AAT3220IQY-3.3-T1 Analogic Tech, AAT3220IQY-3.3-T1 Datasheet - Page 11

• Manufacturer Part Number: AAT3220IQY-3.3-T1
• Description: Low Dropout (LDO) Regulators 150mA NanoPower LDO Linear Regulator
• Manufacturer: Analogic Tech

Specifications of AAT3220IQY-3.3-T1

• Number Of Outputs: 1
• Polarity: Positive
• Input Voltage Max: 6 V
• Output Voltage: 3.3 V
• Output Type: Fixed
• Output Current: 150 mA
• Line Regulation: 0.2 %
• Load Regulation: 1 %
• Voltage Regulation Accuracy: 2 %
• Maximum Power Dissipation: 0.55 W
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Package / Case: SOT-89
• Minimum Operating Temperature: - 40 C
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

At any given ambient temperature (T
mum package power dissipation can be deter-
mined by the following equation:
Constants for the AAT3220 are T
mum junction temperature for the device which is
125°C and Θ
resistance. Typically, maximum conditions are cal-
culated at the maximum operating temperature
where T
T
age power dissipation is 200mW. At T
maximum package power dissipation is 500mW.
The maximum continuous output current for the
AAT3220 is a function of the package power dissi-
pation and the input-to-output voltage drop across
the LDO regulator. Refer to the following simple
equation:
For example, if V
I
tion threshold is set between 150mA and 300mA. If
the output load current were to exceed 250mA or if
the ambient temperature were to increase, the inter-
nal die temperature 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 regulator since the thermal pro-
tection circuit will only activate after a short-circuit
event occurs on the LDO regulator output.
To determine the maximum input voltage for a
given load current, refer to the following equation.
This calculation accounts for the total power dissi-
pation of the LDO regulator, including that caused
by ground current.
3220.2006.01.1.4
OUT(MAX)
A
= 25°C. Given T
A
< 250mA. The output short-circuit protec-
= 85°C; under normal ambient conditions
JA
I
P
OUT(MAX)
IN
D(MAX)
= 200°C/W, the package thermal
= 5V, V
A
= 85°C, the maximum pack-
=
<
T
V
J(MAX)
OUT
P
IN
θ
D(MAX)
- V
JA
= 3V and T
- T
OUT
A
J(MAX)
A
A
), the maxi-
= 25°C, the
, the maxi-
A
= 25°C,
150mA NanoPower™ LDO Linear Regulator
This formula can be solved for V
maximum input voltage.
The following is an example for an AAT3220 set for
a 3.0V output:
From the discussion above, P
mined to equal 417mW at T
Thus, the AAT3220 can sustain a constant 3.0V
output at a 150mA load current as long as V
5.5V at an ambient temperature of 25°C. 5.5V is
the maximum input operating voltage for the
AAT3220, thus at 25°C, the device would not have
any thermal concerns or operational V
This situation can be different at 85°C. The follow-
ing is an example for an AAT3220 set for a 3.0V
output at 85°C:
V
I
I
V
V
V
I
I
V
V
OUT
GND
OUT
GND
IN(MAX)
IN(MAX)
OUT
IN(MAX)
OUT
IN(MAX)
P
D(MAX)
= 3.0V
= 150mA
= 1.1µA
=
= > 5.5V
= 3.0V
= 150mA
= 1.1µA
=
= 4.33V
V
500mW + (3.0V × 150mA)
200mW + (3.0V × 150mA)
IN(MAX)
= (V
150mA + 1.1µA
150mA + 1.1µA
=
IN
P
- V
D(MAX)
OUT
I
OUT
)I
+ (V
OUT
A
+ I
= 25°C.
+ (V
OUT
GND
IN
D(MAX)
AAT3220
to determine the
× I
IN
× I
OUT
IN(MAX)
GND
was deter-
)
)
IN
limits.
is ≤
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