LT1460 Micropower Precision Series Reference Family Features
n n n n n n n n n n
Description
The LT®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. 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.
Trimmed to High Accuracy: 0.075% Max Low Drift: 10ppm/°C Max Industrial Temperature Range Temperature Coefficient Guaranteed to 125°C Low Supply Current: 130µA 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
typical application
Basic Connection
3.4V TO 20V C1 0.1µF LT1460-2.5 IN GND
1460 TA01
Typical Distribution of Output Voltage S8 Package
20 18 2.5V 16 14 UNITS (%) 12 10 8 6 4 2 0 –0.10 –0.06 0.06 –0.02 0 0.02 OUTPUT VOLTAGE ERROR (%) 0.10
1460 TA02
OUT
1400 PARTS FROM 2 RUNS
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LT1460 absolute MaxiMuM ratings
(Note 1)
Input Voltage.............................................................30V Reverse Voltage ...................................................... –15V Output Short-Circuit Duration, TA = 25°C VIN > 10V ............................................................5 sec VIN ≤ 10V ..................................................... Indefinite
Specified Temperature Range (Note 10) Commercial (C) ........................................ 0°C to 70°C Industrial (I) .........................................–40°C to 85°C High (H) ............................................. –40°C to 125°C Storage Temperature Range (Note 2)..... –65°C to 150°C Lead Temperature (Soldering, 10 sec)................... 300°C
pin conFiguration
TOP VIEW IN 1 3 GND OUT 2 S3 PACKAGE 3-LEAD PLASTIC SOT-23 TJMAX = 125°C, θJA = 228°C/W TOP VIEW DNC* 1 VIN 2 DNC* 3 GND 4 8 7 6 5 DNC* DNC* VOUT DNC* DNC* 1 VIN 2 DNC* 3 GND 4 TOP VIEW 8 7 6 5 DNC* DNC* VOUT DNC*
N8 PACKAGE 8-LEAD PLASTIC DIP *CONNECTED INTERNALLY. DO NOT CONNECT EXTERNAL CIRCUITRY TO THESE PINS TJMAX = 150°C, θJA = 130°C/W TOP VIEW DNC* VIN DNC* GND 1 2 3 4 8 7 6 5 DNC* DNC* VOUT DNC*
S8 PACKAGE 8-LEAD PLASTIC SO *CONNECTED INTERNALLY. DO NOT CONNECT EXTERNAL CIRCUITRY TO THESE PINS TJMAX = 150°C, θJA = 190°C/W BOTTOM VIEW 1 VIN 2 VOUT 3 GND
MS8 PACKAGE 8-LEAD PLASTIC MSOP *CONNECTED INTERNALLY. DO NOT CONNECT EXTERNAL CIRCUITRY TO THESE PINS TJMAX = 150°C, θJA = 250°C/W Z PACKAGE 3-LEAD TO-92 PLASTIC TJMAX = 150°C, θJA = 160°C/W
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LT1460 orDer inForMation
Lead Free Finish
TAPE AND REEL (MINI) LT1460HCS3-2.5#TRMPBF LT1460JCS3-2.5#TRMPBF LT1460KCS3-2.5#TRMPBF LT1460HCS3-3#TRMPBF LT1460JCS3-3#TRMPBF LT1460KCS3-3#TRMPBF LT1460HCS3-3.3#TRMPBF LT1460JCS3-3.3#TRMPBF LT1460KCS3-3.3#TRMPBF LT1460HCS3-5#TRMPBF LT1460JCS3-5#TRMPBF LT1460KCS3-5#TRMPBF LT1460HCS3-10#TRMPBF LT1460JCS3-10#TRMPBF TAPE AND REEL LT1460HCS3-2.5#TRMPBF LT1460JCS3-2.5#TRPBF LT1460KCS3-2.5#TRPBF LT1460HCS3-3#TRPBF LT1460JCS3-3#TRPBF LT1460KCS3-3#TRPBF LT1460HCS3-3.3#TRPBF LT1460JCS3-3.3#TRPBF LT1460KCS3-3.3#TRPBF LT1460HCS3-5#TRPBF LT1460JCS3-5#TRPBF LT1460KCS3-5#TRPBF LT1460HCS3-10#TRPBF LT1460JCS3-10#TRPBF PART MARKING* LTAC or LTH8† LTAD or LTH8† LTAE or LTH8† LTAN or LTH9† LTAP or LTH9† LTAQ or LTH9† LTAR or LTJ1† LTAS or LTJ1† LTAT or LTJ1† LTAK or LTJ2† LTAL or LTJ2† LTAM or LTJ2† LTAU or LTJ3† LTAV or LTJ3† LTAW or LTJ3† PACKAGE DESCRIPTION 3-Lead Plastic SOT-23 3-Lead Plastic SOT-23 3-Lead Plastic SOT-23 3-Lead Plastic SOT-23 3-Lead Plastic SOT-23 3-Lead Plastic SOT-23 3-Lead Plastic SOT-23 3-Lead Plastic SOT-23 3-Lead Plastic SOT-23 3-Lead Plastic SOT-23 3-Lead Plastic SOT-23 3-Lead Plastic SOT-23 3-Lead Plastic SOT-23 3-Lead Plastic SOT-23 SPECIFIED TEMPERATURE RANGE 0°C to 70°C 0°C to 70°C 0°C to 70°C 0°C to 70°C 0°C to 70°C 0°C to 70°C 0°C to 70°C 0°C to 70°C 0°C to 70°C 0°C to 70°C 0°C to 70°C 0°C to 70°C 0°C to 70°C 0°C to 70°C 0°C to 70°C
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/ LEAD FREE FINISH LT1460ACN8-2.5#PBF LT1460BIN8-2.5#PBF LT1460DCN8-2.5#PBF LT1460EIN8-2.5#PBF LT1460ACN8-5#PBF LT1460BIN8-5#PBF LT1460DCN8-5#PBF LT1460EIN8-5#PBF LT1460ACN8-10#PBF LT1460BIN8-10#PBF LT1460DCN8-10#PBF LT1460EIN8-10#PBF LT1460ACS8-2.5#PBF LT1460BIS8-2.5#PBF LT1460DCS8-2.5#PBF LT1460EIS8-2.5#PBF LT1460LHS8-2.5#PBF LT1460MHS8-2.5#PBF LT1460ACS8-5#PBF LT1460BIS8-5#PBF TAPE AND REEL LT1460ACN8-2.5#TRPBF LT1460BIN8-2.5#TRPBF LT1460DCN8-2.5#TRPBF LT1460EIN8-2.5#TRPBF LT1460ACN8-5#TRPBF LT1460BIN8-5#TRPBF LT1460DCN8-5#TRPBF LT1460EIN8-5#TRPBF LT1460ACN8-10#TRPBF LT1460BIN8-10#TRPBF LT1460DCN8-10#TRPBF LT1460EIN8-10#TRPBF LT1460ACS8-2.5#TRPBF LT1460BIS8-2.5#TRPBF LT1460DCS8-2.5#TRPBF LT1460EIS8-2.5#TRPBF LT1460LHS8-2.5#TRPBF LT1460MHS8-2.5#TRPBF LT1460ACS8-5#TRPBF LT1460BIS8-5#TRPBF 1460A2 460BI2 1460D2 460EI2 60LH25 60MH25 1460A5 460BI5 PART MARKING PACKAGE DESCRIPTION 8-Lead Plastic DIP 8-Lead Plastic DIP 8-Lead Plastic DIP 8-Lead Plastic DIP 8-Lead Plastic DIP 8-Lead Plastic DIP 8-Lead Plastic DIP 8-Lead Plastic DIP 8-Lead Plastic DIP 8-Lead Plastic DIP 8-Lead Plastic DIP 8-Lead Plastic DIP 8-Lead Plastic SO 8-Lead Plastic SO 8-Lead Plastic SO 8-Lead Plastic SO 8-Lead Plastic SO 8-Lead Plastic SO 8-Lead Plastic SO 8-Lead Plastic SO
SPECIFIED TEMPERATURE RANGE 0°C to 70°C –40°C to 85°C 0°C to 70°C –40°C to 85°C 0°C to 70°C –40°C to 85°C 0°C to 70°C –40°C to 85°C 0°C to 70°C –40°C to 85°C 0°C to 70°C –40°C to 85°C 0°C to 70°C –40°C to 85°C 0°C to 70°C –40°C to 85°C 0°C to 70°C –40°C to 85°C 0°C to 70°C –40°C to 85°C
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LT1460 orDer inForMation
LEAD FREE FINISH LT1460DCS8-5#PBF LT1460EIS8-5#PBF LT1460LHS8-5#PBF LT1460MHS8-5#PBF LT1460ACS8-10#PBF LT1460BIS8-10#PBF LT1460DCS8-10#PBF LT1460EIS8-10#PBF LT1460CCMS8-2.5#PBF LT1460FCMS8-2.5#PBF LT1460CCMS8-5#PBF LT1460FCMS8-5#PBF LT1460CCMS8-10#PBF LT1460FCMS8-10#PBF LT1460GCZ-2.5#PBF LT1460GIZ-2.5#PBF LT1460GCZ-5#PBF LT1460GIZ-5#PBF LT1460GCZ-10#PBF LT1460GIZ-10#PBF TAPE AND REEL LT1460DCS8-5#TRPBF LT1460EIS8-5#TRPBF LT1460LHS8-5#TRPBF LT1460MHS8-5#TRPBF LT1460ACS8-10#TRPBF LT1460BIS8-10#TRPBF LT1460DCS8-10#TRPBF LT1460EIS8-10#TRPBF LT1460CCMS8-2.5#TRPBF LT1460FCMS8-2.5#TRPBF LT1460CCMS8-5#TRPBF LT1460FCMS8-5#TRPBF LT1460CCMS8-10#TRPBF LT1460FCMS8-10#TRPBF LT1460GCZ-2.5#TRPBF LT1460GIZ-2.5#TRPBF LT1460GCZ-5#TRPBF LT1460GIZ-5#TRPBF LT1460GCZ-10#TRPBF LT1460GIZ-10#TRPBF PART MARKING 1460D5 460EI5 460LH5 460MH5 1460A1 460BI1 1460D1 460EI1 LTAA LTAB LTAF LTAG LTAH LTAJ PACKAGE DESCRIPTION 8-Lead Plastic SO 8-Lead Plastic SO 8-Lead Plastic SO 8-Lead Plastic SO 8-Lead Plastic SO 8-Lead Plastic SO 8-Lead Plastic SO 8-Lead Plastic SO 8-Lead Plastic MSOP 8-Lead Plastic MSOP 8-Lead Plastic MSOP 8-Lead Plastic MSOP 8-Lead Plastic MSOP 8-Lead Plastic MSOP 3-Lead Plastic TO-92 3-Lead Plastic TO-92 3-Lead Plastic TO-92 3-Lead Plastic TO-92 3-Lead Plastic TO-92 3-Lead Plastic TO-92 SPECIFIED TEMPERATURE RANGE 0°C to 70°C –40°C to 85°C 0°C to 70°C –40°C to 85°C 0°C to 70°C –40°C to 85°C 0°C to 70°C –40°C to 85°C 0°C to 70°C 0°C to 70°C 0°C to 70°C 0°C to 70°C 0°C to 70°C 0°C to 70°C 0°C to 70°C –40°C to 85°C 0°C to 70°C –40°C to 85°C 0°C to 70°C –40°C to 85°C
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
TEMPERATURE 0°C to 70°C –40°C to 85°C 0°C to 70°C 0°C to 70°C –40°C to 85°C 0°C to 70°C 0°C to 70°C –40°C to 85°C –40°C to 85°C/125°C –40°C to 125°C 0°C to 70°C 0°C to 70°C 0°C to 70°C ACCURACY (%) 0.075 0.10 0.10 0.10 0.125 0.15 0.25 0.25 0.20 0.20 0.20 0.40 0.50 TEMPERATURE COEFFICIENT (ppm/°C) 10 10 15 20 20 25 25 25 20/50 50 20 20 50 LT1460LHS8 LT1460MHS8 LT1460HCS3 LT1460JCS3 LT1460KCS3
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PACKAGE TYPE N8 LT1460ACN8 LT1460BIN8 LT1460DCN8 LT1460EIN8 S8 LT1460ACS8 LT1460BIS8 LT1460CCMS8 LT1460DCS8 LT1460EIS8 LT1460FCMS8 LT1460GCZ LT1460GIZ MS8 Z S3
LT1460 electrical characteristics
PARAMETER Output Voltage
The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VIN = VOUT + 2.5V, IOUT = 0 unless otherwise specified.
CONDITIONS LT1460ACN8-2.5, ACS8-2.5 LT1460BIN8-2.5, BIS8-2.5, CCMS8-2.5, DCN8-2.5, DCS8-2.5 LT1460EIN8-2.5, EIS8-2.5 LT1460FCMS8-2.5 LT1460GCZ-2.5, GIZ-2.5 LT1460LHS8-2.5, MHS8-2.5 LT1460ACN8-5, ACS8-5 LT1460BIN8-5, BIS8-5, CCMS8-5, DCN8-5, DCS8-5 LT1460EIN8-5, EIS8-5 LT1460FCMS8-5 LT1460GCZ-5, GIZ-5 LT1460LHS8-5, MHS8-5 LT1460ACN8-10, ACS8-10 LT1460BIN8-10, BIS8-10, CCMS8-10, DCN8-10, DCS8-10 LT1460EIN8-10, EIS8-10 LT1460FCMS8-10 LT1460GCZ-10, GIZ-10 LT1460HC LT1460JC LT1460KC Output Voltage Temperature Coefficient (Note 3) TMIN ≤ TJ ≤ TMAX LT1460ACN8, ACS8, BIN8, BIS8 LT1460CCMS8 LT1460DCN8, DCS8, EIN8, EIS8 LT1460FCMS8, GCZ, GIZ LT1460LHS8 –40°C to 85°C –40°C to 125°C LT1460MHS8 –40°C to 125°C LT1460HC LT1460JC LT1460KC
l l l l l l l l l l
MIN 2.49813 –0.075 2.4975 –0.10 2.49688 –0.125 2.49625 –0.15 2.49375 –0.25 2.495 –0.20 4.99625 –0.075 4.995 –0.10 4.99375 –0.125 4.9925 –0.15 4.9875 –0.25 4.990 –0.20 9.9925 –0.075 9.990 –0.10 9.9875 –0.125 9.985 –0.15 9.975 –0.25 –0.2 –0.4 –0.5
TYP
MAX 2.50188 0.075 2.5025 0.10 2.50313 0.125 2.50375 0.15 2.50625 0.25 2.505 0.20 5.00375 0.075 5.005 0.10 5.00625 0.125 5.0075 0.15 5.0125 0.25 5.010 0.20 10.0075 0.075 10.010 0.10 10.0125 0.125 10.0015 0.15 10.025 0.25 0.2 0.4 0.5
UNITS V % V % V % V % V % V % V % V % V % V % V % V % V % V % V % V % V % % % % ppm/°C ppm/°C ppm/°C ppm/°C ppm/°C ppm/°C ppm/°C ppm/°C ppm/°C ppm/°C
5 7 10 12 10 25 25 10 10 25
10 15 20 25 20 50 50 20 20 50
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LT1460
The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VIN = VOUT + 2.5V, IOUT = 0 unless otherwise specified.
PARAMETER Line Regulation LT1460A, LT1460B, LT1460C, LT1460D, LT1460E, LT1460F LT1460G, LT1460H, LT1460L, LT1460M , LT1460HC, LT1460JC, LT1460KC CONDITIONS VOUT + 0.9V ≤ VIN ≤ VOUT + 2.5V
l
electrical characteristics
MIN
TYP 30 10
MAX 60 80 25 35 800 1000 100 130 2800 3500 135 180 100 140 3000 4000 200 300 70 100 2.5
UNITS ppm/V ppm/V ppm/V ppm/V ppm/V ppm/V ppm/V ppm/V ppm/mA ppm/mA ppm/mA ppm/mA ppm/mA ppm/mA ppm/mA ppm/mA ppm/mA ppm/mA ppm/mA ppm/mA ppm/mW
VOUT + 2.5V ≤ VIN ≤ 20V
l
VOUT + 0.9V ≤ VIN ≤ VOUT + 2.5V
l
150 50
l
VOUT + 2.5V ≤ VIN ≤ 20V Load Regulation Sourcing (Note 4) LT1460A, LT1460B, LT1460C, LT1460D, LT1460E, LT1460F LT1460G, LT1460H, LT1460L, LT1460M , IOUT = 100µA
l
1500 80
l
IOUT = 10mA IOUT = 20mA 0°C to 70°C
70
l
LT1460HC, LT1460JC, LT1460KC
IOUT = 100µA
l
1000 50
l
IOUT = 10mA IOUT = 20mA
l
20 0.5
Thermal Regulation (Note 5) LT1460A, LT1460B, LT1460C, LT1460D, LT1460E, LT1460F LT1460G, LT1460H, LT1460L, LT1460M , LT1460HC, LT1460JC, LT1460KC Dropout Voltage (Note 6)
ΔP = 200mW
ΔP = 200mW VIN – VOUT, IOUT = 0 VIN – VOUT, IOUT = 10mA
l l
2.5
10 0.9 1.3 1.4
ppm/mW V V V mA µA µA µA µA µA µA µA µA µA µA µA µA µA µA µA µA µA
Output Current Reverse Leakage Supply Current
Short VOUT to GND VIN = –15V LT1460-2.5
l l
40 0.5 100 125
l
10 130 165 175 225 270 360 145 175 180 220 180 220 200 240 270 350
LT1460-5 LT1460-10
l
190 115
l
LT1460S3-2.5 LT1460S3-3
l
145 145
l
LT1460S3-3.3 LT1460S3-5
l
160 215
l
LT1460S3-10
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LT1460 electrical characteristics
PARAMETER Output Voltage Noise (Note 7) LT1460A, LT1460B, LT1460C, LT1460D, LT1460E, LT1460F LT1460G, LT1460H, LT1460L, LT1460M ,
The l denotes the specifications which apply over the full operating temperature range, otherwise specifications are at TA = 25°C. VIN = VOUT + 2.5V, IOUT = 0 unless otherwise specified.
CONDITIONS LT1460-2.5 LT1460-5 LT1460-10 LT1460HC, LT1460JC, LT1460KC 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 ΔT = 0°C to 70°C ΔT = –40°C to 85°C ΔT = 0°C to 70°C ΔT = –40°C to 85°C
l l
MIN 0.1Hz ≤ f ≤ 10Hz 10Hz ≤ f ≤ 1kHz 0.1Hz ≤ f ≤ 10Hz 10Hz ≤ f ≤ 1kHz 0.1Hz ≤ f ≤ 10Hz 10Hz ≤ f ≤ 1kHz
TYP 10 10 20 20 40 35 4 4 40 100 25 160 50 250
MAX
UNITS µVP-P µVRMS µVP-P µVRMS µVP-P µVRMS ppm (P-P) ppm (RMS) ppm/√kHr ppm/√kHr ppm ppm ppm ppm
0.1Hz ≤ f ≤ 10Hz 10Hz ≤ f ≤ 1kHz
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 25°C. 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, ΔVOUT ≤ 0.2%. For all other packages, ΔVOUT ≤ 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
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, 125°C 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 25°C, but the IC is cycled to 85°C or –40°C 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 85°C.
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LT1460 typical perForMance characteristics
LT1460-2.5 (N8, S8, MS8, Z Packages) 2.5V Minimum Input-Output Voltage Differential
100 OUTPUT VOLTAGE CHANGE (mV) 6 OUTPUT VOLTAGE CHANGE (mV) 5 4 3 2 1 0 –55°C 125°C
2.5V Load Regulation, Sourcing
80 70 60 50 40 30 20 10 0
2.5V Load Regulation, Sinking
OUTPUT CURRENT (mA)
125°C
10 –55°C 1 125°C 25°C
25°C
25°C
–55°C
0.1
0
0.5 1.0 1.5 2.0 INPUT-OUTPUT VOLTAGE (V)
2.5
1460 G01
0.1
1 10 OUTPUT CURRENT (mA)
100
1460 G02
0
1.0 0.5 OUTPUT CURRENT (mA)
1.5
1460 G03
2.5V Output Voltage Temperature Drift
2.503 3 TYPICAL PARTS 2.502 SUPPLY CURRENT (µA) OUTPUT VOLTAGE (V) 175 150 125 100 75 50 25 –25 0 25 50 TEMPERATURE (°C) 75 100
1460 G04
2.5V Supply Current vs Input Voltage
2.5014 125°C 25°C OUTPUT VOLTAGE (V) 2.5010 2.5006
2.5V Line Regulation
125°C
2.501
25°C 2.5002 2.4998 –55°C 2.4994 2.4990
2.500
–55°C
2.499
2.498 –50
0
0
5
10 INPUT VOLTAGE (V)
15
20
1460 G05
0
2
4
6 8 10 12 14 16 18 20 INPUT VOLTAGE (V)
1460 G06
2.5V Power Supply Rejection Ratio vs Frequency
90 POWER SUPPLY REJECTION RATIO (dB) 80 OUTPUT IMPEDANCE ( ) 70 60 50 40 30 20 10 0 –10 100 1k 10k 100k FREQUENCY (Hz) 1M
1460 G07
2.5V Output Impedance vs Frequency
1k CL= 0.1µF CL = 0 LOAD CAPACITANCE (µF) 10
2.5V Transient Responses
100
1
0.1
10
0 CL= 1µF IOUT = 10mA
1460 G09
1
10
100
1k 10k FREQUENCY (Hz)
100k
1M
1460 G08
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LT1460 typical perForMance characteristics
2.5V Output Voltage Noise Spectrum
1000
2.5V Output Noise 0.1Hz to 10Hz
2.5000
2.5V Long-Term Drift Three Typical Parts (S8 Package)
NOISE VOLTAGE (nV/√Hz)
OUTPUT NOISE (10µV/DIV)
2.4998 OUTPUT VOLTAGE (V)
2.4996
2.4994
2.4992
100 10 100 1k 10k FREQUENCY (Hz) 100k
1460 G10
0
1
2
3
456 TIME (SEC)
7
8
9
10
2.4990
0
200
600 400 TIME (HOURS)
800
1000
1460 G12
1460 G11
LT1460-5 (N8, S8, MS8, Z Packages) 5V Minimum Input-Output Voltage Differential
100 OUTPUT VOLTAGE CHANGE (mV) 6 OUTPUT VOLTAGE CHANGE (mV) 5 4 3 2 –55°C 1 0 125°C 25°C
5V Load Regulation, Sourcing
100 90 80 70 60 50 40 30 20 10 0.1 1 10 OUTPUT CURRENT (mA) 100
1460 G14
5V Load Regulation, Sinking
OUTPUT CURRENT (mA)
10
125°C
25°C
–55°C
25°C
1
–55°C
125°C
0.1
0
0.5 1.0 1.5 2.0 INPUT-OUTPUT VOLTAGE (V)
2.5
1460 G13
0
0
1
3 4 2 OUTPUT CURRENT (mA)
5
1460 G15
5V Output Voltage Temperature Drift
5.004 3 TYPICAL PARTS 5.002 SUPPLY CURRENT (µA) OUTPUT VOLTAGE (V) 200 180 160
5V Supply Current vs Input Voltage
5.002 125°C 5.000 OUTPUT VOLTAGE (V) 25°C –55°C
5V Line Regulation
25°C
140 120 100 80 60 40 20
5.000
4.998
125°C
4.998
4.996 –55°C
4.996
4.994
4.994 –50
–25
0 25 50 TEMPERATURE (°C)
75
100
1460 G16
0
0
2
4
6
8
10 12 14 16 18 20
1460 G17
4.992
0
2
4
INPUT VOLTAGE (V)
6 8 10 12 14 16 18 20 INPUT VOLTAGE (V)
1460 G18
1460fc
LT1460 typical perForMance characteristics
LT1460-5 (N8, S8, MS8, Z Packages) 5V Power Supply Rejection Ratio vs Frequency
90 POWER SUPPLY REJECTION RATIO (dB) 80 OUTPUT IMPEDANCE ( ) 70 60 50 40 30 20 10 0 100 1k 10k 100k FREQUENCY (Hz) 1M
1460 G19
5V Output Impedance vs Frequency
1k LOAD CAPACITANCE (µF) CL= 0.1µF 100 CL = 0 10
5V Transient Responses
1 0.1 0 0.2ms/DIV
1460 G21
10
1
CL= 1µF IOUT = 10mA
0.1
10
100
1k 10k FREQUENCY (Hz)
100k
1M
1460 G20
5V Output Voltage Noise Spectrum
3000 2000 1000 OUTPUT NOISE (10µV/DIV) NOISE VOLTAGE (nV/√Hz)
5V Output Noise 0.1Hz to 10Hz
100 10 100 1k 10k FREQUENCY (Hz) 100k
1460 G22
0
1
2
3
456 TIME (SEC)
7
8
9
10
1460 G23
LT1460-10 (N8, S8, MS8, Z Packages) 10V Minimum Input/Output Voltage Differential
100 OUTPUT VOLTAGE CHANGE (mV) 10 9 8 7 6 5 4 3 2 1 0.1 0 0.5 1.0 1.5 2.0 INPUT/OUTPUT VOLTAGE (V) 2.5
1460 G24
10V Load Regulation, Sourcing
100 90 OUTPUT VOLTAGE CHANGE (mV) 80 70 60 50 40 30 20 10 100
1460 G25
10V Load Regulation, Sinking
OUTPUT CURRENT (mA)
10
25°C –55°C 125°C
125°C
25°C
1
125°C
–55°C 25°C
–55°C
0 0.1
1 10 OUTPUT CURRENT (mA)
0
0
1
3 4 2 OUTPUT CURRENT (mA)
5
1460 G26
1460fc
0
LT1460 typical perForMance characteristics
10V Output Voltage Temperature Drift
10.006 10.002 SUPPLY CURRENT (µA) OUTPUT VOLTAGE (V) 9.998 9.994 9.990 9.986 9.982 –50 3 TYPICAL PARTS 400 360 320 280 240 200 160 120 80 40 –25 0 25 50 TEMPERATURE (°C) 75 100
1460 G27
10V Supply Current vs Input Voltage
10.004 10.000 OUTPUT VOLTAGE (V) –55°C 25°C 125°C 9.996 9.992 9.988 9.984 9.980
10V Line Regulation
25°C
–55°C 125°C
0
0
2
4
6 8 10 12 14 16 18 20 INPUT VOLTAGE (V)
1460 G28
6
8
14 16 10 12 INPUT VOLTAGE (V)
18
20
1460 G29
10V Power Supply Rejection Ratio vs Frequency
100 POWER SUPPLY REJECTION RATIO (dB) 90 80 70 60 50 40 30 20 10 0 0.1 10 100 1 INPUT FREQUENCY (kHz) 1000
1460 G30
10V Output Impedance vs Frequency
1000 LOAD CAPACITANCE (µF) CL = 0µF OUTPUT IMPEDANCE ( ) 100 CL = 0.1µF 10 CL = 1µF 1 10
10V Transient Responses
1 0.1 0 200µs/DIV
1460 G32
IOUT = 10mA 0.1 0.01 0.1 1 10 FREQUENCY (kHz) 100 1000
1460 G31
10V Output Voltage Noise Spectrum
10
10V Output Noise 0.1Hz to 10Hz
1
0.1 0.01
OUTPUT NOISE (50µV/DIV)
NOISE VOLTAGE (µV/√Hz)
0.1
1 10 FREQUENCY (kHz)
100
1460 G33
0
2
4
6 8 10 TIME (SEC)
12
14
1460 G34
1460fc
LT1460 typical perForMance characteristics
LT1460S3-2.5V Minimum InputOutput Voltage Differential
100 OUTPUT VOLTAGE CHANGE (mV) 0 OUTPUT VOLTAGE CHANGE (mV) –0.5 –1.0 –1.5 –2.0 –2.5 –3.0 –3.5 –4.0 0.1 1 10 OUTPUT CURRENT (mA) 100
1460 G36
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 Load Regulation, Sourcing
120 100 80 60 40 20 0 25°C
LT1460S3-2.5V Load Regulation, Sinking
OUTPUT CURRENT (mA)
10
125°C
–55°C
25°C 1 –55°C
25°C 125°C
125°C
–55°C
0.1
0
0.5 1.0 1.5 2.0 INPUT-OUTPUT VOLTAGE (V)
2.5
1460 G35
0
1
2 3 4 OUTPUT CURRENT (mA)
5
1460 G37
LT1460S3-2.5V Output Voltage Temperature Drift
2.503 2.502 SUPPLY CURRENT (µA) OUTPUT VOLTAGE (V) 2.501 2.500 2.499 2.498 2.497 –50 –25 THREE TYPICAL PARTS 250 200
LT1460S3-2.5V Supply Current vs Input Voltage
2.502 25°C OUTPUT VOLTAGE (V) 125°C –55°C 2.501 2.500 2.499 2.498 2.497 2.496 2.495 0 5 10 INPUT VOLTAGE (V) 15 20
1460 G39
LT1460S3-2.5V Line Regulation
25°C –55°C
150 100
125°C
50
50 25 75 0 TEMPERATURE (°C)
100
125
0
2.494
0
2
4
1460 G38
6 8 10 12 14 16 18 20 INPUT VOLTAGE (V)
1460 G40
LT1460S3-2.5V Power Supply Rejection Ratio vs Frequency
80 POWER SUPPLY REJECTION RATIO (dB) 70 OUTPUT IMPEDANCE ( ) 60 50 40 30 20 10 0 0.1 1 10 100 FREQUENCY (kHz) 1000
1460 G41
LT1460S3-2.5V Output Impedance vs Frequency
1000 CL = 0µF 100 CL = 0.1µF LOAD CURRENT (mA) 20 10
LT1460S3-2.5V Transient Response
10 CL = 1µF 1
1
0.1 200µs/DIV
1460 G43
CLOAD = 0µF 0.1 0.01 0.1 1 10 FREQUENCY (kHz) 100 1000
1460 G42
1460fc
LT1460 typical perForMance characteristics
LT1460S3-2.5V Output Voltage Noise Spectrum 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 Noise 0.1Hz to 10Hz
100
1000
LT1460S3-10V Minimum InputOutput Voltage Differential
NOISE VOLTAGE (nV/√Hz)
OUTPUT NOISE (20µV/DIV)
OUTPUT CURRENT (mA)
10
125°C
25°C 1 –55°C
100 10 100 1k 10k FREQUENCY (Hz) 100k
1460 G44
TIME (2 SEC/DIV)
1460 G45
0.1
0
0.5 1.0 1.5 2.0 INPUT-OUTPUT VOLTAGE (V)
2.5
1460 G46
LT1460S3-10V Load Regulation, Sourcing
35 OUTPUT VOLTAGE CHANGE (mV) OUTPUT VOLTAGE CHANGE (mV) 30 25 20 15 10 5 0 –5 –10 0.1 –55°C 125°C 25°C 100
1460 G47
LT1460S3-10V Load Regulation, Sinking
250 10.006 10.004 200 125°C 150 25°C 100 –55°C 50 10.002 OUTPUT VOLTAGE (V) 10.000 9.998 9.996 9.994 9.992 9.990 9.988 9.986 9.984 0 0 1 3 4 2 OUTPUT CURRENT (mA) 5
1460 G48
LT1460S3-10V Output Voltage Temperature Drift
THREE TYPICAL PARTS
1 10 OUTPUT CURRENT (mA)
9.982 –50
–25
50 0 75 25 TEMPERATURE (°C)
100
125
1460 G49
LT1460S3-10V Supply Current vs Input Voltage
350 300 SUPPLY CURRENT (µA) 25°C 250 200 150 100 50 0 0 6 8 10 12 14 16 18 20 INPUT VOLTAGE (V)
1460 G50
LT1460S3-10V Line Regulation
10.010 10.005 OUTPUT VOLTAGE (V) 10.000 9.995 9.990 9.985 9.980 25°C –55°C 125°C
125°C
–55°C
2
4
6
8
14 12 16 10 INPUT VOLTAGE (V)
18
20
1460 G51
1460fc
LT1460 typical perForMance characteristics
LT1460S3-10V Power Supply Rejection Ratio vs Frequency
1000 CL = 0µF OUTPUT IMPEDANCE ( ) 100 CL = 0.1µF 20 LOAD CURRENT (mA) 10
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 Output Impedance vs Frequency LT1460S3-10V Transient Response
100 POWER SUPPLY REJECTION RATIO (dB) 90 80 70 60 50 40 30 20 10
10 CL = 1µF
1
1
0.1 200µs/DIV
1460 G54
0 0.1
CLOAD = 0µF 1 10 100 FREQUENCY (kHz) 1000
1460 G52
0.1 0.01
0.1
1 10 FREQUENCY (kHz)
100
1000
1460 G53
LT1460S3-10V Output Voltage Noise Spectrum
10
LT1460S3-10V Output Noise 0.1Hz to 10Hz
1
0.1 0.01
0.1
1 10 FREQUENCY (kHz)
100
1460 G55
OUTPUT NOISE (20µV/DIV)
NOISE VOLTAGE (µV/√Hz)
TIME (2 SEC/DIV)
1460 G56
1460fc
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 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. Capacitive Loads 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 100µA 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 1µs for a 100µA pulse and to 0.1% in 1.5µs with a 1mA step. When load capacitance is greater than 0.01µF the refer, ence begins to ring due to the pole formed with the output impedance. Figure 3 shows the response of the reference to a 1mA and 100µA load current step with a 0.01µF load capacitor. The ringing can be greatly reduced with a DC load as small as 200µA. With large output capacitors, ≥1µF ,
VOUT CL RL VGEN 2.5V 1.5V
1460 F01
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 = 2Ω and
VGEN
2.5V 1.5V
VOUT
RL = 10k
VOUT
RL = 1k
1µs/DIV
1460 F02
Figure 2. CL = 0
VGEN
2.5V 1.5V
VOUT
RL = 10k
VOUT
RL = 1k
20µs/DIV
1460 F03
Figure 3. CL = 0.01µF
VOUT
VIN = 5V CIN 0.1µF
LT1460-2.5
RS
RL VGEN CL 2.5V 1.5V
1460 F04
Figure 4. Isolation Resistor Test Circuit
VGEN
2.5V 1.5V
VOUT
RL = 1k RS = 0 RL = 1k RS = 2
VIN = 5V CIN 0.1µF
LT1460-2.5
VOUT
0.1ms/DIV
1460 F05
Figure 1. Response Time Test Circuit
Figure 5. Effect of RS for CL = 1µF
1460fc
LT1460 applications inForMation
CL = 1µF 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 100µA 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 2µs for a 100µA pulse and to 0.1% in 3µs with a 1mA step. When load capacitance is greater than 0.01µF 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
VOUT CL RL VGEN 5V 4V
1460 F06
and 100µA load current step with a 0.01µF 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 100µA for RL = 1k or RL = 10k. Figure 10 shows the response of the reference with no load capacitance. The reference settles to 10mV (0.1%) in 0.4µs for a 100µA pulse and to 0.1% in 0.8µs with a 1mA step. When load capacitance is greater than 0.01µF 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 100µA load current step with a 0.01µF load capacitor.
VOUT CL RL VGEN 10V 9V
1460 F09
VIN = 5V CIN 0.1µF
LT1460-5
VIN = 12.5V CIN 0.1µF
LT1460-10
Figure 6. Response Time Test Circuit
Figure 9. Response Time Test Circuit
VGEN
5V 4V
VGEN
10V 9V
VOUT
RL = 10k
VOUT
RL = 10k
VOUT
RL = 1k
VOUT
RL = 1k
2µs/DIV
1460 F07
2µs/DIV
1460 F10
Figure 7. CL = 0
Figure 10. CL = 0
VGEN
5V 4V VGEN
10V 9V
VOUT
RL = 10k
VOUT
RL = 10k
VOUT
RL = 1k
VOUT
RL = 1k
10µs/DIV
1460 F08
10µs/DIV
1460 F11
Figure 8. CL = 0.01µF
Figure 11. CL = 0.01µF
1460fc
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 = 100Ω or RL = 1k. Figure 13 shows the response of the reference to these
VOUT CL RL VGEN 2.5V 1.5V
1460 F12
1mA and 10mA load steps with no load capacitance, and Figure 14 shows a 1mA and 10mA load step with a 0.1µF output capacitor. Figure 15 shows the response to a 1mA . load step with CL = 1µF and 4.7µF 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.
VIN = 2.5V CIN 0.1µF
LT1460S3-2.5
Figure 12. Response Time Test Circuit
VGEN
2.5V 1.5V
VOUT VGEN 2.5V 1.5V VOUT 1mA 100µs/DIV 10mA
1mA
VOUT
10mA
1460 F14
VOUT
Figure 14. CL = 0.1µF
1µs/DIV
1460 F13
Figure 13. CL = 0µF
VGEN
2.5V 1.5V
VOUT
1µA
VOUT
4.7µA
100µs/DIV
1460 F15
Figure 15. IOUT = 1mA
1460fc
LT1460 applications inForMation
Table 1. Maximum Output Capacitance for LT1460S3
VOLTAGE OPTION 2.5V 3V 3.3V 5V 10V IOUT = 100µA >10µF >10µF >10µF >10µF >10µF IOUT = 1mA >10µF >10µF >10µF >10µF 1µF IOUT = 10mA IOUT = 20mA 2µF 2µF 1µF 1µF 0.15µF 0.68µF 0.68µF 0.68µF 0.68µF 0.1µF
Hysteresis Hysteresis data shown in Figure 17 and Figure 18 represents the worst-case data taken on parts from 0°C to 70°C and from –40°C to 85°C. 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 325°C/W and this dissipation causes a 114°C internal rise producing a junction temperature of TJ = 25°C + 114°C = 139°C. 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 85°C.
18 16 14 NUMBER OF UNITS 12 10 8 6 4 2 70°C TO 25°C 0°C TO 25°C WORST-CASE HYSTERESIS ON 40 UNITS
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 = 30°C, their outputs were scanned regularly and measured with an 8.5 digit DVM. Figure 16 shows typical long-term drift of the LT1460S3s.
150 100 50 ppm 0 –50
0
40 –240 –200 –160 –120 –80 –40 0 HYSTERESIS (ppm)
80
120 160 200 240
1460 F17
Figure 17. 0°C to 70°C Hysteresis
9 8 7 NUMBER OF UNITS WORST-CASE HYSTERESIS ON 34 UNITS 85°C TO 25°C –40°C TO 25°C
–100 –150
6 5 4 3 2 1 0
0 100 200 300 400 500 600 700 800 900 1000 HOURS
1460 F16
Figure 16. Typical Long-Term Drift
–600 –500 –400 –300 –200 –100 0 100 200 300 400 500 600 HYSTERESIS (ppm)
1460 F18
Figure 18. –40°C to 85°C Hysteresis
1460fc
LT1460 applications inForMation
Input Capacitance It is recommended that a 0.1µF 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 75µV 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 100µA load and 0°C to 70°C temperature range: LT1460AC Initial accuracy = 0.075% For IO = 100µA, and using the LT1460-2.5 for calculation, 3500ppm ΔVOUT = 0.1mA 2.5V = 875µV mA Total worst-case output error is: 0.075% + 0.035% + 0.070% = 0.180%. Table 1 gives worst-case accuracy for the LT1460AC, CC, DC, FC, GC from 0°C to 70°C and the LT1460BI, EI, GI from –40°C to 85°C. 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 0.035%. For temperature 0°C to 70°C the maximum ΔT = 70°C, 10ppm ΔVOUT = 70°C 2.5V = 1.75mV °C
( )( )
which is 0.07%.
Table 2. Worst-Case Output Accuracy Over Temperature
IOUT 0 100µA 10mA 20mA LT1460AC 0.145% 0.180% 0.325% 0.425% LT1460BI 0.225% 0.260% 0.405% N/A LT1460CC 0.205% 0.240% 0.385% 0.485% LT1460DC 0.240% 0.275% 0.420% 0.520% LT1460EI 0.375% 0.410% 0.555% N/A
LT1460FC 0.325% 0.360% 0.505% 0.605%
LT1460GC 0.425% 0.460% 0.605% 0.705%
LT1460GI 0.562% 0.597% 0.742% N/A
LT1460HC 0.340% 0.380% 0.640% 0.540%
LT1460JC 0.540% 0.580% 0.840% 0.740%
LT1460KC 0.850% 0.890% 1.15% 1.05%
1460fc
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 125µV and
1 2 3 4
250µV 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. 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.
2 OUTPUT DEVIATION (mV)
1460 F19
Figure 19. Flexure Numbers
2 OUTPUT DEVIATION (mV)
1
1
0
LONG DIMENSION
0
LONG DIMENSION
–1
0
10
20 FLEXURE NUMBER
30
40
1460 F20a
–1
0
10
20 FLEXURE NUMBER
30
40
1460 F20b
Figure 20a. Two Typical LT1460S8-2.5s, Vertical Orientation Without Slots
2 OUTPUT DEVIATION (mV) OUTPUT DEVIATION (mV) 2
Figure 20b. Two Typical LT1460S8-2.5s, Horizontal Orientation Without Slots
1
1
0 SLOT –1
0 SLOT –1
0
10
20 FLEXURE NUMBER
30
40
1460 F21a
0
10
20 FLEXURE NUMBER
30
40
1460 F21b
Figure 21a. Same Two LT1460S8-2.5s in Figure 16a, but with Slots
Figure 21b. Same Two LT1460S8-2.5s in Figure 16b, but with Slots
1460fc
0
LT1460 siMpliFieD scheMatic
VCC
VOUT
GND
1460 SS
package Description
(Reference LTC DWG # 05-08-1631)
0.764 2.80 – 3.04 (.110 – .120) 0.8 ± 0.127
S3 Package 3-Lead Plastic SOT-23
2.74 0.96 BSC
2.10 – 2.64 (.083 – .104)
1.20 – 1.40 (.047 – .060)
1.92 RECOMMENDED SOLDER PAD LAYOUT
0.45 – 0.60 (.017 – .024) 0.89 – 1.03 (.035 – .041) 0.89 – 1.12 (.035 – .044)
0.37 – 0.51 (.015 – .020) 0.01 – 0.10 (.0004 – .004)
0.55 (.022) REF
NOTE: 1. CONTROLLING DIMENSION: MILLIMETERS MILLIMETERS 2. DIMENSIONS ARE IN (INCHES)
0.09 – 0.18 (.004 – .007)
1.78 – 2.05 (.070 – .081)
S3 SOT-23 0502
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
1460fc
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
.255 ± .015* (6.477 ± 0.381)
1 .300 – .325 (7.620 – 8.255)
2
3
4 .130 ± .005 (3.302 ± 0.127)
.045 – .065 (1.143 – 1.651)
.008 – .015 (0.203 – 0.381)
.065 (1.651) TYP
(
+.035 .325 –.015 8.255 +0.889 –0.381
)
.100 (2.54) BSC
.120 (3.048) .020 MIN (0.508) MIN .018 ± .003 (0.457 ± 0.076)
N8 1002
INCHES MILLIMETERS *THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .010 INCH (0.254mm)
NOTE: 1. DIMENSIONS ARE
S8 Package 8-Lead Plastic Small Outline (Narrow .150 Inch)
(Reference LTC DWG # 05-08-1610)
.045 ±.005
8 .189 – .197 (4.801 – 5.004) NOTE 3 7 6 5
.050 BSC
.245 MIN
.160 ±.005
.228 – .244 (5.791 – 6.197)
.150 – .157 (3.810 – 3.988) NOTE 3
.030 ±.005 TYP RECOMMENDED SOLDER PAD LAYOUT
.010 – .020 × 45° (0.254 – 0.508)
.008 – .010 (0.203 – 0.254) 0°– 8° TYP
1
2
3
4
.053 – .069 (1.346 – 1.752)
.004 – .010 (0.101 – 0.254)
.016 – .050 (0.406 – 1.270) NOTE: 1. DIMENSIONS IN
INCHES (MILLIMETERS) 2. DRAWING NOT TO SCALE 3. THESE DIMENSIONS DO NOT INCLUDE MOLD FLASH OR PROTRUSIONS. MOLD FLASH OR PROTRUSIONS SHALL NOT EXCEED .006" (0.15mm)
.014 – .019 (0.355 – 0.483) TYP
.050 (1.270) BSC
SO8 0303
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LT1460 package Description
(Reference LTC DWG # 05-08-1660 Rev F)
0.889 ± 0.127 (.035 ± .005)
MS8 Package 8-Lead Plastic MSOP
5.23 (.206) MIN
3.20 – 3.45 (.126 – .136) 3.00 ± 0.102 (.118 ± .004) (NOTE 3)
0.42 ± 0.038 (.0165 ± .0015) TYP
0.65 (.0256) BSC
8
7 65
0.52 (.0205) REF
RECOMMENDED SOLDER PAD LAYOUT
DETAIL “A” 4.90 ± 0.152 (.193 ± .006)
0.254 (.010)
GAUGE PLANE
3.00 ± 0.102 (.118 ± .004) (NOTE 4)
0° – 6° TYP
1 23 4
0.53 ± 0.152 (.021 ± .006)
DETAIL “A”
1.10 (.043) MAX
0.86 (.034) REF
0.18 (.007) SEATING PLANE 0.22 – 0.38 (.009 – .015) TYP 0.1016 ± 0.0508 (.004 ± .002)
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
0.65 (.0256) BSC
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LT1460 package Description
Z Package 3-Lead Plastic TO-92 (Similar to TO-226)
(Reference LTC DWG # 05-08-1410 Rev C)
.060 .005 (1.524 0.127) DIA .180 (4.572 .005 0.127) .90 (2.286) NOM
.180 (4.572
.005 0.127)
.500 (12.70) MIN
.050 UNCONTROLLED (1.270) LEAD DIMENSION MAX
5 NOM
.050 (1.27) BSC
.016 (0.406
.003 0.076)
.015 (0.381
.002 0.051)
Z3 (TO-92) 1008 REV C
BULK PACK .060 (1.524 .010 0.254)
.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
3
2
1
.140 (3.556
.010 0.127)
10 NOM
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LT1460 revision history
REV C DATE 3/10 DESCRIPTION Change θJA on S3 Package from 325°C/W to 228°C/W
(Revision history begins at Rev C)
PAGE NUMBER 2
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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.
LT1460 typical applications
Handling Higher Load Currents
V+ 40mA
+
47µF
IN LT1460 OUT GND 10mA
R1* VOUT 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
R1 =
V+ – VOUT 40mA
1460 TA03
Boosted Output Current with No Current Limit
V+ ≥ (VOUT + 1.8V) R1 220 2N2905 IN LT1460 OUT GND VOUT 100mA
Boosted Output Current with Current Limit
V+ ≥ VOUT + 2.8V D1* LED R1 220
+
+
8.2 2N2905
47µF
47µF
IN LT1460 OUT GND * GLOWS IN CURRENT LIMIT, DO NOT OMIT VOUT 100mA
+
2µF SOLID TANT
+
2µF SOLID TANT
1460 TA04
1460 TA05
relateD parts
PART NUMBER DESCRIPTION LT1019 LT1027 LT1236 LT1461 LT1634 LT1790 LTC®1798 LTC6652 LT6660 Precision Bandgap Reference Precision 5V Reference Precision Low Noise Reference Micropower Precision Low Dropout Micropower Precision Shunt Reference 1.25V, 2.5V Output Micropower Precision Series References Micropower Low Dropout Reference, Fixed or Adjustable Low Drift Low Noise Buffered Reference Tiny Micropower Precision Series References COMMENTS 0.05% Max, 5ppm/°C Max 0.02%, 2ppm/°C Max 0.05% Max, 5ppm/°C Max, SO Package 0.04% Max, 3ppm/°C Max, 50mA Output Current 0.05%, 25ppm/°C Max 0.05% Max, 10ppm/°C Max, 60µA Supply, SOT23 Package 0.15% Max, 40ppm/°C, 6.5µA Max Supply Current 0.05% Accuracy, 5ppm/°C Drift, 2.1ppm (0.1Hz to 10Hz) Noise 0.075% Max, 10ppm/°C Max, 20mA Output, 2mm × 2mm DFN Package
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Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507
●
LT 0310 REV C • PRINTED IN USA
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LINEAR TECHNOLOGY CORPORATION 2006
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