Datasheet ADM7160 (Analog Devices) - 5

Data Sheet ADM7160 ABSOLUTE MAXIMUM RATINGS Table 3.
The specified values of θJA are based on a 4-layer, 4 inch × 3 inch
Parameter Rating
printed circuit board (PCB). See JEDEC JESD51-7 and JESD51-9 VIN to GND −0.3 V to +6.5 V for detailed information about board construction. For more infor- VOUT to GND −0.3 V to VIN mation about the LFCSP package, see the AN-772 Application EN to GND −0.3 V to +6.5 V Note, A Design and Manufacturing Guide for the Lead Frame Chip Storage Temperature Range −65°C to +150°C Scale Package (LFCSP). Operating Junction Temperature Range −40°C to +125°C ΨJB is the junction-to-board thermal characterization parameter Operating Ambient Temperature Range −40°C to +125°C with units of °C/W. ΨJB of the package is based on modeling and Soldering Conditions JEDEC J-STD-020 calculation using a 4-layer board. Stresses above those listed under Absolute Maximum Ratings JEDEC JESD51-12, Guidelines for Reporting and Using Electronic may cause permanent damage to the device. This is a stress Package Thermal Information, states that thermal characterization rating only; functional operation of the device at these or any parameters are not the same as thermal resistances. ΨJB measures other conditions above those indicated in the operational the component power flowing through multiple thermal paths, section of this specification is not implied. Exposure to absolute rather than through a single path as in thermal resistance (θJB). maximum rating conditions for extended periods may affect Therefore, ΨJB thermal paths include convection from the top of device reliability. the package, as well as radiation from the package, factors that
THERMAL DATA
make ΨJB more useful in real-world applications. Absolute maximum ratings apply individually only, not in Maximum junction temperature (TJ) is calculated from the combination. The ADM7160 can be damaged when the junc- board temperature (TB) and the power dissipation (PD) using tion temperature limits are exceeded. Monitoring ambient the following formula: temperature does not guarantee that TJ is within the specified TJ = TB + (PD × ΨJB) temperature limits. See JEDEC JESD51-8 and JESD51-12 for more detailed infor- In applications with high power dissipation and poor PCB mation about ΨJB. thermal resistance, the maximum ambient temperature may need to be derated. In applications with moderate power
THERMAL RESISTANCE
dissipation and low PCB thermal resistance, the maximum θJA and ΨJB are specified for the worst-case conditions, that is, a ambient temperature can exceed the maximum limit as long device soldered in a circuit board for surface-mount packages. as the junction temperature is within the specification limits.
Table 4. Thermal Resistance
The junction temperature (TJ) of the device is dependent on the
Package Type θ
ambient temperature (T
JA ΨJB Unit
A), the power dissipation of the device 5-Lead TSOT 170 43 °C/W (PD), and the junction-to-ambient thermal resistance of the 6-Lead LFCSP 63.6 28.3 °C/W package (θJA). TJ is calculated using the following formula: TJ = TA + (PD × θJA)
ESD CAUTION
The junction-to-ambient thermal resistance (θJA) of the package is based on modeling and calculation using a 4-layer board. θJA is highly dependent on the application and board layout. In appli- cations where high maximum power dissipation exists, close attention to thermal board design is required. The value of θJA may vary, depending on PCB material, layout, and environmental conditions. Rev. A | Page 5 of 24 Document Outline Features Applications Application Circuit General Description Table of Contents Revision History Specifications Input and Output Capacitors, Recommended Specifications Absolute Maximum Ratings Thermal Data Thermal Resistance ESD Caution Pin Configurations and Function Descriptions Typical Performance Characteristics Theory of Operation Enable Feature Soft Start Current-Limit and Thermal Overload Protection Applications Information Capacitor Selection Output Capacitor Input Bypass Capacitor Input and Output Capacitor Properties Thermal Considerations PCB Layout Considerations Typical Application Circuits Outline Dimensions Ordering Guide