ADP162AUJZ-3.3 Analog Devices Inc, ADP162AUJZ-3.3 Datasheet - Page 16

• Manufacturer Part Number: ADP162AUJZ-3.3
• Description: IC, LDO, 3.3V, 150MA, 5TSOT
• Manufacturer: Analog Devices Inc

Specifications of ADP162AUJZ-3.3

• Primary Input Voltage: 3.8V
• Output Voltage: 3.3V
• Dropout Voltage Vdo: 195mV
• No. Of Pins: 5
• Output Current: 150mA
• Voltage Regulator Case Style: TSOT
• Operating Temperature Range: -40°C To +125°C
• Output Voltage Fixed: 3.3V
• Rohs Compliant: Yes
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

ADP160/ADP161/ADP162/ADP163
Consider the case where a hard short from OUT to ground
occurs. At first, the ADP16x current limit so that only 320 mA
is conducted into the short. If self-heating of the junction is
great enough to cause its temperature to rise above 150°C,
thermal shutdown activates, turning off the output and
reducing the output current to zero. As the junction tempera-
ture cools and drops below 135°C, the output turns on and
conducts 320 mA into the short, again causing the junction
temperature to rise above 150°C. This thermal oscillation
between 135°C and 150°C causes a current oscillation between
320 mA and 0 mA that continues as long as the short remains
at the output.
Current and thermal limit protections are intended to protect
the device against accidental overload conditions. For reliable
operation, device power dissipation must be externally limited
so junction temperatures do not exceed 125°C.
THERMAL CONSIDERATIONS
In most applications, the ADP16x do not dissipate much heat due
to their high efficiency. However, in applications with high ambient
temperature and high supply voltage to output voltage differential,
the heat dissipated in the package is large enough that it can cause
the junction temperature of the die to exceed the maximum
junction temperature of 125°C.
When the junction temperature exceeds 150°C, the converter enters
thermal shutdown. It recovers only after the junction temperature
has decreased below 135°C to prevent any permanent damage.
Therefore, thermal analysis for the chosen application is very
important to guarantee reliable performance over all conditions.
The junction temperature of the die is the sum of the ambient
temperature of the environment and the temperature rise of the
package due to the power dissipation, as shown in Equation 2.
To guarantee reliable operation, the junction temperature of
the ADP16x must not exceed 125°C. To ensure the junction
temperature stays below this maximum value, the user needs to
be aware of the parameters that contribute to junction temperature
changes. These parameters include ambient temperature, power
dissipation in the power device, and thermal resistances between
the junction and ambient air (θ
on the package assembly compounds that are used and the amount
of copper used to solder the package GND pins to the PCB.
Table 8 shows the typical θ
4-ball WLCSP for various PCB copper sizes. Table 9 shows the
typical Ψ
Table 8. Typical θ
Copper Size (mm
0
50
100
300
500
1
Device soldered to minimum size pin traces.
1
JB
value of the 5-lead TSOT and 4-ball WLCSP.
2
JA
)
Values
JA
values of the 5-lead TSOT and the
JA
TSOT
170
152
146
134
131
). The θ
JA
number is dependent
θ
JA
(°C/W)
WLCSP
260
159
157
153
151
Rev. C | Page 16 of 24
Table 9. Typical Ψ
TSOT
42.8
The junction temperature of the ADP16x can be calculated
from the following equation:
where:
T
P
where:
I
I
V
Power dissipation due to ground current is quite small and can be
ignored. Therefore, the junction temperature equation simplifies to
the following:
As shown in Equation 4, for a given ambient temperature, input-
to-output voltage differential, and continuous load current, there
exists a minimum copper size requirement for the PCB to ensure
the junction temperature does not rise above 125°C. Figure 41 to
Figure 48 show the junction temperature calculations for the
different ambient temperatures, load currents, V
differentials, and areas of PCB copper.
In the case where the board temperature is known, use the
thermal characterization parameter, Ψ
temperature rise (see Figure 49 and Figure 50). Maximum
junction temperature (T
temperature (T
following formula:
The typical value of Ψ
and 43°C/W for the 5-lead TSOT package.
LOAD
GND
D
A
IN
is the ambient temperature.
is the power dissipation in the die, given by
and V
is the ground current.
T
P
T
T
is the load current.
D
140
120
100
J
J
J
80
60
40
20
= T
= T
= T
= [(V
0
0.3
OUT
Figure 41. 500 mm
A
A
B
+ (P
+ (P
+ {[(V
IN
are input and output voltages, respectively.
0.8
B
− V
) and power dissipation (P
D
D
× Ψ
× θ
MAXIMUM JUNCTION TEMPERATURE
IN
1.3
OUT
JB
− V
JB
I
I
I
Values
LOAD
LOAD
LOAD
JA
) × I
JB
is 58°C/W for the 4-ball WLCSP package
)
)
J
1.8
) is calculated from the board
OUT
= 1mA
= 10mA
= 50mA
2
LOAD
of PCB Copper, WLCSP, T
Ψ
) × I
V
JB
IN
2.3
] + (V
(°C/W)
– V
LOAD
WLCSP
58.4
OUT
2.8
] × θ
IN
(V)
JB
I
I
I
LOAD
LOAD
LOAD
, to estimate the junction
× I
3.3
JA
GND
= 100mA
= 150mA
= 200mA
}
D
) using the
)
3.8
A
IN
= 25°C
-to-V
4.3
OUT
4.8
(2)
(3)
(4)
(5)