Advanced
AMS116
Monolithic
100mA LOW DROPOUT VOLTAGE REGULATOR
Systems
RoHS compliant
FEATURES
APPLICATIONS
5V Version Available*
Battery Powered Systems
Output Current of 100mA
Portable Consumer Equipment
Very Low Quiescent Current
Cordless Telephones
Reverse Battery Protection
Portable (Notebook) Computers
Input-output Differential less than 0.6V
Portable Instrumentation
Short Circuit protection
Radio Control Systems
Internal Thermal Overload Protection
Personal Communication Equipment
Toys
Low Voltage Systems
GENERAL DESCRIPTION
The AMS116 series consists of positive fixed voltage regulators ideally suited for use in battery-powered systems. These
devices feature very low quiescent current of 1mA or less when supplying 10mA loads. This unique characteristic and the
extremely low input -output differential required for proper regulation (0.2V for output currents of 10mA) make the AMS116
ideal to use for standby power systems.
Like other regulators the AMS116 series also includes internal current limiting, thermal shutdown, and is able to withstand
temporary power-up with mirror-image insertion.
The AMS116 is offered in the 3-pin TO-92 package and SOT-89 package.
ORDERING INFORMATION
PIN CONNECTIONS
PACKAGE TYPE
OPER. TEMP
TO-92 SOT-89 RANGE
AMS116N-X AMS116L-X
IND
TO-92
Plastic Package (N)
SOT-89 Package
(L)
OUTPUT
INPUT
GND
1
2
3
OUTPUT
GND
INPUT
Bottom View
Top View
X =5V
*For additional available fixed voltages contact factory
Advanced Monolithic Systems, Inc. www.advanced-monolithic.com Phone (925) 443-0722 Fax (925) 443-0723
AMS116
ABSOLUTE MAXIMUM RATINGS
(Note 1)
Input Voltage
18V
Maximum Junction Temperature
+125
C
Operating Voltage Range
2.5V to 16V
Storage Temperature
-65
C to +150C
Load Current
150mA
Lead Temperature (Soldering 25 sec)
265
C
Internal Power Dissipation
Internally Limited
ESD
2000V
ELECTRICAL CHARACTERISTICS
Electrical Characteristics at T
J
=25C, C2 = 100
F unless otherwise specified.
PARAMETER
CONDITIONS
(Note 2)
Min.
AMS116-X
Typ.
Max.
Units
Output Voltage
V
IN
= V
OUT
+3V
-3
+3
%
Line Regulation
V
IN
= V
OUT
+3V to 14V
2
30
mV
Load Regulation
5mA
I
O
100 mA
15
60
mV
Dropout Voltage
IO 30 mA
IO = 100 mA
80
170
150
330
mV
mV
Quiescent Current
IO 10 mA, V
IN
= V
OUT
+3V to 14V
400 1000
A
Ripple Rejection
f
O
= 120Hz
80
dB
Temperature Coefficient
IO 10 mA, V
IN
= V
OUT
+3V to 14V
.35
mV/
C
Note 1: Absolute Maximum Ratings are limits beyond which damage to the device may occur. For guaranteed performance limits and associated test
conditions, see the Electrical Characteristics tables.
Note 2: See Circuit in Typical Applications. To ensure constant junction temperature, low duty cycle pulse testing is used.
Note 3: Limits appearing in boldface type apply over the entire junction temperature range for operation. Limits appearing in normal type apply for T
A
= T
J
=
25
C.
V
IN
+
+
V
OUT
Figure 1. SOT-89 Board Layout
Advanced Monolithic Systems, Inc. www.advanced-monolithic.com Phone (925) 443-0722 Fax (925) 443-0723
AMS116
APPLICATION HINTS
Package Power Dissipation
The package power dissipation is the level at which the thermal
sensor monitoring the junction temperature is activated. The
AMS116 shuts down when the junction temperature exceeds the
limit of 150
C. The junction temperature rises as the difference
between the input power and output power increases. The
mounting pad configuration on the PCB, the board material, as
well as the ambient temperature affect the rate of temperature rise.
The junction temperature will be low, even if the power
dissipation is high, when the mounting of the device has good
thermal conductivity. When mounted on the recommended
mounting pad (figure1) the power dissipation for the SOT-89
package is 600mW. For operation above 25
C derate the power
dissipation at 4.8mW/
C. To determine the power dissipation for
shutdown when mounted, attach the device on the PCB and
increase the input-to-output voltage until the thermal protection
circuit is activated. Calculate the power dissipation of the device
by subtracting the output voltage from the input voltage and
multiply by the output current. The measurements should allow
for the ambient temperature of the PCB. The value obtained from
P
D
/ (150
C - T
A
) is the derating factor. The PCB mounting pad
should provide maximum thermal conductivity in order to
maintain low device temperatures. As a general rule, the lower the
temperature, the better the reliability of the device.
The thermal resistance when the device is mounted is equal to:
T
J
=
JA
x P
D
+ T
A
The internal limit for junction temperature is 150
C. If the ambient
temperature is 25
C, then:
150
C =
JA
x P
D
+ 25
C
JA
= 125
C/ P
D
A simple way to determine P
D
is to calculate V
IN
x I
IN
when the
output is shorted. As the temperature rises, the input gradually will
decrease. The P
D
value obtained when the thermal equilibrium is
reached, is the value that should be used.
The range of usable currents can be found from the graph in figure
2.
4
5
75
150
25
50
6
3
P
D
D
PD
T (C)
(mW)
Figure 2
Procedure:
1.
Find P
D
.
2.
P
D1
is calculated as P
D
x (0.8 - 0.9).
3.
Plot P
D1
against 25
C.
4.
Connect P
D1
to the point corresponding to the 150
C.
5.
Take a vertical line from the maximum operating temperature
(75
C) to the derating curve.
6.
Read the value of P
D
at the point where the vertical line
intersects the derating curve. This is the maximum power
dissipation, D
PD
.
The maximum operating current is:
I
OUT
= (D
PD
/ (V
IN(MAX)
- V
O
)
External Capacitors
The AMS116 series require an output capacitor for device
stability. The value required depends on the application circuit
and other factors.
Because high frequency characteristics of electrolytic capacitors
depend greatly on the type and even the manufacturer, the value
of capacitance that works well with AMS116 for one brand or
type may not necessary be sufficient with an electrolytic of
different origin. Sometimes actual bench testing will be the only
means to determine the proper capacitor type and value. To obtain
stability in all general applications a high quality 100
F
aluminum electrolytic or a 47
F tantalum electrolytic can be used.
A critical characteristic of the electrolytic capacitors is their
performance over temperature. The AMS116 is designed to
operate to -40
C, but some electrolytics will freeze around -30C
therefore becoming ineffective. In such case the result is
oscillation at the regulator output. For all application circuits
where cold operation is necessary, the output capacitor must be
rated to operate at the minimum temperature. In applications
where the regulator junction temperature will never be lower than
25
C the output capacitor value can be reduced by a factor of two
over the value required for the entire temperature range (47
F for
a high quality aluminum or 22
F for a tantalum electrolytic
capacitor).
With higher output currents, the stability of AMS116 decreases.
Considering the fact that in many applications the AMS116 is
operated at only a few milliamps (or less) of output current, the
output capacitor value can be reduced even further. For example,
a circuit that is required to deliver a maximum of 10mA of output
current from the regulator output will need an output capacitor of
only half the value compared to the same regulator required to
deliver the full output current of 100mA.
As a general rule, with higher output voltages the value of the
output capacitance decreases, since the internal loop gain is
reduced.
In order to determine the minimum value of the output capacitor,
for an application circuit, the entire circuit including the capacitor
should be bench tested at minimum operating temperatures and
maximum operating currents. To maintain internal power
dissipation and die heating to a minimum, the input voltage should
be maintain at 0.6V above the output. Worst-case occurs just after
input power is applied and before the die had the chance to heat
up. After the minimum capacitance value has been found for the
specific brand and type of electrolytic capacitor, the value should
be doubled for actual use to cover for production variations both
in the regulator and the capacitor.
Advanced Monolithic Systems, Inc. www.advanced-monolithic.com Phone (925) 443-0722 Fax (925) 443-0723
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