ZHCSF17E April 2008 – May 2016 LM2758
PRODUCTION DATA.
The LM2758 is designed to operate from an input voltage supply range from 2.7 V to 5.5 V. This input supply must be well regulated and capable to supply the required input current. If the input supply is located far from the device, additional bulk capacitance may be required in addition to the ceramic bypass capacitors.
The power dissipation (PDISSIPATION) and junction temperature (TJ) can be approximated with the equations below. PIN is the power generated by the 1×/1.5× charge pump, PLED is the power consumed by the LEDs, TA is the ambient temperature, and RθJA is the junction-to-ambient thermal resistance for the 12-pin DSBGA package. VIN is the input voltage to the LM2758, VLED is the nominal LED forward voltage, and ILED is the programmed LED current.
The junction temperature rating takes precedence over the ambient temperature rating. The LM2758 may be operated outside the ambient temperature rating, so long as the junction temperature of the device does not exceed the maximum operating rating of 125°C. The maximum ambient temperature rating must be derated in applications where high power dissipation and/or poor thermal resistance causes the junction temperature to exceed 125°C.