 100k 1M FREQUENCY (Hz) 10M 623012 G32 Distortion vs Frequency –40 VS = ±2.5V AV = 2 –50 VOUT = 2V(P–P) RL = 100Ω, 3RD RL = 100Ω, 2ND RL = 1k, 2ND RL = 1k, 3RD 100k 1M FREQUENCY (Hz) 10M 623012 G33 –100 10k sn623012 623012fas 13 LT6230/LT6230-10/ LT6231/LT6232 TYPICAL PERFOR A CE CHARACTERISTICS (LT6230/LT6231/LT6232) Distortion vs Frequency –40 VS = ±5V AV = 2 –50 VOUT = 2V(P–P) RL = 100Ω, 3RD DISTORTION (dBc) 1V/DIV –60 –70 –80 –90 50mV/DIV VS = ±2.5V AV = –1 RL = 1k 200ns/DIV 623345 G35 RL = 100Ω, 2ND RL = 1k, 3RD –100 10k RL = 1k, 2ND 100k 1M FREQUENCY (Hz) 10M 623012 G34 Large Signal Response VIN (1V/DIV) 5V 2V/DIV 0V VOUT (2V/DIV) –5V VS = ±5V AV = 1 RL = 1k (LT6230) ENABLE Characteristics Supply Current vs ENABLE Pin Voltage 4.5 4.0 SUPPLY CURRENT (mA) 25 ENABLE PIN CURRENT (µA) ENABLE PIN TA = 125°C TA = 25°C TA = –55°C 3.5 3.0 2.5 2.0 1.5 1.0 0.5 0 VS = ±2.5V –2.0 10 5 0 VOUT 1.0 0 –1.0 PIN VOLTAGE (V) 14 UW 2.0 623012 G39 Large Signal Response Small Signal Response 2V 0V 0V –2V VS = ±2.5V AV = 1 RL = 1k 200ns/DIV 623345 G36 Output Overdrive Recovery 0V 0V 200ns/DIV 623345 G37 VS = ±2.5V AV = 3 200ns/DIV 623345 G38 ENABLE Pin Current vs ENABLE Pin Voltage 30 TA = –55°C VS = ±2.5V AV = 1 ENABLE Pin Response Time 5V 0V 20 TA = 25°C 15 T = 125°C A 0.5V 0V VS = ±2.5V VIN = 0.5V AV = 1 RL = 1k 100µs/DIV –2.0 0 1.0 –1.0 PIN VOLTAGE (V) 2.0 623012 G40 623345 G41 sn623012 623012fas LT6230/LT6230-10/ LT6231/LT6232 TYPICAL PERFOR A CE CHARACTERISTICS (LT6230-10) Gain Bandwidth and Phase Margin vs Temperature 1700 1500 GAIN BANDWIDTH (MHz) AV = 10 VS = ±5V GAIN BANDWIDTH PHASE MARGIN (DEG) 1300 1100 900 VS = 3V, 0V SLEW RATE (V/µs) OVERSHOOT (%) VS = ±5V VS = 3V, 0V –50 –25 0 PHASE MARGIN 75 50 25 TEMPERATURE (°C) Open Loop Gain and Phase vs Frequency 90 80 70 60 GAIN PHASE VS = ±5V VS = 3V, 0V 120 100 80 GAIN BANDWIDTH (MHz) GAIN BANDWIDTH (MHz) GAIN (dB) 50 40 30 20 10 0 VS = 3V, 0V –10 100k AV = 10 CL = 5pF RL = 1k VCM = VS/2 1M VS = ±5V 10M 100M FREQUENCY (Hz) Common Mode Rejection Ratio vs Frequency 120 COMMON MODE REJECTION RATIO (dB) VS = 5V, 0V VCM = VS/2 100 80 60 40 20 0 10k OUTPUT VOLTAGE SWING (VP–P) DISTORTION (dBc) 100k 1M 10M FREQUENCY (Hz) 100M UW 100 623012 G42 Slew Rate vs Temperature 600 AV = –10 550 RF = 1k RG = 100Ω 500 450 400 350 300 250 200 150 VS = ±2.5V FALLING 5 25 45 65 85 105 125 TEMPERATURE (°C) 623012 G43 Series Output Resistor and Overshoot vs Capacitive Load 70 60 50 VS = 5V, 0V AV = 10 VS = ±5V FALLING VS = ±5V RISING RS = 10Ω 40 30 20 10 0 10 RS = 20Ω 80 70 60 50 125 40 RS = 50Ω VS = ±2.5V RISING 100 –55 –35 –15 100 1000 CAPACITIVE LOAD (pF) 10000 623012 G44 Gain Bandwidth and Phase Margin vs Supply Voltage 1700 TA = 25°C AV = 10 1450 CL = 5pF RL = 1k 1200 950 100 PHASE MARGIN 50 0 GAIN BANDWIDTH 1600 1400 1200 1000 800 600 400 200 0 PHASE MARGIN (DEG) Gain Bandwidth vs Resistor Load AV = 10 VS ±5V TA = 25°C RF = 1k RG = 100 60 PHASE (DEG) 40 20 0 –20 –40 –60 –80 1G 623012 G45 0 2 10 8 6 TOTAL SUPPLY VOLTAGE (V) 4 12 0 200 623012 G46 1000 400 800 600 TOTAL RESISTOR LOAD (Ω) (INCLUDES FEEDBACK R) 623012 G47 Maximum Undistorted Output Signal vs Frequency 10 9 8 7 6 5 4 3 2 VS = ±5V TA = 25°C 1 AV = 10 HD2 = HD3 ≤ 40dBc 0 100k 1M 10M 10k FREQUENCY (Hz) –90 –60 –70 –40 2nd and 3rd Harmonic Distortion vs Frequency VS = ±2.5V AV = 10 –50 VOUT = 2V(P–P) RL = 100Ω, 3RD RL = 1k, 3RD RL = 1k, 2ND –80 RL = 100Ω, 2ND 1G 100M 623012 G49 –100 10k 100k 1M FREQUENCY (Hz) 10M 623012 G50 623012 G48 sn623012 623012fas 15 LT6230/LT6230-10/ LT6231/LT6232 TYPICAL PERFOR A CE CHARACTERISTICS (LT6230-10) 2nd and 3rd Harmonic Distortion vs Frequency –40 VS = ±5V AV = 10 –50 VOUT = 2V(P–P) DISTORTION (dBc) VOUT (2V/DIV) –60 –70 –80 –90 0V VOUT VIN (0.5V/DIV) (2V/DIV) VS = ±5V 100ns/DIV AV = 10 RF = 900Ω, RG = 100Ω 623345 G52 RL = 100Ω, 3RD RL = 100Ω, 2ND RL = 1k, 3RD RL = 1k, 2ND –100 10k 100k 1M FREQUENCY (Hz) Small Signal Response 10 VOUT (100mV/DIV) 2.5V 1nV/√Hz/DIV VS = 5V, 0V 100ns/DIV AV = 10 RF = 900Ω, RG = 100Ω 16 UW 623012 G51 Large Signal Response Output-Overload Recovery 0V 0V VS = 5V, 0V 100ns/DIV AV = 10 RF = 900Ω, RG = 100Ω 623345 G53 10M Input Referred High Frequency Noise Spectrum 0 100kHz 5MHz/DIV 623345 G54 623345 G55 50MHz sn623012 623012fas LT6230/LT6230-10/ LT6231/LT6232 APPLICATIO S I FOR ATIO Amplifier Characteristics Figure 1 is a simplified schematic of the LT6230/LT6231/ LT6232, which has a pair of low noise input transistors Q1 and Q2. A simple current mirror Q3/Q4 converts the differential signal to a single-ended output, and these transistors are degenerated to reduce their contribution to the overall noise. Capacitor C1 reduces the unity cross frequency and improves the frequency stability without degrading the gain bandwidth of the amplifier. Capacitor CM sets the overall amplifier gain bandwidth. The differential drive generator supplies current to transistors Q5 and Q6 that swing the output from rail-to-rail. +V CM Q3 –V DESD1 –VIN D1 +VIN DESD3 –V +V 623012 F01 1V/DIV Q5 Q4 +V C1 DESD2 –V Q1 D2 Q2 DIFFERENTIAL DRIVE GENERATOR –V Q6 +V DESD4 I1 BIAS Figure 1. Simplified Schematic Input Protection There are back-to-back diodes, D1 and D2 across the + and – inputs of these amplifiers to limit the differential input voltage to ±0.7V. The inputs of the LT6230/LT6231/ LT6232 do not have internal resistors in series with the input transistors. This technique is often used to protect the input devices from over voltage that causes excessive current to flow. The addition of these resistors would significantly degrade the low noise voltage of these amplifiers. For instance, a 100Ω resistor in series with each input would generate 1.8nV/√Hz of noise, and the total amplifier noise voltage would rise from 1.1nV/√Hz to 2.1nV/√Hz. Once the input differential voltage exceeds ±0.7V, steady state current conducted through the protection diodes should be limited to ±40mA. This implies 25Ω of protection resistance is necessary per volt of overdrive beyond ±0.7V. These input diodes are rugged enough to U 2.5V 0V –2.5V 500µs/DIV 623012 F02 W U U Figure 2. VS = ±2.5V, AV = 1 with Large Overdrive handle transient currents due to amplifier slew rate overdrive and clipping without protection resistors. The photo of Figure 2 shows the output response to an input overdrive with the amplifier connected as a voltage follower. With the input signal low, current source I1 saturates and the differential drive generator drives Q6 into saturation so the output voltage swings all the way to V–. The input can swing positive until transistor Q2 saturates into current mirror Q3/Q4. When saturation occurs, the output tries to phase invert, but diode D2 conducts current from the signal source to the output through the feedback connection. The output is clamped a diode drop below the input. In this photo, the input signal generator is limiting at about 20mA. With the amplifier connected in a gain of AV ≥ 2, the output can invert with very heavy overdrive. To avoid this inversion, limit the input overdrive to 0.5V beyond the power supply rails. ESD The LT6230/LT6231/LT6232 have reverse-biased ESD protection diodes on all inputs and outputs as shown in Figure 1. If these pins are forced beyond either supply, unlimited current will flow through these diodes. If the current is transient and limited to one hundred milliamps or less, no damage to the device will occur. Noise The noise voltage of the LT6230/LT6231/LT6232 is equivalent to that of a 75Ω resistor, and for the lowest possible noise it is desirable to keep the source and feedback resistance at or below this value, i.e. RS + RG||RFB ≤ 75Ω. sn623012 623012fas +V DESD5 VOUT DESD6 ENABLE –V 17 LT6230/LT6230-10/ LT6231/LT6232 APPLICATIO S I FOR ATIO eN=√(1.1nV)2+(1.1nV)2 = 1.55nV/√Hz Below this resistance value, the amplifier dominates the noise, but in the region between 75Ω and about 3k, the noise is dominated by the resistor thermal noise. As the total resistance is further increased beyond 3k, the amplifier noise current multiplied by the total resistance eventually dominates the noise. The product of eN • √ISUPPLY is an interesting way to gauge low noise amplifiers. Most low noise amplifiers with low eN have high ISUPPLY current. In applications that require low noise voltage with the lowest possible supply current, this product can prove to be enlightening. The LT6230/ LT6231/LT6232 have an eN • √ISUPPLY product of only 1.9 per amplifier, yet it is common to see amplifiers with similar noise specifications to have eN • √ISUPPLY as high as 13.5. With RS + RG||RFB = 75Ω the total noise of the amplifier is: 18 U For a complete discussion of amplifier noise, see the LT1028 data sheet. Enable Pin The LT6230 includes an ENABLE pin that shuts down the amplifier to 10µA maximum supply current. The ENABLE pin must be driven high to within 0.35V of V+ to shut down the supply current. This can be accomplished with simple gate logic; however care must be taken if the logic and the LT6230 operate from different supplies. If this is the case, then open drain logic can be used with a pull-up resistor to ensure that the amplifier remains off. See Typical Characteristic Curves. The output leakage current when disabled is very low; however, current can flow into the input protection diodes D1 and D2 if the output voltage exceeds the input voltage by a diode drop. sn623012 623012fas W U U LT6230/LT6230-10/ LT6231/LT6232 APPLICATIO S I FOR ATIO U Frequency Response Plot of Bandpass Filter 23 Single Supply, Low Noise, Low Power, Bandpass Filter with Gain = 10 R1 732Ω C2 47pF V+ f0 = 1 = 1MHz 2πRC C1 1000pF VIN R2 732Ω R3 10k 0.1µF – LT6230 VOUT + C3 0.1µF R4 10k EN f0 = 732Ω MHz, MAXIMUM f0 = 1MHz R f–3dB = f0 2.5 AV = 20dB at f0 EN = 4µVRMS INPUT REFERRED IS = 3.7mA FOR V+ = 5V ( ) GAIN (dB) 623012 F03 Low Noise, Low Power, Single Supply, Instrumentation Amplifier with Gain = 100 C2 2200pF R1 30.9Ω VIN1 C1 1µF R6 511Ω R3 30.9Ω R5 511Ω VIN2 C3 1µF W U U C = √C1C2, R = R1 = R2 3 –7 100k 1M FREQUENCY (Hz) 10M 623012 F04 R2 V+ 511Ω – U1 LT6230-10 C8 68pF R15 88.7Ω R13 2k R10 511Ω V+ + EN – U3 LT6230 VOUT + V+ 511Ω R4 R16 88.7Ω R14 2k R12 511Ω C4 10µF C9 68pF EN – U2 LT6230-10 VOUT = 100 (VIN2 – VIN1) GAIN = R2 + 1 R1 + EN ( R10 ) (R15) R1 = R3 R2 = R4 R10 = R12 R15 = R16 INPUT RESISTANCE = R5 = R6 f–3dB = 310Hz TO 11MHz EN = 20µVRMS INPUT REFERRED IS = 10.5mA FOR VS = 5V, 0V 623012 F05 sn623012 623012fas 19 LT6230/LT6230-10/ LT6231/LT6232 PACKAGE DESCRIPTIO U S6 Package 6-Lead Plastic TSOT-23 (Reference LTC DWG # 05-08-1636) 0.62 MAX 0.95 REF 2.90 BSC (NOTE 4) 1.22 REF 1.4 MIN 2.80 BSC 1.50 – 1.75 (NOTE 4) PIN ONE ID 0.95 BSC 0.30 – 0.45 6 PLCS (NOTE 3) 0.80 – 0.90 0.20 BSC 1.00 MAX DATUM ‘A’ 0.01 – 0.10 0.09 – 0.20 (NOTE 3) 1.90 BSC S6 TSOT-23 0302 3.85 MAX 2.62 REF RECOMMENDED SOLDER PAD LAYOUT PER IPC CALCULATOR 0.30 – 0.50 REF NOTE: 1. DIMENSIONS ARE IN MILLIMETERS 2. DRAWING NOT TO SCALE 3. DIMENSIONS ARE INCLUSIVE OF PLATING 4. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR 5. MOLD FLASH SHALL NOT EXCEED 0.254mm 6. JEDEC PACKAGE REFERENCE IS MO-193 sn623012 623012fas 20 LT6230/LT6230-10/ LT6231/LT6232 PACKAGE DESCRIPTIO 3.5 ± 0.05 1.65 ± 0.05 2.15 ± 0.05 (2 SIDES) PACKAGE OUTLINE 0.25 ± 0.05 0.50 BSC 2.38 ± 0.05 (2 SIDES) RECOMMENDED SOLDER PAD PITCH AND DIMENSIONS R = 0.115 TYP 5 0.38 ± 0.10 8 PIN 1 TOP MARK (NOTE 6) (DD8) DFN 1203 0.200 REF 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 U DD Package 8-Lead Plastic DFN (3mm × 3mm) (Reference LTC DWG # 05-08-1698) 0.675 ± 0.05 3.00 ± 0.10 (4 SIDES) 1.65 ± 0.10 (2 SIDES) 0.75 ± 0.05 4 0.25 ± 0.05 2.38 ± 0.10 (2 SIDES) BOTTOM VIEW—EXPOSED PAD 1 0.50 BSC 0.00 – 0.05 sn623012 623012fas 21 LT6230/LT6230-10/ LT6231/LT6232 PACKAGE DESCRIPTIO U S8 Package 8-Lead Plastic Small Outline (Narrow .150 Inch) (Reference LTC DWG # 05-08-1610) .045 ±.005 .050 BSC 8 .189 – .197 (4.801 – 5.004) NOTE 3 7 6 5 .160 ±.005 .228 – .244 (5.791 – 6.197) .150 – .157 (3.810 – 3.988) NOTE 3 1 2 3 4 .053 – .069 (1.346 – 1.752) 0°– 8° TYP .004 – .010 (0.101 – 0.254) .014 – .019 (0.355 – 0.483) TYP .050 (1.270) BSC SO8 0303 .245 MIN .030 ±.005 TYP RECOMMENDED SOLDER PAD LAYOUT .010 – .020 × 45° (0.254 – 0.508) .008 – .010 (0.203 – 0.254) .016 – .050 (0.406 – 1.270) NOTE: 1. DIMENSIONS IN 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) sn623012 623012fas 22 LT6230/LT6230-10/ LT6231/LT6232 PACKAGE DESCRIPTIO U GN Package 16-Lead Plastic SSOP (Narrow .150 Inch) (Reference LTC DWG # 05-08-1641) .045 ± .005 .189 – .196* (4.801 – 4.978) 16 15 14 13 12 11 10 9 .009 (0.229) REF .150 – .165 .229 – .244 (5.817 – 6.198) .0165 ± .0015 .150 – .157** (3.810 – 3.988) .0250 BSC 1 .015 ± .004 × 45° (0.38 ± 0.10) .007 – .0098 (0.178 – 0.249) .016 – .050 (0.406 – 1.270) NOTE: 1. CONTROLLING DIMENSION: INCHES INCHES 2. DIMENSIONS ARE IN (MILLIMETERS) 3. DRAWING NOT TO SCALE *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° – 8° TYP .0532 – .0688 (1.35 – 1.75) 23 4 56 7 8 .004 – .0098 (0.102 – 0.249) .008 – .012 (0.203 – 0.305) TYP .0250 (0.635) BSC GN16 (SSOP) 0204 .254 MIN RECOMMENDED SOLDER PAD LAYOUT sn623012 623012fas 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. 23 LT6230/LT6230-10/ LT6231/LT6232 TYPICAL APPLICATIO S The LT6230 is applied as a transimpedance amplifier with an I-to-V conversion gain of 1.5kΩ set by R1. The LT6230 is ideally suited to this application because of its low input offset voltage and current, and its low noise. This is because the 1.5k resistor has an inherent thermal noise of 5nV/√Hz or 3.4pA/√Hz at room temperature, while the LT6230 contributes only 1.1nV and 2.4pA /√Hz. So, with respect to both voltage and current noises, the LT6230 is actually quieter than the gain resistor. The circuit uses an avalanche photodiode with the cathode biased to approximately 200V. When light is incident on Low Power Avalanche Photodiode Transimpedance Amplifier IS = 3.3mA ≈ 200V BIAS ADVANCED PHOTONIX 012-70-62-541 WWW.ADVANCEDPHOTONIX.COM R1 1.5k C1 4.7pF – R2 1.5k LT6230 5V + ENABLE C2 0.1µF 30mV/DIV OUTPUT OFFSET = 500µV TYPICAL BANDWIDTH = 20MHz OUTPUT NOISE = 1.1mVP–P (100MHz MEASUREMENT BW) RELATED PARTS PART NUMBER LT1028 LT1677 LT1806/LT1807 LT6200/LT6201 LT6202/LT6203/LT6204 DESCRIPTION Single, Ultra Low Noise 50MHz Op Amp Single, Low Noise Rail-to-Rail Amplifier Single/Dual, Low Noise 325MHz Rail-to-Rail Amplifier Single/Dual, Low Noise 165MHz Single/Dual/Quad, Low Noise, Rail-to-Rail Amplifier COMMENTS 0.85nV/√Hz 3V Operation, 2.5mA, 4.5nV/√Hz, 60µV Max VOS 2.5V Operation, 550µV Max VOS, 3.5nV/√Hz 0.95nV√Hz, Rail-to-Rail Input and Output 1.9nV/√Hz, 3mA Max, 100MHz Gain Bandwidth 24 Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 q FAX: (408) 434-0507 q U the photodiode, it induces a current IPD which flows into the amplifier circuit. The amplifier output falls negative to maintain balance at its inputs. The transfer function is therefore VOUT = –IPD • 1.5k. C1 ensures stability and good settling characteristics. Output offset was measured at 280µV, so low in part because R2 serves to cancel the DC effects of bias current. Output noise was measured at 1.1mVP–P on a 100MHz measurement bandwidth, with C2 shunting R2’s thermal noise. As shown in the scope photo, the rise time is 17ns, indicating a signal bandwidth of 20MHz. Photodiode Amplifier Time Domain Response –5V 623012 TA02a 50ns/DIV 623012 TA02b sn623012 623012fas LT/TP 0304 1K REV A • PRINTED IN USA www.linear.com © LINEAR TECHNOLOGY CORPORATION 2003