BU2050F,BU2092F,BU2092FV,BU2099FV,BD7851FP,BU2152FS

Technical Note

22/24

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2009.06 - Rev.A

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Notes for use

1. Absolute maximum ratings

An excess in the absolute maximum ratings, such as supply voltage, temperature range of operating conditions, etc., can

break down the devices, thus making impossible to identify breaking mode, such as a short circuit or an open circuit. If any

over rated values will expect to exceed the absolute maximum ratings, consider adding circuit protection devices, such as

fuses.

2. Connecting the power supply connector backward

Connecting of the power supply in reverse polarity can damage IC. Take precautions when connecting the power supply

lines. An external direction diode can be added.

3. Power supply lines

Design PCB layout pattern to provide low impedance GND and supply lines. To obtain a low noise ground and supply line,

separate the ground section and supply lines of the digital and analog blocks. Furthermore, for all power supply terminals to

ICs, connect a capacitor between the power supply and the GND terminal. When applying electrolytic capacitors in the circuit,

not that capacitance characteristic values are reduced at low temperatures.

4. GND voltage

The potential of GND pin must be minimum potential in all operating conditions.

5. Thermal design

Use a thermal design that allows for a sufficient margin in light of the power dissipation (Pd) in actual operating conditions.

6. Inter-pin shorts and mounting errors

Use caution when positioning the IC for mounting on printed circuit boards. The IC may be damaged if there is any

connection error or if pins are shorted together.

7. Actions in strong electromagnetic field

Use caution when using the IC in the presence of a strong electromagnetic field as doing so may cause the IC to malfunction.

8. Testing on application boards

When testing the IC on an application board, connecting a capacitor to a pin with low impedance subjects the IC to stress.

Always discharge capacitors after each process or step. Always turn the IC's power supply off before connecting it to or

removing it from a jig or fixture during the inspection process. Ground the IC during assembly steps as an antistatic measure.

Use similar precaution when transporting or storing the IC.

9. Ground Wiring Pattern

When using both small signal and large current GND patterns, it is recommended to isolate the two ground patterns, placing

a single ground point at the ground potential of application so that the pattern wiring resistance and voltage variations caused

by large currents do not cause variations in the small signal ground voltage. Be careful not to change the GND wiring pattern

of any external components, either.

10. Unused input terminals

Connect all unused input terminals to VDD or VSS in order to prevent excessive current or oscillation.

Insertion of a resistor (100kΩ approx.) is also recommended.