Datasheet

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LT1460

1460fc

Description

Features

app

lications

typical application

OUTPUT VOLTAGE ERROR (%)

–0.10

UNITS (%)

–0.06

–0.02 0

1460 TA02

0.060.02

0.10

1400 PARTS

FROM 2 RUNS

Micropower Precision

Series Reference Family

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.

Handheld Instruments

Precision Regulators

A/D and D/A Converters

Power Supplies

Hard Disk Drives

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

Basic Connection

Typical Distribution of Output Voltage

S8 Package

LT1460-2.5

GND

IN OUT

1460 TA01

0.1µF

2.5V

3.4V

TO 20V

Summary of content (26 pages)

PAGE 1
LT1460 Micropower Precision Series Reference Family Features n n n n n n n n n n Description 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.
PAGE 2
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)..
PAGE 3
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 0°C to 70°C LT1460JCS3-2.5#TRMPBF LT1460JCS3-2.5#TRPBF LTAD or LTH8† 3-Lead Plastic SOT-23 0°C to 70°C LT1460KCS3-2.5#TRMPBF LT1460KCS3-2.
PAGE 4
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 0°C to 70°C LT1460EIS8-5#PBF LT1460EIS8-5#TRPBF 460EI5 8-Lead Plastic SO –40°C to 85°C LT1460LHS8-5#PBF LT1460LHS8-5#TRPBF 460LH5 8-Lead Plastic SO 0°C to 70°C LT1460MHS8-5#PBF LT1460MHS8-5#TRPBF 460MH5 8-Lead Plastic SO –40°C to 85°C LT1460ACS8-10#PBF LT1460ACS8-10#TRPBF 1460A1 8-Lead Plastic SO 0°C to
PAGE 5
LT1460 Electrical Characteristics 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 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.
PAGE 6
LT1460 Electrical Characteristics 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 CONDITIONS Line Regulation LT1460A, LT1460B, LT1460C, LT1460D, LT1460E, LT1460F, LT1460G, LT1460H, LT1460L, LT1460M VOUT + 0.9V ≤ VIN ≤ VOUT + 2.
PAGE 7
LT1460 Electrical Characteristics 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 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 µVP-P µVRMS LT1460-5 0.1Hz ≤ f ≤ 10Hz 10Hz ≤ f ≤ 1kHz 20 20 µVP-P µVRMS LT1460-10 0.
PAGE 8
LT1460 Typical Performance Characteristics LT1460-2.5 (N8, S8, MS8, Z Packages) 2.5V Minimum Input-Output Voltage Differential 2.5V Load Regulation, Sourcing –55°C 25°C 125°C 0.5 1.0 1.5 2.0 INPUT-OUTPUT VOLTAGE (V) 0 5 4 3 25°C 2 –55°C 1 0 2.5 125°C 0.1 1 10 OUTPUT CURRENT (mA) 2.5V Output Voltage Temperature Drift 2.503 125°C 75 125 25°C 100 –55°C 75 50 1.0 0.5 OUTPUT CURRENT (mA) 0 0 100 0 5 10 20 15 INPUT VOLTAGE (V) 2.
PAGE 9
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 (10µV/DIV) 2.4998 100 0 100k 1k 10k FREQUENCY (Hz) 2.4994 2.4992 100 10 2.4996 1 2 3 4 5 6 TIME (SEC) 7 8 9 2.
PAGE 10
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= 0.1µF OUTPUT IMPEDANCE (Ω) 70 60 50 40 30 20 LOAD CAPACITANCE (µF) POWER SUPPLY REJECTION RATIO (dB) 90 100 10 1 10 1 0.1 0 CL= 1µF 10 0 100 1k 10k 100k FREQUENCY (Hz) 0.1 1M 10 100 1460 G19 1k 10k FREQUENCY (Hz) 100k 1460 G21 0.
PAGE 11
LT1460 Typical Performance Characteristics 10V Output Voltage Temperature Drift 3 TYPICAL PARTS 360 10.000 320 SUPPLY CURRENT (µA) OUTPUT VOLTAGE (V) 10.002 9.998 9.994 9.990 10V Line Regulation 10.004 400 –55°C 280 240 OUTPUT VOLTAGE (V) 10.006 10V Supply Current vs Input Voltage 25°C 200 125°C 160 120 80 9.986 25°C 9.996 –55°C 9.992 125°C 9.988 9.
PAGE 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 Minimum InputOutput Voltage Differential LT1460S3-2.5V Load Regulation, Sourcing 0 125°C 25°C –55°C 1 0.5 1.0 1.5 2.0 INPUT-OUTPUT VOLTAGE (V) 0 –0.
PAGE 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. LT1460S3-2.5V Output Voltage Noise Spectrum 1000 LT1460S3-2.5V Output Noise 0.
PAGE 14
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.
PAGE 15
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.
PAGE 16
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.
PAGE 17
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.
PAGE 18
LT1460 Applications Information Hysteresis VOLTAGE OPTION IOUT = 100µA IOUT = 1mA 2.5V >10µF >10µF 2µF 0.68µF 3V >10µF >10µF 2µF 0.68µF 3.3V >10µF >10µF 1µF 0.68µF 5V >10µF >10µF 1µF 0.68µF 10V >10µF 1µF 0.15µF 0.1µF IOUT = 10mA IOUT = 20mA Long-Term Drift Long-term drift cannot be extrapolated from accelerated high temperature testing. This erroneous technique gives drift numbers that are wildly optimistic.
PAGE 19
LT1460 Applications Information Input Capacitance Total worst-case output error is: 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.
PAGE 20
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.
PAGE 21
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 NOTE: 1. CONTROLLING DIMENSION: MILLIMETERS MILLIMETERS 2. DIMENSIONS ARE IN (INCHES) 0.09 – 0.
PAGE 22
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.
PAGE 23
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) 3.00 ± 0.102 (.118 ± .004) (NOTE 3) 0.65 (.0256) BSC 0.42 ± 0.038 (.0165 ± .0015) TYP 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 0.53 ± 0.152 (.021 ± .006) DETAIL “A” 1 2 3 4 1.10 (.043) MAX 0.86 (.
PAGE 24
LT1460 Package Description 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 (1.27) BSC .050 UNCONTROLLED (1.270) LEAD DIMENSION MAX .016 p .003 (0.406 p 0.076) 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.
PAGE 25
LT1460 Revision History (Revision history begins at Rev C) REV DATE DESCRIPTION PAGE NUMBER C 3/10 Change θJA on S3 Package from 325°C/W to 228°C/W 2 1460fc 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.
PAGE 26
LT1460 Typical Applications Handling Higher Load Currents V+ + 47µF 40mA 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.