The AMS285-2.5/AMS385-2.5 are two-terminal micropower band-gap voltage reference diodes. They feature a very low
dynamic impedance and good temperature coefficient, operating over a 20µA to 20mA current range. On-chip trimming is
used to provide tight voltage tolerance. Since the AMS285-2.5/AMS385-2.5 is a band-gap reference, uses only transistors and
resistors, low noise and good long term stability result. Careful design of the AMS285-2.5/AMS385-2.5 has made the device
exceptionally 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
AMS285-2.5/AMS385-2.5 makes these reference diodes useful for micropower circuitry. These voltage references can be
used to make portable meters, regulators or general purpose analog circuitry with battery life approaching shelf life. Further
more, the wide operating current allows it to replace older references with a tight tolerance part.
The AMS285-2.5 is operational in the full industrial temperature range of -40°C to 85°C while AMS385-2.5 is operating
over a 0°C to 70°C temperature range. The AMS285-2.5/AMS385-2.5 are available in TO-92, SO-8 and SOT-89 packages.
ORDERING INFORMATION:
TOL.
±20mV
±38mV
±75mV
±20mV
±38mV
±75mV
TO-92
AMS285-2.5AN
AMS285-2.5BN
AMS285-2.5CN
AMS385-2.5AN
AMS385-2.5BN
AMS385-2.5CN
PACKAGE TYPE
8 LEAD SOIC
AMS285-2.5AS
AMS285-2.5BS
AMS285-2.5CS
AMS385-2.5AS
AMS385-2.5BS
AMS385-2.5CS
SOT-89
AMS285-2.5AL
AMS285-2.5BL
AMS285-2.5CL
AMS385-2.5AL
AMS385-2.5BL
AMS385-2.5CL
OPERATING
TEMPERATURE RANGE
-40 to 85° C
-40 to 85° C
-40 to 85° C
0 to 70° C
0 to 70° C
0 to 70° C
Advanced Monolithic Systems, Inc.
6680B Sierra Lane, Dublin, CA 94568 Phone (925) 556-9090 Fax (925) 556-9140
AMS285-2.5/AMS385-2.5
ABSOLUTE MAXIMUM RATINGS
Reverse Current
Forward Current
Operating Temperature Range
AMS285-2.5
AMS385-2.5
30mA
10mA
-40°C to 85°C
0°C to 70°C
Storage temperature
Soldering information
TO-92 package: 10 sec.
SOIC package: Vapor phase (60 sec)
Infrared (15 sec.)
SOT-89 package: 10 sec.
-55°C to +150°C
260°C
215°C
220°C
265°C
ELECTRICAL CHARACTERISTICS
Electrical Characteristics at I
R
= 100
µA,
and T
A
= +25°C unless otherwise specified.
Parameter
Reverse Breakdown
Voltage (Note 4)
Reverse Dynamic
Impedance (Note 4)
Reverse Breakdown
Voltage Change with
current (Note 4)
Min. Operating
Current (Note 4)
Wide Band Noise
(Note 5)
Temperature Coeff.
(Note 6)
Long Term Stability
(Note 5)
T
A
=25°C±.1°C
T = 1000 Hr
I
R
- 100
µA,
10Hz
≤
f
≤
10kHz
Conditions
I
R
- 100
µA
I
R
- 100
µA,
f =20Hz
10µA
≤I
R
≤1mA
1mA
≤I
R
≤20mA
AMS285A-2.5
Min
Typ
Max
2.480
2.500
0.2
1.0
10
12
18
20
2.520
0.60
AMS285B-2.5
Min
Typ
Max
2.462
2.500
1
1.0
10
13
20
30
2.538
AMS285C-2.5
Min
Typ
Max
2.425
2.500
1
2.0
20
13
20
30
2.575
Units
V
Ω
mV
µA
µA
µV
120
120
120
25
50
100
150
ppm/°C
20
20
20
ppm
ELECTRICAL CHARACTERISTICS
Electrical Characteristics at I
R
= 100
µA,
and T
A
= +25°C unless otherwise specified.
Parameter
Reverse Breakdown
Voltage (Note 4)
Reverse Dynamic
Impedance (Note 4)
Reverse Breakdown
Voltage Change with
Current (Note 4)
Min. Operating
Current (Note 4)
Wide Band Noise
(Note 5)
Temperature Coeff.
(Note 6)
Long Term Stability
(Note 5)
T
A
=25°C±.1°C
T = 1000 Hr
I
R
- 100
µA,
10Hz
≤
f
≤
10kHz
Conditions
I
R
- 100
µA
I
R
- 100
µA,
f =20Hz
10µA
≤I
R
≤1mA
1mA
≤I
R
≤20mA
AMS385A-2.5
Min
Typ
Max
2.480
2.500
0.2
1.0
10
12
18
20
2.520
0.60
AMS385B-2.5
Min
Typ
Max
2.462
2.500
1
2.0
20
13
20
30
2.538
AMS385C-2.5
Min
Typ
Max
2.425
2.500
1
2.0
20
13
20
30
2.575
Units
V
Ω
mV
µA
µA
µV
120
120
120
25
50
100
150
ppm/°C
20
20
20
ppm
Advanced Monolithic Systems, Inc.
6680B Sierra Lane, Dublin, CA 94568 Phone (925) 556-9090 Fax (925) 556-9140
AMS285-2.5/AMS385-2.5
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:
For elevated temperature operation, T
j
max is:
AMS285
AMS385
+125°C
+100°C
Thermal Resistance
ϕ
JA
(junction to ambient)
TO-92
170°C/W (0.125” leads)
SO-8
165°C/W
SOT-89
160°C/W
Note 3:
Parameters identified with
boldface type
apply at temperature extremes. All other numbers apply at T
A
= T
J
= 25°C.
Note 4:
Guaranteed and 100% production tested.
Note 5:
Guaranteed but not 100% production tested. These limits are not used to calculate average outgoing quality levels.
Note 6:
The average temperature coefficient is defined as the maximum deviation of reference voltage at all measured temperatures between the operating T
MAX and
T
MIN
, divided by T
MAX
- T
MIN
. The measured temperatures are 0°C, 25°C, 70°C and 85°C.
PIN CONNECTIONS
TO-92
Plastic Package (N)
8L SOIC
SO Package (S)
+
8
N/C N/C N/C
7
6
5
SOT-89
(L)
3
2
1
3
1
2
3
N/C N/C N/C
4
-
N/C
2
+
1
-
Bottom View
Top View
Top View
TYPICAL APPLICATIONS
Wide Input
Range Reference
Micropower Reference
from 9V Battery
V
IN
= 3.7V TO 30V
9V
200k
LM334
2.5V
3.3k
AMS385-2.5
OUT
2.5V
AMS385-2.5
Advanced Monolithic Systems, Inc.
6680B Sierra Lane, Dublin, CA 94568 Phone (925) 556-9090 Fax (925) 556-9140
AMS285-2.5/AMS385-2.5
TYPICAL APPLICATIONS
(Continued)
0°C - 100°C Thermometer
°
°
0°C - 100°C Thermometer
°
°
1k
150
0-100µA M
I
OUT
R1
8k
R2
1k
R
AMS385-2.5
R3
100
R4
220
0-50µA
I
OUT
M
R1
4k
R2
1k
R
AMS385-2.5
R3
50
R4
100
V
+
LM334
V
-
3V
V
+
LM334
V
-
3V
Calibration
1. Short AMS385-2.5, adjust R3 for I
OUT
= temp at 1µA/°K
2. Remove short, adjust R2 for correct reading in
°C
Calibration
1. Short AMS385-2.5, adjust R3 for I
OUT
= temp at 1.8µA/°K
2. Remove short, adjust R2 for correct reading in
°F
Micropower* 5V Regulator
I
Q
V
+
LM334
V
-
R
2.2k
3
+
7
LM4250C
2
-
4
6
V
O
= 5V
I
L
≤
100mA
150pF
100k
+
4.7µF
TANTALUM
AMS385-2.5
10M
AMS385-2.5
2k
100k
47k
2N2905
V
IN
≥
5.2V
Micropower* 10V Reference
I
Q
V
IN
= 15V
500k
2
+
7
LM4250C
3
8
-
4
22M
150pF
1.5M
6
10V
8 1N457
1N457
500k
*I
Q
≅
40µA
*I
Q
≅
20µA standby current
Advanced Monolithic Systems, Inc.
6680B Sierra Lane, Dublin, CA 94568 Phone (925) 556-9090 Fax (925) 556-9140
AMS285-2.5/AMS385-2.5
TYPICAL APPLICATIONS
(Continued)
Micropower Thermocouple Cold Junction Compensator
V
+
LM334
2k
1%
18k
1M
1%
V
-
R
Adjustment Procedure
TC ADJ
500
3V +
LITHIUM
AMS385-2.5
ZERO ADJ
100k
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.
Thermocouple
Type
Seebeck
Coefficient
(mV/
°
C)
52.3
42.8
40.8
6.4
R1
(Ω )
Ω
R2
Voltage
Voltage
(Ω ) Across R1
Ω
Across R2
@
25°C (mV)
°
(mV)
1.24k
1k
953Ω
150Ω
15.60
12.77
12.17
1.908
14.32
11.78
11.17
1.766
R2
R1
+
THERMOCOUPLE
+
-
-
COLD JUNCTION
ISO THERMAL
WITH LM334
METER
J
T
K
S
523
432
412
63.4
Typical supply current 50µA
Precision 1µ A to 1mA Current Sources
µ
AMS385-2.5
AMS385-2.5
30V
C1
150pF
R1
68k
2
-
LM312
3
I
OUT
*
-1.5V TO -27V
-30V
+
4
I
OUT
*
R2
1.5V TO 27V
7
6
3
+
C1
150pF
2
-
LM312
4
7
6
R1
68k
R2
*I
OUT
=2.5V/R2
Advanced Monolithic Systems, Inc.
6680B Sierra Lane, Dublin, CA 94568 Phone (925) 556-9090 Fax (925) 556-9140
京公网安备 11010802033920号
EEWORLD
