1
LT1634
Micropower Precision
Shunt Voltage Reference
s
Initial Voltage Accuracy: 0.05%
s
Low Operating Current: 10
A
s
Low Drift: 10ppm/
C Max
s
Less Than 1
Dynamic Impedance
s
Available in 1.25V, 2.5V, 4.096V and 5V in SO-8
and TO-92 Packages
s
1.25V and 2.5V Available in MSOP Package
s
Both Commercial and Industrial Temperature Range
Parts Are Available
FEATURES
DESCRIPTIO
N
U
The LT
1634 is a micropower, precision, shunt voltage
reference. The bandgap reference uses trimmed precision
thin film resistors to achieve 0.05% initial voltage accu-
racy. Improved curvature correction technique guaran-
tees 10ppm/
C maximum temperature drift. Advances in
design, processing and packaging techniques guarantee
10
A operation and low temperature cycling hysteresis.
The LT1634 does not require an output compensation
capacitor, but is stable with capacitive loads. Low dynamic
impedance makes the LT1634 reference easy to use from
unregulated supplies.
The LT1634 reference can be used as a high performance
upgrade to the LM185/LM385, LT1004 and LT1034
where lower power and guaranteed temperature drift is
required.
, LTC and LT are registered trademarks of Linear Technology Corporation.
TYPICAL APPLICATIO
N
U
+
LT1495
5V
5V
LT1634-4.096
I
S
= 200
A
OUTPUT ACCURACY
BETTER THAN 0.075%
AT
500
A OUTPUT
LTC
1043
5V
5V
5V
5V
1634 TA01
1
F
1
F
6
4
17
18
5
15
45k
V
OUT
4.096V
+
LT1495
V
OUT
4.096V
Super Accurate
4.096V Output References
Temperature Drift
TEMPERATURE (
C)
40
REVERSE VOLTAGE CHANGE (mV)
1.5
0
1634
TA02
0
1.0
20
20
1.5
2.0
2.0
1.0
0.5
0.5
40
60
80
100
I
R
= 10
A
V
OUT
= 1.25V
APPLICATIO
N
S
U
s
Portable Meters
s
Precision Regulators
s
A/D and D/A Converters
s
Calibrators
2
LT1634
ABSOLUTE
M
AXI
M
U
M
RATINGS
W
W
W
U
Operating Temperature Range
Commercial ............................................. 0
C to 70
C
Industrial ............................................ 40
C to 85
C
Storage Temperature Range (Note 1) ... 65
C to 150
C
Lead Temperature (Soldering, 10 sec).................. 300
C
Operating Current
1.25V ............................................................. 100mA
2.5V ................................................................. 50mA
4.096V, 5V........................................................ 30mA
Forward Current................................................... 20mA
PACKAGE/ORDER I
N
FOR
M
ATIO
N
W
U
U
T
JMAX
= 125
C,
JA
= 250
C/ W
1
2
3
4
DNC*
DNC*
DNC*
GND
8
7
6
5
DNC*
DNC*
V
OUT
TEST**
TOP VIEW
MS8 PACKAGE
8-LEAD PLASTIC MSOP
T
JMAX
= 125
C,
JA
= 190
C/ W
1
2
3
4
8
7
6
5
TOP VIEW
S8 PACKAGE
8-LEAD PLASTIC SO
DNC*
DNC*
DNC*
GND
DNC*
DNC*
V
OUT
TEST**
LT1634BCMS8-1.25
LT1634BCMS8-2.5
ORDER PART NUMBER
MS8 PART MARKING
LTCV
LTDF
ORDER PART NUMBER
S8 PART MARKING
LT1634ACS8-1.25
LT1634ACS8-2.5
LT1634ACS8-4.096
LT1634ACS8-5
LT1634AIS8-1.25
LT1634AIS8-2.5
LT1634AIS8-4.096
LT1634AIS8-5
LT1634BCS8-1.25
LT1634BCS8-2.5
LT1634BCS8-4.096
LT1634BCS8-5
LT1634BIS8-1.25
LT1634BIS8-2.5
LT1634BIS8-4.096
LT1634BIS8-5
634A1
634A2
634A4
634A5
634AI1
634AI2
634AI4
634AI5
634B1
634B2
634B4
634B5
634BI1
634BI2
634BI4
634BI5
*Connected internally. Do Not Connect external circuitry to these pins.
**Connect to ground in user application.
Consult factory for Military grade parts.
ORDER PART NUMBER
LT1634CCZ-1.25
LT1634CCZ-2.5
LT1634CCZ-4.096
LT1634CCZ-5
1
2
3
BOTTOM VIEW
TEST** V
OUT
GND
Z PACKAGE
3-LEAD PLASTIC TO-92
T
JMAX
= 125
C,
JA
= 190
C/ W
3
LT1634
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Reverse Breakdown Voltage
LT1634ACS8/LT1634BCMS8/LT1634BCS8/
1.24937
1.250
1.25062
V
LT1634AIS8/LT1634BIS8 (I
R
= 10
A)
0.05
0.05
%
LT1634CCZ (I
R
= 10
A)
1.24750
1.250
1.25250
V
0.20
0.20
%
LT1634ACS8 (I
R
= 10
A)
q
1.24849
1.250
1.25149
V
0.12
0.12
%
LT1634AIS8 (I
R
= 10
A)
q
1.24781
1.250
1.25218
V
0.175
0.175
%
LT1634BCS8/LT1634BCMS8 (I
R
= 10
A)
q
1.24718
1.250
1.25281
V
0.225
0.225
%
LT1634BIS8 (I
R
= 10
A)
q
1.24547
1.250
1.25453
V
0.362
0.362
%
LT1634CCZ (I
R
= 10
A)
q
1.24531
1.250
1.25469
V
0.375
0.375
%
Reverse Breakdown Change
10
A
I
R
2mA
0.25
1
mV
with Current (Note 3)
q
0.30
2
mV
2mA
I
R
20mA
2
8
mV
q
2
10
mV
Minimum Operating Current
q
7
A
Temperature Coefficient
LT1634A, I
R
= 10
A
q
4
10
ppm/
C
LT1634B, I
R
= 10
A
q
10
25
ppm/
C
Reverse Dynamic Impedance (Note 4)
10
A
I
R
2mA
0.125
0.5
q
0.150
1.0
Low Frequency Noise (Note 5)
I
R
= 10
A, 0.1Hz
f
10Hz
10
V
P-P
Hysteresis (Note 6)
T = 40
C to 85
C
160
ppm
T = 0
C to 70
C
40
ppm
TEMPERATURE COEFFICIENT
PACKAGE TYPE
TEMPERATURE
ACCURACY (%)
(ppm/
C)
MS8
S8
Z
0
C to 70
C
0.05
10
LT1634ACS8-1.25
LT1634ACS8-2.5
LT1634ACS8-4.096
LT1634ACS8-5
40
C to 85
C
0.05
10
LT1634AIS8-1.25
LT1634AIS8-2.5
LT1634AIS8-4.096
LT1634AIS8-5
0
C to 70
C
0.05
25
LT1634BCMS8-1.25
LT1634BCS8-1.25
LT1634BCMS8-2.5
LT1634BCS8-2.5
LT1634BCS8-4.096
LT1634BCS8-5
40
C to 85
C
0.05
25
LT1634BIS8-1.25
LT1634BIS8-2.5
LT1634BIS8-4.096
LT1634BIS8-5
0
C to 70
C
0.20
25
LT1634CCZ-1.25
LT1634CCZ-2.5
LT1634CCZ-4.096
LT1634CCZ-5
AVAILABLE OPTIO S
U
1.25V ELECTRICAL CHARACTERISTICS
(Note 2)
4
LT1634
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Reverse Breakdown Voltage
LT1634ACS8/LT1634BCMS8/LT1634BCS8/
2.49875
2.500
2.50125
V
LT1634AIS8/LT1634BIS8 (I
R
= 10
A)
0.05
0.05
%
LT1634CCZ (I
R
= 10
A)
2.49500
2.500
2.50500
V
0.20
0.20
%
LT1634ACS8 (I
R
= 10
A)
q
2.49700
2.500
2.50300
V
0.12
0.12
%
LT1634AIS8 (I
R
= 10
A)
q
2.49562
2.500
2.50437
V
0.175
0.175
%
LT1634BCMS8/LT1634BCS8 (I
R
= 10
A)
q
2.49437
2.500
2.50562
V
0.225
0.225
%
LT1634BIS8 (I
R
= 10
A)
q
2.49094
2.500
2.50906
V
0.362
0.362
%
LT1634CCZ (I
R
= 10
A)
q
2.49062
2.500
2.50937
V
0.375
0.375
%
Reverse Breakdown Change
10
A
I
R
2mA
0.30
1.5
mV
with Current (Note 3)
q
0.40
3.0
mV
2mA
I
R
20mA
2
8
mV
q
2
10
mV
Minimum Operating Current
q
8
A
Temperature Coefficient
LT1634A, I
R
= 10
A
q
4
10
ppm/
C
LT1634B, I
R
= 10
A
q
10
25
ppm/
C
Reverse Dynamic Impedance (Note 4)
10
A
I
R
2mA
0.15
0.75
q
0.20
1.50
Low Frequency Noise (Note 5)
I
R
= 10
A, 0.1Hz
f
10Hz
15
V
P-P
Hysteresis (Note 6)
T = 40
C to 85
C
160
ppm
T = 0
C to 70
C
40
ppm
2.5V ELECTRICAL CHARACTERISTICS
(Note 2)
4.096V ELECTRICAL CHARACTERISTICS
(Note 2)
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Reverse Breakdown Voltage
LT1634ACS8/LT1634BCS8/
4.09395
4.096
4.09805
V
LT1634AIS8/LT1634BIS8 (I
R
= 20
A)
0.05
0.05
%
LT1634CCZ (I
R
= 20
A)
4.08780
4.096
4.10419
V
0.20
0.20
%
LT1634ACS8 (I
R
= 20
A)
q
4.09108
4.096
4.10091
V
0.12
0.12
%
LT1634AIS8 (I
R
= 20
A)
q
4.08883
4.096
4.10317
V
0.175
0.175
%
LT1634BCS8 (I
R
= 20
A)
q
4.08678
4.096
4.10522
V
0.225
0.225
%
LT1634BIS8 (I
R
= 20
A)
q
4.08115
4.096
4.11085
V
0.362
0.362
%
LT1634CCZ (I
R
= 20
A)
q
4.08064
4.096
4.11137
V
0.375
0.375
%
Reverse Breakdown Change
20
A
I
R
2mA
0.3
1.5
mV
with Current (Note 3)
q
0.4
3.0
mV
2mA
I
R
20mA
2
8
mV
q
2
10
mV
Minimum Operating Current
q
15
A
5
LT1634
4.096V ELECTRICAL CHARACTERISTICS
(Note 2)
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Temperature Coefficient
LT1634A, I
R
= 20
A
q
4
10
ppm/
C
LT1634B, I
R
= 20
A
q
10
25
ppm/
C
Reverse Dynamic Impedance (Note 4)
20
A
I
R
2mA
0.15
0.75
q
0.20
1.50
Low Frequency Noise (Note 5)
I
R
= 20
A, 0.1Hz
f
10Hz
30
V
P-P
Hysteresis (Note 6)
T = 40
C to 85
C
160
ppm
T = 0
C to 70
C
40
ppm
5V ELECTRICAL CHARACTERISTICS
PARAMETER
CONDITIONS
MIN
TYP
MAX
UNITS
Reverse Breakdown Voltage
LT1634ACS8/LT1634BCS8/
4.99750
5.000
5.00250
V
LT1634AIS8/LT1634BIS8 (I
R
= 20
A)
0.05
0.05
%
LT1634CCZ (I
R
= 20
A)
4.99000
5.000
5.01000
V
0.20
0.20
%
LT1634ACS8 (I
R
= 20
A)
q
4.99400
5.000
5.00600
V
0.12
0.12
%
LT1634AIS8 (I
R
= 20
A)
q
4.99125
5.000
5.00875
V
0.175
0.175
%
LT1634BCS8 (I
R
= 20
A)
q
4.98875
5.000
5.01125
V
0.225
0.225
%
LT1634BIS8 (I
R
= 20
A)
q
498188
5.000
5.01813
V
0.362
0.362
%
LT1634CCZ (I
R
= 20
A)
q
4.98126
5.000
5.01876
V
0.375
0.375
%
Reverse Breakdown Change
20
A
I
R
2mA
0.3
1.5
mV
with Current (Note 3)
q
0.4
3.0
mV
2mA
I
R
20mA
2
8
mV
q
2
10
mV
Minimum Operating Current
q
15
A
Temperature Coefficient
LT1634A, I
R
= 20
A
q
4
10
ppm/
C
LT1634B, I
R
= 20
A
q
10
25
ppm/
C
Reverse Dynamic Impedance (Note 4)
20
A
I
R
2mA
0.15
0.75
q
0.20
1.50
Low Frequency Noise (Note 5)
I
R
= 20
A, 0.1Hz
f
10Hz
35
V
P-P
Hysteresis (Note 6)
T = 40
C to 85
C
160
ppm
T = 0
C to 70
C
40
ppm
(Note 2)
The
q
denotes specifications which apply over the full operating
temperature range.
Note 1: If the part is stored outside of the specific operating temperature
range, the output may shift due to hysteresis.
Note 2: ESD (Electrostatic Discharge) sensitive device. Use proper ESD
handling precautions.
Note 3: Output requires 0.1
F for operating current greater than 1mA.
Note 4: This parameter is guaranteed by "reverse breakdown change with
current" test.
Note 5: Peak-to-peak noise is measured with a single highpass filter at
0.1Hz and 2-pole lowpass filter at 10Hz.
Note 6: 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. Hysteresis
is not normally a problem for operational temperature excursions where
the instrument might be stored at high or low temperature.
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