LT1031BCH

LT1031/LH0070 Precision 10V Reference U FEATURES ■ ■ ■ ■ ■ ■ ■ ■ DESCRIPTIO The LT ®1031 is a precision 10V reference with ultralow drift and noise, extremely good long term stability, and almost total immunity to input voltage variations. The reference output will both source and sink up to 10mA and can be used as a shunt regulator (two terminal Zener) with the same precision characteristics as the three terminal connection. Special care has been taken to minimize thermal regulation effects and temperature induced hysteresis. Pin Compatible with LH0070 and AD581* Ultralow Drift—5ppm/°C Max Slope Trimmed Output Voltage Operates in Series or Shunt Mode Output Sinks and Sources in Series Mode Very Low Noise < 1ppmP-P 0.1Hz to 10Hz > 100dB Ripple Rejection Minimum Input Voltage of 11V U APPLICATIO S ■ ■ ■ ■ ■ ■ The LT1031 reference is based on a buried Zener diode structure which eliminates noise and stability problems associated with surface breakdown devices. Further, a subsurface Zener exhibits better temperature drift and time stability than even the best band-gap references. A-to-D and D-to-A Converters Precision Regulators Digital Voltmeters lnertial Navigation Systems Precision Scales Portable Reference Standard Unique circuit design makes the LT1031 the first three terminal IC reference to offer ultralow drift without the use of high power on-chip heaters. Output voltage is pretrimmed to 0.05% accuracy. The LT1031 can be used as a plug-in replacement for the AD581 and LH0070,* with improved electrical and thermal performance. , LTC and LT are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. *See LH0070 Electrical Characteristics table and AD581 cross reference guide. U TYPICAL APPLICATIO Basic Positive and Negative Connections IN TA = 25°C 35 DISTRIBUTION FROM 5 RUNS LT1031 OUT VOUT OUT GND GND – VOUT R1 = VIN – VOUT ILOAD + 1.5mA PERCENT OF UNITS (%) LT1031 VIN Distribution of Output Accuracy 40 30 25 20 15 10 R1 5 – VIN LT1031 • TA01 0 –0.10 –0.06 –0.02 0 0.02 0.06 OUTPUT ACCURACY (%) 0.10 LT1031 TA02 1031fb 1 LT1031/LH0070 W W W AXI U U ABSOLUTE RATI GS U U W PACKAGE/ORDER I FOR ATIO (Note 1) Input Voltage ........................................................... 40V Input-Output Voltage Differential ............................. 35V Output to Ground Voltage (Shunt Mode Current Limit) ................................. 16V Trim Pin to Ground Voltage Positive ................................................. Equal to VOUT Negative ............................................................. –20V Output Short-Circuit Duration VIN = 35V ......................................................... 10 sec VIN ≤ 20V ..................................................... Indefinite Operating Temperature Range LT1031M .......................................... –55°C to 125°C LT1031C .................................................. 0°C to 70°C Lead Temperature (Soldering, 10 sec).................. 300°C BOTTOM VIEW INPUT 1 2 OUTPUT 3 GROUND H PACKAGE 3-LEAD TO-39 METAL CAN TJMAX = 150°C, θJA = 150°C/W, θJC = 45°C/W (LH0070) TJMAX = 150°C, θJA = 150°C/W, θJC = 45°C/W (LT1031M) TJMAX = 85°C, θJA = 150°C/W, θJC = 45°C/W (LT1031C) ORDER PART NUMBER LH0070-0H LH0070-1H LH0070-2H LT1031BMH LT1031DMH LT1031BCH LT1031CCH LT1031DCH ELECTRICAL CHARACTERISTICS (LT1031) The ● denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VIN = 15V, IOUT = 0, Mil or Comm version, unless noted. SYMBOL PARAMETER CONDITIONS MIN LT1031 TYP MAX VR Output Voltage (Note 2) LT1031B LT1031C LT1031D 9.995 9.990 9.980 10.000 10.000 10.000 10.005 10.010 10.020 ∆VR ∆T Output Voltage Temperature Coefficient (Note 3) TMIN ≤ TJ ≤ TMAX LT1031B LT1031C LT1031D 3 6 10 5 15 25 ppm/°C ppm/°C ppm/°C ∆VR ∆VIN Line Regulation (Note 4) 11.5V ≤ VIN ≤ 14.5V 1 4 6 ppm/V ppm/V 0.5 2 4 ppm/V ppm/V 12 25 40 ppm/mA ppm/mA 50 100 150 ppm/mA ppm/mA 1.2 1.7 2.0 mA mA 1.1 1.5 mA 4.5V ≤ VIN ≤ 40V ● ● ● ● ● 0 ≤ IOUT ≤ 10mA (Note 4) ● 1.7mA ≤ ISHUNT ≤ 10mA (Notes 4, 5) ● UNITS V V V ∆VR ∆IO Load Regulation (Sourcing Current) ∆VR ∆IO Load Regulation (Shunt Mode) IQ Series Mode Supply Current IMIN Shunt Mode Minimum Current VIN is Open Output Short-Circuit Current 11V ≤ VIN ≤ 35V Minimum Input Voltage (Note 7) lOUT ≤ 1mA en Output Voltage Noise 0.1Hz ≤ f ≤ 10Hz 10Hz ≤ f ≤ 10kHz 6 11 µVP-P µVRMS ∆VR ∆Time Long Term Stability of Output Voltage ∆t = 1000 Hrs Non-Cumulative 15 ppm Temperature Hysteresis of Output ∆T = 50°C 5 ● 30 10.8 mA 11.0 V ppm 1031fb 2 LT1031/LH0070 ELECTRICAL CHARACTERISTICS (LH0070) The ● denotes the specifications which apply over the full operating temperature range. VIN = 15V, RL = 10kΩ, – 55°C ≤ TA ≤ 125°C, unless noted. SYMBOL PARAMETER CONDITIONS VR Output Voltage TA = 25°C ∆VR Output Accuracy – 0, –1 –2 TA = 25°C Output Accuracy – 0, –1 –2 TA = –55°C, 125°C Output Voltage Change with Temperature –0 –1 –2 Note 6 Line Regulation – 0, –1 –2 13V ≤ VIN ≤ 33V, TA = 25°C ∆VR ∆VR ∆T ∆VR ∆VIN MIN LH0070 TYP MAX 10.000 ± 0.03 ± 0.02 ● Input Voltage Range V ± 0.1 ± 0.05 % % 0.3 0.2 % % ± 0.02 ± 0.01 ± 0.2 ± 0.1 ± 0.04 % % % 0.006 0.006 0.1 0.03 % % 40 V ● ● ● ● UNITS 11.4 ∆VR ∆IO Load Regulation 0mA ≤ lOUT ≤ 5mA ● 0.01 0.03 % IQ Quiescent Current 13V ≤ VIN ≤ 33V ● 1.2 5 mA ∆lQ ∆VIN Change in Quiescent Current ∆VIN = 20V from 13V TO 33V ● 0.1 1.5 mA en Output Noise Voltage Ripple Rejection rO Output Resistance ∆VZ ∆Time Long Term Stability – 0, –1 –2 f = 120Hz TA = 25°C (Note 8) Note 1: Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. Note 2: Output voltage is measured immediately after turn-on. Changes due to chip warm-up are typically less than 0.005%. Note 3: Temperature coefficient is measured by dividing the change in output voltage over the temperature range by the change in temperature. Separate tests are done for hot and cold: TMIN to 25°C and 25°C to TMAX. Incremental slope is also measured at 25°C. For LT1031BMH, the 5ppm/°C drift specification is for – 25°C to 85°C. Drift over the full – 55°C to 125°C range is guaranteed to 7ppm/°C. 6 µVP-P ● 0.001 %/VP-P ● 0.2 0.6 ± 0.2 ± 0.05 Ω %/Yr %/Yr Note 4: Line and load regulation are measured on a pulse basis. Output changes due to die temperature change must be taken into account separately. Package thermal resistance is 150°C/W. Note 5: Shunt mode regulation is measured with the input open. With the input connected, shunt mode current can be reduced to 0mA. Load regulation will remain the same. Note 6: Temperature drift is guaranteed from –25°C to 85°C on LH0070. Note 7: See curve for guaranteed minimum VIN versus IOUT. Note 8: Guaranteed by design. 1031fb 3 LT1031/LH0070 U CROSS REFERENCE The following cross reference guide may be used to select LT1031 grades which meet or exceed output voltage, temperature drift, load and line regulation, and output current specifications of the AD581 reference. Parameters such as noise, hysteresis, and long term stability will be significantly better for all LT1031 grades compared to the AD581. CROSS REFERENCE GUIDE/LT1031 TO AD581 AD581J order LT1031DCH AD581K order LT1031CCH AD581L order LT1031BCH A0581S order LT1031DMH A0581U order LT1031BMH U W TYPICAL PERFOR A CE CHARACTERISTICS Ripple Rejection 115 Ripple Rejection 130 f = 150Hz VIN = 15V COUT = 0 120 110 Minimum Input Voltage 11.6 95 90 INPUT VOLTAGE (V) REJECTION (dB) REJECTION (dB) 100 100 90 80 0 5 10 15 20 25 30 INPUT VOLTAGE (V) 35 10.8 10.6 10.4 60 10.2 40 TJ = 25°C 11.0 70 10.0 50 85 TJ = –55°C 11.2 110 105 TJ = 125°C GUARANTEED CURVE-ALL TEMPS 11.4 10 100 1k FREQUENCY (Hz) 10k 0 2 4 6 8 10 12 14 16 18 20 OUTPUT CURRENT (mA) LT1031 • TPC02 LT1031 • TPC01 LT1031 • TPC03 Start-Up (Series Mode) 12 Start-Up (Shunt Mode) VIN = 0 TO 12V 400 350 10 OUTPUT VOLTAGE (V) 11 OUTPUT VOLTAGE (V) Output Voltage Noise Spectrum 11 10 9 8 7 6 9 8 –12V 1k VOUT 0V 7 OUT NC 5 NOISE VOLTAGE (nV/√Hz) 13 IN 5 2 4 6 8 TIME (µs) 10 12 14 LT1031 • TPC04 200 150 100 50 4 0 250 GND 6 3 300 0 2 6 4 TIME (µs) 8 10 12 LT1031 • TPC05 0 10 100 1k FREQUENCY (Hz) 10k LT1031 • TPC06 1031fb 4 LT1031/LH0070 U W TYPICAL PERFOR A CE CHARACTERISTICS Output Voltage Noise Load Regulation 5 COUT = 0 FILTER = 1 POLE fLOW = 0.1Hz 14 VIN = 12V 4 10.004 3 OUTPUT CHANGE (mV) 12 RMS NOISE (µV) Output Voltage Temperature 10.006 10 8 6 4 OUTPUT VOLTAGE (V) 16 2 1 0 –1 –2 –3 2 10.002 10.000 9.998 9.996 –4 –5 –10 –8 –6 –4 –2 0 2 4 6 8 SOURCING SINKING OUTPUT CURRENT (mA) 0 10 100 1k BANDWIDTH (Hz) 10k LT1031 • TPC07 10 9.994 –50 –25 50 25 75 0 TEMPERATURE (˚C) 100 LT1031 • TPC09 LT1031 • TPC08 Input Supply Current 1.8 TJ = –55°C 60 INPUT PIN OPEN 1.6 TJ = 25°C 1.2 Shunt Mode Current Limit TJ = 125°C 1.0 0.8 0.6 0.4 CURRENT INTO OUTPUT (mA) IOUT = 0 1.4 1.4 TJ = –55°C 1.2 1.0 TJ = 25°C 0.8 0.6 0.4 TJ = 125°C 40 30 20 10 0.2 0.2 0 0 0 5 10 15 20 35 25 30 INPUT VOLTAGE (V) 0 2 4 6 10 8 OUTPUT TO GROUND VOLTAGE (V) 0 40 ∆ISOURCE = 100µAp-p VIN = 30V ∆POWER = 200mW LOAD REGULATION THERMAL* REGULATION –1.5 ILOAD = 10mA OUTPUT VOLTAGE CHANGE ISOURCE = 0 0 –1.0 40 60 80 100 120 140 TIME (ms) *INDEPENDENT OF TEMPERATURE COEFFICIENT 0 20 LT1031 • TPC13 2 4 6 8 10 12 14 OUTPUT VOLTAGE (V) ∆ISOURCE = 100µAp-p ISOURCE = 0 ISINK = 0.8mA –2 0 1 ISINK = 1.0mA ∆ISINK = 100µAp-p ISINK = 0.8mA 20mV 5mV ISINK = 1.2mA ISOURCE = 0.5mA ISOURCE = 2 TO 10mA ISINK = 1.4mA ISINK = 2 TO 10mA ISINK = 2 TO 10mA 3 4 5 6 7 8 TIME (µs) NOTE VERTICAL SCALE CHANGE BETWEEN SOURCING AND SINKING 2 18 LT1031 • TPC12 ∆ISINK = 100µAp-p ISINK = 0.6mA 10mV ISOURCE = 0.2mA 16 Load Transient Response CLOAD = 1000pF 50mV ISOURCE = 2 TO 10mA –20 0 Load Transient Response CLOAD = 0 Thermal Regulation –0.5 12 LT1031 • TPC11 LT1031 • TPC10 OUTPUT CHANGE (mV) INPUT PIN IS OPEN 50 OUTPUT VOLTAGE CHANGE INPUT CURRENT (mA) Shunt Characteristics CURRENT INTO OUTPUT (mA) 1.8 1.6 125 9 LT1031 • TPC14 0 2 6 8 0 2 4 6 TIME (µs) NOTE VERTICAL SCALE CHANGE BETWEEN SOURCING AND SINKING 4 8 LT1031 • TPC15 1031fb 5 LT1031/LH0070 U W TYPICAL PERFOR A CE CHARACTERISTICS Output Noise 0.1Hz to 10Hz OUTPUT VOLTAGE NOISE (10µV/DIV) FILTERING = 1 ZERO AT 0.1Hz 2 POLES AT 10Hz 10µV (1ppm) 0 1 4 3 2 TIME (MINUTES) 5 6 LT1031 • TPC16 U W U U APPLICATIO S I FOR ATIO Trimming Output Voltage Effect of Reference Drift on System Accuracy The LT1031 output can be trimmed by driving the ground pin. The suggested method is shown in the illustration below. A 5Ω resistor is inserted in series with the ground pin. The top of the resistor is supplied current from a trim potentiometer. This technique requires fairly high trim current of up to 1.5mA from the LT1031 or 3.5mA from the –15V supply; however it is necessary to maintain low drift in the reference. Ground pin current changes in the LT1031, with temperature, could be as high as 4µA/°C. This, coupled with the 5Ω external resistor, creates up to 2ppm/°C drift in the reference (5Ω • 4µA/°C = 20µV/°C = 2ppm/°C). If induced drift higher than this can be tolerated, all resistor values in the trim circuit can be raised proportionately to reduce current drain. A large portion of the temperature drift error budget in many systems is the system reference voltage. The graph below indicates the maximum temperature coefficient allowable if the reference is to contribute no more than 1/2LSB error to the overall system performance. The example shown is a 12-bit system designed to operate over a temperature range from 25°C to 65°C. Assuming the system calibration is performed at 25°C, the temperature span is 40°C. The graph shows that the temperature coefficient of the reference must be no worse than 3ppm/°C if it is to contribute less than 1/2LSB error. For this reason, the LT1031 has been optimized for low drift. LT1031 VIN IN OUT VOUT GND R2* 4.3k R3 50k R1** 5Ω –15V *CAN BE INCREASED TO 5.6k FOR LT1031B AND LH0070-2 **INCREASE TO 10Ω FOR LT1031D LT1031 • TA04 MAXIMUM TEMPERATURE COEFFICIENT FOR 1/2LSB ERROR (ppm/°C) Output Voltage Trimming Maximum Allowable Reference Drift 100 8-BIT 10-BIT 10 12-BIT 14-BIT 1.0 10 20 30 40 50 60 70 80 90 100 TEMPERATURE SPAN (°C) LT1031 • TA03 1031fb 6 LT1031/LH0070 U W U U APPLICATIO S I FOR ATIO Series Mode with Boost Transistor Capacitive Loading and Transient Response The LT1031 is stable with all capacitive loads, but for optimum settling with load transients, output capacitance should be under 1000pF. The output stage of the reference is class AB with a fairly low idling current. This makes transient response worst-case at light load currents. Because of internal current drain on the output, actual worst-case occurs at I LOAD = 1.4mA (sinking). Significantly better load transient response is obtained by moving slightly away from these points. See Load Transient Response curves for details. In general, best transient response is obtained when the output is sourcing current. In critical applications, a 10µF solid tantalum capacitor with several ohms in series provides optimum output bypass. Kelvin Connections The following circuits show proper hook-up to minimize errors due to ground loops and line losses. Losses in the output lead can be greatly reduced by adding a PNP boost transistor if load currents are 5mA or higher. R2 can be added to further reduce current in the output sense lead. Standard Series Mode LT1031 IN OUT R1 220Ω 2N3906 IN LT1031 GND OUT R2* 5.6k LOAD GROUND RETURN *OPTIONAL—REDUCES CURRENT IN OUTPUT SENSE LEAD LT1031 • TA06 Effects of Air Movement on Low Frequency Noise Although the LT1031 does not have true force/sense capability at its outputs, significant improvements in ground loop and line loss problems can be achieved with proper hook-up. In series mode operation, the ground pin of the LT1031 carries only ≈1mA and can be used as a sense line, greatly reducing ground loop and loss problems on the low side of the reference. The high side supplies load current so line resistance must be kept low. Twelve feet of #22 gauge hook up wire or 1 foot of 0.025 inch printed circuit trace will create 2mV loss at 10mA output current. This is equivalent to 1LSB in a 10V, 12-bit system. INPUT INPUT KEEP THIS LINE RESISTANCE LOW + GND LOAD GROUND RETURN LT1031 • TA05 The LT1031 has very low noise because of the buried zener used in its design. In the 0.1Hz to 10Hz band, peak-to-peak noise is about 0.5ppm of the DC output. To achieve this low noise, however, care must be taken to shield the reference from ambient air turbulence. Air movement can create noise because of thermoelectric differences between IC package leads (especially kovar lead TO-5) and printed circuit board materials and/or sockets. Power dissipation in the reference, even though it rarely exceeds 20mW, is enough to cause small temperature gradients in the package leads. Variations in thermal resistance, caused by uneven airflow, create differential lead temperatures, thereby causing thermoelectric voltage noise at the output of the reference. The XY plotter trace shown on the following page dramatically illustrates this effect. The first half of the plot was done with the LT1031 shielded from ambient air with a small foam cup. The cup was then removed for the second half of the trace. Ambient in both cases was a lab environment with no excessive air turbulence from air conditioners, opening/closing doors, etc. Removing the foam cup increases the output noise by almost an order of magnitude in the 0.01Hz to 1Hz band! The kovar leads of the TO-5 (H) package are the primary culprit. Alloy 42 and copper lead frames used on dual-inline packages are not nearly as sensitive to thermally generated noise because they are intrinsically matched. 1031fb 7 LT1031/LH0070 U W U U APPLICATIO S I FOR ATIO (TO-5 PACKAGE) f = 0.01Hz to 10Hz OUTPUT VOLTAGE NOISE (20µV/DIV) There is nothing magical about foam cups—any enclosure which blocks air flow from the reference will do. Smaller enclosures are better since they do not allow the build-up of internally generated air movement. Naturally, heat generating components external to the reference itself should not be included inside the enclosure. Noise Induced by Air Turbulence (TO-5 Package) 20µV 0 FOAM CUP REMOVED 8 6 4 TIME (MINUTES) 2 10 12 LT1031 • TA07 U APPLICATIO CIRCUITS Negative Series Reference Boosted Output Current with No Current Limit V+ ≥ 11.8V 15V R1 4.7k IN R2 4.7k R1 220Ω LT1031 2N2905 OUT D1 15V IN GND LT1031 –15V –10V AT 50mA Q1 2N2905 OUT + GND LT1031 • AC01 10V AT 100mA 2µF SOLID TANT LT1031 • AC02 Boosted Output Current with Current Limit Handling Higher Load Currents 15V V+ ≥ 12.8V D1* LED R1 220Ω 8.2Ω 2N2905 GND R1* 169Ω IN LT1031 VOUT = 10V OUT GND IN LT1031 30mA RL OUT + *GLOWS IN CURRENT LIMIT DO NOT OMIT 10V AT 100mA 2µF SOLID TANT TYPICAL LOAD CURRENT = 30mA *SELECT R1 TO DELIVER TYPICAL LOAD CURRENT LT1031 WILL THEN SOURCE OR SINK AS NECESSARY TO MAINTAIN PROPER OUTPUT. DO NOT REMOVE LOAD, AS OUTPUT WILL BE DRIVEN (UNREGULATED) HIGH. LINE REGULATION IS DEGRADED IN THIS APPLICATION LT1031 • AC04 LT1031 • AC03 1031fb 8 LT1031/LH0070 U APPLICATIO CIRCUITS Strain Gauge Conditioner for 350Ω Bridge R1 357Ω 1/2W 28mA LT1031 28.5mA OUT 5V 350Ω STRAIN GUAGE BRIDGE** + 6 3 R2 20k 2 2 R4 20k 3 † LM301A 1 100pF – R3 2MΩ LT1012C 6 VOUT • 100 + GND – IN 15V R5 2M 8 R6 2MΩ* –5V 357Ω 1/2W –15V *THIS RESISTOR PROVIDES POSITIVE FEEDBACK TO THE BRIDGE TO ELIMINATE LOADING EFFECT OF THE AMPLIFIER. EFFECTIVE ZIN OF AMPLIFIER STAGE IS ≥ 1MΩ. IF R2–R5 ARE CHANGED, SET R6 = R3 **BRIDGE IS ULTRA LINEAR WHEN ALL LEGS ARE ACTIVE, TWO IN COMPRESSION AND TWO IN TENSION, OR WHEN ONE SIDE IS ACTIVE WITH ONE COMPRESSED AND ONE TENSIONED LEG † OFFSET AND DRIFT OF LM301A ARE VIRTUALLY ELIMINATED BY DIFERENTIAL CONNECTION OF LT1012C LT1031 • AC05 Ultralinear Platinum Temperature Sensor* LT1031 OUT IN 20V GND R2* 5k R1** 253k R9 100k R14 5k R10 182k 1% R11 6.65M 1% R15 10k Rf** 654k R8 10M R12 1k R4 4.75k 1% R3** 5k RS† 100Ω AT 0°C R7 392k 1% –15V R5 200k 1% 2 LT1001 3 R6 619k 1% – + R13 24.3k 20V 7 6 VOUT = 100mV/°C –50°C ≤ T ≤ 150°C 4 –15V † STANDARD INDUSTRIAL 100Ω PLATINUM 4-WIRE SENSOR, ROSEMOUNT 78S, OR EQUIVALENT. α = 0.00385 TRIM R9 FOR VOUT = 0 AT 0°C TRIM R12 FOR VOUT = 10V AT 100°C TRIM R14 FOR VOUT = 5V AT 50°C USE TRIM SEQUENCE AS SHOWN. TRIMS ARE NON-INTERACTIVE SO THAT ONLY ONE TRIM SEQUENCE IS NORMALLY REQUIRED. *FEEDBACK LINEARIZES OUTPUT TO ±0.005°C FROM – 50°C TO 150°C **WIREWOUND RESISTORS WITH LOW TC LT1031 • AC06 1031fb 9 LT1031/LH0070 U APPLICATIO CIRCUITS 2-Pole Lowpass Filtered Reference MYLAR 1µF VIN – R1 36k LT1031 VIN IN LT1001 + OUT GND +VREF R2 36k f = 10Hz 0.5µF MYLAR TOTAL NOISE ≤ 2µVRMS 1Hz ≤ f ≤ 10kHz –VREF LT1031 • AC07 Negative Shunt Reference Driven by Current Source LT1031 OUT GND –10V (ILOAD ≤ 1mA) 2.5mA LM334 27Ω –11V TO –40V LT1031 • AC08 1031fb 10 LT1031/LH0070 U APPLICATIO CIRCUITS Precision DAC Reference with System TC Trim LT1031 15V IN OUT 8.87k 1% GND D1 IN457 50k TC TRIM* 1.24k 1% 10k 1% 10k 1% D2 IN457 50k ROOM TEMP TRIM 10.36k 1% 200k 1% 50k 8.45k 1mA *TRIMS 1mA REFERENCE CURRENT TC BY ± 40ppm/°C. THIS TRIM SCHEME HAS VERY LITTLE EFFECT ON ROOM TEMPERATURE CURRENT TO MINIMIZE ITERATIVE TRIMMING. DAC LT1031 • AC09 W U EQUIVALENT SCHEMATIC INPUT Q3 D1 D2 OUTPUT D3 R1 Q1 – + A1 R2 D4 6.3V Q2 GND LT1031 • ES01 1031fb 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. 11 LT1031/LH0070 U PACKAGE DESCRIPTIO H Package 3-Lead TO-39 Metal Can (Reference LTC DWG # 05-08-1330) .350 – .370 (8.890 – 9.398) .305 – .335 (7.747 – 8.509) .050 (1.270) MAX .165 – .185 (4.191 – 4.699) REFERENCE PLANE * .016 – .019** (0.406 – 0.483) DIA .500 (12.700) MIN .200 (5.080) TYP .100 (2.540) PIN 1 .029 – .045 (0.737 – 1.143) .100 (2.540) .028 – .034 (0.711 – 0.864) 45° H3(TO-39) 0801 *LEAD DIAMETER IS UNCONTROLLED BETWEEN THE REFERENCE PLANE AND .050" BELOW THE REFERENCE PLANE .016 – .024 **FOR SOLDER DIP LEAD FINISH, LEAD DIAMETER IS (0.406 – 0.610) 1031fb 12 Linear Technology Corporation LT 1105 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 2005