LM185/LM285/LM385
Adjustable Micropower Voltage References
General Description
The LM185/LM285/LM385 are micropower 3-terminal ad-
justable band-gap voltage reference diodes. Operating from
1.24 to 5.3V and over a 10A to 20mA current range, they
feature exceptionally low dynamic impedance and good tem-
perature 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. Fur-
ther, the wide operating current allows it to replace older
references with a tighter tolerance part.
The LM185 is rated for operation over a -55C to 125C
temperature range, while the LM285 is rated -40C to 85C
and the LM385 0C to 70C. The LM185 is available in a
hermetic TO-46 package and a leadless chip carrier pack-
age, while the LM285/LM385 are available in a low-cost
TO-92 molded package, as well as S.O.
Features
n
Adjustable from 1.24V to 5.30V
n
Operating current of 10A to 20mA
n
1% and 2% initial tolerance
n
1
dynamic impedance
n
Low temperature coefficient
Connection Diagrams
TO-92
Plastic Package
TO-46
Metal Can Package
00525009
Bottom View
00525001
Bottom View
SOIC Package
20-Leadless Chip Carrier
00525010
Top View
00525015
Top View
February 2000
LM185/LM285/LM385
Adjustable
Micropower
V
oltage
Reference
2004 National Semiconductor Corporation
DS005250
www.national.com
Ordering Information
Package
Temperature Range
NSC
Drawing
-55C to 125C
-40C to 85C
0C to 70C
TO-46
LM185BH
H03H
LM185BH/883
LM185BYH
LM185BYH/883
TO-92
LM285BXZ
LM385BXZ
Z03A
LM285BYZ
LM385BYZ
LM285Z
LM385BZ
LM385Z
8-Pin SOIC
LM285M
LM385M
M08A
LM285BYM
LM385BM
20-Leadless Chip
Carrier
LM185BE/883
E20A
Block Diagram
00525013
Typical Applications
1.2V Reference
5.0V Reference
00525014
00525002
LM185/LM285/LM385
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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)
LM185 Series
-55C to 125C
LM285 Series
-40C to 85C
LM385 Series
0C to 70C
Storage Temperature
-55C to 150C
Soldering Information
TO-92 Package (10 sec.)
260C
TO-46 Package (10 sec.)
300C
SO Package
Vapor Phase (60 sec.)
215C
Infrared (15 sec.)
220C
See An-450 "Surface Mounting Methods and Their Effect
on Product Reliability" for other methods of soldering
surface mount devices.
Electrical Characteristics
(Note 4)
Parameter
Conditions
LM185, LM285
LM385
Typ
LM185BX,
LM185BY
Typ
LM385BX,
LM185B,
LM285BX,
LM285
LM385BY
LM385
Units
LM285BY
(Limit)
Tested Design Tested Design
Tested Design Tested Design
Limit
Limit
Limit
Limit
Limit
Limit
Limit
Limit
(Note
5)
(Note
6)
(Note
5)
(Note
6)
(Note
5)
(Note
6)
(Note
5)
(Note
6)
Reference
Voltage
I
R
= 100A
1.240
1.252
1.265
1.270 1.240
1.252
1.255
1.265
1.270
V
1.255
(max)
1.228
1.215
1.205
1.228
1.215
1.215
1.205
V
1.215
(min)
Reference
Voltage
I
MIN
<
I
R
<
1mA
0.2
1
1.5
1
1.5
0.2
1
1.5
1
1.5
mV
Change with
Current
1mA
<
I
R
<
20mA
4
10
20
10
20
5
15
25
15
25
(max)
Dynamic Output I
R
= 100A, f = 100Hz
Impedance
I
AC
= 0.1 I
R
V
OUT
=
V
REF
0.3
0.4
V
OUT
=
5.3V
0.7
1
Reference
Voltage
I
R
= 100A
mV
Change with
Output
1
3
6
3
6
2
5
10
5
10
(max)
Voltage
Feedback
Current
13
20
25
20
25
16
30
35
30
35
nA
(max)
Minimum
Operating
V
OUT
= V
REF
6
9
10
9
10
7
11
13
11
13
A
Current (see
curve)
V
OUT
= 5.3V
30
45
50
45
50
35
55
60
55
60
(max)
Output
Wideband
I
R
= 100A, 10Hz
<
f
<
10kHz
Noise
V
OUT
= V
REF
50
50
V
rms
V
OUT
= 5.3V
170
170
LM185/LM285/LM385
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3
Electrical Characteristics
(Note 4) (Continued)
Parameter
Conditions
LM185, LM285
LM385
Typ
LM185BX,
LM185BY
Typ
LM385BX,
LM185B,
LM285BX,
LM285
LM385BY
LM385
Units
LM285BY
(Limit)
Tested Design Tested Design
Tested Design Tested Design
Limit
Limit
Limit
Limit
Limit
Limit
Limit
Limit
(Note
5)
(Note
6)
(Note
5)
(Note
6)
(Note
5)
(Note
6)
(Note
5)
(Note
6)
Average
Temperature
I
R
= 100A
X Suffix
30
30
ppm/c
Coefficient
(Note 7)
Y Suffix
50
50
(max)
All Others
150
150
150
150
Long Term
Stability
I
R
= 100A, T = 1000
Hr,
20
20
ppm
T
A
= 25C
0.1C
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, T
J
max is:
LM185
150C
LM285
125C
LM385
100C
Thermal Resistance
TO-92
TO-46
SO-8
JA
(Junction to Ambient)
180C/W (0.4" leads)
440C/W
165C/W
170C/W (0.125" leads)
JC
(Junction to Case)
N/A
80C/W
N/A
Note 4: Parameters identified with boldface type apply at temperature extremes. All other numbers apply at T
A
= T
J
= 25C. Unless otherwise specified, all
parameters apply for V
REF
<
V
OUT
<
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 T
MIN
to T
MAX
, divided
by T
MAX
- T
MIN
. The measured temperatures are -55, -40, 0, 25, 70, 85, 125C.
LM185/LM285/LM385
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4
Typical Performance Characteristics
Temperature Drift of 3
Representative Units
Feedback Current
00525016
00525017
Minimum Operating Current
Reverse Characteristics
00525018
00525019
Reverse Characteristics
Forward Characteristics
00525020
00525021
LM185/LM285/LM385
www.national.com
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