LM185-2.5QML
LM185-2.5QML Micropower Voltage Reference Diode
Literature Number: SNVS385
LM185-2.5QML
Micropower Voltage Reference Diode
General Description
The LM185-2.5 are micropower 2-terminal band-gap voltage
regulator diodes. Operating over a 20 µA to 20 mA current
range, they feature exceptionally low dynamic impedance
and good temperature stability. On-chip trimming is used to
provide tight voltage tolerance. Since the LM185-2.5 band-
gap reference uses only transistors and resistors, low noise
and good long term stability result.
Careful design of the LM185-2.5 has made the device ex-
ceptionally 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 LM185-2.5 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. For applications
requiring 1.2V see LM185-1.2.
Features
nOperating current of 20 µA to 20 mA
n0.6Ωdynamic impedance (A grade)
nLow temperature coefficient
nLow voltage reference — 2.5V
Ordering Information
NS Part Number JAN Part Number NS Package Number Package Description
LM185H-2.5-SMD 5962–8759402XA H02A 2LD, T0–46 Metal Can
LM185H-2.5/883 H02A 2LD, T0–46 Metal Can
LM185WG-2.5-QV 5962–8759402VYA WG10A 10LD Ceramic SOIC
LM185WG-2.5/883 5962–8759402YA WG10A 10LD Ceramic SOIC
LM185BYH2.5/883 H02A 2LD, T0–46 Metal Can
LM185BYH2.5-SMD 5962–8759406XA H02A 2LD, T0–46 Metal Can
LM185BYH2.5-QV 5962–8759406VXA H02A 2LD, T0–46 Metal Can
Connection Diagrams
Ceramic SOIC (WG) TO-46 Metal Can Package (H)
20156203
See NS Package Number WG10A 20156213
Bottom View
See NS Package Number H02A
November 2005
LM185-2.5QML Micropower Voltage Reference Diode
© 2005 National Semiconductor Corporation DS201562 www.national.com
Schematic Diagram
20156201
LM185-2.5QML
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Absolute Maximum Ratings (Note 1)
Reverse Current 30 mA
Forward Current 10 mA
Operating Temperature Range −55˚C ≤T
A
≤+ 125˚C
Storage Temperature −55˚C ≤T
A
≤+ 150˚C
Maximum Junction Temperature (T
Jmax
) (Note 2) 150˚C
Lead Temperature (Soldering, 10 sec)
TO-46 Metal Can 300˚C
Ceramic SOIC 260˚C
Thermal Resistance
θ
JA
T0–46 Metal Can (Still Air) 300˚C/W
T0–46 Metal Can (500LF / Min Air Flow) 139˚C/W
Ceramic SOIC (Still Air) 194˚C/W
Ceramic SOIC (500LF / Min Air Flow) 128˚C/W
θ
JC
T0–46 Metal Can 57˚C/W
Ceramic SOIC 23˚C/W
Package Weight (Typical)
T0–46 Metal Can TBD
Ceramic SOIC 210 mg
ESD Tolerance (Note 3) 4000V
Quality Conformance Inspection
Mil-Std-883, Method 5005 - Group A
Subgroup Description Temp ˚C
1 Static tests at 25
2 Static tests at 125
3 Static tests at -55
4 Dynamic tests at 25
5 Dynamic tests at 125
6 Dynamic tests at -55
7 Functional tests at 25
8A Functional tests at 125
8B Functional tests at -55
9 Switching tests at 25
10 Switching tests at 125
11 Switching tests at -55
12 Settling time at 25
13 Settling time at 125
14 Settling time at -55
LM185-2.5QML
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LM185–2.5 Electrical Characteristics
DC Parameters
Symbol Parameter Conditions Notes Min Max Units Sub-
groups
V
Ref
Reverse Breakdown Voltage I
R
= 20µA 2.462 2.538 V 1
I
R
= 30µA 2.425 2.575 V 2, 3
I
R
= 1mA 2.462 2.538 V 1
2.425 2.575 V 2, 3
I
R
= 20mA 2.462 2.538 V 1
2.425 2.575 V 2, 3
∆V
Ref
/∆I
R
Reverse Breakdown Voltage
Change with Current
20µA ≤I
R
≤1mA -1.0 1.0 mV 1
30µA ≤I
R
≤1mA -1.5 1.5 mV 2, 3
1mA ≤I
R
≤20mA -10.0 10.0 mV 1
-20.0 20.0 mV 2, 3
V
F
Forward Bias Voltage I
F
= 2mA -1.0 -0.4 V 1
DC Drift Parameters
Delta calculations performed on QMLV devices at group B , subgroup 5, unless otherwise specified on IPI.
Symbol Parameter Conditions Notes Min Max Units Sub-
groups
V
Ref
Reverse Breakdown Voltage I
R
= 20µA -10 10 mV 1
I
R
= 20mA -10 10 mV 1
LM185BY–2.5 Electrical Characteristics
DC Parameters
Symbol Parameter Conditions Notes Min Max Units Sub-
groups
V
Ref
Reverse Breakdown Voltage I
R
= 20µA 2.462 2.538 V 1
I
R
= 30µA 2.425 2.575 V 2, 3
I
R
= 1mA 2.462 2.538 V 1
2.425 2.575 V 2, 3
I
R
= 20mA 2.462 2.538 V 1
2.425 2.575 V 2, 3
∆V
Ref
/∆I
R
Reverse Breakdown Voltage
Change with Current
20µA ≤I
R
≤1mA -1.0 1.0 mV 1
30µA ≤I
R
≤1mA -1.5 1.5 mV 2, 3
1mA ≤I
R
≤20mA -10.0 10.0 mV 1
-20.0 20.0 mV 2, 3
V
F
Forward Bias Voltage I
F
= 2mA −1.0 −0.4 V 1
T
C
Temperature Coefficient (Note 4) 50 PPM/˚C 2, 3
DC Drift Parameters
Delta calculations performed on QMLV devices at group B , subgroup 5, unless otherwise specified on IPI.
Symbol Parameter Conditions Notes Min Max Units Sub-
groups
V
Ref
1 Reverse Breakdown Voltage I
R
= 20µA -10 10 mV 1
V
Ref
2 Reverse Breakdown Voltage I
R
= 20mA -10 10 mV 1
LM185-2.5QML
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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
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. Some performance characteristics may degrade when the device is not operated under the listed test
conditions.
Note 2: The maximum power dissipation must be derated at elevated temperatures and is dictated by TJmax (maximum junction temperature), θJA (package junction
to ambient thermal resistance), and TA(ambient temperature). The maximum allowable power dissipation at any temperature is PDmax =(T
Jmax -T
A)/θJA or the
number given in the Absolute Maximum Ratings, whichever is lower.
Note 3: Human body model, 1.5 kΩin series with 100 pF
Note 4: The average temperature coefficient is defined as the maximum deviation of reference voltage, at all measured temperatures between the operating TMin
&T
Max, divided by (TMax −T
Min). The measured temperatures (TMeasured) are −55˚C, 25˚C, & 125˚C or ∆VRef /(T
Max −T
Min)
Typical Performance Characteristics
Reverse Characteristics Reverse Characteristics
20156215 20156216
Forward Characteristics Temperature Drift
20156217 20156218
LM185-2.5QML
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Typical Performance Characteristics (Continued)
Reverse Dynamic
Impedance
Reverse Dynamic
Impedance
20156219 20156220
Noise Voltage Filtered Output Noise
20156221 20156222
Response Time
20156223
LM185-2.5QML
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Applications (Continued)
Precision 1 µA to 1 mA Current Sources
20156224
20156225
METER THERMOMETERS
0˚C–100˚C Thermometer
20156226
Calibration
1. Short LM385-2.5, adjust R3 for I
OUT
=temp at 1µA/˚K
2. Remove short, adjust R2 for correct reading in
centigrade
0˚F–50˚F Thermometer
20156227
Calibration
1. Short LM385-2.5, adjust R3 for I
OUT
=temp at 1.8 µA/˚K
2. Remove short, adjust R2 for correct reading in ˚F
LM185-2.5QML
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Applications (Continued)
Improving Regulation of Adjustable Regulators
20156207
Micropower Thermocouple Cold Junction Compensator
20156206
Adjustment Procedure
1. Adjust TC ADJ pot until voltage across R1 equals Kelvin temperature multiplied by the thermocouple Seebeck coefficient.
2. Adjust zero ADJ pot until voltage across R2 equals the thermocouple Seebeck coefficient multiplied by 273.2.
Seebeck Voltage Voltage
Thermocouple Co- R1 R2 Across R1 Across R2
Type efficient (Ω)(Ω)@25˚C (mV)
(
µ
V/˚C) (mV)
J 52.3 523 1.24k 15.60 14.32
T 42.8 432 1k 12.77 11.78
K 40.8 412 953Ω12.17 11.17
S 6.4 63.4 150Ω1.908 1.766
Typical supply current 50 µA
LM185-2.5QML
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Revision History Section
Released Revision Section Originator Changes
11/08/05 A New Release, Corporate format L. Lytle 2 MDS data sheets converted into one Corp.
data sheet format. MNLM185-2.5-X Rev 2A2
and MNLM185-2.5BY-X Rev 1B1 will be
archived.
LM185-2.5QML
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Physical Dimensions inches (millimeters) unless otherwise noted
Ceramic SOIC Package (WG)
NS Package Number WG10A
TO-46 Metal Can Package (H)
NS Package Number H02A
LM185-2.5QML
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Notes
National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves
the right at any time without notice to change said circuitry and specifications.
For the most current product information visit us at www.national.com.
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LM185-2.5QML Micropower Voltage Reference Diode
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