AIC1189 AIC [Analog Intergrations Corporation], AIC1189 Datasheet - Page 13

• Manufacturer Part Number: AIC1189
• Description: Ultra LDO 2A Linear Regulator With Adjustable & Bypass Pin
• Manufacturer: AIC [Analog Intergrations Corporation]

The AIC1189 is a high performance linear regulator
that provides low-dropout voltage and low quiescent-
current. The device is available in an adjustable
version and fixed output voltages ranging from 1.2V to
3.8V, and the device can supply loads up to 2A.
SHUTDOWN
By connecting EN(EN) pin to V
can be shut down to reduce the supply current to
0.01µA(typ.). At this operation mode, the output
voltage of AIC1189 is equal to 0V.
CURRENT LIMIT
The AIC1189 includes a current limiter, which monitors
and controls the maximum output current. If the output
is overloaded or shorted to ground, this can protect the
device from being damaged.
THERMAL PROTECTION
The AIC1189 includes a thermal-limiting circuit, which
is designed to protect the device against overload
condition. When the junction temperature exceeds
T
transistor and allows the IC to cool. For continuous
load condition, maximum rating of junction temperature
must not be exceeded.
INPUT-OUTPUT CAPACITORS
Linear regulators require input and output capacitors to
maintain stability. Input capacitor at 4.7µF with a 4.7µF
ceramic output capacitor is recommended. To avoid
oscillation, it is recommended to follow the figure of
“Region of Stable C
choose proper capacitor specifications.
When
capacitors, X5R and X7R types are recommended
because they retain their capacitance over wider
ranges of voltage and temperature than other types.
NOISE BYPASS CAPACITOR
A 22nF bypass capacitor at BP pin can reduce output
voltage noise. The bypass pin can be floating if it’s
unnecessary.
OUTPUT VOLTAGE PROGRAMMING
J
=150ºC, the thermal-limiting circuit turns off the pass
APPLICATION INFORMATION
choosing
the
OUT
input
ESR vs. Load Current” to
IN
and
(ground), the AIC1189
output
ceramic
The output voltage of AIC1189 linear regulator can be
set by its internal feedback resistors when the ADJ pin
is grounded. In addition, the output voltage of AIC1189
linear regulator can be set by the external feedback
resistors when connecting a resistive divider R
While connecting a resistive divider, V
calculated as:
The resistive divider should sit as close to ADJ pin as
possible.
POWER DISSIPATION
The maximum power dissipation of AIC1189 depends
on the thermal resistance of its case and circuit board,
the temperature difference between the die junction
and ambient air, and the rate of airflow. The rate of
temperature rise is greatly affected by the mounting
pad configuration on the PCB, the board material, and
the ambient temperature. When the IC mounting with
good thermal conductivity is used, the junction
temperature will be low even when large power
dissipation applies.
The power dissipation across the device is
P = I
The maximum power dissipation is:
Where T
temperature
temperature suitable in application.
As a general rule, the lower temperature is, the better
reliability of the device is. So the PCB mounting pad
should provide maximum thermal conductivity to
maintain low device temperature.
LAYOUT CONSIDERATION
Connect the bottom-side pad (available in SOP-8
Exposed Pad) to a large ground plane. Use as much
copper
resistance of the device.
P
V
MAX
OUT
OUT
=
=
(T
0
(V
8 .
as possible to decrease the thermal
- J
J-max
IN
Rθ
max
×
-V

 

1
JA
OUT
-
(150°C),
+
T
is the maximum allowable junction
R
A
R
)
)
2
1

 

and
T
A
is
AIC1189
the
OUT
1
ambient
can be
and R
13
2
.