February 2000
LM185/LM285/LM385
Adjustable Micropower Voltage References
General Description
The LM185/LM285/LM385 are micropower 3-terminal adjustable band-gap voltage reference diodes. Operating from 1.24 to 5.3V and over a 10µA to 20mA current range, they feature exceptionally low dynamic impedance and good temperature stability. On-chip trimming is used to provide tight voltage tolerance. Since the LM185 band-gap reference uses only transistors and resistors, low noise and good long-term stability result.
Careful design of the LM185 has made the device tolerant of capacitive loading, making it easy to use in almost any reference application. The wide dynamic operating range allows its use with widely varying supplies with excellent regulation.
The extremely low power drain of the LM185 makes it useful for micropower circuitry. This voltage reference can be used to make portable meters, regulators or general purpose analog circuitry with battery life approaching shelf life. Further, the wide operating current allows it to replace older references with a tighter tolerance part.
The LM185 is rated for operation over a −55ÊC to 125ÊC temperature range, while the LM285 is rated −40ÊC to 85ÊC and the LM385 0ÊC to 70ÊC. The LM185 is available in a hermetic TO-46 package and a leadless chip carrier package, while the LM285/LM385 are available in a low-cost TO-92 molded package, as well as S.O.
Features
nAdjustable from 1.24V to 5.30V
nOperating current of 10µA to 20mA
n1% and 2% initial tolerance
n1Ω dynamic impedance
nLow temperature coefficient
Connection Diagrams
SOIC Package
TO-92
Plastic Package
DS005250-9
Bottom View
TO-46 |
DS005250-10 |
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Top View |
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Metal Can Package |
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20-Leadless Chip Carrier |
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DS005250-1 |
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Bottom View |
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DS005250-15
Top View
Reference Voltage Micropower Adjustable LM185/LM285/LM385
© 2000 National Semiconductor Corporation |
DS005250 |
www.national.com |
LM185/LM285/LM385
Ordering Information
Package |
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Temperature Range |
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NSC |
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Drawing |
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−55ÊC to 125ÊC |
−40ÊC to 85ÊC |
0ÊC to 70ÊC |
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LM185BH |
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TO-46 |
LM185BH/883 |
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H03H |
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LM185BYH |
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LM185BYH/883 |
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LM285BXZ |
LM385BXZ |
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TO-92 |
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LM285BYZ |
LM385BYZ |
Z03A |
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LM285Z |
LM385BZ |
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LM385Z |
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8-Pin SOIC |
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LM285M |
LM385M |
M08A |
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LM285BYM |
LM385BM |
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20-Leadless Chip |
LM185BE/883 |
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E20A |
Carrier |
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Block Diagram
DS005250-13
Typical Applications
1.2V Reference |
5.0V Reference |
DS005250-14
DS005250-2
www.national.com |
2 |
Absolute Maximum Ratings (Note 1)
If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications.
(Note 2)
Reverse Current |
30mA |
Forward Current |
10mA |
Operating Temperature Range (Note 3) |
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LM185 Series |
−55ÊC to 125ÊC |
LM285 Series |
−40ÊC to 85ÊC |
LM385 Series |
0ÊC to 70ÊC |
Storage Temperature |
−55ÊC to 150ÊC |
Soldering Information |
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TO-92 Package (10 sec.) |
260ÊC |
TO-46 Package (10 sec.) |
300ÊC |
SO Package |
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Vapor Phase (60 sec.) |
215ÊC |
Infrared (15 sec.) |
220ÊC |
See An-450 ªSurface Mounting Methods and Their Effect on Product Reliabilityº for other methods of soldering surface mount devices.
Electrical Characteristics (Note 4)
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LM185, LM285 |
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LM385 |
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LM185BX, |
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LM385BX, |
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LM185BY |
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LM185B, |
LM285 |
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LM385BY |
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Units |
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Parameter |
Conditions |
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LM285BX, |
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Typ |
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Typ |
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LM285BY |
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(Limit) |
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Tested |
Design |
Tested |
Design |
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Tested |
Design |
Tested |
Design |
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Limit |
Limit |
Limit |
Limit |
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Limit |
Limit |
Limit |
Limit |
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(Note 5) |
(Note 6) |
(Note 5) |
(Note 6) |
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(Note 5) |
(Note 6) |
(Note 5) |
(Note 6) |
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Reference Voltage |
IR = 100µA |
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1.240 |
1.252 |
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1.265 |
1.270 |
1.240 |
1.252 |
1.255 |
1.265 |
1.270 |
V |
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1.255 |
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(max) |
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1.228 |
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1.215 |
1.205 |
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1.228 |
1.215 |
1.215 |
1.205 |
V |
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1.215 |
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(min) |
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Reference Voltage |
IMIN< IR < 1mA |
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0.2 |
1 |
1.5 |
1 |
1.5 |
0.2 |
1 |
1.5 |
1 |
1.5 |
mV |
Change with Current |
1mA < IR < 20mA |
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4 |
10 |
20 |
10 |
20 |
5 |
15 |
25 |
15 |
25 |
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Dynamic Output |
IR = 100µA, |
f = 100Hz |
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Impedance |
IAC = 0.1 IR |
VOUT = |
0.3 |
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0.4 |
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Ω |
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VREF |
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VOUT = 5.3V |
0.7 |
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1 |
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Reference Voltage |
IR = 100µA |
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mV |
Change with Output |
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1 |
3 |
6 |
3 |
6 |
2 |
5 |
10 |
5 |
10 |
(max) |
Voltage |
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Feedback Current |
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13 |
20 |
25 |
20 |
25 |
16 |
30 |
35 |
30 |
35 |
nA |
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(max) |
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Minimum Operating |
VOUT = VREF |
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6 |
9 |
10 |
9 |
10 |
7 |
11 |
13 |
11 |
13 |
µA |
Current (see curve) |
VOUT = 5.3V |
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30 |
45 |
50 |
45 |
50 |
35 |
55 |
60 |
55 |
60 |
(max) |
Output Wideband |
IR = 100µA, 10Hz < f < 10kHz |
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Noise |
VOUT = VREF |
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50 |
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50 |
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µVrms |
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VOUT = 5.3V |
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170 |
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170 |
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Average |
IR = 100µA |
X Suffix |
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30 |
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30 |
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ppm/Êc |
Temperature |
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Coefficient (Note 7) |
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Y Suffix |
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50 |
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50 |
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(max) |
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All Others |
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150 |
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150 |
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150 |
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150 |
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Long Term Stability |
IR = 100µA, T = 1000 Hr, |
20 |
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20 |
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ppm |
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TA = 25ÊC ± 0.1ÊC |
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Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is intended to be functional, but do not guarantee specific performance limits. For guaranteed specifications and test conditions, see the Electrical Characteristics. The guaranteed specifications apply only for the test conditions listed.
Note 2: Refer to RETS185H for military specifications.
Note 3: For elevated temperature operation, TJmax is:
LM185 |
150ÊC |
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LM285 |
125ÊC |
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LM385 |
100ÊC |
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Thermal Resistance |
TO-92 |
TO-46 |
SO-8 |
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θJA (Junction to Ambient) |
180ÊC/W (0.4" leads) |
440ÊC/W |
165ÊC/W |
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170ÊC/W (0.125" leads) |
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θJC (Junction to Case) |
N/A |
80ÊC/W |
N/A |
LM185/LM285/LM385
3 |
www.national.com |
LM185/LM285/LM385
Electrical Characteristics (Note 4) (Continued)
Note 4: Parameters identified with boldface type apply at temperature extremes. All other numbers apply at TA = TJ = 25ÊC. Unless otherwise specified, all parameters apply for VREF < VOUT < 5.3V.
Note 5: Guaranteed and 100% production tested.
Note 6: Guaranteed, but not 100% production tested. These limits are not to be used to calculate average outgoing quality levels.
Note 7: The average temperature coefficient is defined as the maximum deviation of reference voltage at all measured temperatures from TMIN to TMAX, divided by TMAX − T MIN. The measured temperatures are −55, −40, 0, 25, 70, 85, 125ÊC.
Typical Performance Characteristics
Temperature Drift of 3 |
Feedback Current |
Minimum Operating Current |
Representative Units |
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DS005250-17 |
DS005250-18 |
DS005250-16 |
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Reverse Characteristics Reverse Characteristics Forward Characteristics
DS005250-19 DS005250-20 DS005250-21
Output Noise Voltage Dynamic Output Impedance Response Time
DS005250-22 |
DS005250-23 |
DS005250-24 |
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www.national.com |
4 |