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FEATURES
1
■
0.2% Output Tolerance
■
0.6Ω Shunt Impedance
■
700µA to 10mA Operating Current
■
Pin Compatible with LM136-5
■
20ppm/°C Max Drift
■
Output Voltage Trim does not Affect Drift
■
Can be Used as Positive or Negative Reference
U
APPLICATIO S
LT1029/LT1029A
5V Bandgap Reference
U
DESCRIPTIO
®
The LT
in the shunt or “Zener” mode, allowing it to be used as
either a positive or negative reference. The output is
pretrimmed to ± 0.2% accuracy with 20ppm/°C maximum
temperature drift. A trim pin allows additional output
adjustment for even more precise output voltage.
Operating current range for the LT1029 is 700µA to 10mA.
Extremely low dynamic impedance allows excellent
output regulation even with fluctuating operating current.
1029 is a 5V bandgap reference intended for use
■
A-to-D and D-to-A Converters
■
Precision Regulators
■
Precision Current Sources
■
V to F and F to V Converters
TYPICAL APPLICATIO
15V
R1
10k
LT1029
LT1029
R2
10k
–15V
LT1029 • TA0
5V
–5V
U
The LT1029 will replace an LM136-5 or LM336-5 and
simplify circuits using the “minimum temperature coefficient” trim network. The LT1029 does not require this
special network to meet its temperature drift specification;
these application network components are simply
removed. If output trimming is required for initial
accuracy, the diodes in the trim network should be
replaced with jumpers.
, LTC and LT are registered trademarks of Linear Technology Corporation.
Output Voltage Drift
5.015
5.010
5.005
5.000
4.995
OUTPUT VOLTAGE (V)
4.990
4.895
–25 0 25 50 75 100 125
–50
TEMPERATURE (°C)
LT1029 • TA02
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LT1029/LT1029A
WWWU
ABSOLUTE AXI U RATI GS
(Note 1)
Reverse Current .................................................... 15mA
Forward Current ................................................... 10mA
Storage Temperature ............................ – 65°C to 150°C
Lead Temperature (Soldering, 10 sec).................. 300°C
Operating Temperature Range
LT1029C/LT1029AC ............................... 0°C to 70°C
LT1029M/LT1029AM (OBSOLETE)....– 55°C to 125°C
UU
W
PACKAGE/ORDER I FOR ATIO
BOTTOM VIEW
ADJ
T
JMAX
Consult LTC Marketing for parts specified with wider operating temperature ranges.
TO-46 METAL CAN
= 150°C, θJA = 440°C/W, θJC = 80°C/W
+
–
H PACKAGE
OBSOLETE PACKAGE
Consider the Z Package as an Alternate Source
ORDER PART
NUMBER
LT1029AMH
LT1029MH
LT1029ACH
LT1029CH
BOTTOM VIEW
+
ADJ
Z PACKAGE
TO-92 PLASTIC
T
= 100°C, θJA = 160°C/W
JMAX
ORDER PART
NUMBER
–
LT1029ACZ
LT1029CZ
ELECTRICAL CHARACTERISTICS
temperature range, otherwise specifications are TA = 25°C.
PARAMETER CONDITIONS MIN TYP MAX UNITS
Reverse Breakdown Voltage IR = 1mA LT1029AM/LT1029AC 4.99 5.00 5.01 V
Reverse Breakdown Change with Current 700µA ≤ IR ≤ 10mA 2 5 mV
Reverse Dynamic Impedance IR = 1mA 0.2 0.6 Ω
Temperature Stability IR = 1mA LT1029AC ● 37 mV
Equivalent Temperature Drift LT1029AM/LT1029AC ● 820ppm/°C
Long Term Stability 20 ppm/kHr
Trim Range ± 3+ 5, – 13 %
Note 1: Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
The ● denotes the specifications which apply over the full operating
LT1029M/LT1029C 4.95 5.00 5.05 V
● 38 mV
● 0.3 1.0 Ω
LT1029C
LT1029AM
LT1029M
LT1029C
LT1029M
● 512 mV
● 718 mV
● 10 36 mV
● 12 34 ppm/°C
● 15 40 ppm/°C
2
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TYPICAL PERFOR A CE CHARACTERISTICS
Reverse Characteristics
1.0
0.9
0.8
0.7
0.6
0.5
0.4
CURRENT (mA)
0.3
TJ = 125°C
0.2
0.1
0
0
13
OUTPUT TO GROUND VOLTAGE (V)
TJ = – 55°C
2
TJ = 25°C
7
4
6
5
LT1029 • TPC01
WUUU
APPLICATIO S I FOR ATIO
LT1029/LT1029A
8
Output Trimming
Output voltage trimming on the LT1029 is nominally
accomplished with a potentiometer connected from
output to ground with the wiper tied to the trim pin. The
LT1029 was made compatible with existing references, so
the trim range is large; 5%, – 13%. This large trim range
makes precision trimming rather difficult. One solution is
to insert resistors in series with both ends of the
potentiometer. This has the disadvantage of potentially
poor tracking between the fixed resistors and the
potentiometer. A second method of reducing trim range is
to insert a resistor in series with the wiper of the
potentiometer. This works well only for a very small trim
range because of the mismatch in TCs between the series
resistor and the internal thin film resistors. These film
resistors can have a TC as high as 500ppm/°C. That same
TC is then transferred to the change in output voltage;
a 1% shift in output voltage causes a (500ppm) (1%) =
5ppm/°C change in output voltage drift. The worst case
error in initial output voltage for the LT1029A is 0.2% and
the LT1029 is 1%, so a series resistor is satisfactory if the
output is simply trimmed to nominal value. 1ppm/°C TC
shift would be the maximum expected for the LT1029A
and 5ppm/°C for the LT1029.
Shunt Capacitance
The LT1029 is stable with all values of shunt capacitance,
but values between 300pF and 0.01µF are not recom-
mended because they cause longer settling following a
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.
transient in operating current. A 1µF solid tantalum
capacitor is suggested for most situations where
bypassing is desirable.
Wide Trim Range (5%, – 13%)
+
V
I ≥ 900µA
V
REF
25k
LT1029 • AI01
Narrow Trim Range
+
V
I ≥ 800µA
V
= 5.000V
R1*
LT1029 • TA02
REF
100k
TRIM RANGE
0.4% – LT1029A, R1 = 750k
1.2% – LT1029, R1 = 250k
Trimming Output to 5.120V
+
V
I ≥ 800µA
V
= 5.120V
REF
R1
41.2k
R2
5k
R3
4.02k
LT1029 • AI03
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Page 4
LT1029/LT1029A
WUUU
APPLICATIO S I FOR ATIO
Split ± 2.5V References
PACKAGE DESCRIPTIO
.209 – .219
(5.309 – 5.537)
.178 – .195
(4.521 – 4.953)
.500
(12.700)
REFERENCE
MIN
PLANE
.016 – .019**
(0.406 – 0.483)
DIA
R1
LT1029
25k
0.1%
R2
25k
0.1%
5V
–
LT1001
+
–5V
R3
1k
5%
–5V
U
H Package
2-Lead and 3-Lead TO-46 Metal Can
(Reference LTC DWG # 05-08-1340)
.100
.050
(2.540)
(1.270)
.085 – .105
(2.159 – 2.667)
SEATING*
.025
(0.635)
MAX
*
LEAD DIAMETER IS UNCONTROLLED BETWEEN THE REFERENCE PLANE
AND .050" BELOW THE REFERENCE PLANE
**
FOR SOLDER DIP LEAD FINISH, LEAD DIAMETER IS
PLANE
.036 – .046
(0.914 – 1.168)
TYP
PIN 1
45°
.016 – .024
(0.406 – 0.610)
TYP
2.5V
– 2.5V
LT1029 • AI04
.050
(1.270)
TYP
FOR 3-LEAD PACKAGE ONLY
.028 – .048
(0.711 – 1.219)
H02/03(TO-46) 0801
4
OBSOLETE PACKAGE
3-Lead Plastic TO-92 (Similar to TO-226)
(Reference LTC DWG # 05-08-1330)
.060 ± .005
(1.524± 0.127)
DIA
.180 ± .005
(4.572 ± 0.127)
.500
(12.70)
MIN
.050
(1.27)
BSC
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507
.180 ± .005
(4.572 ± 0.127)
.90
(2.286)
NOM
.050
UNCONTROLLED
LEAD DIMENSION
(1.270)
MAX
.016 ± .003
(0.406 ± 0.076)
●
www.linear.com
Z Package
5°
NOM
.015 ± .002
(0.381 ± 0.051)
Z3 (TO-92) 0801
.098 +.016/–.04
(2.5 +0.4/–0.1)
2 PLCS
.060 ± .010
(1.524 ± 0.254)
321
10° NOM
TO-92 TAPE AND REEL
REFER TO TAPE AND REEL SECTION OF
LTC DATA BOOK FOR ADDITIONAL INFORMATION
LINEAR TE CHNO LOGY CORP O RATION 1985
.140 ± .010
(3.556 ± 0.127)
LT/TP 1102 1K REV A • PRINTED IN USA
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