BH□□RB1WGUT series

Technical Note

6/8

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2011.01 - Rev.C

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Output capacitors

Mounting input capacitor between input pin and GND (as close to pin as possible), and also output capacitor between output

pin and GND(as close to pin as possible) is recommended. The input capacitor reduces the output impedance of the voltage

supply source connected to the VCC. The higher value the output capacitor goes the more stable the whole operation

becomes. This leads to high load transient response. Please confirm the whole operation on actual application board.

Generally, ceramic capacitor has wide range of tolerance, temperature coefficient, and DC bias characteristic. And also its value

goes lower as time progresses. Please choose ceramic capacitors after obtaining more detailed data by asking capacitor makers.

BH□□RB1WGUT

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Operation Notes

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. Thermal design

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

3. 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.

4. Thermal shutdown circuit (TSD)

The IC incorporates a built-in thermal shutdown circuit (TSD circuit). The thermal shutdown circuit is designed only to shut

the IC off to prevent runaway thermal operation. It is not designed to protect the IC or guarantee its operation. Do not

continue to use the IC after operating this circuit or use the IC in an environment where the operation of this circuit is

assumed.

5. Overcurrent protection circuit

The IC incorporates a built-in overcurrent protection circuit that operates according to the output current capacity. This

circuit serves to protect the IC from damage when the load is shorted. The protection circuit is designed to limit current

flow by not latching in the event of a large and instantaneous current flow originating from a large capacitor or other

component. These protection circuits are effective in preventing damage due to sudden and unexpected accidents.

However, the IC should not be used in applications characterized by the continuous operation or transitioning of the

protection circuits. At the time of thermal designing, keep in mind that the current capability has negative characteristics to

temperatures.

6. 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.

7. Ground wiring patterns

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.

8. Influence of strong light

Exposure of the IC to strong light sources such as infrared light from a halogen lamp may cause the IC to malfunction.

When it is necessary to use the IC in such environments, implement measures to block exposure to light from the light

source. During testing, exposure to neither fluorescent lighting nor white LEDs had a significant effect on the IC.

Fig. 29 Stable Operating Region Characteristics (Example)

0.01

0.1

1

10

100

0

50

100

150

Stable region

Ta = +25°C

Output Current Iout [mA]