BU33DV7NUX Datasheet, PDF (21/27 Pages) Rohm – 1.8V to 5.5V, 300mA 1ch Synchronous Boost DC/DC Converter

BU33DV7NUX
Datasheet
●Caution on use
（1）Absolute Maximum Ratings
An excess in the absolute maximum rating, such as supply voltage, temperature range of operating conditions, etc., can
break down devices, thus making impossible to identify breaking mode such as a short circuit or an open circuit. If any
special mode exceeding the absolute maximum ratings is assumed, consideration should be given to take physical safety
measures including the use of fuses, etc.
（2）The power supply and the GND lines
Design PCB pattern to provide low impedance for the wiring between the power supply and the GND lines. Please take
care about interference by common impedance of the wiring pattern when there are two or more power supply and
GND line. For the GND line, please note the separation of the large current route and the small signal route including
the external circuit.Furthermore, for all power supply terminals to ICs; mount a capacitor between the power supply and the
GND terminal. At the same time, in order to use an electrolytic capacitor, thoroughly check to be sure the characteristics of
the capacitor to be used present no problem including the occurrence of capacity dropout at a low temperature, thus
determining the constant.
（3）GND voltage
Make setting of the potential of the GND terminal so that it will be maintained at the minimum in any operating state.
（4）Short circuit between terminals and erroneous mounting
In order to mount ICs on a set PCB, pay thorough attention to the direction and offset of the ICs. Erroneous mounting can break
down the ICs. Furthermore, if a short circuit occurs due to foreign matters entering between terminals or between the terminal
and the power supply or the GND terminal, the ICs can break down.
（5）Operation in strong electromagnetic field
Be noted that using ICs in the strong electromagnetic field can malfunction them.
（6）Input terminals
In terms of the construction of IC, parasitic elements are inevitably formed in relation to potential. The operation of the parasitic
element can cause interference with circuit operation, thus resulting in a malfunction and then breakdown of the input terminal.
Therefore, pay thorough attention not to handle the input terminals, such as to apply to the input terminals a voltage lower than
the GND respectively, so that any parasitic element will operate. Furthermore, do not apply a voltage to the input terminals when
no power supply voltage is applied to the IC. In addition, even if the power supply voltage is applied, apply to the input terminals
a voltage lower than the power supply voltage or within the guaranteed value of electrical characteristics.
（7）External capacitor
In order to use a ceramic capacitor as the external capacitor, determine the constant with consideration given to a
degradation in the nominal capacitance due to DC bias and changes in the capacitance due to temperature, etc.
（8）Thermal design
Perform thermal design in which there are adequate margins by taking into account the permissible dissipation (Pd) in
actual states of use. Moreover, please use it within the range where output Tr doesn't exceed the rated voltage and ASO.
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TSZ22111・15・001
21/24
TSZ02201-0Q1Q0AH00110-1-2
02.Aug.2012 Rev.001