LT6654 SOT-23 Precision Wide Supply High Output Drive Low Noise Reference Description Features Low Drift: A Grade: 10ppm/°C Max B Grade: 20ppm/°C Max n High Accuracy: A Grade: ±0.05% Max B Grade: ±0.10% Max n Low Noise: 1.6ppm P-P (0.1Hz to 10Hz) n Wide Supply Range to 36V n Low Thermal Hysteresis n Line Regulation (Up to 36V): 5ppm/V Max n Low Dropout Voltage: 100mV Max n Sinks and Sources ±10mA n Load Regulation at 10mA: 8ppm/mA Max n Easily Configured for Negative Voltage Output n Fully Specified from –55°C to 125°C n Available Output Voltage Options: 1.25V, 2.048V, 2.5V, 3V, 3.3V, 4.096V, 5V n Low Profile (1mm) ThinSOT™ Package n n n n n n 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. Applications n 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. 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. Automotive Control and Monitoring High Temperature Industrial High Resolution Data Acquisition Systems Instrumentation and Process Control Precision Regulators Medical Equipment Typical Application Output Voltage Temperature Drift 0.10 (VOUT + 0.5V) < VIN < 36V 4 CIN 0.1µF 6 LT6654 1 2 VOUT CL 1µF 6654 TA01a VOUT ACCURACY (%) Basic Connection 3 TYPICAL PARTS LT6654-2.5 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 Pin Configuration (Note 1) 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 TOP VIEW GND* 1 6 VOUT GND 2 5 DNC DNC 3 4 VIN 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/ 2 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 LT6654 Available Options OUTPUT VOLTAGE 1.25V 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. 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 Electrical Characteristics 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 CONDITIONS MIN Output Voltage Accuracy LT6654A LT6654B LT6654AH LT6654BH LT6654AMP LT6654BMP l l l l –0.05 –0.10 –0.215 –0.43 –0.23 –0.46 Output Voltage Temperature Coefficient (Note 3) LT6654A LT6654B l l Line Regulation VOUT + 0.5V ≤ VIN ≤ 36V LT6654-2.048, LT6654-2.5, LT6654-3, LT6654-3.3, LT6654-4.096, LT6654-5 l 2.4V ≤ VIN ≤ 36V LT6654-1.25 l 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 TYP UNITS 0.05 0.10 0.215 0.43 0.23 0.46 % % % % % % 3 10 10 20 ppm/°C ppm/°C 1.2 5 10 ppm/V ppm/V 1.2 5 10 ppm/V ppm/V 3 8 15 15 20 ppm/mA ppm/mA ppm/mA ppm/mA l 6 l MAX 6654fb 3 LT6654 Electrical Characteristics 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 CONDITIONS MIN Load Regulation (Note 4) IOUT(SINK) = 10mA LT6654-2.048, LT6654-2.5, LT6654-3, LT6654-3.3, LT6654-4.096, LT6654-5 LT6654-1.25 TYP MAX 9 20 30 25 30 ppm/mA ppm/mA ppm/mA ppm/mA l 100 120 mV mV l l 450 50 mV mV 1.6 1.8 2.4 V V V 600 µA µA l 15 l Dropout Voltage (Note 5) Minimum Input Voltage 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 55 1.5 l l No Load 350 l UNITS Output Short-Circuit Current Short VOUT to GND Short VOUT to VIN 40 30 mA mA Output Voltage Noise (Note 6) 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 0.8 1.0 1.5 1.6 1.7 2.0 2.2 2.0 ppmP-P ppmP-P ppmP-P ppmP-P ppmP-P ppmP-P ppmP-P ppmRMS Turn-On Time 0.1% Settling, CLOAD = 1µF 150 µs 60 ppm/√kHr 30 40 90 100 ppm ppm ppm ppm Long-Term Drift of Output Voltage (Note 7) Hysteresis (Note 8) ∆T = 0°C to 70°C ∆T = –40°C to 85°C ∆T = –40°C to 125°C ∆T = –55°C to 125°C 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 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 Output Voltage Temperature Drift 1.2520 1.25V Output Impedance vs Frequency 1.25V Turn-On Characteristics 100 THREE TYPICAL PARTS 1.2510 OUTPUT IMPEDANCE (Ω) REFERENCE VOLTAGE (V) 1.2515 VIN 1V/DIV 1.2505 GND 1.2500 1.2495 VOUT 0.5V/DIV 1.2490 GND 1.2485 –60 –40 –20 0 20 40 60 80 100 120 140 TEMPERATURE (°C) CLOAD = 1µF CL = 1µF 1 CL = 10µF 0.1 0.01 0.1 6654 G02 20µs/DIV 10 1 1000 10 100 FREQUENCY (kHz) 6654 G03 6654 G01 1.25V Load Regulation (Sinking) 200 20 180 –55°C 10 –40°C 0 –10 125°C –20 25°C –30 –40 125°C 160 140 120 100 25°C 80 60 40 –40°C 20 –50 0.1 –55°C 0 0.1 10 1 OUTPUT CURRENT (mA) 1.25V Output Noise 0.1Hz to 10Hz OUTPUT NOISE (1µV/DIV) 30 OUTPUT VOLTAGE CHANGE (ppm) OUTPUT VOLTAGE CHANGE (ppm) 1.25V Load Regulation (Sourcing) 6654 G04 0 10 1 OUTPUT CURRENT (mA) 1 2 3 4 5 6 7 TIME (1s/DIV) 1.25V Minimum Input Voltage (Sinking) 10 9 10 6654 G06 6654 G05 1.25V Minimum Input Voltage (Sourcing) 8 1.2V Output Voltage Noise Spectrum 10 400 350 25°C –40°C 1 –55°C 125°C NOISE VOLTAGE (nV√Hz) 125°C OUTPUT CURRENT (mA) OUTPUT CURRENT (mA) 25°C –55°C 1 –40°C 300 250 200 150 IO = 0µA 100 IO = 5mA 50 0.1 1 1.2 1.4 1.6 1.8 2 2.2 MINIMUM INPUT VOLTAGE (V) 2.4 6654 G07 0.1 1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 MINIMUM INPUT VOLTAGE (V) 1.8 6654 G08 0 0.01 0.1 1 10 FREQUENCY (kHz) 100 6654 G09 6654fb 5 LT6654 Typical Performance Characteristics 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 Output Voltage Temperature Drift THREE TYPICAL PARTS 2.5050 INPUT CURRENT (µA) 2.501 2.500 2.499 2.5040 –40°C 500 OUTPUT VOLTAGE (V) 2.5V Line Regulation 600 –55°C 400 2.5030 OUTPUT VOLTAGE (V) 2.502 2.5V Supply Current vs Input Voltage 25°C 300 125°C 200 2.5020 2.5010 25°C 2.5000 2.4990 125°C 2.4980 –55°C 2.4970 100 2.4960 2.498 –60 –20 20 60 100 TEMPERATURE (°C) 0 140 0 5 10 15 20 25 30 INPUT VOLTAGE (V) 35 6654 G10 2.5V Load Regulation (Sourcing) 0 5 10 15 20 25 30 INPUT VOLTAGE (V) 40 35 6654 G12 2.5V Load Regulation (Sinking) 2.5V Output Noise 0.1Hz to 10Hz 180 –40°C –10 125°C 25°C –20 –30 –40 0.1 1 OUTPUT CURRENT (mA) 160 140 OUTPUT NOISE (1µV/DIV) –55°C 0 OUTPUT VOLTAGE CHANGE (ppm) 120 100 125°C 80 25°C 60 40 –40°C 20 0 0.1 10 –55°C 10 1 OUTPUT CURRENT (mA) 6654 G14 6654 G13 2.5V Minimum VIN to VOUT Differential (Sourcing) 2.5V Minimum VIN to VOUT Differential (Sinking) 10 2.5V Output Voltage Noise Spectrum 10 –55°C 400 25°C 350 OUTPUT CURRENT (mA) –40°C 125°C 1 6654 G15 TIME (1s/DIV) –55°C NOISE VOLTAGE (nV√Hz) OUTPUT VOLTAGE CHANGE (ppm) 2.4950 6654 G11 10 OUTPUT CURRENT (mA) 40 –40°C –40°C 125°C 25°C 1 300 250 IO = 0µA 200 150 IO = 5mA 100 50 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 6654 G17 0 0.01 0.1 1 10 FREQUENCY (kHz) 100 6654 G18 6654fb 6 LT6654 Typical Performance Characteristics 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 Integrated Noise 10Hz to 10kHz 2.5V Power Supply Rejection Ratio vs Frequency –20 10 1 0.1 0.01 –30 –40 CL = 1µF –50 –60 –70 CL = 10µF –80 10 CL = 1µF 1 1 1000 10 100 FREQUENCY (kHz) 6654 G19 0.1 1 1000 10 100 FREQUENCY (kHz) 6654 G20 2.5V Turn-On Characteristics 6654 G21 2.5V Load Transient Response (Sourcing) 2.5V Line Transient Response VIN 0.5V/DIV 3V/DC VIN 1V/DIV CL = 10µF –90 –100 0.1 10 0.1 1 FREQUENCY (kHz) 100 OUTPUT IMPEDANCE (Ω) POWER SUPPLY REJECTION RATIO (dB) INTEGRATED NOISE (µVRMS) 100 2.5V Output Impedance vs Frequency IOUT 0mA 5mA GND VOUT 2mV/DIV/AC 2.5V/DC VOUT 1V/DIV VOUT 20mV/DIV/AC 2.5V/DC GND CLOAD = 1µF 20µs/DIV 6654 G22 CLOAD = 1µF 2.5V Hysteresis Plot for –40°C and 125°C 48 44 150 OUTPUT VOLTAGE CHANGE (ppm) NUMBER OF UNITS 36 32 28 24 20 16 12 8 50µs/DIV 6654 G24 2.5V Load Transient Response (Sinking) TA = 35°C 120 IOUT 5mA 90 60 0mA 30 0 –30 VOUT 20mV/DIV/AC 2.5V/DC –60 –90 4 –120 0 –150 –125 –100 –75 –50 –25 0 25 50 75 100 125 150 DISTRIBUTION (ppm) –150 6654 G25 CLOAD = 1µF 2.5V Long Term Drift 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 6654 G23 50µs/DIV 0 400 800 1200 TIME (HOURS) 1600 2000 CLOAD = 1µF 50µs/DIV 6654 G27 6654 G26 6654fb 7 LT6654 Typical Performance Characteristics 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 Output Voltage Temperature Drift 5.003 100 THREE TYPICAL PARTS 5.002 5.001 5.000 OUTPUT IMPEDANCE (Ω) REFERENCE VOLTAGE (V) 5V Output Impedance vs Frequency 5V Turn-On Characteristics VIN 2V/DIV 4.999 GND 4.998 4.997 4.996 VOUT 2V/DIV 4.995 10 CL = 1µF 1 CL = 10µF 0.1 GND 4.994 4.993 –60 –40 –20 0 20 40 60 80 100 120 140 TEMPERATURE (°C) 0.01 0.1 6654 G29 50µs/DIV CLOAD = 1µF 1 1000 10 100 FREQUENCY (kHz) 6654 G28 6654 G30 5V Load Regulation (Sourcing) 5V Load Regulation (Sinking) 200 30 20 –55°C –40°C 10 125°C 0 25°C –10 180 OUTPUT NOISE (4µV/DIV) 40 160 140 120 –55°C –40°C 100 80 125°C 60 25°C 40 20 –20 0.1 1 OUTPUT CURRENT (mA) 0 0.1 10 0 10 1 OUTPUT CURRENT (mA) 6654 G31 2 3 4 5 6 7 TIME (1s/DIV) 8 9 10 6654 G33 5V Minimum VIN to VOUT Differential (Sinking) 10 5V Output Voltage Noise Spectrum 10 600 25°C 550 OUTPUT CURRENT (mA) –40°C 125°C 1 500 –55°C NOISE VOLTAGE (nV√Hz) –55°C 1 6654 G32 5V Minimum VIN to VOUT Differential (Sourcing) OUTPUT CURRENT (mA) 5V Output Noise 0.1Hz to 10Hz 220 OUTPUT VOLTAGE CHANGE (ppm) OUTPUT VOLTAGE CHANGE (ppm) 50 25°C 125°C –40°C 1 IO = 0µA 450 400 350 300 250 IO = 5mA 200 150 100 50 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 6654 G35 0 0.01 0.1 1 10 FREQUENCY (kHz) 100 6654 G36 6654fb 8 LT6654 Pin Functions GND (Pin 1): Internal Function. This pin must be tied to ground, near Pin 2. DNC (Pin 5): Do Not Connect. Keep leakage current from this pin to VIN or GND to a minimum. GND (Pin 2): Primary Device Ground. VOUT (Pin 6): Output Voltage. An output capacitor of 1µF minimum is required for stable operation. 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. Block Diagram 4 3 5 2 VIN DNC DNC GND + BANDGAP VOUT 6 – 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 CLOAD = 1µF 6654 F01 20µs/DIV CLOAD = 1µF Figure 1. Turn-On Characteristics of LT6654-2.5 VIN 3V 4 CIN 0.1µF 50µs/DIV 6654 F02 Figure 2. Output Response to 0.5V Ripple on VIN 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 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. 0.5mA VOUT 20mV/DIV/AC 2.5V/DC CLOAD = 1µF 50µs/DIV 6654 F04 Figure 4. LT6654-2.5 Sourcing and Sinking 0.5mA 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 IOUT 4mA 3V 4 5mA 6 LT6654-2.5 0.1µF 1, 2 VOUT = –2.5V VOUT 10mV/DIV/AC 2.5V/DC V – VOUT R ≤ EE 550µA + IOUT C1 1µF VEE CLOAD = 1µF 50µs/DIV 6654 F05 6654 F07 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 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 OUTPUT VOLTAGE CHANGE (ppm) OUTPUT VOLTAGE CHANGE (ppm) 80 40 0 –40 –80 0 200 400 600 TIME (HOURS) LONG TERM DRIFT: FIRST THOUSAND HOURS 800 1000 6654 F08a 40 0 –40 –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 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. T = 150°C θJA = 192°C/W 0.6 POWER (W) 0.5 0.4 0.3 130mW 0.2 0.1 0 0 20 40 60 80 100 TEMPERATURE (°C) 140 Figure 9. Maximum Allowed Power Dissipation of the LT6654 0.40 335mW 0.35 0.30 0.25 10mA LOAD 0.20 0.15 0.10 0.05 0 NO LOAD 5 0 10 Hysteresis 15 20 25 VIN (V) 30 35 40 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 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. 120 6654 F09 POWER (W) 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. 0.7 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 IR Reflow Shift 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. 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. 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. 380s 14 TP = 260°C TL = 217°C TS(MAX) = 200°C TS = 190°C 225 RAMP DOWN tP 30s T = 150°C 150 tL 130s RAMP TO 150°C 75 40s 120s 0 0 2 4 6 MINUTES 12 NUMBER OF UNITS TEMPERATURE (°C) 300 260°C 3 CYCLES 260°C 1 CYCLE 10 8 6 4 2 8 10 6654 F12 Figure 12. Lead Free Reflow Profile 0 –140 –120 –100 –80 –60 –40 –20 CHANGE IN OUTPUT (ppm) 0 6654 F13 Figure 13. Output Voltage Shift Due to IR Reflow (%) 6654fb 14 LT6654 Typical Applications Extended Supply Range Reference Boosted Output Current Reference 4.5V < VIN < 36V UP TO 160V 4.7µF 220Ω 330k MMBT5551 2N2905 IN BZX84C12 LT6654-2.5 0.1µF IOUT UP TO 300mA LT6654-2.5 OUT 1µF 1µF 6654 TA02 6654 TA03 Boosted Output Current with Current Limit Octal DAC Reference 4.5V < VIN < 36V LT6654-2.5 2.65V < VIN < 5V IN OUT VIN 1 LED1* 4.7µF 220Ω 0.1µF 10Ω 10µF 2 VREF 2N2905 VCC CS LT6654-2.5 IN IOUT UP TO 100mA OUT 1µF SCK 0.1µF DAC A LTC2600 DAC B SDI DAC C CLEAR DAC D DAC E 6654 TA04 DAC F *LED CANNOT BE OMMITTED THE LED CLAMPS THE VOLTAGE DROP ACROSS THE 220Ω AND LIMITS OUTPUT CURRENT DAC G GND DAC H 6654 TA05 6654fb 15 LT6654 Package Description S6 Package 6-Lead Plastic TSOT-23 (Reference LTC DWG # 05-08-1636) 0.62 MAX 2.90 BSC (NOTE 4) 0.95 REF 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 0.30 – 0.45 6 PLCS (NOTE 3) 0.95 BSC 0.80 – 0.90 0.20 BSC 0.01 – 0.10 1.00 MAX DATUM ‘A’ 0.30 – 0.50 REF 0.09 – 0.20 (NOTE 3) 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 1.90 BSC S6 TSOT-23 0302 REV B 6654fb 16 LT6654 Revision History REV DATE DESCRIPTION PAGE NUMBER A 12/10 Added voltage options (1.250V, 2.048V, 3.000V, 4.096V, 5.000V) reflected throughout the data sheet. B 3/11 Revised conditions for Output Voltage Noise in the Electrical Characteristics section. 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 OUT 10µF 0.1µF + IN+ –2.048V < VDIFFERENTIAL < 2.048V – VREF VCC LTC2480 IN– GND fO SDO SDI CS TO MCU SCK 6654 TA06 Related Parts PART NUMBER DESCRIPTION COMMENTS LT1460 Micropower Series Reference 0.075% Max, 10ppm/°C Max Drift, 2.5V, 5V and 10V Versions, MSOP, PDIP, S0-8, SOT-23 and TO-92 Packages LT1461 Micropower Precision LDO Series Reference 3ppm/°C Max Drift, 0°C to 70°C, –40°C to 85°C, –40°C to 125°C Options in SO-8 LT1790 Micropower Precision Series References 0.05% Max, 10ppm/°C Max, 60µA Supply, SOT-23 Package LT6650 Micropower Reference with Buffer Amplifier 0.05% Max, 5.6µA Supply, SOT-23 Package LTC6652 Precision Low Drift Low Noise Buffered Reference 0.5% Max, 5ppm/°C Max, 2.1ppmP-P Noise (0.1Hz to 10Hz) 100% Tested at –40°C, 25°C and 125°C LT6660 Tiny Micropower Series Reference 0.2% Max, 20ppm/°C Max, 20mA Output Current, 2mm × 2mm DFN LTC6655 Precision Low Noise Reference 2ppm/°C Max, 650nVP-P Noise (0.1Hz to 10Hz) 100% Tested at –40°C, 25°C and 125°C LT6656 800nA Precision Voltage Reference 800nA, 10ppm/°C Max, 0.05% Max, SOT-23 Package 6654fb 18 Linear Technology Corporation LT 0311 REV B • PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com LINEAR TECHNOLOGY CORPORATION 2010