LTC6652

FeaTures n LT6654 SOT-23 Precision Wide Supply High Output Drive Low Noise Reference DescripTion The LT®6654 is a family of small precision voltage references that offers high accuracy, low noise, low drift, low dropout and low power. The LT6654 operates from voltages up to 36V and is fully specified from –55°C to 125°C. A buffered output ensures ±10mA of output drive with low output impedance and precise load regulation. These features, in combination, make the LT6654 ideal for portable equipment, industrial sensing and control, and automotive applications. The LT6654 was designed with advanced manufacturing techniques and curvature compensation to provide 10ppm/°C temperature drift and 0.05% initial accuracy. Low thermal hysteresis ensures high accuracy and 1.6ppmP-P noise minimizes measurement uncertainty. Since the LT6654 can also sink current, it can operate as a low power negative voltage reference with the same precision as a positive reference. The LT6654 is offered in a 6-lead SOT-23 package. L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and ThinSOT is a trademark of Linear Technology Corporation. All other trademarks are the property of their respective owners. n n n n n n n n n n n n Low Drift: A Grade: 10ppm/°C Max B Grade: 20ppm/°C Max High Accuracy: A Grade: ±0.05% Max B Grade: ±0.10% Max Low Noise: 1.6ppmP-P (0.1Hz to 10Hz) Wide Supply Range to 36V Low Thermal Hysteresis Line Regulation (Up to 36V): 5ppm/V Max Low Dropout Voltage: 100mV Max Sinks and Sources ±10mA Load Regulation at 10mA: 8ppm/mA Max Easily Configured for Negative Voltage Output Fully Specified from –55°C to 125°C Available Output Voltage Options: 1.25V, 2.048V, 2.5V, 3V, 3.3V, 4.096V, 5V Low Profile (1mm) ThinSOT™ Package Automotive Control and Monitoring High Temperature Industrial High Resolution Data Acquisition Systems Instrumentation and Process Control Precision Regulators Medical Equipment applicaTions n n n n n n Typical applicaTion Basic Connection (VOUT + 0.5V) < VIN < 36V 4 CIN 0.1µF LT6654 1 2 6 CL 1µF 6654 TA01a Output Voltage Temperature Drift 0.10 3 TYPICAL PARTS LT6654-2.5 VOUT ACCURACY (%) VOUT 0.05 0.00 –0.05 –0.10 –60 –40 –20 0 20 40 60 80 100 120 140 TEMPERATURE (°C) 6654 TA01b 6654fb 1 LT6654 absoluTe MaxiMuM raTings (Note 1) pin conFiguraTion TOP VIEW GND* 1 GND 2 DNC 3 6 VOUT 5 DNC 4 VIN Input Voltage VIN to GND ........................... –0.3V to 38V Output Voltage VOUT .........................–0.3V to VIN + 0.3V Output Short-Circuit Duration ......................... Indefinite Specified Temperature Range H-Grade ............................................. –40°C to 125°C MP-Grade .......................................... –55°C to 125°C Operating Temperature Range................ –55°C to 125°C Storage Temperature Range (Note 2)..... – 65°C to 150°C Lead Temperature (Soldering, 10 sec.) (Note 9)................................................................. 300°C S6 PACKAGE 6-LEAD PLASTIC TSOT-23 TJMAX = 150°C, θJA = 192°C/W DNC: DO NOT CONNECT *CONNECT PIN TO DEVICE GND (PIN 2) orDer inForMaTion Lead Free Finish TAPE AND REEL (MINI) TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION LT6654AHS6-1.25#TRMPBF LT6654AHS6-1.25#TRPBF LTFVD 6-Lead Plastic TSOT-23 LT6654BHS6-1.25#TRMPBF LT6654BHS6-1.25#TRPBF LTFVD 6-Lead Plastic TSOT-23 LT6654AMPS6-1.25#TRMPBF LT6654AMPS6-1.25#TRPBF LTFVD 6-Lead Plastic TSOT-23 LT6654BMPS6-1.25#TRMPBF LT6654BMPS6-1.25#TRPBF LTFVD 6-Lead Plastic TSOT-23 LT6654AHS6-2.048#TRMPBF LT6654AHS6-2.048#TRPBF LTFVF 6-Lead Plastic TSOT-23 LT6654BHS6-2.048#TRMPBF LT6654BHS6-2.048#TRPBF LTFVF 6-Lead Plastic TSOT-23 LT6654AMPS6-2.048#TRMPBF LT6654AMPS6-2.048#TRPBF LTFVF 6-Lead Plastic TSOT-23 LT6654BMPS6-2.048#TRMPBF LT6654BMPS6-2.048#TRPBF LTFVF 6-Lead Plastic TSOT-23 LT6654AHS6-2.5#TRMPBF LT6654AHS6-2.5#TRPBF LTFJY 6-Lead Plastic TSOT-23 LT6654BHS6-2.5#TRMPBF LT6654BHS6-2.5#TRPBF LTFJY 6-Lead Plastic TSOT-23 LT6654AMPS6-2.5#TRMPBF LT6654AMPS6-2.5#TRPBF LTFJY 6-Lead Plastic TSOT-23 LT6654BMPS6-2.5#TRMPBF LT6654BMPS6-2.5#TRPBF LTFJY 6-Lead Plastic TSOT-23 LT6654AHS6-3#TRMPBF LT6654AHS6-3#TRPBF LTFVG 6-Lead Plastic TSOT-23 LT6654BHS6-3#TRMPBF LT6654BHS6-3#TRPBF LTFVG 6-Lead Plastic TSOT-23 LT6654AMPS6-3#TRMPBF LT6654AMPS6-3#TRPBF LTFVG 6-Lead Plastic TSOT-23 LT6654BMPS6-3#TRMPBF LT6654BMPS6-3#TRPBF LTFVG 6-Lead Plastic TSOT-23 LT6654AHS6-3.3#TRMPBF LT6654AHS6-3.3#TRPBF LTFVH 6-Lead Plastic TSOT-23 LT6654BHS6-3.3#TRMPBF LT6654BHS6-3.3#TRPBF LTFVH 6-Lead Plastic TSOT-23 LT6654AMPS6-3.3#TRMPBF LT6654AMPS6-3.3#TRPBF LTFVH 6-Lead Plastic TSOT-23 LT6654BMPS6-3.3#TRMPBF LT6654BMPS6-3.3#TRPBF LTFVH 6-Lead Plastic TSOT-23 LT6654AHS6-4.096#TRMPBF LT6654AHS6-4.096#TRPBF LTFVJ 6-Lead Plastic TSOT-23 LT6654BHS6-4.096#TRMPBF LT6654BHS6-4.096#TRPBF LTFVJ 6-Lead Plastic TSOT-23 LT6654AMPS6-4.096#TRMPBF LT6654AMPS6-4.096#TRPBF LTFVJ 6-Lead Plastic TSOT-23 LT6654BMPS6-4.096#TRMPBF LT6654BMPS6-4.096#TRPBF LTFVJ 6-Lead Plastic TSOT-23 LT6654AHS6-5#TRMPBF LT6654AHS6-5#TRPBF LTFVK 6-Lead Plastic TSOT-23 LT6654BHS6-5#TRMPBF LT6654BHS6-5#TRPBF LTFVK 6-Lead Plastic TSOT-23 LT6654AMPS6-5#TRMPBF LT6654AMPS6-5#TRPBF LTFVK 6-Lead Plastic TSOT-23 LT6654BMPS6-5#TRMPBF LT6654BMPS6-5#TRPBF LTFVK 6-Lead Plastic TSOT-23 TRM = 500 pieces. *Temperature grades are identified by a label on the shipping container. Consult LTC Marketing for parts specified with wider operating temperature ranges. Consult LTC Marketing for information on lead based finish parts. For more information on lead free part marking, go to: http://www.linear.com/leadfree/ For more information on tape and reel specifications, go to: http://www.linear.com/tapeandreel/ SPECIFIED TEMPERATURE RANGE –40°C to 125°C –40°C to 125°C –55°C to 125°C –55°C to 125°C –40°C to 125°C –40°C to 125°C –55°C to 125°C –55°C to 125°C –40°C to 125°C –40°C to 125°C –55°C to 125°C –55°C to 125°C –40°C to 125°C –40°C to 125°C –55°C to 125°C –55°C to 125°C –40°C to 125°C –40°C to 125°C –55°C to 125°C –55°C to 125°C –40°C to 125°C –40°C to 125°C –55°C to 125°C –55°C to 125°C –40°C to 125°C –40°C to 125°C –55°C to 125°C –55°C to 125°C 6654fb 2 LT6654 available opTions INITIAL ACCURACY TEMPERATURE COEFFICIENT 0.05% 10ppm/°C 0.1% 20ppm/°C 0.05% 10ppm/°C 0.1% 20ppm/°C 2.048V 0.05% 10ppm/°C 0.1% 20ppm/°C 0.05% 10ppm/°C 0.1% 20ppm/°C 2.5V 0.05% 10ppm/°C 0.1% 20ppm/°C 0.05% 10ppm/°C 0.1% 20ppm/°C 3V 0.05% 10ppm/°C 0.1% 20ppm/°C 0.05% 10ppm/°C 0.1% 20ppm/°C 3.3V 0.05% 10ppm/°C 0.1% 20ppm/°C 0.05% 10ppm/°C 0.1% 20ppm/°C 4.096V 0.05% 10ppm/°C 0.1% 20ppm/°C 0.05% 10ppm/°C 0.1% 20ppm/°C 5V 0.05% 10ppm/°C 0.1% 20ppm/°C 0.05% 10ppm/°C 0.1% 20ppm/°C ** See the Order Information section for complete part number listing. OUTPUT VOLTAGE 1.25V ORDER PART NUMBER** LT6654AHS6-1.25 LT6654BHS6-1.25 LT6654AMPS6-1.25 LT6654BMPS6-1.25 LT6654AHS6-2.048 LT6654BHS6-2.048 LT6654AMPS6-2.048 LT6654BMPS6-2.048 LT6654AHS6-2.5 LT6654BHS6-2.5 LT6654AMPS6-2.5 LT6654BMPS6-2.5 LT6654AHS6-3 LT6654BHS6-3 LT6654AMPS6-3 LT6654BMPS6-3 LT6654AHS6-3.3 LT6654BHS6-3.3 LT6654AMPS6-3.3 LT6654BMPS6-3.3 LT6654AHS6-4.096 LT6654BHS6-4.096 LT6654AMPS6-4.096 LT6654BMPS6-4.096 LT6654AHS6-5 LT6654BHS6-5 LT6654AMPS6-5 LT6654BMPS6-5 SPECIFIED TEMPERATURE RANGE –40°C to 125°C –40°C to 125°C –55°C to 125°C –55°C to 125°C –40°C to 125°C –40°C to 125°C –55°C to 125°C –55°C to 125°C –40°C to 125°C –40°C to 125°C –55°C to 125°C –55°C to 125°C –40°C to 125°C –40°C to 125°C –55°C to 125°C –55°C to 125°C –40°C to 125°C –40°C to 125°C –55°C to 125°C –55°C to 125°C –40°C to 125°C –40°C to 125°C –55°C to 125°C –55°C to 125°C –40°C to 125°C –40°C to 125°C –55°C to 125°C –55°C to 125°C The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C, CL = 1µF and VIN = VOUT + 0.5V, unless otherwise noted. For LT6654-1.25, VIN = 2.4V, unless otherwise noted. PARAMETER Output Voltage Accuracy CONDITIONS LT6654A LT6654B LT6654AH LT6654BH LT6654AMP LT6654BMP LT6654A LT6654B VOUT + 0.5V ≤ VIN ≤ 36V LT6654-2.048, LT6654-2.5, LT6654-3, LT6654-3.3, LT6654-4.096, LT6654-5 2.4V ≤ VIN ≤ 36V LT6654-1.25 Load Regulation (Note 4) IOUT(SOURCE) = 10mA LT6654-2.048, LT6654-2.5, LT6654-3, LT6654-3.3, LT6654-4.096, LT6654-5 LT6654-1.25 MIN –0.05 –0.10 –0.215 –0.43 –0.23 –0.46 3 10 1.2 l elecTrical characTerisTics TYP MAX 0.05 0.10 0.215 0.43 0.23 0.46 10 20 5 10 5 10 8 15 15 20 UNITS % % % % % % ppm/°C ppm/°C ppm/V ppm/V ppm/V ppm/V ppm/mA ppm/mA ppm/mA ppm/mA 6654fb l l l l l l Output Voltage Temperature Coefficient (Note 3) Line Regulation 1.2 l 3 l 6 l 3 LT6654 The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C, CL = 1µF and VIN = VOUT + 0.5V, unless otherwise noted. For LT6654-1.25, VIN = 2.4V, unless otherwise noted. PARAMETER Load Regulation (Note 4) CONDITIONS IOUT(SINK) = 10mA LT6654-2.048, LT6654-2.5, LT6654-3, LT6654-3.3, LT6654-4.096, LT6654-5 LT6654-1.25 VIN – VOUT , ∆VOUT = 0.1% IOUT = 0mA LT6654-2.048, LT6654-2.5, LT6654-3, LT6654-3.3, LT6654-4.096, LT6654-5 IOUT(SOURCE) = 10mA IOUT(SINK) = –10mA LT6654-1.25, ∆VOUT = 0.1%, IOUT = 0mA LT6654-1.25, ∆VOUT = 0.1%, IOUT = ±10mA Supply Current Output Short-Circuit Current Output Voltage Noise (Note 6) No Load l l l elecTrical characTerisTics MIN TYP 9 MAX 20 30 25 30 100 120 450 50 UNITS ppm/mA ppm/mA ppm/mA ppm/mA mV mV mV mV V V V µA µA mA mA ppmP-P ppmP-P ppmP-P ppmP-P ppmP-P ppmP-P ppmP-P ppmRMS µs ppm/√kHr ppm ppm ppm ppm l 15 l Dropout Voltage (Note 5) 55 l l l Minimum Input Voltage 1.5 1.6 1.8 2.4 600 350 40 30 0.8 1.0 1.5 1.6 1.7 2.0 2.2 2.0 150 60 30 40 90 100 Short VOUT to GND Short VOUT to VIN 0.1Hz ≤ f ≤ 10Hz LT6654-1.25 LT6654-2.048 LT6654-2.5 LT6654-3 LT6654-3.3 LT6654-4.096 LT6654-5 10Hz ≤ f ≤ 1kHz 0.1% Settling, CLOAD = 1µF ∆T = 0°C to 70°C ∆T = –40°C to 85°C ∆T = –40°C to 125°C ∆T = –55°C to 125°C Turn-On Time Long-Term Drift of Output Voltage (Note 7) Hysteresis (Note 8) 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: If the parts are stored outside of the specified temperature range, the output may shift due to hysteresis. Note 3: Temperature coefficient is measured by dividing the maximum change in output voltage by the specified temperature range. Note 4: Load regulation is measured on a pulse basis from no load to the specified load current. Output changes due to die temperature change must be taken into account separately. Note 5: Excludes load regulation errors. Note 6: Peak-to-peak noise is measured with a 1-pole highpass filter at 0.1Hz and 2-pole lowpass filter at 10Hz. The unit is enclosed in a still-air environment to eliminate thermocouple effects on the leads. The test time is 10 seconds. RMS noise is measured on a spectrum analyzer in a shielded environment where the intrinsic noise of the instrument is removed to determine the actual noise of the device. Note 7: Long-term stability typically has a logarithmic characteristic and therefore, changes after 1000 hours tend to be much smaller than before that time. Total drift in the second thousand hours is normally less than one third that of the first thousand hours with a continuing trend toward reduced drift with time. Long-term stability will also be affected by differential stresses between the IC and the board material created during board assembly. Note 8: Hysteresis in output voltage is created by package stress that differs depending on whether the IC was previously at a higher or lower temperature. Output voltage is always measured at 25°C, but the IC is cycled to the hot or cold temperature limit before successive measurements. Hysteresis measures the maximum output change for the averages of three hot or cold temperature cycles. For instruments that are stored at well controlled temperatures (within 20 or 30 degrees of operational temperature), it’s usually not a dominant error source. Note 9: The stated temperature is typical for soldering of the leads during manual rework. For detailed IR reflow recommendations, refer to the Applications Information section. 6654fb 4 LT6654 Typical perForMance characTerisTics 1.25V Output Voltage Temperature Drift 1.2520 1.2515 1.2510 1.2505 1.2500 1.2495 1.2490 1.2485 –60 –40 –20 0 20 40 60 80 100 120 140 TEMPERATURE (°C) 6654 G01 The characteristic curves are similar across the LT6654 family. Curves from the LT6654-1.25, LT6654-2.5 and the LT6654-5 represent the full range of typical performance of all voltage options. Characteristic curves for other output voltages fall between these curves and can be estimated based on their output. 1.25V Turn-On Characteristics 100 1.25V Output Impedance vs Frequency THREE TYPICAL PARTS VIN 1V/DIV GND OUTPUT IMPEDANCE (Ω) REFERENCE VOLTAGE (V) 10 CL = 1µF 1 VOUT 0.5V/DIV GND 20µs/DIV 6654 G02 0.1 CL = 10µF CLOAD = 1µF 0.01 0.1 1 10 100 FREQUENCY (kHz) 1000 6654 G03 1.25V Load Regulation (Sourcing) 30 OUTPUT VOLTAGE CHANGE (ppm) –55°C OUTPUT VOLTAGE CHANGE (ppm) 20 10 0 –10 –20 –30 –40 –50 0.1 1 OUTPUT CURRENT (mA) 10 6654 G04 1.25V Load Regulation (Sinking) 200 180 160 140 120 100 80 60 40 20 0 0.1 –55°C 1 OUTPUT CURRENT (mA) 10 6654 G05 1.25V Output Noise 0.1Hz to 10Hz 125°C OUTPUT NOISE (1µV/DIV) –40°C 0 –40°C 125°C 25°C 25°C 1 2 3 4567 TIME (1s/DIV) 8 9 10 6654 G06 1.25V Minimum Input Voltage (Sourcing) 10 10 1.25V Minimum Input Voltage (Sinking) 400 350 25°C 1.2V Output Voltage Noise Spectrum OUTPUT CURRENT (mA) OUTPUT CURRENT (mA) NOISE VOLTAGE (nV√Hz) 300 250 200 150 100 50 IO = 0µA IO = 5mA 125°C 1 25°C –55°C –40°C 125°C 1 –55°C –40°C 0.1 1 1.2 1.4 1.6 1.8 2 2.2 MINIMUM INPUT VOLTAGE (V) 2.4 0.1 1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 MINIMUM INPUT VOLTAGE (V) 1.8 0 0.01 0.1 1 10 FREQUENCY (kHz) 100 6654 G09 6654 G07 6654 G08 6654fb 5 LT6654 Typical perForMance characTerisTics 2.5V Output Voltage Temperature Drift 2.502 THREE TYPICAL PARTS 600 500 INPUT CURRENT (µA) OUTPUT VOLTAGE (V) 2.501 400 300 200 100 2.498 –60 0 –40°C –55°C OUTPUT VOLTAGE (V) 25°C 125°C The characteristic curves are similar across the LT6654 family. Curves from the LT6654-1.25, LT6654-2.5 and the LT6654-5 represent the full range of typical performance of all voltage options. Characteristic curves for other output voltages fall between these curves and can be estimated based on their output. 2.5V Supply Current vs Input Voltage 2.5050 2.5040 2.5030 2.5020 2.5010 2.5000 2.4990 2.4980 2.4970 2.4960 –20 20 60 100 TEMPERATURE (°C) 140 6654 G10 2.5V Line Regulation 2.500 25°C 125°C –55°C 2.499 –40°C 35 40 0 5 10 15 20 25 30 INPUT VOLTAGE (V) 35 40 2.4950 0 5 10 15 20 25 30 INPUT VOLTAGE (V) 6654 G11 6654 G12 2.5V Load Regulation (Sourcing) 10 OUTPUT VOLTAGE CHANGE (ppm) –55°C –40°C 125°C –20 25°C OUTPUT VOLTAGE CHANGE (ppm) 180 160 2.5V Load Regulation (Sinking) 2.5V Output Noise 0.1Hz to 10Hz 120 100 80 60 40 20 0 0.1 25°C –40°C –55°C 1 OUTPUT CURRENT (mA) 10 6654 G14 –10 125°C –30 –40 0.1 OUTPUT NOISE (1µV/DIV) 0 140 1 OUTPUT CURRENT (mA) 10 6654 G13 TIME (1s/DIV) 6654 G15 2.5V Minimum VIN to VOUT Differential (Sourcing) 10 –55°C OUTPUT CURRENT (mA) –40°C 25°C 10 2.5V Minimum VIN to VOUT Differential (Sinking) 400 350 –40°C 125°C 1 25°C NOISE VOLTAGE (nV√Hz) OUTPUT CURRENT (mA) –55°C 300 250 200 150 100 50 2.5V Output Voltage Noise Spectrum 1 125°C IO = 0µA IO = 5mA 0.1 0 50 100 150 200 250 300 350 400 INPUT-OUTPUT VOLTAGE (mV) 6654 G16 0.1 50 –300 –250 –200 –150 –100 –50 0 INPUT-OUTPUT VOLTAGE (mV) 100 0 0.01 0.1 1 10 FREQUENCY (kHz) 100 6654 G18 6654 G17 6654fb 6 LT6654 Typical perForMance characTerisTics 2.5V Integrated Noise 10Hz to 10kHz 100 POWER SUPPLY REJECTION RATIO (dB) –20 –30 CL = 1µF OUTPUT IMPEDANCE (Ω) –40 –50 –60 –70 –80 –90 –100 0.1 1 10 100 FREQUENCY (kHz) 1000 6654 G20 The characteristic curves are similar across the LT6654 family. Curves from the LT6654-1.25, LT6654-2.5 and the LT6654-5 represent the full range of typical performance of all voltage options. Characteristic curves for other output voltages fall between these curves and can be estimated based on their output. 2.5V Power Supply Rejection Ratio vs Frequency 100 2.5V Output Impedance vs Frequency INTEGRATED NOISE (µVRMS) 10 10 CL = 1µF 1 CL = 10µF 1 CL = 10µF 0.1 0.01 0.1 1 FREQUENCY (kHz) 10 6654 G19 0.1 1 10 100 FREQUENCY (kHz) 1000 6654 G21 2.5V Turn-On Characteristics VIN 0.5V/DIV 3V/DC 2.5V Line Transient Response IOUT 0mA 5mA 2.5V Load Transient Response (Sourcing) VIN 1V/DIV GND VOUT 1V/DIV GND 20µs/DIV 6654 G22 VOUT 2mV/DIV/AC 2.5V/DC VOUT 20mV/DIV/AC 2.5V/DC CLOAD = 1µF CLOAD = 1µF 50µs/DIV 6654 G23 CLOAD = 1µF 50µs/DIV 6654 G24 2.5V Hysteresis Plot for –40°C and 125°C 48 44 40 36 NUMBER OF UNITS 32 28 24 20 16 12 8 4 0 –150 –125 –100 –75 –50 –25 0 25 50 75 100 125 150 DISTRIBUTION (ppm) 6654 G25 2.5V Long Term Drift 150 OUTPUT VOLTAGE CHANGE (ppm) 120 90 60 30 0 –30 –60 –90 –120 –150 0 400 800 1200 TIME (HOURS) 1600 2000 6654 G26 2.5V Load Transient Response (Sinking) IOUT 5mA 0mA MAX AVG HOT CYCLE MAX AVG COLD CYCLE 25°C TO 125°C TO 25°C 25°C TO –40°C TO 25°C TA = 35°C VOUT 20mV/DIV/AC 2.5V/DC CLOAD = 1µF 50µs/DIV 6654 G27 6654fb 7 LT6654 Typical perForMance characTerisTics 5V Output Voltage Temperature Drift 5.003 5.002 REFERENCE VOLTAGE (V) 5.001 5.000 4.999 4.998 4.997 4.996 4.995 4.994 4.993 –60 –40 –20 0 20 40 60 80 100 120 140 TEMPERATURE (°C) 6654 G28 The characteristic curves are similar across the LT6654 family. Curves from the LT6654-1.25, LT6654-2.5 and the LT6654-5 represent the full range of typical performance of all voltage options. Characteristic curves for other output voltages fall between these curves and can be estimated based on their output. 5V Turn-On Characteristics 100 5V Output Impedance vs Frequency THREE TYPICAL PARTS VIN 2V/DIV GND OUTPUT IMPEDANCE (Ω) 10 CL = 1µF 1 VOUT 2V/DIV GND 50µs/DIV 6654 G29 0.1 CL = 10µF CLOAD = 1µF 0.01 0.1 1 10 100 FREQUENCY (kHz) 1000 6654 G30 5V Load Regulation (Sourcing) 50 OUTPUT VOLTAGE CHANGE (ppm) OUTPUT VOLTAGE CHANGE (ppm) 40 30 20 10 0 –10 –20 0.1 25°C –55°C –40°C 125°C 220 200 160 140 120 100 80 60 40 20 1 OUTPUT CURRENT (mA) 10 6654 G31 5V Load Regulation (Sinking) 5V Output Noise 0.1Hz to 10Hz –55°C –40°C 125°C 25°C 0 0.1 OUTPUT NOISE (4µV/DIV) 0 180 1 OUTPUT CURRENT (mA) 10 6654 G32 1 2 3 4567 TIME (1s/DIV) 8 9 10 6654 G33 5V Minimum VIN to VOUT Differential (Sourcing) 10 –55°C OUTPUT CURRENT (mA) –40°C 125°C 1 25°C 10 5V Minimum VIN to VOUT Differential (Sinking) 600 550 NOISE VOLTAGE (nV√Hz) OUTPUT CURRENT (mA) –55°C 25°C 125°C 1 –40°C 500 450 400 350 300 250 200 150 100 50 5V Output Voltage Noise Spectrum IO = 0µA IO = 5mA 0.1 0 50 100 150 200 250 300 350 400 INPUT-OUTPUT VOLTAGE (mV) 6654 G34 0.1 –300 –250 –200 –150 –100 –50 0 50 INPUT-OUTPUT VOLTAGE (mV) 100 0 0.01 0.1 1 10 FREQUENCY (kHz) 100 6654 G36 6654 G35 6654fb 8 LT6654 pin FuncTions GND (Pin 1): Internal Function. This pin must be tied to ground, near Pin 2. GND (Pin 2): Primary Device Ground. DNC (Pin 3): Do Not Connect. Keep leakage current from this pin to VIN or GND to a minimum. VIN (Pin 4): Power Supply. Bypass VIN with a 0.1µF capacitor to ground. DNC (Pin 5): Do Not Connect. Keep leakage current from this pin to VIN or GND to a minimum. VOUT (Pin 6): Output Voltage. An output capacitor of 1µF minimum is required for stable operation. block DiagraM 4 VIN 3 DNC BANDGAP + – VOUT 5 DNC 6 2 GND GND 1 6654 BD 6654fb 9 LT6654 applicaTions inForMaTion Bypass and Load Capacitors The LT6654 voltage references should have an input bypass capacitor of 0.1µF or larger, however the bypassing on other components nearby is sufficient. In high voltage applications, VIN > 30V, an output short-circuit to ground can create an input voltage transient that could exceed the maximum input voltage rating. To prevent this worst-case condition, an RC input line filter of 10µs (i.e. 10Ω and 1µF) is recommended. These references also require an output capacitor for stability. The optimum output capacitance for most applications is 1µF, although larger values work as well. This capacitor affects the turn-on and settling time for the output to reach its final value. Figure 1 shows the turn-on time for the LT6654-2.5 with a 0.1µF input bypass and 1µF load capacitor. Figure 2 shows the output response to a 0.5V transient on VIN with the same capacitors. The test circuit of Figure 3 is used to measure the stability with various load currents. With RL = 1k, the 1V step produces a current step of 1mA. Figure 4 shows the response to a ± 0.5mA load. Figure 5 is the output response to a sourcing step from 4mA to 5mA, and Figure 6 is the output response of a sinking step from 4mA to 5mA. VIN 0.5V/DIV 3V/DC VIN 1V/DIV GND VOUT 2mV/DIV/AC 2.5V/DC VOUT 1V/DIV GND 20µs/DIV 6654 F01 CLOAD = 1µF CLOAD = 1µF 50µs/DIV 6654 F02 Figure 1. Turn-On Characteristics of LT6654-2.5 Figure 2. Output Response to 0.5V Ripple on VIN VIN 3V 4 CIN 0.1µF LT6654-2.5 1, 2 6 1k CL 1µF VGEN 1V 6654 F03 Figure 3. Load Current Response Time Test Circuit 6654fb 10 LT6654 applicaTions inForMaTion Positive or Negative Operation IOUT –0.5mA 0.5mA In addition to the series connection, as shown on the front page of this data sheet, the LT6654 can be operated as a negative voltage reference. The circuit in Figure 7 shows an LT6654 configured for negative operation. In this configuration, a positive voltage is required at VIN (Pin 4) to bias the LT6654 internal circuitry. This voltage must be current limited with R1 to keep the output PNP transistor from turning on and driving the grounded output. C1 provides stability during load transients. This connection maintains the same accuracy and temperature coefficient of the positive connected LT6654. R1 4.7k 4 6 LT6654-2.5 1, 2 VOUT = –2.5V 0.1µF VOUT 20mV/DIV/AC 2.5V/DC CLOAD = 1µF 50µs/DIV 6654 F04 Figure 4. LT6654-2.5 Sourcing and Sinking 0.5mA IOUT 4mA 5mA 3V VOUT 10mV/DIV/AC 2.5V/DC V – VOUT R ≤ EE 550µA + IOUT VEE C1 1µF 6654 F07 CLOAD = 1µF 50µs/DIV 6654 F05 Figure 7. Using the LT6654-2.5 to Build a –2.5V Reference Figure 5. LT6654-2.5 Sourcing 4mA to 5mA IOUT –5mA –4mA VOUT 10mV/DIV/AC 2.5V/DC CLOAD = 1µF 50µs/DIV 6654 F06 Figure 6. LT6654-2.5 Sinking 4mA to 5mA 6654fb 11 LT6654 applicaTions inForMaTion Long-Term Drift Long-term drift cannot be extrapolated from accelerated high temperature testing. This erroneous technique gives drift numbers that are wildly optimistic. The only way long-term drift can be determined is to measure it over the time interval of interest. The LT6654 drift data was taken on 40 parts that were soldered into PC boards 80 OUTPUT VOLTAGE CHANGE (ppm) OUTPUT VOLTAGE CHANGE (ppm) 0 400 600 TIME (HOURS) LONG TERM DRIFT: FIRST THOUSAND HOURS 200 800 1000 6654 F08a similar to a real world application. The boards were then placed into a constant temperature oven with TA = 35°C, their outputs scanned regularly and measured with an 8.5 digit DVM. Long-term drift curves are shown in Figure 8. Their drift is much smaller after the first thousand hours. 80 40 40 0 0 –40 –40 –80 –80 1000 2000 1400 1600 1800 TIME (HOURS) 6654 F08b LONG TERM DRIFT: SECOND THOUSAND HOURS (NORMALIZED TO THE FIRST THOUSAND HOURS) 1200 Figure 8. LT6654-2.5 Long Term Drift 6654fb 12 LT6654 applicaTions inForMaTion Power Dissipation The power dissipation in the LT6654 is dependent on VIN, load current and the package. The LT6654 package has a thermal resistance, or θJA, of 192°C/W. A curve that illustrates allowed power dissipation versus temperature for the 6-lead SOT-23 package is shown in Figure 9. The power dissipation of the LT6654-2.5 as a function of input voltage is shown in Figure 10. The top curve shows power dissipation with a 10mA load and the bottom curve shows power dissipation with no load. When operated within its specified limits of VIN = 36V and sourcing 10mA, the LT6654-2.5 consumes about 335mW at room temperature. The power-derating curve in Figure 9 shows the LT66542.5 can only safely dissipate 130mW at 125°C, which is less than its maximum power output. Care must be taken when designing the circuit so that the maximum junction temperature is not exceeded. For best performance, junction temperature should be kept below 125°C. The LT6654 includes output current limit circuitry, as well as thermal limit circuitry, to protect the reference from damage in the event of excessive power dissipation. The LT6654 is protected from damage by a thermal shutdown circuit. However, changes in performance may occur as a result of operation at high temperature. Hysteresis The hysteresis data is shown in Figure 11. The LT6654 is capable of dissipating relatively high power. For example, with a 36V input voltage and 10mA load current applied to the LT6654-2.5, the power dissipation is PD = 33.5V • 10mA = 335mW, which causes an increase in the die temperature of 64°C. This could increase the junction temperature above 125°C (TJMAX is 150°C) and may cause the output to shift due to thermal hysteresis. 0.7 0.6 0.5 POWER (W) 0.4 0.3 0.2 0.1 0 0 20 40 60 80 100 TEMPERATURE (°C) 120 140 T = 150°C θJA = 192°C/W 130mW 6654 F09 Figure 9. Maximum Allowed Power Dissipation of the LT6654 0.40 0.35 0.30 POWER (W) 0.25 0.20 0.15 0.10 0.05 0 0 5 10 15 NO LOAD 20 25 VIN (V) 30 35 40 10mA LOAD 335mW 6654 F10 Figure 10. Typical Power Dissipation of the LT6654 50 MAX AVG HOT CYCLE MAX AVG COLD CYCLE 25°C TO 125°C TO 25°C 25°C TO –40°C TO 25°C 40 NUMBER OF UNITS 30 20 10 0 –150 –100 –50 0 50 100 DISTRIBUTION (ppm) 150 6654 F11 Figure 11. Thermal Hysteresis –40°C to 125°C 6654fb 13 LT6654 applicaTions inForMaTion PC Board Layout The mechanical stress of soldering a surface mount voltage reference to a PC board can cause the output voltage to shift and temperature coefficient to change. These two changes are not correlated. For example, the voltage may shift but the temperature coefficient may not. To reduce the effects of stress-related shifts, mount the reference near the short edge of the PC board or in a corner. In addition, slots can be cut into the board on two sides of the device. The capacitors should be mounted close to the LT6654. The GND and VOUT traces should be as short as possible to minimize I • R drops, since high trace resistance directly impacts load regulation. IR Reflow Shift The different expansion and contraction rates of the materials that make up the LT6654 package may cause the output voltage to shift after undergoing IR reflow. Lead free solder reflow profiles reach over 250°C, considerably more than with lead based solder. A typical lead free IR reflow profile is shown in Figure 12. Similar profiles are found using a convection reflow oven. LT6654 devices run up to three times through this reflow process show that the standard deviation of the output voltage increases with a slight negative mean shift of 0.003% as shown in Figure 13. While there can be up to 0.014% of output voltage shift, the overall drift of the LT6654 after IR reflow does not vary significantly. 300 380s 14 TP = 260°C RAMP DOWN NUMBER OF UNITS 12 10 8 6 4 2 8 10 6654 F12 260°C 3 CYCLES 260°C 1 CYCLE TEMPERATURE (°C) 225 TL = 217°C TS(MAX) = 200°C TS = 190°C T = 150°C RAMP TO 150°C 120s tP 30s tL 130s 40s 150 75 0 0 2 4 6 MINUTES 0 –140 –120 –100 –80 –60 –40 –20 CHANGE IN OUTPUT (ppm) 0 6654 F13 Figure 12. Lead Free Reflow Profile Figure 13. Output Voltage Shift Due to IR Reflow (%) 6654fb 14 LT6654 Typical applicaTions Extended Supply Range Reference UP TO 160V 330k MMBT5551 BZX84C12 0.1µF LT6654-2.5 1µF 6654 TA02 Boosted Output Current Reference 4.5V < VIN < 36V 220 4.7µF 2N2905 IN LT6654-2.5 OUT 1µF 6654 TA03 IOUT UP TO 300mA Boosted Output Current with Current Limit 4.5V < VIN < 36V Octal DAC Reference LT6654-2.5 2.65V < VIN < 5V IN 0.1µF OUT VIN 10µF 0.1µF 1 LED1* 2 2N2905 220 4.7µF 10 VREF CS VCC DAC A LTC2600 DAC B DAC C DAC D DAC E DAC F LT6654-2.5 IN OUT 1µF 6654 TA04 IOUT UP TO 100mA SCK SDI CLEAR *LED CANNOT BE OMMITTED THE LED CLAMPS THE VOLTAGE DROP ACROSS THE 220 AND LIMITS OUTPUT CURRENT DAC G GND DAC H 6654 TA05 6654fb 15 LT6654 package DescripTion (Reference LTC DWG # 05-08-1636) S6 Package 6-Lead Plastic TSOT-23 0.62 MAX 0.95 REF 2.90 BSC (NOTE 4) 1.22 REF 3.85 MAX 2.62 REF 1.4 MIN 2.80 BSC 1.50 – 1.75 (NOTE 4) PIN ONE ID RECOMMENDED SOLDER PAD LAYOUT PER IPC CALCULATOR 0.95 BSC 0.80 – 0.90 0.30 – 0.45 6 PLCS (NOTE 3) 0.20 BSC DATUM ‘A’ 1.00 MAX 0.01 – 0.10 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 0.09 – 0.20 (NOTE 3) 1.90 BSC S6 TSOT-23 0302 REV B 6654fb 16 LT6654 revision hisTory REV A B DATE 12/10 3/11 DESCRIPTION Added voltage options (1.250V, 2.048V, 3.000V, 4.096V, 5.000V) reflected throughout the data sheet. Revised conditions for Output Voltage Noise in the Electrical Characteristics section. PAGE NUMBER 1-18 4 6654fb 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. 17 LT6654 Typical applicaTion 16-Bit ADC Reference 4.6V < VS < 36V LT6654-4.096 IN 0.1µF OUT 10µF + –2.048V < VDIFFERENTIAL < 2.048V IN+ VREF VCC SDO SDI CS SCK 6654 TA06 LTC2480 IN– GND fO TO MCU – relaTeD parTs PART NUMBER DESCRIPTION LT1460 LT1461 LT1790 LT6650 LTC6652 LT6660 LTC6655 LT6656 Micropower Series Reference Micropower Precision LDO Series Reference Micropower Precision Series References Micropower Reference with Buffer Amplifier Precision Low Drift Low Noise Buffered Reference Tiny Micropower Series Reference Precision Low Noise Reference 800nA Precision Voltage Reference COMMENTS 0.075% Max, 10ppm/°C Max Drift, 2.5V, 5V and 10V Versions, MSOP PDIP S0-8, , , SOT-23 and TO-92 Packages 3ppm/°C Max Drift, 0°C to 70°C, –40°C to 85°C, –40°C to 125°C Options in SO-8 0.05% Max, 10ppm/°C Max, 60µA Supply, SOT-23 Package 0.05% Max, 5.6µA Supply, SOT-23 Package 0.5% Max, 5ppm/°C Max, 2.1ppmP-P Noise (0.1Hz to 10Hz) 100% Tested at –40°C, 25°C and 125°C 0.2% Max, 20ppm/°C Max, 20mA Output Current, 2mm × 2mm DFN 2ppm/°C Max, 650nVP-P Noise (0.1Hz to 10Hz) 100% Tested at –40°C, 25°C and 125°C 800nA, 10ppm/°C Max, 0.05% Max, SOT-23 Package 6654fb 18 Linear Technology Corporation 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● LT 0311 REV B • PRINTED IN USA www.linear.com  LINEAR TECHNOLOGY CORPORATION 2010