AAT3221IGV-3.0-T1 Analogic Tech, AAT3221IGV-3.0-T1 Datasheet - Page 11

• Manufacturer Part Number: AAT3221IGV-3.0-T1
• Description: Low Dropout (LDO) Regulators 150mA NanoPower LDO Linear Regulator
• Manufacturer: Analogic Tech

Specifications of AAT3221IGV-3.0-T1

• Number Of Outputs: 1
• Polarity: Positive
• Input Voltage Max: 7 V
• Output Voltage: 3 V
• Output Type: Fixed
• Dropout Voltage (max): 0.225 V at 100 mA
• Output Current: 150 mA
• Line Regulation: 0.4 % / V
• Load Regulation: 1.15 %
• Voltage Regulation Accuracy: 2 %
• Maximum Power Dissipation: 0.667 W
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Package / Case: SOT-23-5
• Minimum Operating Temperature: - 40 C
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

PowerLinear
maximum conditions are calculated at the maximum
operating temperature where T
ambient conditions T
maximum package power dissipation is 267mW. At T
25°C, the maximum package power dissipation is
667mW.
The maximum continuous output current for the
AAT3221/2 is a function of the package power dissipa-
tion and the input-to-output voltage drop across the
LDO regulator. Refer to the following simple equation:
For example, if V
I
threshold is set between 150mA and 300mA. If the out-
put load current were to exceed 267mA or if the ambient
temperature were to increase, the internal die tempera-
ture would increase. If the condition remained constant
and the short-circuit protection did not activate, there
would be a potential damage hazard to the LDO regula-
tor since the thermal protection circuit would only acti-
vate after a short-circuit event occured on the LDO
regulator output.
To determine the maximum input voltage for a given
load current, refer to the following equation. This calcu-
lation accounts for the total power dissipation of the LDO
regulator, including that caused by ground current.
This formula can be solved for V
maximum input voltage.
The following is an example for an AAT3221/2 set for a
2.5 volt output:
V
I
I
3221.2007.11.1.12
OUT(MAX)
OUT
GND
OUT
= 150mA
= 1.1μA
= 2.5 volts
< 267mA.
V
V
P
IN(MAX)
IN(MAX)
D(MAX)
V
IN(MAX)
TM
= (V
=
= 6.95V
I
IN
OUT(MAX)
(667mW + [2.5V · 150mA])
=
= 5V, V
The output short-circuit protection
A
IN
(P
= 25°C. Given T
- V
(150mA + 1.1µA)
D(MAX)
=
OUT
(I
(V
OUT
OUT
)I
+ [V
IN
P
OUT
A
D(MAX)
- V
+ I
= 2.5V and T
= 85°C, under normal
OUT
+ (V
GND
OUT
IN
· I
)
)
IN
to determine the
OUT
· I
A
GND
])
= 85°C, the
)
A
w w w . a n a l o g i c t e c h . c o m
= 25°C,
A
=
150mA NanoPower™ LDO Linear Regulator
From the discussion above, P
equal 667mW at T
sustain a constant 2.5V output at a 150mA load current
as long as V
25°C. 5.5V is the maximum input operating voltage for
the AAT3221/2, thus at 25°C the device would not have
any thermal concerns or operational V
This situation can be different at 85°C. The following is
an example for an AAT3221/2 set for a 2.5 volt output
at 85°C:
V
I
I
From the discussion above, P
equal 267mW at T
Higher input-to-output voltage differentials can be
obtained with the AAT3221/2, while maintaining device
functions in the thermal safe operating area. To accom-
plish this, the device thermal resistance must be reduced
by increasing the heat sink area or by operating the LDO
regulator in a duty-cycled mode.
For example, an application requires V
V
greater than 4.28V, which is the maximum safe continu-
ous input level for V
To maintain this high input voltage and output current
level, the LDO regulator must be operated in a duty-
cycled mode. Refer to the following calculation for duty-
cycle operation:
I
I
V
V
P
OUT
GND
GND
OUT
D(MAX)
OUT
OUT
IN
OUT
= 5.0 volts
%DC = 100
%DC = 100
%DC = 71.2%
= 150mA
= 150mA
= 1.1μA
= 1.1μA
= 2.5 volts
= 2.5 volts
= 2.5V at a 150mA load and T
is assumed to be 267mW.
V
V
IN(MAX)
IN(MAX)
IN
is ≤6.95V at an ambient temperature of
([V
([5.0V - 2.5V]150mA + [5.0V · 1.1µA])
=
= 4.28V
A
IN
A
(267mW + [2.5V · 150mA])
= 85°C.
OUT
= 25°C. Thus, the AAT3221/2 can
- V
PRODUCT DATASHEET
OUT
= 2.5V at 150mA for T
(150mA + 1.1µA)
AAT3221/2
P
]I
OUT
D(MAX)
267mW
+ [V
D(MAX)
D(MAX)
IN
· I
was determined to
was determined to
A
IN(MAX)
GND
= 85°C.
IN
])
= 5.0V while
limits.
A
= 85°C.
V
IN
11
is