Advanced Monolithic Systems AMS431 Service Manual

www.BDTIC.com/AMS

Advanced AMS431
Monolithic PRECISION ADJUSTABLE SHUNT REGULATOR
Systems

RoHS compliant

FEATURES APPLICATIONS

•••• Trimmed 0.25% Reference •••• Battery Powered Systems

•••• Wide Operating Current Range 250µµµµA to 150mA •••• Switching Power Supplies

•••• Low Dynamic Output Impedance •••• Adjustable Power Supplies

•••• Low Output Noise •••• Linear Regulators

•••• Nominal Temperature Range -40°°°°C to 125°°°°C •••• Error Amplifiers

•••• Temperature-Compensated: 60ppm/°°°°C typ •••• Notebook/Personal Computer

•••• Internal Amplifier with 150mA Capability •••• Monitors/ VCR/ TV

GENERAL DESCRIPTION

he AMS431 is a three-terminal adjustable shunt regulator with guaranteed temperature stability over the entire range of

T
operation. The output voltage can be set to any value between 2.5V (VREF) and 36V by adding two external resistors. Due to
the sharp turn-on characteristics this device is an excellent replacement for zener diodes in many applications.
AMS431 is available in TO-92, SO-8, SOT-89 and SOT-23 packages.

ORDERING INFORMATION:

TOL. PACKAGE TYPE OPERATING

TO-92 8 LEAD SOIC SOT-89 3 LEAD SOT-23

±0.25%
±0.5%
±1.0%

AMS431AN AMS431AS AMS431AL AMS431AM
AMS431BN AMS431BS AMS431BL AMS431BM
AMS431CN AMS431CS AMS431CL AMS431CM

PIN CONNECTIONS

TO-92 8L SOIC SOT-89 3L SOT-23

Plastic Package (N) SO Package (S) (L) (M)

1 2 3

REF

ANODE

CATHODE

Bottom View

Top View Top View Top View

REF

CATHODE

ANODE

ANODE

N/C

1

2

3

4

8

7

6

5

ANODE

ANODE

N/C

•••• Pagers

1 2 3

TEMP. RANGE

-40 to +125° C

-40 to +125° C

-40 to +125° C

ANODE

CATHODEANODEREF

CATHODEREF

Advanced Monolithic Systems, Inc.

www.BDTIC.com/AMS

AMS431

ABSOLUTE MAXIMUM RATINGS (Note 1)

Cathode Voltage (VZ) 37V Internal Power Dissipation (PD)
Continuous Cathode Current (IZ) -10mA to +150mA TO-92 Package 0.78W
Reference Input Current (I
Junction Temperature (TJ)
SOT-23 Package 0.28W
Storage temperature
Lead Temperature (Soldering, 10sec.)
SO-8 Package
SOT-89 Package
SOT-23 Package

Note 1 : Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the

evice is intended to be functional, but do not guarantee specific performance limits. For guaranteed specifications and test conditions, see the Electrical

d
Characteristics. The guaranteed specifications apply only for the test conditions listed.

ELECTRICAL CHARACTERISTICS

Electrical Characteristics at IZ =10 mA and TA = +25°C unless otherwise specified.

Parameter

Conditions

) 10mA SO-8 Package 0.71W

REF

-40°C to +125°C

-65°C to +150°C
265°C

SOT-89 Package 0.91W

Thermal Resistance (ϕJA)

TO-92 Package

160°C/W
175°C/W
110°C/W
410°C/W

AMS431A

Min Typ Max

AMS431B

Min Typ Max

AMS431C

Min Typ Max

Units

Reference Voltage 2.489 2.495 2.501 2.483 2.495 2.507 2.470 2.495 2.520 V

Deviation of Reference
Input Voltage over
Temperature

Ratio of Change in

Reference Voltage to
Cathode Voltage

Reference Input
Current

Reference Input
Current Deviation over
Temperature

Off State Cathode
Current

Dynamic Output
Impedance

Minimum Operating
Current

VZ = V
TA = 25°C to
+125°C
TA = -40°C to +25°C

VZ from V
10V

VZ from V
36V

R1 =10kΩ, R2 = ∞Ω

(test circuit 2)

R1 =10kΩ, R2 = ∞Ω

TA = Full Range
(test circuit 2)

VZ = 36V, V
0V

( test circuit 3)

f < 1KHz, VZ = V

IZ =100µA to 100mA
(test circuit 1)

VZ = V

(test circuit 1)

REF

REF

REF

REF

(circuit 1)

to

to

=

REF

REF

0.5 4.0 0.5 4.0 0.5 4.0

0.4 1.2 0.4 1.2 0.4 1.2

0.04 0.5 0.04 0.5 0.04 0.5

0.25 0.5 0.25 0.5 0.25 0.5

100 250 100 250 100 250

8.0

8.0

-0.5

-1.0

15

15

-2.7 -0.5 -2.7 -0.5 -2.7 mV/V

-2.0 -1.0 -2.0 -1.0 -2.0 mV/V

8.0

10

15

20

8.0

12

15

25

mV

mV

µA

µA

µA

µA

RECOMMENDED OPERATING CONDITIONS:

M

Cathode Voltage, (VZ) V
Cathode Current, (IZ) 0.25mA 120mA

Advanced Monolithic Systems, Inc.

in Max

36 V

REF

Ω

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AMS431

TEST CIRCUITS

I

Z

VZ = V

REF

V

IN

R1

R2

V

IN

I

REF

V

REF

Figure 1. Test Circuit for VZ=V

Figure 2. Test Circuit for V

REF

Test circuit for I

TYPICAL APPLICATIONS

Shunt Regulator

V+

V

O

V

Z

I

REF

V

REF

I

Z

V

IN

V

Z

IZ OFF

REF

REF

vs IZ.

.

Temperature Compensated Threshold

Figure 3. Test Circuit for Off-State Current

Single Supply Comparator with

V+

R1

V

REF

R2

VO ≈ (1+R1/R2)V

REF

Series Regulator

V+

30

Ω

0.01µF
R1

R2

V

O

≈ (1+R1/R2)V

V

O

REF

≈ (1+R1/R2)V

V

O

IN

V

≈

2.5V

TH

Higher Current Shunt Regulator

V+

R1

R1

REF

OUT

V

≈

2V

ON

= V+

V

OFF

GND

V

O

Advanced Monolithic Systems, Inc.