LT1389
Nanopower Precision
Shunt Voltage Reference
FEATURES
s
s
s
s
s
DESCRIPTIO
Initial Voltage Accuracy: 0.05%
Low Operating Current: 800nA
Low Drift: 10ppm/
°
C Max
Less Than 1Ω Dynamic Impedance
Available in 1.25V, 2.5V, 4.096V and
5V SO-8 Packages
APPLICATIO S
s
s
s
s
The LT
®
1389 is a nanopower, precision shunt voltage
reference. The bandgap reference uses trimmed preci-
sion thin-film resistors and improved curvature correction
techniques to achieve 0.05% initial voltage accuracy with
guaranteed 10ppm/°C maximum temperature drift. Volt-
age regulation is maintained to an ultralow 800nA operating
current. Advances in design, processing and packaging
achieve low temperature cycling hysteresis.
The LT1389 does not require an output compensation
capacitor, but is stable with capacitive loads. Low dy-
namic impedance makes the LT1389 reference easy to
use from unregulated supplies.
The LT1389 reference can be used as a high performance
upgrade to the LM185/LM385, LT1004, LT1034 and
LT1634 where lowest power and guaranteed tempera-
ture drift are required.
, LTC and LT are registered trademarks of Linear Technology Corporation.
Portable Meters
Precision Regulators
A/D and D/A Converters
Calibrators
TYPICAL APPLICATIO
2.0
REFERENCE VOLTAGE CHANGE (mV)
1.5
1.0
0.5
0
– 0.5
–1.0
–1.5
– 2.0
0
I
R
= 0.8µA
V
OUT
= 1.25V
5V
4.7M
V
OUT
1.25V
LT1389-1.25
1389 TA01
10
U
Temperature Drift
20
40
50
30
TEMPERATURE (°C)
60
70
1389 TA02
U
U
1
LT1389
ABSOLUTE
(Note 1)
AXI U
RATI GS
PACKAGE/ORDER I FOR ATIO
ORDER PART
NUMBER
TOP VIEW
DNC* 1
DNC* 2
DNC* 3
GND 4
8 DNC*
7 DNC*
6 V
OUT
5 GND
Operating Current
1.25V ............................................................... 20mA
2.5V ................................................................. 20mA
4.096V ............................................................. 10mA
5V .................................................................... 10mA
Forward Current .................................................. 20mA
Operating Temperature Range ..................... 0°C to 70°C
Storage Temperature Range (Note 2) ... – 65°C to 150°C
Lead Temperature (Soldering, 10 sec).................. 300°C
LT1389ACS8-1.25
LT1389BCS8-1.25
LT1389BCS8-2.5
LT1389BCS8-4.096
LT1389BCS8-5
S8 PART MARKING
389A12
389B12
389B25
1389B4
1389B5
S8 PACKAGE
8-LEAD PLASTIC SO
T
JMAX
= 125°C,
θ
JA
= 190°C/ W
*Connected internally. Do Not Connect external circuitry to these pins.
Consult factory for Industrial and Military grade parts.
AVAILABLE OPTIO S
TEMPERATURE
0°C to 70°C
OUTPUT
VOLTAGE
1.250
1.250
2.500
4.096
5.000
ACCURACY (%)
0.05
0.05
0.05
0.075
0.075
TEMPERATURE COEFFICIENT
(ppm/°C)
10
20
20
50
50
PART TYPE
LT1389ACS8-1.25
LT1389BCS8-1.25
LT1389BCS8-2.5
LT1389BCS8-4.096
LT1389BCS8-5
PART MARKING
389A12
389B12
389B25
1389B4
1389B5
1.25V ELECTRICAL CHARACTERISTICS
PARAMETER
Reverse Breakdown Voltage
CONDITIONS
The
q
denotes specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. (Note 3)
MIN
1.24937
– 0.05
q
q
TYP
1.250
1.250
1.250
0.20
0.20
0.3
0.3
4
4
0.25
0.25
25
MAX
1.25062
0.05
1.25149
0.12
1.25237
0.19
0.4
1.0
1.0
2.0
0.6
10
20
0.7
1.5
UNITS
V
%
V
%
V
%
mV
mV
mV
mV
µA
ppm/°C
ppm/°C
Ω
Ω
µV
P-P
LT1389ACS8/LT1389BCS8 (I
R
= 0.8µA)
LT1389ACS8 (I
R
= 0.8µA)
LT1389BCS8 (I
R
= 0.8µA)
1.24849
– 0.12
1.24762
– 0.19
Reverse Breakdown Change
with Current (Note 4)
0.8µA
≤
I
R
≤
200µA
q
200µA
≤
I
R
≤
2mA
q
Minimum Operating Current
Temperature Coefficient
Reverse Dynamic Impedance (Note 5)
Low Frequency Noise (Note 6)
LT1389ACS8 (I
R
= 0.8µA)
LT1389BCS8 (I
R
= 0.8µA)
0.8µA
≤
I
R
≤
2mA
q
q
q
q
I
R
= 0.8µA, 0.1Hz
≤
f
≤
10Hz
2
U
W
U
U
W W
U
W
LT1389
2.5V ELECTRICAL CHARACTERISTICS
PARAMETER
Reverse Breakdown Voltage
CONDITIONS
LT1389BCS8 (I
R
= 0.9µA)
LT1389BCS8 (I
R
= 0.9µA)
Reverse Breakdown Change
with Current (Note 4)
0.9µA
≤
I
R
≤
200µA
The
q
denotes specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. (Note 3)
MIN
2.49875
– 0.05
q
TYP
2.500
2.500
0.2
0.2
0.3
0.3
8
0.25
0.25
50
MAX
2.50125
0.05
2.50475
0.19
0.5
1.5
1.0
2.5
0.7
20
0.75
2
UNITS
V
%
V
%
mV
mV
mV
mV
µA
ppm/°C
Ω
Ω
µV
P-P
2.49525
– 0.19
q
200µA
≤
I
R
≤
2mA
q
Minimum Operating Current
Temperature Coefficient
Reverse Dynamic Impedance (Note 5)
Low Frequency Noise (Note 6)
I
R
= 0.9µA
0.9µA
≤
I
R
≤
2mA
q
q
q
I
R
= 0.9µA, 0.1Hz
≤
f
≤
10Hz
The
q
denotes specifications which apply over the full
operating temperature range, otherwise specifications are at T
A
= 25°C. (Note 3)
PARAMETER
Reverse Breakdown Voltage
CONDITIONS
LT1389BCS8 (I
R
= 1.5µA)
LT1389BCS8 (I
R
= 1.5µA)
Reverse Breakdown Change
with Current (Note 4)
1.5µA
≤
I
R
≤
200µA
q
q
4.096V ELECTRICAL CHARACTERISTICS
MIN
4.09293
– 0.075
4.0788
– 0.42
TYP
4.096
4.096
0.2
0.2
0.3
0.3
12
0.75
0.75
80
MAX
4.09907
0.075
4.1132
0.42
1.5
3
4
6
1
50
2
3
UNITS
V
%
V
%
mV
mV
mV
mV
µA
ppm/°C
Ω
Ω
µV
P-P
200µA
≤
I
R
≤
2mA
q
Minimum Operating Current
Temperature Coefficient
Reverse Dynamic Impedance (Note 5)
Low Frequency Noise (Note 6)
I
R
= 1.5µA
1.5µA
≤
I
R
≤
2mA
q
q
q
I
R
= 1.5µA, 0.1Hz
≤
f
≤
10Hz
3
LT1389
The
q
denotes specifications which apply over the full operating
temperature range, otherwise specifications are at T
A
= 25°C. (Note 3)
PARAMETER
Reverse Breakdown Voltage
CONDITIONS
LT1389BCS8 (I
R
= 1.5µA)
LT1389BCS8 (I
R
= 1.5µA)
Reverse Breakdown Change
with Current (Note 4)
1.5µA
≤
I
R
≤
200µA
q
q
5V ELECTRICAL CHARACTERISTICS
MIN
4.99625
– 0.075
4.979
– 0.42
TYP
5.000
5.000
0.2
0.2
0.3
0.3
12
0.75
0.75
100
MAX
5.00375
0.075
5.021
0.42
1.5
3
4
6
1
50
2
3
UNITS
V
%
V
%
mV
mV
mV
mV
µA
ppm/°C
Ω
Ω
µV
P-P
200µA
≤
I
R
≤
2mA
q
Minimum Operating Current
Temperature Coefficient
Reverse Dynamic Impedance (Note 5)
Low Frequency Noise (Note 6)
I
R
= 1.5µA
1.5µA
≤
I
R
≤
2mA
q
q
q
I
R
= 1.5µA, 0.1Hz
≤
f
≤
10Hz
Note 1:
Absolute Maximum Ratings are those values beyond which the life
of a device may be impaired.
Note 2:
If the part is stored outside of the specific operating temperature
range, the output may shift due to hysteresis.
Note 3:
ESD (Electrostatic Discharge) sensitive device. Use proper ESD
handling precautions.
Note 4:
Output requires 0.1µF for operating current greater than 1mA.
Note 5:
This parameter is guaranteed by “reverse breakdown change with
current” test.
Note 6:
Peak-to-peak noise is measured with a single highpass filter at
0.1Hz and 2-pole lowpass filter at 10Hz.
4
LT1389
1.25V TYPICAL PERFOR A CE CHARACTERISTICS
Reverse Characteristics
1.0
2.0
T
A
= – 40°C TO 85°C
REFERENCE VOLTAGE CHANGE (mV)
REVERSE VOLTAGE CHANGE (mV)
1.5
1.0
0.5
0
I
R
= 250µA
– 0.5
–1.0
I
R
= 0.8µA
–1.5
– 2.0
– 40
–20
40
20
TEMPERATURE (°C)
0
60
80
1.0
0.8
– 40°C
0.6
0.4
0.2
0
0.001
25°C
REVERSE CURRENT (µA)
0.8
0.6
0.4
0.2
0
0
0.8
0.4
1.2
REVERSE VOLTAGE (V)
1.6
1389-1.25 G01
Reverse Dynamic Impedance
1000
T
A
= 25°C
f = 25Hz
100
DYNAMIC IMPEDANCE (kΩ)
DYNAMIC IMPEDANCE (Ω)
FORWARD VOLTAGE (V)
10
1
0.1
0.001
0.01
0.1
1
REVERSE CURRENT (mA)
10
1389-1.25 G04
0.1Hz to 10Hz Noise
25
20
I
R
= 0.8µA
NOISE VOLTAGE (µV/DIV)
15
10
5
0
–5
–10
–15
– 20
– 25
0
10
20
30
40
50
TIME (SEC)
60
70
1389-1.25 G07
U W
100
10
1
0.1
1.5V
1V
0.5V
0V
5V
0V
Temperature Drift
1.2
Reverse Voltage Change
vs Current
85°C
0.1
1
0.01
REVERSE CURRENT (mA)
10
1389-1.25 G03
1389-1.25 G02
Dynamic Impedance vs Frequency
T
A
= 25°C
1.0
0.9
0.8
0.7
0.6
0.5
0.4
0.3
0.2
0.1
Forward Characteristics
T
A
= 25°C
I
R
= 0.8µA
C
OUT
= 0µF
I
R
= 0.8µA
C
OUT
= 0.047µF
I
R
= 10µA
C
OUT
= 0.1µF
I
R
= 10µA
C
OUT
= 0µF
0.01
0.01
0.1
1
FREQUENCY (kHz)
10
1389-1.25 G05
0
0.001
0.01
0.1
1
10
FORWARD CURRENT (mA)
100
1389-1.25 G06
Response Time
1.5V
1V
0.5V
0V
5V
0V
I
R
= 0.8µA
C
OUT
= 0µF
1ms/DIV
1389-1.25 G08
Response Time
I
R
= 0.8µA
C
OUT
= 0.1µF
200ms/DIV
1389-1.25 G09
5