Datasheet ADP7112 (Analog Devices) - 5

Data Sheet ADP7112 ABSOLUTE MAXIMUM RATINGS Table 3.
θJA of the package is based on modeling and calculation using a 4-layer board. The θ
Parameter Rating
JA is highly dependent on the application and board layout. In applications where high maximum power VIN to GND −0.3 V to +24 V dissipation exists, close attention to thermal board design is VOUT to GND −0.3 V to VIN required. The value of θ EN to GND −0.3 V to +24 V JA can vary, depending on PCB material, layout, and environmental conditions. The specified values of θ SENSE/ADJ to GND −0.3 V to +6 V JA are based on a 4-layer, 4 in. × 3 in. circuit board. See JESD51-7 and SS to GND −0.3 V to VIN or +6 V (whichever is less) JESD51-9 for detailed information on the board construction. Storage Temperature Range −65°C to +150°C ΨJB is the junction-to-board thermal characterization parameter Operating Junction Temperature −40°C to +125°C with units of °C/W. The ΨJB of the package is based on (TJ) Range modeling and calculation using a 4-layer board. The JESD51-12, Operating Ambient Temperature −40°C to +85°C Guidelines for Reporting and Using Electronic Package Thermal (TA) Range Information, states that thermal characterization parameters are Soldering Conditions JEDEC J-STD-020 not the same as thermal resistances. ΨJB measures the component power flowing through multiple thermal paths rather than a Stresses at or above those listed under Absolute Maximum single path as in thermal resistance (θJB). Therefore, ΨJB thermal Ratings may cause permanent damage to the product. This is a paths include convection from the top of the package as well as stress rating only; functional operation of the product at these radiation from the package, factors that make ΨJB more useful in or any other conditions above those indicated in the real-world app-lications. Maximum TJ is calculated from the operational section of this specification is not implied. board temperature (TB) and PD using the formula Operation beyond the maximum operating conditions for extended periods may affect product reliability. TJ = TB + (PD × ΨJB) (2) See JESD51-8 and JESD51-12 for more detailed information
THERMAL DATA
about ΨJB. Absolute maximum ratings apply individually only, not in combination. The ADP7112 can be damaged when the junction
THERMAL RESISTANCE
temperature limits are exceeded. Monitoring ambient temperature θJA, θJC, and ΨJB are specified for the worst-case conditions, that does not guarantee that TJ is within the specified temperature is, a device soldered in a circuit board for surface-mount limits. In applications with high power dissipation and poor packages. thermal resistance, the maximum ambient temperature can
Table 4. Thermal Resistance
have to be derated.
Package Type θJA θJC ΨJB Unit
In applications with moderate power dissipation and low 6-Ball WLCSP 260 4 58 °C/W printed circuit board (PCB) thermal resistance, the maximum ambient temperature can exceed the maximum limit as long as
ESD CAUTION
the junction temperature is within specification limits. The junction temperature of the device is dependent on the ambient temperature, the power dissipation (PD) of the device, and the junction-to-ambient thermal resistance of the package (θJA). Maximum TJ is calculated from the TA and PD using the formula T J = TA + (PD × θJA) (1) Rev. D | Page 5 of 21 Document Outline Features Applications Typical Application Circuits General Description Revision History Specifications Input and Output Capacitance, Recommended Specifications Absolute Maximum Ratings Thermal Data Thermal Resistance ESD Caution Pin Configuration and Function Descriptions Typical Performance Characteristics Theory of Operation Applications Information Capacitor Selection Output Capacitor Input Bypass Capacitor Input and Output Capacitor Properties Programable Precision Enable Soft Start Noise Reduction of the ADP7112 in Adjustable Mode Current-Limit and Thermal Overload Protection Effect of Noise Reduction on Start-Up Time Thermal Considerations PCB Layout Considerations Outline Dimensions Ordering Guide