Date:05/21/04
SPX385-2.5 Micropower Voltage Reference
Copyright 2004 Sipex Corporation
1
FEATURES
Trimmed Bandgap ............................ 1% and 2%
Wide Operating Current ............... 20
A to 20mA
Extended Temperature Range ... -40
C to +85
C
Dynamic Impedance .............................. 1
max
Offered in SOT-23, TO-92, SOIC, and SOT-89
Improved Replacement for LM185/285/385-2.5V,
AS385-2.5
Low Cost Solution
Micropower Voltage Reference
SPX385-2.5
The SPX385-2.5 is a micropower 2-terminal band-gap voltage reference with a very wide
operating current range from 20
A to 20mA that provides a stable voltage. The high stability of
this device is primarily the result of the low temperature coefficient Thin Film Resistor process and
Laser Trimming of the output voltage at the wafer level.
The SPX385-2.5 is available in a SOT-23, TO-92, SOIC-8 and SOT-89 package with an operating
temperature range of -40
C to 85
C. A 1.2 and 5 volt device is also available - SPX385-1.2 and
SPX385-5.
Figure 1: Block Diagram
APPLICATIONS
Battery Operating Equipment
Adjustable Supplies
Switching Power Supplies
Error Amplifiers
Single Supply Amplifier
Monitors / VCR / TV
Personal Computers
Anode (A)
Cathode (K)
1.25V
+
-
500k
500k
DESCRIPTION
BLOCK DIAGRAM
SPX385
3 Pin SOT-23
Cathode
N/C
Anode
Refer to page 4 for pinouts.
Date:05/21/04
SPX385-2.5 Micropower Voltage Reference
Copyright 2004 Sipex Corporation
2
SPX385A-2.5
SPX385-2.5
PARAMETER
CONDITIONS
MIN.
TYP.
MAX
MIN.
TYP.
MAX.
UNIT
Reference Voltage
2.475 2.500
2.525
2.450
2.500
2.550
V
Dynamic Output
F = 20Hz
0.6
1.0
0.6
1.0
Impedance
I
R
= 100
A
Reference Voltage
20
A
I
R
20mA
10
20
10
20
mV
Change with I
R
.
Temperature Coefficient
Note 1
60
100
60
100
ppm/
C
Minimum Operating Current
15
20
15
20
A
Output Wideband Noise
10Hz
f
10kHz
120
120
Vrms
Long Term Stability
T=1000Hr;
60
60
ppm
T
A
= 25
C
0.1
C
Operating Temperature
-40
+85
-40
+85
C
Stresses greater than those listed under ABSOLUTE MAXIMUM RAT-
INGS may cause permanent damage to the device. This is a stress rating
only and functional operation of the device at these or any other conditions
above those indicated in the operational sections of this specification is not
implied. Exposure to absolute maximum rating conditions for extended
periods may affect reliability.
Reverse Current (I
KA
) ............................................................. 30mA
Forward Current (I
AK
) ............................................................. 10mA
Operating Temperature Range (T
A
) ............................ -40 to +85
C
Junction Temperature (T
J
) ..................................................... 150
C
Storage Temperature (T
STG
) ....................................... - 65 to 150
C
Lead Temperature (Soldering 10 sec.), T
L
............................. 300
C
I
IN
= 100
A, T
A
= 25
C, unless otherwise specified.
*CALCULATING AVERAGE TEMPERATURE COEFFICIENT (TC)
D
DV
KA
0
15
30
45
60
75
90
105
-10
0.5
5000
0
0
0
0.07 mV/
C
0.003 %/
C
27 ppm/
C
TC in mV/
C =
TC in % /
C =
DV
KA
(mV)
DT
A
DT
A
DV
KA
at 25
C
DV
KA
x 100
(
)
TC in ppm/
C =
DT
A
DV
KA
at 25
C
DV
KA
x 10
6
(
)
ppm
%
mV
Junction Temperature (
C)
Figure 2. V
KA
vs. Temperature
Note 1. Three-point measurement guarantees the error band over the specified temperature range.
ABSOLUTE MAXIMUM RATINGS
TYPICAL THERMAL RESISTANCES
PACKAGE 0
JA
0
JC
TYPICAL DERATING
TO-92
160
C/W 80
C/W
6.3 mW/
C
SOT-23
575
C/W 150
C/W
1.7 mW/
C
SOIC-8
175
C/W 45
C/W
5.7 mW/
C
SOT-89
110
C/W
8
C/W
9.1 mW/
C
Typical deratings of the thermal resistances are
given for ambient temperature >25
.
ELECTRICAL CHARACTERISTICS
Date:05/21/04
SPX385-2.5 Micropower Voltage Reference
Copyright 2004 Sipex Corporation
3
Figure 3. Test Circuit
Figure 4. High Current Operating Characteristics
Figure 5. Reference Voltage vs. Ambient Temperature
Figure 6. Low Current Operating Characteristics
V
IN
V
KA
I
K
-2
-1
0
1
2
3
-20
I
K
- Cathode Current (mA)
V
KA
- Cathode Voltage (V)
V
KA
Temperature Range: 0
C to 85C
-15
-10
-5
0
5
10
15
20
25
30
V
KA
- Voltage (V)
T
A
- Ambient Temperature (C)
90
120
-60
-30
0
30
60
2.53
I
K
= 10mA
2.52
2.51
2.50
2.49
2.48
2.47
2.46
2.45
V
REF
= 2.500V at 25
C
45
85C
V
KA
- Cathode Voltage (V)
I
K
- Cathode Current (A)
30
15
0
-1.0
0
1.0
2.0
3.0
25C
-0C
Figure 7a. Precision 1
A to 1mA Current Sink
Figure 7b. Precision 1
A to 1mA Current Source
LM312
R1
68k
+
R2
C1
150pF
7
6
4
3
2
SPX385-2.5
I
OUT
*
-1.5V to -27V
-30V
* I
OUT
= 2.5V
R2
LM312
R1
68k
+
R2
C1
150pF
7
6
4
3
2
SPX385-2.5
I
OUT
*
1.5V to 27V
30V
* I
OUT
= 2.5V
R2
TYPICAL PERFORMANCE CHARACTERISTICS
Date:05/21/04
SPX385-2.5 Micropower Voltage Reference
Copyright 2004 Sipex Corporation
4
TYPICAL PERFORMANCE CHARACTERISTICS
Figure 8. Improving Regulation of Adjustable Regula-
tors
Figure 9. Micropower Reference from 9V Battery
Figure 10. Wide Input Range Reference
Figure 11: Precision Micropower 10V Reference
375
V
IN
SPX385-2.5
5V
LM338
120
200k
9V
SPX385-2.5
2.5V
3.3k
V
IN
= 3.7V to 30V
SPX385-2.5
OUT
2.5V
LM334
SPX385-2.5
500k
+
-
V
IN
= 15V
LM4250C
3
7
2
4
8
22M
1.5M
500k
150pF
6
10V
I
Q
30
A Standby Current
I
Q
Bottom View
TO-92 (N)
1
3
2
N/C
CATHODE
ANODE
Top View
2
1
3
4
8
7
6
5
8-Pin NSOIC
N/C
N/C
N/C
SOT-23-3 (M)
3
2
Top View
Top View
SOT-89 (M1)
1
2
3
ANODE CATHODE
ANODE
CATHODE
N/C
1
CATHODE
ANODE
N/C
N/C
N/C
N/C
PACKAGE PINOUTS
Date:05/21/04
SPX385-2.5 Micropower Voltage Reference
Copyright 2004 Sipex Corporation
5
PACKAGE: 3 PIN SOT-23
A
A2
A1
SIDE VIEW
A
A
Seating Plane
C
E
E1
e
e1
D
b
1
2
3
L
Gauge Plane
VIEW C
SEE VIEW C
B
B
- - 1.25
Dimensions in (mm)
3 PIN SOT-23
1.050 1.100 1.150
0.36 0.38 0.45
0.15 - 0.20
0.37 0.45 0.53
0 - 8
A
A2
b
c
D
E
E1
L
L2
MIN NOM MAX
2.901 2.926 2.951
1.601 1.626 1.651
e
e1
VIEW A-A
Seating Plane
0.925 0.950 0.975
1.850 1.900 1.950
2.700 2.800 2.900
SEE VIEW D
c
WITH PLATING
BASE METAL
b
SECTION B-B
VIEW D
L2
- - 0.05
A1
0 - 0.10
3 PIN SOT-23
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