Advanced Monolithic Systems, Inc. 6680B Sierra Lane, Dublin, CA 94568 Phone (925) 556-9090 Fax (925) 556-9140
Advanced
AMS285/AMS385
Monolithic
ADJUSTABLE MICROPOWER VOLTAGE REFERENCE DIODE
Systems
FEATURES
APPLICATIONS
Adjustable from 1.24V to 5.30V
Battery Powered Systems
Operating Current 10
A to 20mA
Instrumentation
1% and 2% Initial Tolerance
A/D, D/A Converters
1
Dynamic Impedance
Temperature measurement
Low Temperature Coefficient
Current sources
1.2V Device and 2.5V Device also available
Notebook/Personal Computer
AMS285-1.2 and AMS285-2.5 series, respectively
Monitors/ VCR/ TV
AMS385-1.2 and AMS385-2.5 series.
Pagers
GENERAL DESCRIPTION
The AMS285/AMS385 are three-terminal micropower band-gap voltage reference diodes. They feature a very low dynamic
impedance and good temperature coefficient, operating from 1.24V to 5.3V and over a 10
A to 20mA current range. On-chip
trimming is used to provide tight voltage tolerance. Since the AMS285/AMS385 is a band-gap reference, uses only transistors
and resistors, low noise and good long-term stability result. Careful design of the AMS285/AMS385 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/AMS385 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 is operational in the full industrial temperature range of -40
C to 85
C while AMS385 is operating over a 0
C
to 70
C temperature range. The AMS285/AMS385 are available in TO-92, SO-8 and SOT-89 packages.
ORDERING INFORMATION:
TOL.
PACKAGE TYPE
OPERATING
TO-92
8 LEAD SOIC
SOT-89
TEMPERATURE RANGE
12mV AMS285AN
AMS285AS
AMS285AL
-40 to 85
C
25mV AMS285BN
AMS285BS
AMS285BL
-40 to 85
C
25mV AMS285CN
AMS285CS
AMS285CL
-40 to 85
C
12mV AMS385AN
AMS385AS
AMS385AL
0 to 70
C
25mV AMS385BN
AMS385BS
AMS385BL
0 to 70
C
25mV AMS385CN
AMS385CS
AMS385CL
0 to 70
C
Advanced Monolithic Systems, Inc. 6680B Sierra Lane, Dublin, CA 94568 Phone (925) 556-9090 Fax (925) 556-9140
AMS285/AMS385
ABSOLUTE MAXIMUM RATINGS
Reverse Current
30mA
Storage temperature
-55
C to +150
C
Forward Current
10mA
Soldering information
Operating Temperature Range
TO-92 package: 10 sec.
260
C
AMS285
-40
C to 85
C
SOIC package: Vapor phase (60 sec)
215
C
AMS385
0
C to 70
C
Infrared (15 sec.)
220
C
SOT-89 package: 10 sec.
265
C
ELECTRICAL CHARACTERISTICS
Electrical Characteristics at I
R
= 100
A, and T
A
= +25C unless otherwise specified.
Parameter
Conditions
AMS285A
Min Typ Max
AMS285B
Min Typ Max
AMS285C
Min Typ Max
Units
Reference Voltage
I
R
=100
A
1.228
1.240
1.252
1.215
1.240
1.265
1.215
1.240
1.265
V
Dynamic Output
Impedance
I
AC
=0.1I
R
, f = 20Hz
V
OUT
= V
REF
V
OUT
= 5.3V
0.3
0.7
0.3
0.7
0.3
0.7
Reference Voltage
Change with Current
10
A
I
R
1mA
1mA
I
R
20mA
0.2
4
1.0
10
0.2
4
1.0
10
0.2
4
1.0
10
mV
mV
Min. Operating
Current (Note 4)
V
OUT
= V
REF
V
OUT
= 5.3V
6
30
9
45
6
30
9
45
6
30
9
45
A
A
Wide Band Noise
(Note 5)
10Hz
f
10kHz
V
OUT
= V
REF
V
OUT
= 5.3V
50
170
50
170
50
170
V
rms
V
rms
Temperature Coeff.
(Note 6)
25
50
100
150
ppm/C
Long Term Stability
(Note 5)
T
A
=25C.1C
T = 1000 Hr
20
20
20
ppm
ELECTRICAL CHARACTERISTICS
Electrical Characteristics at I
R
= 100
A, and T
A
= +25C unless otherwise specified.
Parameter
Conditions
AMS285A
Min Typ Max
AMS285B
Min Typ Max
AMS285C
Min Typ Max
Units
Reference Voltage
I
R
=100
A
1.228
1.240
1.252
1.215
1.240
1.265
1.215
1.240
1.265
V
Dynamic Output
Impedance
I
AC
=0.1I
R
, f = 20Hz
V
OUT
= V
REF
V
OUT
= 5.3V
0.3
0.7
0.3
0.7
0.3
0.7
Reference Voltage
Change with Current
10
A
I
R
1mA
1mA
I
R
20mA
0.2
4
1.0
10
0.2
4
1.0
10
0.2
4
1.0
10
mV
mV
Min. Operating
Current (Note 4)
V
OUT
= V
REF
V
OUT
= 5.3V
6
30
9
45
6
30
9
45
6
30
9
45
A
A
Wide Band Noise
(Note 5)
10Hz
f
10kHz
V
OUT
= V
REF
V
OUT
= 5.3V
50
170
50
170
50
170
V
rms
V
rms
Temperature Coeff.
(Note 6)
25
50
100
150
ppm/C
Long Term Stability
(Note 5)
T
A
=25C.1C
T = 1000 Hr
20
20
20
ppm
Advanced Monolithic Systems, Inc. 6680B Sierra Lane, Dublin, CA 94568 Phone (925) 556-9090 Fax (925) 556-9140
AMS285/AMS385
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
+125C
AMS385
+100C
Thermal Resistance
TO-92
SO-8
SOT-89
JA
(junction to ambient)
170C/W (0.125" leads)
165C/W
160C/W
Note 3:
Parameters identified with boldface type apply at temperature extremes. All other numbers apply at T
A
= T
J
= 25C.
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
8L SOIC
SOT-89
Plastic Package (N)
SO Package (S)
(L)
Bottom View
Top View
Top View
TYPICAL APPLICATIONS
1.2V Reference
5.0V Reference
Precision 10V Reference
+
-
FB
AMS385
1.2V
R1
500k
9V
R3
364k
R2
120k
+
-
FB
AMS385
R1
50k
9V
5V
+
=
1
R2
R3
1.24
V
OUT
R3
68.1k
1%
R2
301k
1%
+
-
FB
AMS385
R1
5k
15V
V
OUT
10V
1
2
3
FB
-
+
1
2
8
4
3
7
5
6
N/C ADJ
N/C
N/C N/C
N/C
+
-
FB
-
+
1
2
3
Advanced Monolithic Systems, Inc. 6680B Sierra Lane, Dublin, CA 94568 Phone (925) 556-9090 Fax (925) 556-9140
AMS285/AMS385
TYPICAL APPLICATIONS (Continued)
Low AC Noise Reference
Current Source
25V Low Current Shunt Regulator
200mA Shunt Regulator
Voltage Level Detector
Voltage Level Detector
R3
360k
R2
120k
+
-
FB
AMS385
R1
100k
15V
V
OUT
10V
R4
33
C1
0.47
F
C2
10
F
+
R2
120k
R1
120k
+
-
FB
AMS385
R4
V+
V
OUT
2.5V
R3
1k
50
A< I < 200 mA
2N2219
R1
+
AMS385
FB
R2
120k
-
2N2905
2N3964
1
A< I < 100 mA
+15V
R1
1.24V
I
OUT
=
R2
2.4M
R1
120k
+
-
FB
AMS385
R3
V+
V
OUT
25V
2N5115
100
A< I < 5 mA
R2
1M
R1
120k
+
-
FB
AMS385
R3
200
-5V
< -12V
LED ON
D1
R2
1M
R1
120k
+
-
FB
AMS385
R3
330
-5V
> -12V
LED ON
D1
Advanced Monolithic Systems, Inc. 6680B Sierra Lane, Dublin, CA 94568 Phone (925) 556-9090 Fax (925) 556-9140
AMS285/AMS385
TYPICAL APPLICATIONS (Continued)
Bidirectional Clamp
2.4V
Bidirectional Adjustable Clamp
1.8V to
2.4V
Bidirectional Adjustable Clamp
2.4V to
6V
TYPICAL PERFORMANCE CHARACTERISTICS
R3
510k
R2
510k
+
-
FB
AMS385
R1
V
IN
D1
1N457
-
+
AMS385
D2
1N457
FB
V
OUT
I
R4
390k
R3
510k
R2
510k
+
-
FB
AMS385
R1
V
IN
D1
1N457
-
+
AMS385
D2
1N457
FB
V
OUT
I
R3
1M
R2
330k
+
-
FB
AMS385
R1
V
IN
D1
1N457
-
+
AMS385
D2
1N457
FB
V
OUT
I
R4
330k
T
Y
TEMPCO
=
0
-5
AMS285 Typical Temperature Coefficient
REFERENCE VOLTAGE CHANGE (mV) -10
0
25
50
75
100 125
TEMPERATURE ( C)
-50
-25
T
Y
0
-5
REFERENCE VOLTAGE CHANGE (mV) -10
0
25
70
TEMPERATURE ( C)
T
Y
AMS385 Typical Temperature Coefficient
80
-40
Advanced Monolithic Systems, Inc. 6680B Sierra Lane, Dublin, CA 94568 Phone (925) 556-9090 Fax (925) 556-9140
AMS285/AMS385
TYPICAL PERFORMANCE CHARACTERISTICS (Continued)
-2
2
4
8
10
0.1
1
10
100
Reverse Characteristics
0
6
OUTPUT VOLTAGE CHANGE (mV)
T
A
=25 C
0.1
100
100
1k
10k
100k
Dynamic Output Impedance
1
10
OUTPUT IMPEDANCE (
)
0.01
0
0.4
1.2
0.1
1
10
0.8
0.01
REVERSE CURRENT (mA)
FREQUENCY (Hz)
0
0.2
0.4
0.6
0.8
1.0
1.2
0.1
100
10
1.4
REVERSE VOLTAGE (V)
REVERSE CURRENT (
A)
1
Reverse Characteristics
Forward Characteristics
FORWARD VOLTAGE (V)
1
2
3
4
5
0
70
30
Minimum Operating Current
OUTPUT VOLTAGE (V)
MINIMUM CURRENT (
A)
10
80
60
-55
5
25 45 65 85 105
1.260
1.240
125
REFERENCE VOLTAGE (V)
Temperature Drift of 3
Representative Units
0
10
0
4
6
0
50
100
200
TIME (
s)
Response Time
VOLTAGE (V)
3
5
Output Noise Voltage
NOISE (nV/
Hz)
TEMPERATURE ( C)
1.250
1.230
1.220
-35 -15
I
R
= 100
A
T
A
=-55 C
T
A
=125 C
T
A
=125 C
T
A
=-55 C
T
A
=25 C
T
A
=-55 C
T
A
=25 C
T
A
=125 C
TYP @ 25 C
AMS385
WORST
CASE
OUTPUT
OUTPUT
INPUT
10
364k
120k
AMS385
50k
INPUT
10
10,000
100
1k
10k
100k
100
1,000
FREQUENCY (Hz)
10
20
10
Feedback Current
FEEDBACK CURRENT (nA)
5
25
15
V
OUT
= V
REF
I
R
= 100
A
0
0
25
50
75
100 125
TEMPERATURE ( C)
-50
-25
V
OUT
= 5.3V
20
50
40
V
OUT
= V
REF
V
OUT
= 5.3V
I
R
= 100
A
I
R
= 100
A
I
R
= 0.1I
R
T
A
=25 C
V
OUT
= V
REF
V
OUT
= 5.3V
150
2
1
Advanced Monolithic Systems, Inc. 6680B Sierra Lane, Dublin, CA 94568 Phone (925) 556-9090 Fax (925) 556-9140
AMS285/AMS385
PACKAGE DIMENSIONS
inches (millimeters) unless otherwise noted.
3 LEAD TO-92 PLASTIC PACKAGE (N)
8 LEAD SOIC PLASTIC PACKAGE (S)
0.1400.010
(3.5560.127)
0.0600.010
(1.5240.254)
0.0150.002
(0.3810.051)
0.0160.003
(0.4060.076)
0.0500.005
(1.2700.127)
0.0600.005
(1.5240.127)
DIA
0.1800.005
(4.5720.127)
0.1800.005
(4.5720.127)
0.050
(1.270)
MAX
0.500
(12.70)
MIN
UNCONTROLLED
LEAD DIMENSIONS
10
NOM
5 NOM
N (TO-92 ) AMS DRW# 042391
0.90
(2.286)
NOM
0-8 TYP
0.010-0.020
(0.254-0.508)
S (SO-8 ) AMS DRW# 042293
x 45
0.016-0.050
(0.406-1.270)
0.008-0.010
(0.203-0.254)
0.004-0.010
(0.101-0.254)
0.014-0.019
(0.355-0.483)
0.053-0.069
(1.346-1.752)
0.050
(1.270)
TYP
0.150-0.157**
(3.810-3.988)
0.228-0.244
(5.791-6.197)
0.189-0.197*
(4.801-5.004)
*DIMENSION DOES NOT INCLUDE MOLD FLASH. MOLD FLASH
SHALL NOT EXCEED 0.006" (0.152mm) PER SIDE
**DIMENSION DOES NOT INCLUDE INTERLEAD FLASH. INTERLEAD
FLASH SHALL NOT EXCEED 0.010" (0.254mm) PER SIDE
1
2
3
4
8
7
6
5
Advanced Monolithic Systems, Inc. 6680B Sierra Lane, Dublin, CA 94568 Phone (925) 556-9090 Fax (925) 556-9140
AMS285/AMS385
PACKAGE DIMENSIONS
inches (millimeters) unless otherwise noted (Continued).
SOT-89 PLASTIC PACKAGE (L)
0.090-0.102
(2.29-2.60)
0.173-0.181
(4.40-4.60)
0.064-0.072
(1.62-1.83)
0.155-0.167
(3.94-4.25)
0.059
(1.50)
BSC
0.035-0.047
(0.89-1.20)
L (SOT-89 ) AMS DRW# 042392
0.118
(3.00)
BSC
0.014-0.019
(0.36-0.48)
0.017-0.022
(0.44-0.56)
0.084-0.090
(2.13-2.29)
0.055-0.063
(1.40-1.60)
0.014-0.017
(0.35-0.44)
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