Datasheet

Data Sheet ADP1754/ADP1755
Rev. F | Page 5 of 20
ABSOLUTE MAXIMUM RATINGS
Table 3.
Parameter Rating
VIN to GND −0.3 V to +4.0 V
VOUT to GND
−0.3 V to VIN
EN to GND −0.3 V to VIN
SS to GND −0.3 V to VIN
PG to GND −0.3 V to +4.0 V
SENSE/ADJ to GND −0.3 V to VIN
Storage Temperature Range −65°C to +150°C
Junction Temperature Range −40°C to +125°C
Junction Temperature 150°C
Soldering Conditions JEDEC J-STD-020
Stresses above those listed under Absolute Maximum Ratings
may cause permanent damage to the device. This is a stress
rating only; functional operation of the device at these or any
other conditions above those indicated in the operational
section of this specification is not implied. Exposure to absolute
maximum rating conditions for extended periods may affect
device reliability.
THERMAL DATA
Absolute maximum ratings apply individually only, not in
combination. The ADP1754/ADP1755 may be damaged if the
junction temperature limits are exceeded. Monitoring ambient
temperature does not guarantee that T
J
is within the specified
temperature limits. In applications with high power dissipation
and poor thermal resistance, the maximum ambient temperature
may need to be derated. In applications with moderate power
dissipation and low PCB thermal resistance, the maximum
ambient temperature can exceed the maximum limit as long
as the junction temperature is within specification limits.
The junction temperature (T
J
) of the device is dependent on the
ambient temperature (T
A
), the power dissipation of the device
(P
D
), and the junction-to-ambient thermal resistance of the
package (θ
JA
). T
J
is calculated using the following formula:
T
J
= T
A
+ (P
D
× θ
JA
)
Junction-to-ambient thermal resistance (θ
JA
) of the package is
based on modeling and calculation using a 4-layer board. The
junction-to-ambient thermal resistance is highly dependent
on the application and board layout. In applications where high
maximum power dissipation exists, close attention to thermal
board design is required. The value of θ
JA
may vary, depending
on PCB material, layout, and environmental conditions. The
specified values of θ
JA
are based on a 4-layer, 4 in × 3 in circuit
board. Refer to JEDEC JESD51-7 for detailed information about
board construction. For more information, see the AN-772
Application Note, A Design and Manufacturing Guide for the
Lead Frame Chip Scale Package (LFCSP).
Ψ
JB
is the junction-to-board thermal characterization parameter
with units of °C / W. Ψ
JB
of the package is based on modeling and
calculation using a 4-layer board. The JESD51-12 document,
Guidelines for Reporting and Using Electronic Package Thermal
Information, states that thermal characterization parameters are
not the same as thermal resistances. Ψ
JB
measures the component
power flowing through multiple thermal paths rather than through
a single path as in thermal resistance, θ
JB
. Therefore, Ψ
JB
thermal
paths include convection from the top of the package as well as
radiation from the package, factors that make Ψ
JB
more useful in
real-world applications. Maximum junction temperature (T
J
)
is calculated from the board temperature (T
B
) and the power
dissipation (P
D
) using the following formula:
T
J
= T
B
+ (P
D
× Ψ
JB
)
Refer to the JEDEC JESD51-8 and JESD51-12 documents for more
detailed information about Ψ
JB
.
THERMAL RESISTANCE
θ
JA
and Ψ
JB
are specified for the worst-case conditions, that is, a
device soldered in a circuit board for surface-mount packages.
Table 4. Thermal Resistance
Package Type θ
JA
Ψ
JB
Unit
16-Lead LFCSP with Exposed Pad (CP-16-4) 42 25.5 °C/W
ESD CAUTION