LT1460 Micropower Precision Series Reference Family FEATURES DESCRIPTION n The LT(R)1460 is a micropower bandgap reference that combines very high accuracy and low drift with low power dissipation and small package size. This series reference uses curvature compensation to obtain low temperature coefficient and trimmed precision thin-film resistors to achieve high output accuracy. The reference will supply up to 20mA with excellent line regulation characteristics, making it ideal for precision regulator applications. n n n n n n n n n Trimmed to High Accuracy: 0.075% Max Low Drift: 10ppm/C Max Industrial Temperature Range Temperature Coefficient Guaranteed to 125C Low Supply Current: 130A Max (LT1460-2.5) Minimum Output Current: 20mA No Output Capacitor Required Reverse Battery Protection Minimum Input/Output Differential: 0.9V Available in S0-8, MSOP-8, PDIP-8, TO-92 and SOT- 23 Package APPLICATIONS n n n n n Handheld Instruments Precision Regulators A/D and D/A Converters Power Supplies Hard Disk Drives This series reference provides supply current and power dissipation advantages over shunt references that must idle the entire load current to operate. Additionally, the LT1460 does not require an output compensation capacitor, yet is stable with capacitive loads. This feature is important where PC board space is a premium or fast settling is demanded. In the event of a reverse battery connection, these references will not conduct current, and are therefore protected from damage. The LT1460 is available in the 8-lead MSOP, SO, PDIP and the 3-lead TO-92 and SOT23 packages. L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks of Linear Technology Corporation. All other trademarks are the property of their respective owners. TYPICAL APPLICATION Typical Distribution of Output Voltage S8 Package Basic Connection 20 LT1460-2.5 IN C1 0.1F OUT 18 2.5V 1400 PARTS FROM 2 RUNS 16 GND 14 1460 TA01 UNITS (%) 3.4V TO 20V 12 10 8 6 4 2 0 -0.10 -0.06 -0.02 0 0.02 0.06 OUTPUT VOLTAGE ERROR (%) 0.10 1460 TA02 1460fb 1 LT1460 ABSOLUTE MAXIMUM RATINGS (Note 1) Input Voltage.............................................................30V Reverse Voltage ......................................................-15V Output Short-Circuit Duration, TA = 25C VIN > 10V ............................................................5 sec VIN 10V ..................................................... Indefinite Specified Temperature Range (Note 10) Commercial (C)........................................ 0C to 70C Industrial (I) ......................................... -40C to 85C High (H) ............................................. -40C to 125C Storage Temperature Range (Note 2)..... -65C to 150C Lead Temperature (Soldering, 10 sec) .................. 300C PIN CONFIGURATION TOP VIEW IN 1 3 GND OUT 2 S3 PACKAGE 3-LEAD PLASTIC SOT-23 TJMAX = 125C, JA = 325C/W TOP VIEW TOP VIEW DNC* 1 8 DNC* DNC* 1 8 DNC* VIN 2 7 DNC* VIN 2 7 DNC* DNC* 3 6 VOUT DNC* 3 6 VOUT GND 4 5 DNC* GND 4 5 DNC* N8 PACKAGE 8-LEAD PLASTIC DIP S8 PACKAGE 8-LEAD PLASTIC SO *CONNECTED INTERNALLY. DO NOT CONNECT EXTERNAL CIRCUITRY TO THESE PINS TJMAX = 150C, JA = 130C/W *CONNECTED INTERNALLY. DO NOT CONNECT EXTERNAL CIRCUITRY TO THESE PINS TJMAX = 150C, JA = 190C/W TOP VIEW DNC* VIN DNC* GND 1 2 3 4 BOTTOM VIEW 8 7 6 5 DNC* DNC* VOUT DNC* 1 2 3 VIN VOUT GND MS8 PACKAGE 8-LEAD PLASTIC MSOP *CONNECTED INTERNALLY. DO NOT CONNECT EXTERNAL CIRCUITRY TO THESE PINS TJMAX = 150C, JA = 250C/W Z PACKAGE 3-LEAD TO-92 PLASTIC TJMAX = 150C, JA = 160C/W 1460fb 2 LT1460 ORDER INFORMATION Lead Free Finish TAPE AND REEL (MINI) TAPE AND REEL PART MARKING* PACKAGE DESCRIPTION SPECIFIED TEMPERATURE RANGE LT1460HCS3-2.5#TRMPBF LT1460HCS3-2.5#TRMPBF LTAC or LTH8 3-Lead Plastic SOT-23 0C to 70C LT1460JCS3-2.5#TRMPBF LT1460JCS3-2.5#TRPBF LTAD or LTH8 3-Lead Plastic SOT-23 0C to 70C LT1460KCS3-2.5#TRMPBF LT1460KCS3-2.5#TRPBF LTAE or LTH8 3-Lead Plastic SOT-23 0C to 70C LT1460HCS3-3#TRMPBF LT1460HCS3-3#TRPBF LTAN or LTH9 3-Lead Plastic SOT-23 0C to 70C LT1460JCS3-3#TRMPBF LT1460JCS3-3#TRPBF LTAP or LTH9 3-Lead Plastic SOT-23 0C to 70C LT1460KCS3-3#TRMPBF LT1460KCS3-3#TRPBF LTAQ or LTH9 3-Lead Plastic SOT-23 0C to 70C LT1460HCS3-3.3#TRMPBF LT1460HCS3-3.3#TRPBF LTAR or LTJ1 3-Lead Plastic SOT-23 0C to 70C LT1460JCS3-3.3#TRMPBF LT1460JCS3-3.3#TRPBF LTAS or LTJ1 3-Lead Plastic SOT-23 0C to 70C LT1460KCS3-3.3#TRMPBF LT1460KCS3-3.3#TRPBF LTAT or LTJ1 3-Lead Plastic SOT-23 0C to 70C LT1460HCS3-5#TRMPBF LT1460HCS3-5#TRPBF LTAK or LTJ2 3-Lead Plastic SOT-23 0C to 70C LT1460JCS3-5#TRMPBF LT1460JCS3-5#TRPBF LTAL or LTJ2 3-Lead Plastic SOT-23 0C to 70C LT1460KCS3-5#TRMPBF LT1460KCS3-5#TRPBF LTAM or LTJ2 3-Lead Plastic SOT-23 0C to 70C LT1460HCS3-10#TRMPBF LT1460HCS3-10#TRPBF LTAU or LTJ3 3-Lead Plastic SOT-23 0C to 70C LT1460JCS3-10#TRMPBF LT1460JCS3-10#TRPBF LTAV or LTJ3 3-Lead Plastic SOT-23 0C to 70C LTAW or LTJ3 3-Lead Plastic SOT-23 LT1460KCS3-10#TRMPBF LT1460KCS3-10#TRPBF TRM = 500 pieces. *Temperature grades and parametric grades are identified by a label on the shipping container. Product grades are identified with either part marking. 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/ PART MARKING 0C to 70C LEAD FREE FINISH TAPE AND REEL PACKAGE DESCRIPTION SPECIFIED TEMPERATURE RANGE LT1460ACN8-2.5#PBF LT1460ACN8-2.5#TRPBF 8-Lead Plastic DIP 0C to 70C LT1460BIN8-2.5#PBF LT1460BIN8-2.5#TRPBF 8-Lead Plastic DIP -40C to 85C LT1460DCN8-2.5#PBF LT1460DCN8-2.5#TRPBF 8-Lead Plastic DIP 0C to 70C LT1460EIN8-2.5#PBF LT1460EIN8-2.5#TRPBF 8-Lead Plastic DIP -40C to 85C LT1460ACN8-5#PBF LT1460ACN8-5#TRPBF 8-Lead Plastic DIP 0C to 70C LT1460BIN8-5#PBF LT1460BIN8-5#TRPBF 8-Lead Plastic DIP -40C to 85C LT1460DCN8-5#PBF LT1460DCN8-5#TRPBF 8-Lead Plastic DIP 0C to 70C LT1460EIN8-5#PBF LT1460EIN8-5#TRPBF 8-Lead Plastic DIP -40C to 85C LT1460ACN8-10#PBF LT1460ACN8-10#TRPBF 8-Lead Plastic DIP 0C to 70C LT1460BIN8-10#PBF LT1460BIN8-10#TRPBF 8-Lead Plastic DIP -40C to 85C LT1460DCN8-10#PBF LT1460DCN8-10#TRPBF 8-Lead Plastic DIP 0C to 70C LT1460EIN8-10#PBF LT1460EIN8-10#TRPBF 8-Lead Plastic DIP -40C to 85C LT1460ACS8-2.5#PBF LT1460ACS8-2.5#TRPBF 1460A2 8-Lead Plastic SO 0C to 70C LT1460BIS8-2.5#PBF LT1460BIS8-2.5#TRPBF 460BI2 8-Lead Plastic SO -40C to 85C LT1460DCS8-2.5#PBF LT1460DCS8-2.5#TRPBF 1460D2 8-Lead Plastic SO 0C to 70C LT1460EIS8-2.5#PBF LT1460EIS8-2.5#TRPBF 460EI2 8-Lead Plastic SO -40C to 85C LT1460LHS8-2.5#PBF LT1460LHS8-2.5#TRPBF 60LH25 8-Lead Plastic SO 0C to 70C LT1460MHS8-2.5#PBF LT1460MHS8-2.5#TRPBF 60MH25 8-Lead Plastic SO -40C to 85C LT1460ACS8-5#PBF LT1460ACS8-5#TRPBF 1460A5 8-Lead Plastic SO 0C to 70C LT1460BIS8-5#PBF LT1460BIS8-5#TRPBF 460BI5 8-Lead Plastic SO -40C to 85C 1460fb 3 LT1460 ORDER INFORMATION LEAD FREE FINISH TAPE AND REEL PART MARKING PACKAGE DESCRIPTION SPECIFIED TEMPERATURE RANGE LT1460DCS8-5#PBF LT1460DCS8-5#TRPBF 1460D5 8-Lead Plastic SO 0C to 70C LT1460EIS8-5#PBF LT1460EIS8-5#TRPBF 460EI5 8-Lead Plastic SO -40C to 85C LT1460LHS8-5#PBF LT1460LHS8-5#TRPBF 460LH5 8-Lead Plastic SO 0C to 70C LT1460MHS8-5#PBF LT1460MHS8-5#TRPBF 460MH5 8-Lead Plastic SO -40C to 85C LT1460ACS8-10#PBF LT1460ACS8-10#TRPBF 1460A1 8-Lead Plastic SO 0C to 70C LT1460BIS8-10#PBF LT1460BIS8-10#TRPBF 460BI1 8-Lead Plastic SO -40C to 85C LT1460DCS8-10#PBF LT1460DCS8-10#TRPBF 1460D1 8-Lead Plastic SO 0C to 70C LT1460EIS8-10#PBF LT1460EIS8-10#TRPBF 460EI1 8-Lead Plastic SO -40C to 85C LT1460CCMS8-2.5#PBF LT1460CCMS8-2.5#TRPBF LTAA 8-Lead Plastic MSOP 0C to 70C LT1460FCMS8-2.5#PBF LT1460FCMS8-2.5#TRPBF LTAB 8-Lead Plastic MSOP 0C to 70C LT1460CCMS8-5#PBF LT1460CCMS8-5#TRPBF LTAF 8-Lead Plastic MSOP 0C to 70C LT1460FCMS8-5#PBF LT1460FCMS8-5#TRPBF LTAG 8-Lead Plastic MSOP 0C to 70C LT1460CCMS8-10#PBF LT1460CCMS8-10#TRPBF LTAH 8-Lead Plastic MSOP 0C to 70C LT1460FCMS8-10#PBF LT1460FCMS8-10#TRPBF LTAJ 8-Lead Plastic MSOP 0C to 70C LT1460GCZ-2.5#PBF LT1460GCZ-2.5#TRPBF 3-Lead Plastic TO-92 0C to 70C LT1460GIZ-2.5#PBF LT1460GIZ-2.5#TRPBF 3-Lead Plastic TO-92 -40C to 85C LT1460GCZ-5#PBF LT1460GCZ-5#TRPBF 3-Lead Plastic TO-92 0C to 70C LT1460GIZ-5#PBF LT1460GIZ-5#TRPBF 3-Lead Plastic TO-92 -40C to 85C LT1460GCZ-10#PBF LT1460GCZ-10#TRPBF 3-Lead Plastic TO-92 0C to 70C LT1460GIZ-10#PBF LT1460GIZ-10#TRPBF 3-Lead Plastic TO-92 -40C to 85C Consult LTC Marketing for parts specified with wider operating temperature ranges. Consult LTC Marketing for information on non-standard 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/ AVAILABLE OPTIONS ACCURACY (%) TEMPERATURE COEFFICIENT (ppm/C) N8 S8 0C to 70C 0.075 10 LT1460ACN8 LT1460ACS8 -40C to 85C 0.10 10 LT1460BIN8 LT1460BIS8 0C to 70C 0.10 15 0C to 70C 0.10 20 LT1460DCN8 LT1460DCS8 -40C to 85C 0.125 20 LT1460EIN8 LT1460EIS8 0C to 70C 0.15 25 0C to 70C 0.25 25 LT1460GCZ -40C to 85C 0.25 25 LT1460GIZ -40C to 85C/125C 0.20 20/50 LT1460LHS8 -40C to 125C 0.20 50 LT1460MHS8 0C to 70C 0.20 20 0C to 70C 0.40 20 LT1460JCS3 0C to 70C 0.50 50 LT1460KCS3 TEMPERATURE PACKAGE TYPE MS8 Z S3 LT1460CCMS8 LT1460FCMS8 LT1460HCS3 1460fb 4 LT1460 ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25C. VIN = VOUT + 2.5V, IOUT = 0 unless otherwise specified. PARAMETER CONDITIONS Output Voltage LT1460ACN8-2.5, ACS8-2.5 2.49813 -0.075 MIN 2.50188 0.075 V % LT1460BIN8-2.5, BIS8-2.5, CCMS8-2.5, DCN8-2.5, DCS8-2.5 2.4975 -0.10 2.5025 0.10 V % LT1460EIN8-2.5, EIS8-2.5 2.49688 -0.125 2.50313 0.125 V % LT1460FCMS8-2.5 2.49625 -0.15 2.50375 0.15 V % LT1460GCZ-2.5, GIZ-2.5 2.49375 -0.25 2.50625 0.25 V % 2.495 -0.20 2.505 0.20 V % 4.99625 -0.075 5.00375 0.075 V % 4.995 -0.10 5.005 0.10 V % LT1460EIN8-5, EIS8-5 4.99375 -0.125 5.00625 0.125 V % LT1460FCMS8-5 4.9925 -0.15 5.0075 0.15 V % LT1460GCZ-5, GIZ-5 4.9875 -0.25 5.0125 0.25 V % LT1460LHS8-5, MHS8-5 4.990 -0.20 5.010 0.20 V % LT1460ACN8-10, ACS8-10 9.9925 -0.075 10.0075 0.075 V % LT1460BIN8-10, BIS8-10, CCMS8-10, DCN8-10, DCS8-10 9.990 -0.10 10.010 0.10 V % LT1460EIN8-10, EIS8-10 9.9875 -0.125 10.0125 0.125 V % LT1460FCMS8-10 9.985 -0.15 10.0015 0.15 V % LT1460GCZ-10, GIZ-10 9.975 -0.25 10.025 0.25 V % LT1460HC LT1460JC LT1460KC -0.2 -0.4 -0.5 0.2 0.4 0.5 % % % LT1460LHS8-2.5, MHS8-2.5 LT1460ACN8-5, ACS8-5 LT1460BIN8-5, BIS8-5, CCMS8-5, DCN8-5, DCS8-5 Output Voltage Temperature Coefficient (Note 3) TYP MAX UNITS TMIN TJ TMAX LT1460ACN8, ACS8, BIN8, BIS8 LT1460CCMS8 LT1460DCN8, DCS8, EIN8, EIS8 LT1460FCMS8, GCZ, GIZ LT1460LHS8 -40C to 85C -40C to 125C LT1460MHS8 -40C to 125C l l l l l l l 5 7 10 12 10 25 25 10 15 20 25 20 50 50 ppm/C ppm/C ppm/C ppm/C ppm/C ppm/C ppm/C LT1460HC LT1460JC LT1460KC l l l 10 10 25 20 20 50 ppm/C ppm/C ppm/C 1460fb 5 LT1460 ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25C. VIN = VOUT + 2.5V, IOUT = 0 unless otherwise specified. PARAMETER CONDITIONS Line Regulation LT1460A, LT1460B, LT1460C, LT1460D, LT1460E, LT1460F, LT1460G, LT1460H, LT1460L, LT1460M VOUT + 0.9V VIN VOUT + 2.5V LT1460HC, LT1460JC, LT1460KC TYP MAX UNITS 30 60 80 ppm/V ppm/V 10 25 35 ppm/V ppm/V 150 800 1000 ppm/V ppm/V 50 100 130 ppm/V ppm/V 1500 2800 3500 ppm/mA ppm/mA 80 135 180 ppm/mA ppm/mA 70 100 140 ppm/mA ppm/mA 1000 3000 4000 ppm/mA ppm/mA 50 200 300 ppm/mA ppm/mA 20 70 100 ppm/mA ppm/mA P = 200mW 0.5 2.5 ppm/mW P = 200mW 2.5 10 ppm/mW l 0.9 V l 1.3 1.4 V V VOUT + 2.5V VIN 20V VOUT + 0.9V VIN VOUT + 2.5V VOUT + 2.5V VIN 20V Load Regulation Sourcing (Note 4) LT1460A, LT1460B, LT1460C, LT1460D, LT1460E, LT1460F, LT1460G, LT1460H, LT1460L, LT1460M IOUT = 100A IOUT = 10mA IOUT = 20mA 0C to 70C LT1460HC, LT1460JC, LT1460KC IOUT = 100A IOUT = 10mA IOUT = 20mA Thermal Regulation (Note 5) LT1460A, LT1460B, LT1460C, LT1460D, LT1460E, LT1460F, LT1460G, LT1460H, LT1460L, LT1460M LT1460HC, LT1460JC, LT1460KC Dropout Voltage (Note 6) VIN - VOUT, IOUT = 0 VIN - VOUT, IOUT = 10mA Output Current Short VOUT to GND Reverse Leakage VIN = -15V Supply Current LT1460-2.5 LT1460-5 LT1460-10 LT1460S3-2.5 LT1460S3-3 LT1460S3-3.3 LT1460S3-5 LT1460S3-10 MIN l l l l l l l l l l 40 l l l l l l l l l mA 0.5 10 A 100 130 165 A A 125 175 225 A A 190 270 360 A A 115 145 175 A A 145 180 220 A A 145 180 220 A A 160 200 240 A A 215 270 350 A A 1460fb 6 LT1460 ELECTRICAL CHARACTERISTICS The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25C. VIN = VOUT + 2.5V, IOUT = 0 unless otherwise specified. PARAMETER CONDITIONS Output Voltage Noise (Note 7) LT1460A, LT1460B, LT1460C, LT1460D, LT1460E, LT1460F, LT1460G, LT1460H, LT1460L, LT1460M LT1460-2.5 0.1Hz f 10Hz 10Hz f 1kHz 10 10 VP-P VRMS LT1460-5 0.1Hz f 10Hz 10Hz f 1kHz 20 20 VP-P VRMS LT1460-10 0.1Hz f 10Hz 10Hz f 1kHz 40 35 VP-P VRMS 4 4 ppm (P-P) ppm (RMS) 40 ppm/kHr 100 ppm/kHr 25 160 ppm ppm 50 250 ppm ppm LT1460HC, LT1460JC, LT1460KC MIN 0.1Hz f 10Hz 10Hz f 1kHz Long-Term Stability of Output Voltage (Note 8) S8 Pkg LT1460HC, LT1460JC, LT1460KC Hysteresis (Note 9) LT1460A, LT1460B, LT1460C, LT1460D, LT1460E, LT1460F, LT1460G, LT1460H, LT1460L, LT1460M LT1460HC, LT1460JC, LT1460KC T = 0C to 70C T = -40C to 85C T = 0C to 70C T = -40C to 85C 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 part is stored outside of the specified temperature range, the output may shift due to hysteresis. Note 3: Temperature coefficient is measured by dividing the change in output voltage by the specified temperature range. Incremental slope is also measured at 25C. 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: Thermal regulation is caused by die temperature gradients created by load current or input voltage changes. This effect must be added to normal line or load regulation. This parameter is not 100% tested. Note 6: Excludes load regulation errors. For LT1460S3, VOUT 0.2%. For all other packages, VOUT 0.1%. Note 7: Peak-to-peak noise is measured with a single 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 sec. RMS noise is measured with a single highpass filter at 10Hz and a 2-pole lowpass filter at 1kHz. The resulting output is full wave rectified l l TYP MAX UNITS and then integrated for a fixed period, making the final reading an average as opposed to RMS. A correction factor of 1.1 is used to convert from average to RMS and a second correction of 0.88 is used to correct for the nonideal pass band of the filters. Note 8: 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. Significant improvement in long-term drift can be realized by preconditioning the IC with a 100 hour to 200 hour, 125C burn-in. Long-term stability will also be affected by differential stresses between the IC and the board material created during board assembly. See PC Board Layout in the Applications Information section. Note 9: 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 25C, but the IC is cycled to 85C or -40C before successive measurements. Hysteresis is roughly proportional to the square of the temperature change. For instruments that are stored at reasonably well-controlled temperatures (within 20 or 30 degrees of operating temperature) hysteresis is generally not a problem. Note 10: The LT1460S3 is guaranteed functional over the operating temperature range of -40 to 85C. 1460fb 7 LT1460 TYPICAL PERFORMANCE CHARACTERISTICS LT1460-2.5 (N8, S8, MS8, Z Packages) 2.5V Minimum Input-Output Voltage Differential 2.5V Load Regulation, Sourcing 2.5V Load Regulation, Sinking 6 10 -55C 25C 125C 1 0.1 0 0.5 1.0 1.5 2.0 INPUT-OUTPUT VOLTAGE (V) 5 125C 4 3 25C 2 -55C 1 0 2.5 80 OUTPUT VOLTAGE CHANGE (mV) OUTPUT VOLTAGE CHANGE (mV) OUTPUT CURRENT (mA) 100 70 125C 60 50 25C 40 30 20 -55C 10 0.1 1 10 OUTPUT CURRENT (mA) 0 100 1.0 0.5 OUTPUT CURRENT (mA) 0 1460 G02 1460 G01 2.5V Output Voltage Temperature Drift 1460 G03 2.5V Supply Current vs Input Voltage 2.503 1.5 2.5V Line Regulation 175 2.5014 3 TYPICAL PARTS 125C 150 2.500 OUTPUT VOLTAGE (V) SUPPLY CURRENT (A) 25C 100 -55C 75 50 2.499 0 0 25 50 TEMPERATURE (C) -25 75 100 0 5 10 20 15 -55C 2.4990 0 2 4 6 8 10 12 14 16 18 20 INPUT VOLTAGE (V) 1460 G05 2.5V Power Supply Rejection Ratio vs Frequency 1460 G06 2.5V Output Impedance vs Frequency 90 POWER SUPPLY REJECTION RATIO (dB) 2.4998 INPUT VOLTAGE (V) 1460 G04 2.5V Transient Responses 1k CL= 0.1F 80 OUTPUT IMPEDANCE () 70 60 50 40 30 20 CL = 0 100 10 10 1 0.1 0 10 IOUT = 10mA CL= 1F 0 -10 100 25C 2.5002 2.4994 25 2.498 -50 2.5006 LOAD CAPACITANCE (F) OUTPUT VOLTAGE (V) 2.501 125 125C 2.5010 2.502 1460 G09 1 1k 10k 100k FREQUENCY (Hz) 1M 1460 G07 10 100 1k 10k FREQUENCY (Hz) 100k 1M 1460 G08 1460fb 8 LT1460 TYPICAL PERFORMANCE CHARACTERISTICS 2.5V Output Voltage Noise Spectrum 2.5V Long-Term Drift Three Typical Parts (S8 Package) 2.5V Output Noise 0.1Hz to 10Hz 1000 2.5000 OUTPUT VOLTAGE (V) NOISE VOLTAGE (nV/Hz) OUTPUT NOISE (10V/DIV) 2.4998 2.4996 2.4994 2.4992 100 2.4990 10 100 1k 10k FREQUENCY (Hz) 0 100k 1 2 3 4 5 6 TIME (SEC) 7 8 9 200 0 10 600 400 TIME (HOURS) 800 1460 G11 1460 G10 1000 1460 G12 LT1460-5 (N8, S8, MS8, Z Packages) 5V Minimum Input-Output Voltage Differential 5V Load Regulation, Sourcing 5V Load Regulation, Sinking 6 100 100 10 25C -55C 1 OUTPUT VOLTAGE CHANGE (mV) 125C OUTPUT VOLTAGE CHANGE (mV) OUTPUT CURRENT (mA) 90 5 4 125C 25C 3 2 -55C 1 80 70 60 25C -55C 50 40 30 125C 20 10 0.1 0 0 0.5 1.0 1.5 2.0 INPUT-OUTPUT VOLTAGE (V) 2.5 0 0.1 1 10 OUTPUT CURRENT (mA) 1460 G13 0 5.004 3 TYPICAL PARTS 5.002 125C 180 25C 160 5.000 25C 140 120 OUTPUT VOLTAGE (V) SUPPLY CURRENT (A) 5.002 -55C 100 80 60 40 4.996 5 5V Line Regulation 200 4.998 3 4 2 OUTPUT CURRENT (mA) 1460 G15 5V Supply Current vs Input Voltage 5.000 1 1460 G14 5V Output Voltage Temperature Drift OUTPUT VOLTAGE (V) 100 125C 4.998 4.996 -55C 4.994 20 4.994 -50 0 -25 0 25 50 TEMPERATURE (C) 75 100 0 2 4 6 8 10 12 14 16 18 20 INPUT VOLTAGE (V) 1460 G16 1460 G17 4.992 0 2 4 6 8 10 12 14 16 18 20 INPUT VOLTAGE (V) 1460 G18 1460fb 9 LT1460 TYPICAL PERFORMANCE CHARACTERISTICS LT1460-5 (N8, S8, MS8, Z Packages) 5V Power Supply Rejection Ratio vs Frequency 5V Output Impedance vs Frequency 5V Transient Responses 1k 80 CL = 0 CL= 0.1F OUTPUT IMPEDANCE () 70 60 50 40 30 20 LOAD CAPACITANCE (F) POWER SUPPLY REJECTION RATIO (dB) 90 100 10 10 1 0.1 0 1 CL= 1F 1460 G21 0.2ms/DIV 10 IOUT = 10mA 0 100 10k 100k FREQUENCY (Hz) 1k 0.1 1M 100 10 1k 10k FREQUENCY (Hz) 100k 1460 G19 1M 1460 G20 5V Output Voltage Noise Spectrum 5V Output Noise 0.1Hz to 10Hz 3000 NOISE VOLTAGE (nV/Hz) OUTPUT NOISE (10V/DIV) 2000 1000 100 10 100 1k 10k FREQUENCY (Hz) 0 100k 1 2 3 4 5 6 TIME (SEC) 7 8 1460 G22 9 10 1460 G23 LT1460-10 (N8, S8, MS8, Z Packages) 10V Minimum Input/Output Voltage Differential 10V Load Regulation, Sourcing 10 125C 1 -55C 25C 100 9 90 8 7 6 5 0 0.5 1.0 1.5 2.0 INPUT/OUTPUT VOLTAGE (V) 2.5 1460 G24 125C 25C 4 3 2 1 0.1 10V Load Regulation, Sinking 10 OUTPUT VOLTAGE CHANGE (mV) OUTPUT VOLTAGE CHANGE (mV) OUTPUT CURRENT (mA) 100 0 0.1 -55C 80 70 25C 60 -55C 50 125C 40 30 20 10 1 10 OUTPUT CURRENT (mA) 100 1460 G25 0 0 1 3 4 2 OUTPUT CURRENT (mA) 5 1460 G26 1460fb 10 LT1460 TYPICAL PERFORMANCE CHARACTERISTICS 10V Output Voltage Temperature Drift 10.006 10V Supply Current vs Input Voltage 10V Line Regulation 400 3 TYPICAL PARTS 10.004 360 10.000 320 9.998 9.994 9.990 -55C 280 240 OUTPUT VOLTAGE (V) SUPPLY CURRENT (A) OUTPUT VOLTAGE (V) 10.002 25C 200 125C 160 120 80 9.986 25C 9.996 -55C 9.992 125C 9.988 9.984 40 -25 75 0 25 50 TEMPERATURE (C) 0 100 0 2 4 6 8 10 12 14 16 18 20 INPUT VOLTAGE (V) 10V Power Supply Rejection Ratio vs Frequency 8 16 14 12 10 INPUT VOLTAGE (V) 18 20 1460 G29 10V Output Impedance vs Frequency 100 10V Transient Responses 1000 90 CL = 0F OUTPUT IMPEDANCE () 80 70 60 50 40 30 20 100 CL = 0.1F 10 CL = 1F 1 10 1 0.1 0 200s/DIV 10 1460 G32 IOUT = 10mA 1 10 100 INPUT FREQUENCY (kHz) 1000 0.1 0.01 0.1 1 10 FREQUENCY (kHz) 1000 100 1460 G30 1460 G31 10V Output Voltage Noise Spectrum 10V Output Noise 0.1Hz to 10Hz OUTPUT NOISE (50V/DIV) 10 NOISE VOLTAGE (V/Hz) POWER SUPPLY REJECTION RATIO (dB) 6 1460 G28 1460 G27 0 0.1 9.980 LOAD CAPACITANCE (F) 9.982 -50 1 0.1 0.01 0.1 1 10 FREQUENCY (kHz) 100 1460 G33 0 2 4 6 8 10 TIME (SEC) 12 14 1460 G34 1460fb 11 LT1460 TYPICAL PERFORMANCE CHARACTERISTICS Characteristic curves are similar for all voltage options of the LT1460S3. Curves from the LT1460S3-2.5 and the LT1460S3-10 represent the extremes of the voltage options. Characteristic curves for other output voltages fall between these curves, and can be estimated based on their voltage output. LT1460S3-2.5V Minimum InputOutput Voltage Differential LT1460S3-2.5V Load Regulation, Sourcing 0 125C 25C -55C 1 0.5 1.0 1.5 2.0 INPUT-OUTPUT VOLTAGE (V) -1.0 -55C -1.5 -2.0 25C -2.5 125C -3.0 -3.5 -4.0 0.1 0.1 0 -0.5 2.5 1 10 OUTPUT CURRENT (mA) LT1460S3-2.5V Output Voltage Temperature Drift 25C THREE TYPICAL PARTS 2.500 2.499 -55C 20 1 5 2 3 4 OUTPUT CURRENT (mA) 1460 G37 LT1460S3-2.5V Line Regulation 2.502 2.501 25C 200 2.501 125C 40 0 250 SUPPLY CURRENT (A) OUTPUT VOLTAGE (V) 60 LT1460S3-2.5V Supply Current vs Input Voltage 2.502 25C 125C -55C 150 100 2.500 -55C 2.499 2.498 125C 2.497 2.496 50 2.498 2.495 2.497 -50 -25 50 25 75 0 TEMPERATURE (C) 100 0 125 2.494 5 0 10 15 2 4 1460 G40 LT1460S3-2.5V Output Impedance vs Frequency 80 6 8 10 12 14 16 18 20 INPUT VOLTAGE (V) 1460 G39 LT1460S3-2.5V Power Supply Rejection Ratio vs Frequency LT1460S3-2.5V Transient Response 1000 CL = 0F OUTPUT IMPEDANCE () 60 50 40 30 20 20 LOAD CURRENT (mA) 70 CL = 0.1F 100 10 CL = 1F 10 1 0.1 1 200s/DIV 10 0 0.1 0 20 INPUT VOLTAGE (V) 1460 G38 POWER SUPPLY REJECTION RATIO (dB) 80 1460 G36 1460 G35 2.503 100 0 100 OUTPUT VOLTAGE (V) 10 120 OUTPUT VOLTAGE CHANGE (mV) OUTPUT VOLTAGE CHANGE (mV) OUTPUT CURRENT (mA) 100 LT1460S3-2.5V Load Regulation, Sinking 1460 G43 CLOAD = 0F 1 10 100 FREQUENCY (kHz) 1000 1460 G41 0.1 0.01 0.1 1 10 FREQUENCY (kHz) 100 1000 1460 G42 1460fb 12 LT1460 TYPICAL PERFORMANCE CHARACTERISTICS Characteristic curves are similar for all voltage options of the LT1460S3. Curves from the LT1460S3-2.5 and the LT1460S3-10 represent the extremes of the voltage options. Characteristic curves for other output voltages fall between these curves, and can be estimated based on their voltage output. LT1460S3-2.5V Output Voltage Noise Spectrum LT1460S3-2.5V Output Noise 0.1Hz to 10Hz LT1460S3-10V Minimum InputOutput Voltage Differential 1000 OUTPUT CURRENT (mA) NOISE VOLTAGE (nV/Hz) OUTPUT NOISE (20V/DIV) 100 100 10 100 1k 10k FREQUENCY (Hz) 25C -55C 1 0.1 TIME (2 SEC/DIV) 100k 125C 10 0.5 1.0 1.5 2.0 INPUT-OUTPUT VOLTAGE (V) 0 1460 G45 1460 G46 1460 G44 LT1460S3-10V Load Regulation, Sourcing LT1460S3-10V Load Regulation, Sinking 15 10 5 -55C 0 -5 125C 10.000 125C 150 25C 100 -55C 50 9.998 9.996 9.994 9.992 9.990 9.988 9.986 9.984 25C 1 10 OUTPUT CURRENT (mA) THREE TYPICAL PARTS 10.002 200 OUTPUT VOLTAGE (V) OUTPUT VOLTAGE CHANGE (mV) 20 100 0 0 1 3 4 2 OUTPUT CURRENT (mA) 5 9.982 -50 -25 50 25 0 75 TEMPERATURE (C) LT1460S3-10V Supply Current vs Input Voltage 100 125 1460 G49 1460 G48 1460 G47 LT1460S3-10V Line Regulation 10.010 350 300 10.005 25C 250 125C -55C 200 150 100 OUTPUT VOLTAGE (V) SUPPLY CURRENT (A) OUTPUT VOLTAGE CHANGE (mV) 10.006 10.004 25 -10 0.1 LT1460S3-10V Output Voltage Temperature Drift 250 35 30 2.5 25C 10.000 -55C 9.995 125C 9.990 9.985 50 9.980 0 0 2 4 6 8 10 12 14 16 18 20 INPUT VOLTAGE (V) 1460 G50 6 8 14 12 16 10 INPUT VOLTAGE (V) 18 20 1460 G51 1460fb 13 LT1460 TYPICAL PERFORMANCE CHARACTERISTICS Characteristic curves are similar for all voltage options of the LT1460S3. Curves from the LT1460S3-2.5 and the LT1460S3-10 represent the extremes of the voltage options. Characteristic curves for other output voltages fall between these curves, and can be estimated based on their voltage output. LT1460S3-10V Power Supply Rejection Ratio vs Frequency LT1460S3-10V Output Impedance vs Frequency 1000 90 20 70 60 50 40 30 20 LOAD CURRENT (mA) CL = 0F 80 OUTPUT IMPEDANCE () POWER SUPPLY REJECTION RATIO (dB) 100 LT1460S3-10V Transient Response 100 CL = 0.1F 10 CL = 1F 1 0.1 1 200s/DIV 10 0 0.1 10 1460 G54 CLOAD = 0F 1 10 100 FREQUENCY (kHz) 1000 0.1 0.01 0.1 1 10 FREQUENCY (kHz) 100 1460 G52 1000 1460 G53 LT1460S3-10V Output Voltage Noise Spectrum LT1460S3-10V Output Noise 0.1Hz to 10Hz OUTPUT NOISE (20V/DIV) NOISE VOLTAGE (V/Hz) 10 1 0.1 0.01 0.1 1 10 FREQUENCY (kHz) 100 TIME (2 SEC/DIV) 1460 G56 1460 G55 1460fb 14 LT1460 APPLICATIONS INFORMATION Longer Battery Life Series references have a large advantage over older shunt style references. Shunt references require a resistor from the power supply to operate. This resistor must be chosen to supply the maximum current that can ever be demanded by the circuit being regulated. When the circuit being controlled is not operating at this maximum current, the shunt reference must always sink this current, resulting in high dissipation and short battery life. the ringing can be reduced with a small resistor in series with the reference output as shown in Figure 4. Figure 5 shows the response of the LT1460-2.5 with a RS = 2 and 2.5V VGEN 1.5V The LT1460 series reference does not require a current setting resistor and can operate with any supply voltage from VOUT + 0.9V to 20V. When the circuitry being regulated does not demand current, the LT1460 reduces its dissipation and battery life is extended. If the reference is not delivering load current it dissipates only a few mW, yet the same configuration can deliver 20mA of load current when demanded. VOUT RL = 10k VOUT RL = 1k 1460 F02 1s/DIV Figure 2. CL = 0 2.5V VGEN Capacitive Loads 1.5V The LT1460 is designed to be stable with capacitive loads. With no capacitive load, the reference is ideal for fast settling, applications where PC board space is a premium, or where available capacitance is limited. The test circuit for the LT1460-2.5 shown in Figure 1 is used to measure the response time for various load currents and load capacitors. The 1V step from 2.5V to 1.5V produces a current step of 1mA or 100A for RL = 1k or RL = 10k. Figure 2 shows the response of the reference with no load capacitance. The reference settles to 2.5mV (0.1%) in less than 1s for a 100A pulse and to 0.1% in 1.5s with a 1mA step. When load capacitance is greater than 0.01F, the reference begins to ring due to the pole formed with the output impedance. Figure 3 shows the response of the reference to a 1mA and 100A load current step with a 0.01F load capacitor. The ringing can be greatly reduced with a DC load as small as 200A. With large output capacitors, 1F, VIN = 5V CIN 0.1F LT1460-2.5 RL VOUT VGEN CL RL = 10k VOUT RL = 1k 1460 F03 20s/DIV Figure 3. CL = 0.01F RS VIN = 5V VOUT RL LT1460-2.5 VGEN CIN 0.1F 2.5V 1.5V CL 1460 F04 Figure 4. Isolation Resistor Test Circuit VGEN 2.5V 1.5V VOUT RL = 1k RS = 0 VOUT RL = 1k RS = 2 2.5V 1.5V 1460 F01 Figure 1. Response Time Test Circuit VOUT 0.1ms/DIV 1460 F05 Figure 5. Effect of RS for CL = 1F 1460fb 15 LT1460 APPLICATIONS INFORMATION CL = 1F. RS should not be made arbitrarily large because it will limit the load regulation. Figure 6 to Figure 8 illustrate response in the LT1460-5. The 1V step from 5V to 4V produces a current step of 1mA or 100A for RL = 1k or RL = 10k. Figure 7 shows the response of the reference with no load capacitance. The reference settles to 5mV (0.1%) in less than 2s for a 100A pulse and to 0.1% in 3s with a 1mA step. When load capacitance is greater than 0.01F, the reference begins to ring due to the pole formed with the output impedance. Figure 8 shows the response of the reference to a 1mA VIN = 5V LT1460-5 RL VOUT The reference settles to 10mV (0.1%) in 0.4s for a 100A pulse and to 0.1% in 0.8s with a 1mA step. When load capacitance is greater than 0.01F, the reference begins to ring due to the pole formed with the output impedance. Figure 11 shows the response of the reference to a 1mA and 100A load current step with a 0.01F load capacitor. VIN = 12.5V VGEN CIN 0.1F and 100A load current step with a 0.01F load capacitor. Figure 9 to Figure 11 illustrate response of the LT1460-10. The 1V step from 10V to 9V produces a current step of 1mA or 100A for RL = 1k or RL = 10k. Figure 10 shows the response of the reference with no load capacitance. 5V 4V CL LT1460-10 RL VOUT CIN 0.1F VGEN 10V 9V CL 1460 F09 1460 F06 Figure 6. Response Time Test Circuit Figure 9. Response Time Test Circuit 5V VGEN 10V VGEN 4V VOUT RL = 10k VOUT RL = 1k 2s/DIV 9V VOUT RL = 10k VOUT 1460 F07 RL = 1k 2s/DIV Figure 7. CL = 0 1460 F10 Figure 10. CL = 0 VGEN 10V 5V 4V VOUT RL = 10k VOUT RL = 1k 10s/DIV Figure 8. CL = 0.01F 1460 F08 VGEN 9V VOUT RL = 10k RL = 1k VOUT 10s/DIV 1460 F11 Figure 11. CL = 0.01F 1460fb 16 LT1460 APPLICATIONS INFORMATION The LT1460S3 family of references are designed to be stable with a large range of capacitive loads. With no capacitive load, these references are ideal for fast settling or applications where PC board space is a premium. The test circuit shown in Figure 12 is used to measure the response time and stability of various load currents and load capacitors. This circuit is set for the 2.5V option. For other voltage options, the input voltage must be scaled up and the output voltage generator offset voltage must be adjusted. The 1V step from 2.5V to 1.5V produces a current step of 10mA or 1mA for RL = 100 or RL = 1k. Figure 13 shows the response of the reference to these VIN = 2.5V LT1460S3-2.5 RL VOUT CIN 0.1F VGEN 1mA and 10mA load steps with no load capacitance, and Figure 14 shows a 1mA and 10mA load step with a 0.1F output capacitor. Figure 15 shows the response to a 1mA load step with CL = 1F and 4.7F. The frequency compensation of the LT1460S3 version is slightly different than that of the other packages. Additional care must be taken when choosing load capacitance in an application circuit. Table 1 gives the maximum output capacitance for various load currents and output voltages of the LT1460S3 to avoid instability. Load capacitors with low ESR (effective series resistance) cause more ringing than capacitors with higher ESR such as polarized aluminum or tantalum capacitors. 2.5V 1.5V CL 1460 F12 VGEN Figure 12. Response Time Test Circuit VGEN 2.5V 1.5V VOUT 1mA VOUT 10mA 2.5V 1.5V VOUT 1mA 100s/DIV VOUT Figure 14. CL = 0.1F 10mA 1s/DIV Figure 13. CL = 0F 1460 F14 1460 F13 VGEN 2.5V 1.5V VOUT 1A VOUT 4.7A 100s/DIV 1460 F15 Figure 15. IOUT = 1mA 1460fb 17 LT1460 APPLICATIONS INFORMATION Hysteresis VOLTAGE OPTION IOUT = 100A IOUT = 1mA 2.5V >10F >10F 2F 0.68F 3V >10F >10F 2F 0.68F IOUT = 10mA IOUT = 20mA 3.3V >10F >10F 1F 0.68F 5V >10F >10F 1F 0.68F 10V >10F 1F 0.15F 0.1F 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 LT1460S3 long-term drift data was taken on over 100 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 = 30C, their outputs were scanned regularly and measured with an 8.5 digit DVM. Figure 16 shows typical long-term drift of the LT1460S3s. Hysteresis data shown in Figure 17 and Figure 18 represents the worst-case data taken on parts from 0C to 70C and from -40C to 85C. The device is capable of dissipating relatively high power, i.e., for the LT1460S3-2.5, PD = 17.5V * 20mA = 350mW. The thermal resistance of the SOT-23 package is 325C/W and this dissipation causes a 114C internal rise producing a junction temperature of TJ = 25C + 114C = 139C. This elevated temperature will cause the output to shift due to thermal hysteresis. For highest performance in precision applications, do not let the LT1460S3's junction temperature exceed 85C. 18 16 WORST-CASE HYSTERESIS ON 40 UNITS 14 NUMBER OF UNITS Table 1. Maximum Output Capacitance for LT1460S3 12 10 70C TO 25C 0C TO 25C 8 6 4 2 150 0 40 -240 -200 -160 -120 -80 -40 0 HYSTERESIS (ppm) 100 80 120 160 200 240 1460 F17 Figure 17. 0C to 70C Hysteresis ppm 50 0 9 8 -50 WORST-CASE HYSTERESIS ON 34 UNITS -150 0 100 200 300 400 500 600 700 800 900 1000 HOURS 1460 F16 Figure 16. Typical Long-Term Drift NUMBER OF UNITS 7 -100 85C TO 25C -40C TO 25C 6 5 4 3 2 1 0 -600 -500 -400 -300 -200 -100 0 100 200 300 400 500 600 HYSTERESIS (ppm) 1460 F18 Figure 18. -40C to 85C Hysteresis 1460fb 18 LT1460 APPLICATIONS INFORMATION Input Capacitance Total worst-case output error is: It is recommended that a 0.1F or larger capacitor be added to the input pin of the LT1460. This can help with stability when large load currents are demanded. Output Accuracy Like all references, either series or shunt, the error budget of the LT1460-2.5 is made up of primarily three components: initial accuracy, temperature coefficient and load regulation. Line regulation is neglected because it typically contributes only 30ppm/V, or 75V for a 1V input change. The LT1460-2.5 typically shifts less than 0.01% when soldered into a PCB, so this is also neglected (see PC Board Layout section). The output errors are calculated as follows for a 100A load and 0C to 70C temperature range: LT1460AC Initial accuracy = 0.075% For IO = 100A, and using the LT1460-2.5 for calculation, 3500ppm VOUT = 0.1mA 2.5V = 875V mA ( )( ) which is 0.035%. For temperature 0C to 70C the maximum T = 70C, 10ppm VOUT = 70C 2.5V = 1.75mV C ( )( ) 0.075% + 0.035% + 0.070% = 0.180%. Table 1 gives worst-case accuracy for the LT1460AC, CC, DC, FC, GC from 0C to 70C and the LT1460BI, EI, GI from -40C to 85C. Note that the LT1460-5 and LT1460-10 give identical accuracy as a fraction of their respective output voltages. PC Board Layout In 13- to 16-bit systems where initial accuracy and temperature coefficient calibrations have been done, the mechanical and thermal stress on a PC board (in a cardcage for instance) can shift the output voltage and mask the true temperature coefficient of a reference. In addition, the mechanical stress of being soldered into a PC board can cause the output voltage to shift from its ideal value. Surface mount voltage references (MS8 and S8) are the most susceptible to PC board stress because of the small amount of plastic used to hold the lead frame. A simple way to improve the stress-related shifts is to mount the reference near the short edge of the PC board, or in a corner. The board edge acts as a stress boundary, or a region where the flexure of the board is minimum. The package should always be mounted so that the leads absorb the stress and not the package. The package is generally aligned with the leads parallel to the long side of the PC board as shown in Figure 20a. A qualitative technique to evaluate the effect of stress on voltage references is to solder the part into a PC board and which is 0.07%. Table 2. Worst-Case Output Accuracy Over Temperature IOUT LT1460AC LT1460BI LT1460CC LT1460DC LT1460EI LT1460FC LT1460GC LT1460GI LT1460HC LT1460JC LT1460KC 0 0.145% 0.225% 0.205% 0.240% 0.375% 0.325% 0.425% 0.562% 0.340% 0.540% 0.850% 100A 0.180% 0.260% 0.240% 0.275% 0.410% 0.360% 0.460% 0.597% 0.380% 0.580% 0.890% 10mA 0.325% 0.405% 0.385% 0.420% 0.555% 0.505% 0.605% 0.742% 0.640% 0.840% 1.15% 20mA 0.425% N/A 0.485% 0.520% N/A 0.605% 0.705% N/A 0.540% 0.740% 1.05% 1460fb 19 LT1460 APPLICATIONS INFORMATION deform the board a fixed amount as shown in Figure 19. The flexure #1 represents no displacement, flexure #2 is concave movement, flexure #3 is relaxation to no displacement and finally, flexure #4 is a convex movement. This motion is repeated for a number of cycles and the relative output deviation is noted. The result shown in Figure 20a is for two LT1460S8-2.5s mounted vertically and Figure 20b is for two LT1460S8-2.5s mounted horizontally. The parts oriented in Figure 20a impart less stress into the package because stress is absorbed in the leads. Figures 20a and 20b show the deviation to be between 125V and 1 2 The most effective technique to improve PC board stress is to cut slots in the board around the reference to serve as a strain relief. These slots can be cut on three sides of the reference and the leads can exit on the fourth side. This "tongue" of PC board material can be oriented in the long direction of the board to further reduce stress transferred to the reference. The results of slotting the PC boards of Figures 20a and 20b are shown in Figures 21a and 21b. In this example the slots can improve the output shift from about 100ppm to nearly zero. 3 4 250V and implies a 50ppm and 100ppm change respectively. This corresponds to a 13- to 14-bit system and is not a problem for most 10- to 12-bit systems unless the system has a calibration. In this case, as with temperature hysteresis, this low level can be important and even more careful techniques are required. 1460 F19 Figure 19. Flexure Numbers 2 OUTPUT DEVIATION (mV) OUTPUT DEVIATION (mV) 2 1 LONG DIMENSION 0 1 LONG DIMENSION 0 -1 -1 0 10 20 30 FLEXURE NUMBER 0 40 20 30 40 FLEXURE NUMBER 1460 F20a 1460 F20b Figure 20a. Two Typical LT1460S8-2.5s, Vertical Orientation Without Slots Figure 20b. Two Typical LT1460S8-2.5s, Horizontal Orientation Without Slots 2 OUTPUT DEVIATION (mV) 2 OUTPUT DEVIATION (mV) 10 1 0 SLOT -1 1 0 SLOT -1 0 10 20 30 FLEXURE NUMBER Figure 21a. Same Two LT1460S8-2.5s in Figure 16a, but with Slots 40 1460 F21a 0 10 20 30 FLEXURE NUMBER 40 1460 F21b Figure 21b. Same Two LT1460S8-2.5s in Figure 16b, but with Slots 1460fb 20 LT1460 SIMPLIFIED SCHEMATIC VCC VOUT GND 1460 SS PACKAGE DESCRIPTION S3 Package 3-Lead Plastic SOT-23 (Reference LTC DWG # 05-08-1631) 0.764 2.80 - 3.04 (.110 - .120) 0.8 0.127 2.10 - 2.64 (.083 - .104) 2.74 1.20 - 1.40 (.047 - .060) 0.96 BSC 1.92 0.45 - 0.60 (.017 - .024) 0.89 - 1.03 (.035 - .041) RECOMMENDED SOLDER PAD LAYOUT 0.37 - 0.51 (.015 - .020) 0.89 - 1.12 (.035 - .044) 0.55 (.022) REF 0.09 - 0.18 (.004 - .007) 0.01 - 0.10 (.0004 - .004) 1.78 - 2.05 (.070 - .081) S3 SOT-23 0502 NOTE: 1. CONTROLLING DIMENSION: MILLIMETERS MILLIMETERS 2. DIMENSIONS ARE IN (INCHES) 3. DRAWING NOT TO SCALE 4. DIMENSIONS ARE INCLUSIVE OF PLATING 5. DIMENSIONS ARE EXCLUSIVE OF MOLD FLASH AND METAL BURR 6. MOLD FLASH SHALL NOT EXCEED .254mm 7. PACKAGE JEDEC REFERENCE IS TO-236 VARIATION AB 1460fb 21 LT1460 PACKAGE DESCRIPTION N8 Package 8-Lead PDIP (Narrow .300 Inch) (Reference LTC DWG # 05-08-1510) .400* (10.160) MAX 8 7 6 5 1 2 3 4 .255 .015* (6.477 0.381) .300 - .325 (7.620 - 8.255) .065 (1.651) TYP .008 - .015 (0.203 - 0.381) ( +.035 .325 -.015 8.255 +0.889 -0.381 .130 .005 (3.302 0.127) .045 - .065 (1.143 - 1.651) ) .120 (3.048) .020 MIN (0.508) MIN .018 .003 .100 (2.54) BSC (0.457 0.076) N8 1002 NOTE: 1. DIMENSIONS ARE INCHES MILLIMETERS *THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .010 INCH (0.254mm) S8 Package 8-Lead Plastic Small Outline (Narrow .150 Inch) (Reference LTC DWG # 05-08-1610) .189 - .197 (4.801 - 5.004) NOTE 3 .045 .005 .050 BSC 8 .245 MIN 7 6 5 .160 .005 .150 - .157 (3.810 - 3.988) NOTE 3 .228 - .244 (5.791 - 6.197) .030 .005 TYP 1 RECOMMENDED SOLDER PAD LAYOUT .010 - .020 x 45 (0.254 - 0.508) .008 - .010 (0.203 - 0.254) 0- 8 TYP .016 - .050 (0.406 - 1.270) NOTE: 1. DIMENSIONS IN .053 - .069 (1.346 - 1.752) .014 - .019 (0.355 - 0.483) TYP 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) 2 3 4 .004 - .010 (0.101 - 0.254) .050 (1.270) BSC SO8 0303 1460fb 22 LT1460 PACKAGE DESCRIPTION MS8 Package 8-Lead Plastic MSOP (Reference LTC DWG # 05-08-1660 Rev F) 0.889 0.127 (.035 .005) 5.23 (.206) MIN 3.20 - 3.45 (.126 - .136) 0.42 0.038 (.0165 .0015) TYP 3.00 0.102 (.118 .004) (NOTE 3) 0.65 (.0256) BSC 8 7 6 5 0.52 (.0205) REF RECOMMENDED SOLDER PAD LAYOUT 0.254 (.010) 3.00 0.102 (.118 .004) (NOTE 4) 4.90 0.152 (.193 .006) DETAIL "A" 0 - 6 TYP GAUGE PLANE 1 0.53 0.152 (.021 .006) 2 3 4 1.10 (.043) MAX DETAIL "A" 0.86 (.034) REF 0.18 (.007) SEATING PLANE 0.22 - 0.38 (.009 - .015) TYP 0.1016 0.0508 (.004 .002) 0.65 (.0256) BSC MSOP (MS8) 0307 REV F NOTE: 1. DIMENSIONS IN MILLIMETER/(INCH) 2. DRAWING NOT TO SCALE 3. DIMENSION DOES NOT INCLUDE MOLD FLASH, PROTRUSIONS OR GATE BURRS. MOLD FLASH, PROTRUSIONS OR GATE BURRS SHALL NOT EXCEED 0.152mm (.006") PER SIDE 4. DIMENSION DOES NOT INCLUDE INTERLEAD FLASH OR PROTRUSIONS. INTERLEAD FLASH OR PROTRUSIONS SHALL NOT EXCEED 0.152mm (.006") PER SIDE 5. LEAD COPLANARITY (BOTTOM OF LEADS AFTER FORMING) SHALL BE 0.102mm (.004") MAX Z Package 3-Lead Plastic TO-92 (Similar to TO-226) (Reference LTC DWG # 05-08-1410 Rev C) .060 p .005 (1.524p 0.127) DIA .180 p .005 (4.572 p 0.127) .90 (2.286) NOM .180 p .005 (4.572 p 0.127) .500 (12.70) MIN .050 UNCONTROLLED (1.270) LEAD DIMENSION MAX .016 p .003 (0.406 p 0.076) .050 (1.27) BSC BULK PACK .060 p .010 (1.524 p 0.254) 3 2 1 5o NOM .015 p .002 (0.381 p 0.051) Z3 (TO-92) 1008 REV C .098 +.016/-.04 (2.5 +0.4/-0.1) 2 PLCS TO-92 TAPE AND REEL REFER TO TAPE AND REEL SECTION OF LTC DATA BOOK FOR ADDITIONAL INFORMATION .140 p .010 (3.556 p 0.127) 10o NOM 1460fb 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 LT1460 TYPICAL APPLICATIONS Handling Higher Load Currents V+ 40mA + 47F IN R1* LT1460 10mA VOUT OUT GND RL TYPICAL LOAD CURRENT = 50mA *SELECT R1 TO DELIVER 80% OF TYPICAL LOAD CURRENT. LT1460 WILL THEN SOURCE AS NECESSARY TO MAINTAIN PROPER OUTPUT. DO NOT REMOVE LOAD AS OUTPUT WILL BE DRIVEN UNREGULATED HIGH. LINE REGULATION IS DEGRADED IN THIS APPLICATION Boosted Output Current with No Current Limit V+ (VOUT + 1.8V) V+ - VOUT 40mA 1460 TA03 Boosted Output Current with Current Limit V+ VOUT + 2.8V + R1 220 R1 = D1* LED 47F + R1 220 47F 8.2 2N2905 2N2905 IN IN LT1460 VOUT 100mA OUT GND + LT1460 OUT 2F SOLID TANT GND 1460 TA04 + VOUT 100mA 2F SOLID TANT * GLOWS IN CURRENT LIMIT, DO NOT OMIT 1460 TA05 RELATED PARTS PART NUMBER DESCRIPTION COMMENTS LT1019 Precision Bandgap Reference 0.05% Max, 5ppm/C Max LT1027 Precision 5V Reference 0.02%, 2ppm/C Max LT1236 Precision Low Noise Reference 0.05% Max, 5ppm/C Max, SO Package LT1461 Micropower Precision Low Dropout 0.04% Max, 3ppm/C Max, 50mA Output Current LT1634 Micropower Precision Shunt Reference 1.25V, 2.5V Output 0.05%, 25ppm/C Max LT1790 Micropower Precision Series References 0.05% Max, 10ppm/C Max, 60A Supply, SOT23 Package (R) LTC 1798 Micropower Low Dropout Reference, Fixed or Adjustable 0.15% Max, 40ppm/C, 6.5A Max Supply Current LTC6652 Low Drift Low Noise Buffered Reference 0.05% Accuracy, 5ppm/C Drift, 2.1ppm (0.1Hz to 10Hz) Noise LT6660 Tiny Micropower Precision Series References 0.075% Max, 10ppm/C Max, 20mA Output, 2mm x 2mm DFN Package 1460fb 24 Linear Technology Corporation LT 0509 REV B * PRINTED IN USA 1630 McCarthy Blvd., Milpitas, CA 95035-7417 (408) 432-1900 FAX: (408) 434-0507 www.linear.com (c) LINEAR TECHNOLOGY CORPORATION 2006