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: 0.9V
Available in S0-8, MSOP-8, PDIP-8, TO-92 and
SOT- 23 Package
Applications
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Handheld Instruments
Precision Regulators
A/D and D/A Converters
Power Supplies
Hard Disk Drives
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.
Typical Application
Typical Distribution of Output Voltage
S8 Package
Basic Connection
20
LT1460-2.5
IN
C1
0.1µF
OUT
18
2.5V
16
GND
1400 PARTS
FROM 2 RUNS
14
1460 TA01
UNITS (%)
3.4V
TO 20V
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
1460fc
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
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 = 150°C, θJA = 130°C/W
*CONNECTED INTERNALLY.
DO NOT CONNECT EXTERNAL CIRCUITRY TO THESE PINS
TJMAX = 150°C, θJA = 190°C/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 = 150°C, θJA = 250°C/W
Z PACKAGE
3-LEAD TO-92 PLASTIC
TJMAX = 150°C, θJA = 160°C/W
1460fc
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
LT1460KCS3-2.5#TRPBF
LTAE or LTH8†
3-Lead Plastic SOT-23
0°C to 70°C
LT1460HCS3-3#TRMPBF
LT1460HCS3-3#TRPBF
LTAN or LTH9†
3-Lead Plastic SOT-23
0°C to 70°C
LT1460JCS3-3#TRMPBF
LT1460JCS3-3#TRPBF
LTAP or LTH9†
3-Lead Plastic SOT-23
0°C to 70°C
LT1460KCS3-3#TRMPBF
LT1460KCS3-3#TRPBF
LTAQ or LTH9†
3-Lead Plastic SOT-23
0°C to 70°C
LT1460HCS3-3.3#TRMPBF
LT1460HCS3-3.3#TRPBF
LTAR or LTJ1†
3-Lead Plastic SOT-23
0°C to 70°C
LT1460JCS3-3.3#TRMPBF
LT1460JCS3-3.3#TRPBF
LTAS or LTJ1†
3-Lead Plastic SOT-23
0°C to 70°C
LT1460KCS3-3.3#TRMPBF
LT1460KCS3-3.3#TRPBF
LTAT or LTJ1†
3-Lead Plastic SOT-23
0°C to 70°C
LT1460HCS3-5#TRMPBF
LT1460HCS3-5#TRPBF
LTAK or LTJ2†
3-Lead Plastic SOT-23
0°C to 70°C
LT1460JCS3-5#TRMPBF
LT1460JCS3-5#TRPBF
LTAL or LTJ2†
3-Lead Plastic SOT-23
0°C to 70°C
LT1460KCS3-5#TRMPBF
LT1460KCS3-5#TRPBF
LTAM or LTJ2†
3-Lead Plastic SOT-23
0°C to 70°C
LT1460HCS3-10#TRMPBF
LT1460HCS3-10#TRPBF
LTAU or LTJ3†
3-Lead Plastic SOT-23
0°C to 70°C
LT1460JCS3-10#TRMPBF
LT1460JCS3-10#TRPBF
LTAV or LTJ3†
3-Lead Plastic SOT-23
0°C to 70°C
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/
0°C to 70°C
LEAD FREE FINISH
TAPE AND REEL
PACKAGE DESCRIPTION
SPECIFIED TEMPERATURE RANGE
LT1460ACN8-2.5#PBF
LT1460ACN8-2.5#TRPBF
8-Lead Plastic DIP
0°C to 70°C
LT1460BIN8-2.5#PBF
LT1460BIN8-2.5#TRPBF
8-Lead Plastic DIP
–40°C to 85°C
LT1460DCN8-2.5#PBF
LT1460DCN8-2.5#TRPBF
8-Lead Plastic DIP
0°C to 70°C
LT1460EIN8-2.5#PBF
LT1460EIN8-2.5#TRPBF
8-Lead Plastic DIP
–40°C to 85°C
LT1460ACN8-5#PBF
LT1460ACN8-5#TRPBF
8-Lead Plastic DIP
0°C to 70°C
LT1460BIN8-5#PBF
LT1460BIN8-5#TRPBF
8-Lead Plastic DIP
–40°C to 85°C
LT1460DCN8-5#PBF
LT1460DCN8-5#TRPBF
8-Lead Plastic DIP
0°C to 70°C
LT1460EIN8-5#PBF
LT1460EIN8-5#TRPBF
8-Lead Plastic DIP
–40°C to 85°C
LT1460ACN8-10#PBF
LT1460ACN8-10#TRPBF
8-Lead Plastic DIP
0°C to 70°C
LT1460BIN8-10#PBF
LT1460BIN8-10#TRPBF
8-Lead Plastic DIP
–40°C to 85°C
LT1460DCN8-10#PBF
LT1460DCN8-10#TRPBF
8-Lead Plastic DIP
0°C to 70°C
LT1460EIN8-10#PBF
LT1460EIN8-10#TRPBF
8-Lead Plastic DIP
–40°C to 85°C
LT1460ACS8-2.5#PBF
LT1460ACS8-2.5#TRPBF
1460A2
8-Lead Plastic SO
0°C to 70°C
LT1460BIS8-2.5#PBF
LT1460BIS8-2.5#TRPBF
460BI2
8-Lead Plastic SO
–40°C to 85°C
LT1460DCS8-2.5#PBF
LT1460DCS8-2.5#TRPBF
1460D2
8-Lead Plastic SO
0°C to 70°C
LT1460EIS8-2.5#PBF
LT1460EIS8-2.5#TRPBF
460EI2
8-Lead Plastic SO
–40°C to 85°C
LT1460LHS8-2.5#PBF
LT1460LHS8-2.5#TRPBF
60LH25
8-Lead Plastic SO
0°C to 70°C
LT1460MHS8-2.5#PBF
LT1460MHS8-2.5#TRPBF
60MH25
8-Lead Plastic SO
–40°C to 85°C
LT1460ACS8-5#PBF
LT1460ACS8-5#TRPBF
1460A5
8-Lead Plastic SO
0°C to 70°C
LT1460BIS8-5#PBF
LT1460BIS8-5#TRPBF
460BI5
8-Lead Plastic SO
–40°C to 85°C
PART MARKING
1460fc
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 70°C
LT1460BIS8-10#PBF
LT1460BIS8-10#TRPBF
460BI1
8-Lead Plastic SO
–40°C to 85°C
LT1460DCS8-10#PBF
LT1460DCS8-10#TRPBF
1460D1
8-Lead Plastic SO
0°C to 70°C
LT1460EIS8-10#PBF
LT1460EIS8-10#TRPBF
460EI1
8-Lead Plastic SO
–40°C to 85°C
LT1460CCMS8-2.5#PBF
LT1460CCMS8-2.5#TRPBF
LTAA
8-Lead Plastic MSOP
0°C to 70°C
LT1460FCMS8-2.5#PBF
LT1460FCMS8-2.5#TRPBF
LTAB
8-Lead Plastic MSOP
0°C to 70°C
LT1460CCMS8-5#PBF
LT1460CCMS8-5#TRPBF
LTAF
8-Lead Plastic MSOP
0°C to 70°C
LT1460FCMS8-5#PBF
LT1460FCMS8-5#TRPBF
LTAG
8-Lead Plastic MSOP
0°C to 70°C
LT1460CCMS8-10#PBF
LT1460CCMS8-10#TRPBF
LTAH
8-Lead Plastic MSOP
0°C to 70°C
LT1460FCMS8-10#PBF
LT1460FCMS8-10#TRPBF
LTAJ
8-Lead Plastic MSOP
0°C to 70°C
LT1460GCZ-2.5#PBF
LT1460GCZ-2.5#TRPBF
3-Lead Plastic TO-92
0°C to 70°C
LT1460GIZ-2.5#PBF
LT1460GIZ-2.5#TRPBF
3-Lead Plastic TO-92
–40°C to 85°C
LT1460GCZ-5#PBF
LT1460GCZ-5#TRPBF
3-Lead Plastic TO-92
0°C to 70°C
LT1460GIZ-5#PBF
LT1460GIZ-5#TRPBF
3-Lead Plastic TO-92
–40°C to 85°C
LT1460GCZ-10#PBF
LT1460GCZ-10#TRPBF
3-Lead Plastic TO-92
0°C to 70°C
LT1460GIZ-10#PBF
LT1460GIZ-10#TRPBF
3-Lead Plastic TO-92
–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
ACCURACY
(%)
TEMPERATURE
COEFFICIENT
(ppm/°C)
N8
S8
0°C to 70°C
0.075
10
LT1460ACN8
LT1460ACS8
–40°C to 85°C
0.10
10
LT1460BIN8
LT1460BIS8
0°C to 70°C
0.10
15
0°C to 70°C
0.10
20
LT1460DCN8
LT1460DCS8
–40°C to 85°C
0.125
20
LT1460EIN8
LT1460EIS8
0°C to 70°C
0.15
25
0°C to 70°C
0.25
25
LT1460GCZ
–40°C to 85°C
0.25
25
LT1460GIZ
–40°C to 85°C/125°C
0.20
20/50
LT1460LHS8
–40°C to 125°C
0.20
50
LT1460MHS8
0°C to 70°C
0.20
20
0°C to 70°C
0.40
20
LT1460JCS3
0°C to 70°C
0.50
50
LT1460KCS3
TEMPERATURE
PACKAGE TYPE
MS8
Z
S3
LT1460CCMS8
LT1460FCMS8
LT1460HCS3
1460fc
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
–0.15
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
–40°C to 85°C
–40°C to 125°C
LT1460MHS8 –40°C to 125°C
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
1460fc
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 + 2.5V
MIN
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
ΔP = 200mW
0.5
2.5
ppm/mW
ΔP = 200mW
2.5
10
ppm/mW
l
0.9
V
l
1.3
1.4
V
V
l
VOUT + 2.5V ≤ VIN ≤ 20V
l
LT1460HC, LT1460JC, LT1460KC
VOUT + 0.9V ≤ VIN ≤ VOUT + 2.5V
l
VOUT + 2.5V ≤ VIN ≤ 20V
l
Load Regulation Sourcing (Note 4)
LT1460A, LT1460B, LT1460C, LT1460D, LT1460E,
LT1460F, LT1460G, LT1460H, LT1460L, LT1460M
IOUT = 100µA
l
IOUT = 10mA
l
IOUT = 20mA
0°C to 70°C
LT1460HC, LT1460JC, LT1460KC
l
IOUT = 100µA
l
IOUT = 10mA
l
IOUT = 20mA
l
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
40
l
10
µA
100
130
165
µA
µA
125
175
225
µA
µA
190
270
360
µA
µA
115
145
175
µA
µA
145
180
220
µA
µA
145
180
220
µA
µA
160
200
240
µA
µA
215
270
350
µA
µA
l
LT1460-5
l
LT1460-10
l
LT1460S3-2.5
l
LT1460S3-3
l
LT1460S3-3.3
l
LT1460S3-5
l
LT1460S3-10
l
mA
0.5
1460fc
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
0.1Hz ≤ f ≤ 10Hz
10Hz ≤ f ≤ 1kHz
40
35
µVP-P
µVRMS
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
ΔT = 0°C to 70°C
ΔT = –40°C to 85°C
ΔT = 0°C to 70°C
ΔT = –40°C to 85°C
Note 1: Stresses beyond those listed under Absolute Maximum Ratings
may cause permanent damage to the device. Exposure to any Absolute
Maximum Rating condition for extended periods may affect device
reliability and lifetime.
Note 2: If the 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
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, 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.
1460fc
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)
2.5V Power Supply Rejection
Ratio vs Frequency
125°C
2.5006
25°C
2.5002
2.4998
–55°C
2.4990
0
2
4
1460 G05
6 8 10 12 14 16 18 20
INPUT VOLTAGE (V)
1460 G06
2.5V Output Impedance vs
Frequency
90
1.5
2.4994
1460 G04
POWER SUPPLY REJECTION RATIO (dB)
–55°C
10
2.5010
25
2.5V Transient Responses
1k
CL= 0.1µF
80
OUTPUT IMPEDANCE (Ω)
70
60
50
40
30
20
10
CL = 0
100
10
10k
100k
FREQUENCY (Hz)
1M
1460 G07
1
1
0.1
IOUT = 10mA
CL= 1µF
1k
10
0
0
–10
100
20
2.5V Line Regulation
OUTPUT VOLTAGE (V)
SUPPLY CURRENT (µA)
OUTPUT VOLTAGE (V)
2.499
0
25
50
TEMPERATURE (°C)
30
2.5014
150
2.502
2.500
25°C
40
1460 G03
175
3 TYPICAL PARTS
–25
50
2.5V Supply Current vs Input
Voltage
2.501
125°C
60
1460 G02
1460 G01
2.498
–50
70
0
100
LOAD CAPACITANCE (µF)
1
80
OUTPUT VOLTAGE CHANGE (mV)
10
0.1
2.5V Load Regulation, Sinking
6
OUTPUT VOLTAGE CHANGE (mV)
OUTPUT CURRENT (mA)
100
10
100
1k
10k
FREQUENCY (Hz)
100k
1460 G09
1M
1460 G08
1460fc
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
2.4990
10
200
0
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
25°C
–55°C
1
0.5
1.0
1.5
2.0
INPUT-OUTPUT VOLTAGE (V)
0
90
5
4
125°C
3
25°C
2
–55°C
1
0
2.5
100
80
70
60
40
30
0.1
1
10
OUTPUT CURRENT (mA)
0
100
5.004
1
3
4
2
OUTPUT CURRENT (mA)
3 TYPICAL PARTS
5.002
125°C
180
25°C
160
5.000
25°C
140
120
OUTPUT VOLTAGE (V)
SUPPLY CURRENT (µA)
5.002
5
5V Line Regulation
200
–55°C
100
80
60
40
4.996
0
1460 G15
5V Supply Current vs Input
Voltage
4.998
125°C
20
1460 G14
5V Output Voltage
Temperature Drift
5.000
25°C
–55°C
50
10
1460 G13
OUTPUT VOLTAGE (V)
OUTPUT VOLTAGE CHANGE (mV)
OUTPUT VOLTAGE CHANGE (mV)
OUTPUT CURRENT (mA)
125°C
10
0.1
5V Load Regulation, Sinking
6
100
125°C
4.998
4.996
–55°C
4.994
20
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
INPUT VOLTAGE (V)
1460 G17
4.992
0
2
4
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
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
0.2ms/DIV
IOUT = 10mA
1M
1460 G20
5V Output Voltage Noise
Spectrum
5V Output Noise 0.1Hz to 10Hz
3000
NOISE VOLTAGE (nV/√Hz)
OUTPUT NOISE (10µV/DIV)
2000
1000
100
10
100
1k
10k
FREQUENCY (Hz)
0
100k
1
2
3
1460 G22
4 5 6
TIME (SEC)
7
8
9
10
1460 G23
LT1460-10 (N8, S8, MS8, Z Packages)
10V Minimum Input/Output
Voltage Differential
10V Load Regulation, Sourcing
10
125°C
1
–55°C
25°C
100
9
90
8
7
6
5
0
0.5
1.0
1.5
2.0
INPUT/OUTPUT VOLTAGE (V)
2.5
1460 G24
125°C
25°C
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
–55°C
1
10
OUTPUT CURRENT (mA)
80
70
25°C
60
–55°C
50
125°C
40
30
20
10
100
1460 G25
0
0
1
3
4
2
OUTPUT CURRENT (mA)
5
1460 G26
1460fc
10
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
9.984
40
–25
0
25
50
TEMPERATURE (°C)
75
0
100
0
2
4
6 8 10 12 14 16 18 20
INPUT VOLTAGE (V)
10V Power Supply Rejection
Ratio vs Frequency
14
16
10
12
INPUT VOLTAGE (V)
8
18
20
1460 G29
10V Output Impedance vs
Frequency
100
10V Transient Responses
1000
90
CL = 0µF
OUTPUT IMPEDANCE (Ω)
80
70
60
50
40
30
20
100
CL = 0.1µF
10
CL = 1µF
1
10
10
1
0.1
0
200µs/DIV
IOUT = 10mA
10
100
1
INPUT FREQUENCY (kHz)
1000
0.1
0.01
0.1
1460 G30
1
10
FREQUENCY (kHz)
100
1460 G32
1000
1460 G31
10V Output Voltage Noise
Spectrum
10V Output Noise 0.1Hz to 10Hz
OUTPUT NOISE (50µV/DIV)
10
NOISE VOLTAGE (µV/√Hz)
POWER SUPPLY REJECTION RATIO (dB)
6
1460 G28
1460 G27
0
0.1
9.980
LOAD CAPACITANCE (µF)
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
1460fc
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
125°C
25°C
–55°C
1
0.5
1.0
1.5
2.0
INPUT-OUTPUT VOLTAGE (V)
0
–0.5
–1.0
–55°C
–1.5
–2.0
25°C
–2.5
125°C
–3.0
–3.5
–4.0
0.1
2.5
1
10
OUTPUT CURRENT (mA)
SUPPLY CURRENT (µA)
OUTPUT VOLTAGE (V)
2.500
2.499
50
25
75
0
TEMPERATURE (°C)
100
–55°C
100
0
125
0
1
5
2
3
4
OUTPUT CURRENT (mA)
25°C
2.500
–55°C
2.499
2.498
125°C
2.497
2.496
2.495
5
0
10
15
INPUT VOLTAGE (V)
1460 G38
20
2.494
0
2
4
6 8 10 12 14 16 18 20
INPUT VOLTAGE (V)
1460 G40
1460 G39
LT1460S3-2.5V Output Impedance
vs Frequency
80
LT1460S3-2.5V Transient
Response
1000
CL = 0µF
70
60
OUTPUT IMPEDANCE (Ω)
POWER SUPPLY REJECTION RATIO (dB)
125°C
150
LT1460S3-2.5V Power Supply
Rejection Ratio vs Frequency
50
40
30
20
20
CL = 0.1µF
100
10
CL = 1µF
10
1
0.1
1
10
0
0.1
20
2.501
50
2.498
–55°C
LT1460S3-2.5V Line Regulation
25°C
200
2.501
125°C
2.502
250
2.502
25°C
40
LT1460S3-2.5V Supply Current
vs Input Voltage
THREE TYPICAL PARTS
2.497
–50 –25
60
1460 G37
LOAD CURRENT (mA)
2.503
80
1460 G36
1460 G35
LT1460S3-2.5V Output Voltage
Temperature Drift
100
0
100
OUTPUT VOLTAGE (V)
10
120
OUTPUT VOLTAGE CHANGE (mV)
OUTPUT VOLTAGE CHANGE (mV)
OUTPUT CURRENT (mA)
100
0.1
LT1460S3-2.5V Load Regulation,
Sinking
CLOAD = 0µF
1
10
100
FREQUENCY (kHz)
1000
1460 G41
0.1
0.01
0.1
1
10
FREQUENCY (kHz)
100
200µs/DIV
1460 G43
1000
1460 G42
1460fc
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
1000
LT1460S3-2.5V Output Noise
0.1Hz to 10Hz
LT1460S3-10V Minimum InputOutput Voltage Differential
OUTPUT CURRENT (mA)
NOISE VOLTAGE (nV/√Hz)
OUTPUT NOISE (20µV/DIV)
100
100
10
100
25°C
–55°C
1
0.1
TIME (2 SEC/DIV)
100k
1k
10k
FREQUENCY (Hz)
125°C
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
–55°C
0
–5
125°C
150
25°C
100
–55°C
50
9.998
9.996
9.994
9.992
9.990
9.988
9.986
9.984
100
0
0
1
3
4
2
OUTPUT CURRENT (mA)
5
9.982
–50
–25
50
0
75
25
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
250
125°C
200
–55°C
150
100
OUTPUT VOLTAGE (V)
10.005
25°C
25°C
10.000
–55°C
9.995
125°C
9.990
9.985
50
0
10.000
125°C
25°C
1
10
OUTPUT CURRENT (mA)
THREE TYPICAL PARTS
10.002
200
OUTPUT VOLTAGE (V)
OUTPUT VOLTAGE CHANGE (mV)
20
SUPPLY CURRENT (µA)
OUTPUT VOLTAGE CHANGE (mV)
10.006
10.004
25
–10
0.1
LT1460S3-10V Output Voltage
Temperature Drift
250
35
30
2.5
0
2
4
6 8 10 12 14 16 18 20
INPUT VOLTAGE (V)
1460 G50
9.980
6
8
14
12
16
10
INPUT VOLTAGE (V)
18
20
1460 G51
1460fc
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 Output Impedance
vs Frequency
LT1460S3-10V Transient
Response
1000
90
20
70
60
50
40
30
20
100
LOAD CURRENT (mA)
CL = 0µF
80
OUTPUT IMPEDANCE (Ω)
POWER SUPPLY REJECTION RATIO (dB)
100
LT1460S3-10V Power Supply
Rejection Ratio vs Frequency
CL = 0.1µF
10
CL = 1µF
1
1
0.1
10
0
0.1
10
CLOAD = 0µF
1
10
100
FREQUENCY (kHz)
1000
0.1
0.01
0.1
1460 G52
1
10
FREQUENCY (kHz)
100
200µs/DIV
1460 G54
1000
1460 G53
LT1460S3-10V Output Voltage
Noise Spectrum
LT1460S3-10V Output Noise
0.1Hz to 10Hz
OUTPUT NOISE (20µV/DIV)
NOISE VOLTAGE (µV/√Hz)
10
1
0.1
0.01
0.1
1
10
FREQUENCY (kHz)
100
TIME (2 SEC/DIV)
1460 G56
1460 G55
1460fc
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 = 2Ω and
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.
RL = 10k
VOUT
RL = 1k
1460 F02
Figure 2. CL = 0
2.5V
VGEN
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 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 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 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,
CIN
0.1µF
VOUT
1µs/DIV
Capacitive Loads
VIN = 5V
2.5V
VGEN
LT1460-2.5
RL
VOUT
VGEN
CL
RL = 10k
VOUT
RL = 1k
1460 F03
20µs/DIV
Figure 3. CL = 0.01µF
VIN = 5V
LT1460-2.5
RS
VOUT
RL
VGEN
CIN
0.1µF
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 = 2Ω
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 = 1µF
1460fc
15
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
VIN = 5V
LT1460-5
RL
VOUT
CIN
0.1µF
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.
VIN = 12.5V
VGEN
5V
4V
CL
LT1460-10
RL
VOUT
CIN
0.1µF
VGEN
1460 F09
1460 F06
Figure 9. Response Time Test Circuit
Figure 6. Response Time Test Circuit
5V
VGEN
10V
VGEN
4V
VOUT
RL = 10k
VOUT
RL = 1k
2µs/DIV
9V
VOUT
RL = 10k
VOUT
1460 F07
RL = 1k
2µs/DIV
Figure 7. CL = 0
1460 F10
Figure 10. CL = 0
VGEN
10V
5V
4V
VOUT
RL = 10k
VOUT
RL = 1k
10µs/DIV
Figure 8. CL = 0.01µF
10V
9V
CL
1460 F08
VGEN
9V
VOUT
RL = 10k
RL = 1k
VOUT
10µs/DIV
1460 F11
Figure 11. CL = 0.01µF
1460fc
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 = 100Ω or RL = 1k.
Figure 13 shows the response of the reference to these
VIN = 2.5V
LT1460S3-2.5
RL
VOUT
CIN
0.1µF
VGEN
CL
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.
2.5V
1.5V
1460 F12
VGEN
Figure 12. Response Time Test Circuit
VGEN
2.5V
1.5V
2.5V
1.5V
VOUT
1mA
VOUT
10mA
VOUT
1mA
VOUT
10mA
100µs/DIV
1µs/DIV
Figure 13. CL = 0µF
1460 F14
Figure 14. CL = 0.1µF
1460 F13
VGEN
2.5V
1.5V
VOUT
1µA
VOUT
4.7µA
100µs/DIV
1460 F15
Figure 15. IOUT = 1mA
1460fc
17
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. 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.
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
WORST-CASE HYSTERESIS
ON 40 UNITS
14
NUMBER OF UNITS
Table 1. Maximum Output Capacitance for LT1460S3
12
10
8
70°C TO 25°C
0°C TO 25°C
6
4
2
150
0
100
ppm
80
120 160 200 240
1460 F17
Figure 17. 0°C to 70°C Hysteresis
50
0
9
8
–50
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
–150
40
–240 –200 –160 –120 –80 –40 0
HYSTERESIS (ppm)
6
WORST-CASE HYSTERESIS
ON 34 UNITS
85°C TO 25°C
–40°C TO 25°C
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. –40°C to 85°C Hysteresis
1460fc
18
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.
0.075% + 0.035% + 0.070% = 0.180%.
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
(
)( )
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
( )( )
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 0.07%.
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%
100µA
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%
1460fc
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 125µV 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
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.
1460 F19
Figure 19. Flexure Numbers
2
OUTPUT DEVIATION (mV)
OUTPUT DEVIATION (mV)
2
1
LONG DIMENSION
0
–1
0
10
20
30
FLEXURE NUMBER
1
–1
40
LONG DIMENSION
0
0
1460 F20a
30
40
1460 F20b
Figure 20b. Two Typical LT1460S8-2.5s, Horizontal
Orientation Without Slots
2
OUTPUT DEVIATION (mV)
2
OUTPUT DEVIATION (mV)
20
FLEXURE NUMBER
Figure 20a. Two Typical LT1460S8-2.5s, Vertical
Orientation Without Slots
1
0
SLOT
–1
10
0
10
20
30
FLEXURE NUMBER
Figure 21a. Same Two LT1460S8-2.5s in Figure 16a,
but with Slots
20
40
1460 F21a
1
0
SLOT
–1
0
10
20
30
FLEXURE NUMBER
Figure 21b. Same Two LT1460S8-2.5s in Figure 16b,
but with Slots
40
1460 F21b
1460fc
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 – 0.18
(.004 – .007)
0.01 – 0.10
(.0004 – .004)
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
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)
.050 BSC
.189 – .197
(4.801 – 5.004)
NOTE 3
.045 ±.005
8
.245
MIN
.160 ±.005
.010 – .020
× 45°
(0.254 – 0.508)
NOTE:
1. DIMENSIONS IN
5
.150 – .157
(3.810 – 3.988)
NOTE 3
1
RECOMMENDED SOLDER PAD LAYOUT
.053 – .069
(1.346 – 1.752)
0°– 8° TYP
.016 – .050
(0.406 – 1.270)
6
.228 – .244
(5.791 – 6.197)
.030 ±.005
TYP
.008 – .010
(0.203 – 0.254)
7
.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
1460fc
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)
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
(.034)
REF
0.18
(.007)
SEATING
PLANE
0.22 – 0.38
(.009 – .015)
TYP
0.65
(.0256)
BSC
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
1460fc
23
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/–0.1)
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
1460fc
24
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.
25
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 + 1.8V)
V+ – VOUT
40mA
1460 TA03
Boosted Output Current with Current Limit
V+ ≥ VOUT + 2.8V
+
R1
220Ω
R1 =
D1*
LED
47µF
+
R1
220Ω
8.2Ω
2N2905
47µF
2N2905
IN
IN
LT1460
OUT
GND
+
2µF
SOLID
TANT
LT1460
VOUT
100mA
OUT
GND
1460 TA04
+
2µF
SOLID
TANT
VOUT
100mA
* 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, 60µA Supply, SOT23 Package
LTC®1798
Micropower Low Dropout Reference, Fixed or Adjustable
0.15% Max, 40ppm/°C, 6.5µA 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 × 2mm DFN Package
1460fc
26
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507
●
www.linear.com
LT 0310 REV C • PRINTED IN USA
LINEAR TECHNOLOGY CORPORATION 2006
工商网监
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