D E S C R I P T I O N
K E Y F E A T U R E S
s
s
s
s
s GUARANTEED 1% INITIAL ACCURACY
(LM385B-1.2)
s
s
s
s
s GUARANTEED 2.5% INITIAL ACCURACY
(LM385-1.2)
s
s
s
s
s GUARANTEED 1.5% INITIAL ACCURACY
(LM385B-2.5)
s
s
s
s
s GUARANTEED 3% INITIAL ACCURACY
(LM385-2.5)
p GUARANTEED 20A OPERATING CURRENT
p LOW TEMPERATURE COEFFICIENT
p OPERATING CURRENT OF 20A TO 20mA
p VERY LOW DYNAMIC IMPEDANCE . . . 1
The LM385/385B Micropower Voltage
References are two terminal bandgap
reference diodes designed and optimized
for accurate low power operation in
portable and other power sensitive
systems. Operating currents are
guaranteed from as low as 15A up to
20mA for the LM385/385B-1.2, and 20A
up to 20mA for the LM385/385B-2.5,
giving designers a great deal of flexibility
in optimizing power consumption, noise
and ultimate application performance. As
an added feature, the references output
impedance is extraordinarily low over the
entire operating range of quiescent
currents. This enables an extremely wide
dynamic load range with little effect on
the overall reference accuracy.
The LM385 family is available in fixed
1.2V and 2.5V reference values. Process
and circuit design optimization provide
for high accuracy with initial tolerance
values of 1% for the LM385B-1.2, 2% for
the LM385-1.2, 1.5% for the LM385B-2.5,
and 3% for the LM385-2.5.
Complementing their initial accuracy, the
bandgap reference is temperature
compensated to deliver 20ppm
performance over the 0 to 70C
operating temperature range.
The LM385 family from Linfinity is a
pin-for-pin replacement for the LM385/
385B family of voltage references.
P A C K A G E O R D E R I N F O R M A T I O N
T
A
(C)
1.2V
30mV
LM385DM-1.2
LM385LP-1.2
0 to 70
12mV
LM385BDM-1.2
LM385BLP-1.2
2.5V
75mV
LM385DM-2.5
LM385LP-2.5
38mV
LM385BDM-2.5
LM385BLP-2.5
Reference
Voltage
DM
Plastic TO-92
3-pin
LP
Plastic SOIC
8-pin
Initial
Tolerance
A P P L I C A T I O N S
s
s
s
s
s PORTABLE METER REFERENCES
p PORTABLE TEST INSTRUMENTS
p BATTERY OPERATED SYSTEMS
p CURRENT LOOP INSTRUMENTATION
P R O D U C T H I G H L I G H T
M
I C R O P O W E R
R
E F E R E N C E
F
R O M
9V B
A T T E R Y
1.2V R
E F E R E N C E
1.2V
LM385-1.2V
5V
38k
2.5V
LM385-2.5V
9V
200k
1.2 & 2.5V M
I C R O P O W E R
V
O LTA G E
R
E F E R E N C E
P
R O D U C T I O N
D
A T A
S
H E E T
T
H E
I
N F I N I T E
P
O W E R
O F
I
N N O V A T I O N
Copyright 1996
Rev. 1.2 7/96
F O R F U R T H E R I N F O R M A T I O N C A L L ( 7 1 4 ) 8 9 8 - 8 1 2 1
11861 W
ESTERN
A
VENUE
, G
ARDEN
G
ROVE
, CA. 92841
LM385/385B
LIN D
O C
#: 385
1
Note: All surface-mount packages are available in Tape & Reel.
Append the letter "T" to part number. (i.e. LM385DM-2.5T)
1.2 & 2.5V M
I C R O P O W E R
V
O LTA G E
R
E F E R E N C E
LM385/385B
P R O D U C T D A T A B O O K 1 9 9 6 / 1 9 9 7
Copyright 1996
Rev. 1.2 7/96
2
P
R O D U C T I O N
D
A T A
S
H E E T
ABSOLUTE MAXIMUM RATINGS
(Note 1)
PACKAGE PIN OUTS
Reverse Breakdown Current .................................................................................... 30mA
Forward Current ........................................................................................................ 10mA
Operating Temperature Range
LM385 ........................................................................................................... 0C to 70C
Storage Temperature Range ...................................................................... -65C to 150C
Lead Temperature (soldering, 10 seconds) ............................................................. 300C
THERMAL DATA
DM PACKAGE:
THERMAL RESISTANCE-JUNCTION TO AMBIENT,
JA
165C/W
LP PACKAGE:
THERMAL RESISTANCE-JUNCTION TO AMBIENT,
JA
165C/W
The
JA
numbers are guidelines for the thermal performance of the device/pc-board system.
All of the above assume no ambient airflow.
1. ANODE
2. CATHODE
3. N/C
LP PACKAGE
(Top View)
8.
7.
6.
5.
1.
2.
3 .
4.
N/C
N/C
N/C
ANODE
CATHODE
N/C
CATHODE
N/C
DM PACKAGE
(Top View)
Note 1. Values beyond which damage may occur. All voltages are specified with respect to
ground, and all currents are positive into the specified terminal
1.2 & 2.5V M
I C R O P O W E R
V
O LTA G E
R
E F E R E N C E
LM385/385B
P R O D U C T D A T A B O O K 1 9 9 6 / 1 9 9 7
3
Copyright 1996
Rev. 1.2 7/96
P
R O D U C T I O N
D
A T A
S
H E E T
E L E C T R I C A L C H A R A C T E R I S T I C S
(Unless otherwise specified, these specifications apply to T
A
= 25C. Typ number represents T
A
= 25C value.)
Parameter
Symbol
Test Conditions
Units
LM385/385B-1.2
Min.
Typ.
Max.
1.205
1.235
1.260
V
1.223
1.235
1.247
V
20
ppm/C
8
15
A
1.5
mV
20
mV
1
60
V
20
ppm/kHr
Reverse Breakdown Voltage
LM385
V
Z
I
MIN
I
R
I
MAX
LM385B
I
MIN
I
R
I
MAX
Average Temperature Coefficient
V
Z
I
R
= 100A
Temp
Minimum Operating Current
I
MIN
Reverse Breakdown Voltage Chang
e
V
Z
I
MIN
I
R
1mA
with Current
I
R
1mA
I
R
20mA
Reverse Dynamic Impedance
r
z
I
R
= 100A
Wide Band Noise (RMS)
e
n
I
R
= 100A, 10Hz
f
10kHz
Long Term Stability
V
Z
I
R
= 100A, T
A
= 25C 0.1C
Time
GRAPH / CURVE INDEX
Characteristic Curves
LM385/385B-1.2
FIGURE #
1.
RESPONSE TIME
2.
REVERSE CHARACTERISTICS
3.
FORWARD CHARACTERISTICS
4.
TEMPERATURE DRIFT
5.
REVERSE VOLTAGE CHANGE
6.
REVERSE DYNAMIC IMPEDANCE
7.
NOISE VOLTAGE
Parameter
Symbol
Test Conditions
Units
LM385/385B-2.5
Min.
Typ.
Max.
2.425
2.500
2.575
V
2.462
2.500
2.538
V
20
ppm/C
13
20
A
2
mV
20
mV
1
120
V
20
ppm/kHr
Reverse Breakdown Voltage
LM385
V
Z
I
MIN
I
R
I
MAX
LM385B
I
MIN
I
R
I
MAX
Average Temperature Coefficient
V
Z
I
R
= 100A
Temp
Minimum Operating Current
I
MIN
Reverse Breakdown Voltage Chang
e
V
Z
I
MIN
I
R
1mA
with Current
I
R
1mA
I
R
20mA
Reverse Dynamic Impedance
r
z
I
R
= 100A, f = 20Hz
Wide Band Noise (RMS)
e
n
I
R
= 100A, 10Hz
f
10kHz
Long Term Stability
V
Z
I
R
= 100A, T
A
= 25C 0.1C
Time
Characteristic Curves
LM385/385B-2.5
FIGURE #
8.
RESPONSE TIME
9.
REVERSE CHARACTERISTICS
10. FORWARD CHARACTERISTICS
11. TEMPERATURE DRIFT
12. REVERSE DYNAMIC IMPEDANCE
13. NOISE VOLTAGE
LM385/385B-1.2
LM385/385B-2.5
1.2 & 2.5V M
I C R O P O W E R
V
O LTA G E
R
E F E R E N C E
LM385/385B
P R O D U C T D A T A B O O K 1 9 9 6 / 1 9 9 7
Copyright 1996
Rev. 1.2 7/96
4
P
R O D U C T I O N
D
A T A
S
H E E T
C H A R A C T E R I S T I C C U R V E S -- LM385/385B-1.2V
FIGURE 2. -- REVERSE CHARACTERISTICS
FIGURE 3. -- FORWARD CHARACTERISTICS
FIGURE 4. -- TEMPERATURE DRIFT
FIGURE 1. -- RESPONSE TIME
Reverse Voltage - (V)
Reverse Current - (A)
0.1
0
0.2
0.4
0.6
0.8
1.0
1
10
100
T
A
= 0 to 70C
1.2
1.4
0
Forward Current - (mA)
Forward Voltage - (V)
0.4
0.01
0.1
1
10
100
0.8
1.2
T
A
= 25C
Temperature - (C)
Reference Voltage - (V)
1.226
0
20
30
40
60
70
1.23
1.236
1.242
1.232
1.24
10
50
1.228
1.234
1.238
I
R
= 100A
Time - (s)
Output Voltage
0
5V
0
1.0V
Input Voltage
0.5V
1.5V
V
IN
V
OUT
36k
0
50
100
500
550
1.2 & 2.5V M
I C R O P O W E R
V
O LTA G E
R
E F E R E N C E
LM385/385B
P R O D U C T D A T A B O O K 1 9 9 6 / 1 9 9 7
5
Copyright 1996
Rev. 1.2 7/96
P
R O D U C T I O N
D
A T A
S
H E E T
C H A R A C T E R I S T I C C U R V E S -- LM385/385B-1.2V
FIGURE 6. -- REVERSE DYNAMIC IMPEDANCE
FIGURE 7. -- NOISE VOLTAGE
FIGURE 5. -- REVERSE VOLTAGE CHANGE
0.1
(f) Frequency - (Hz)
Dynamic Impedance - (
)
1
10
100
1k
10k
100k
10
1000
T
A
= 25C
I
R
= 100A
100
100
(f) Frequency - (Hz)
(V
N
) Noise Voltage - (nV/ Hz)
300
10
100
1k
10k
100k
600
700
400
500
I
R
= 100A
T
A
= 25C
200
800
Reverse Current - (mA)
Output Voltage Change - (mV)
-4
0.01
0.1
1
10
100
0
6
12
2
10
-2
4
8
14
16
T
A
= 0 to 70C
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