Technical Note
BH□□NB1WHFV series
6/8
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2011.01 - Rev.B
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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□□NB1WHFV
●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. Action 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 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.
0.01
0.1
1
10
100
0 50 100 150
Output Current IOUT [mA]
ESR[
]
Stable region
Fig.30 Stable Operation Region (Example)
COUT = 2.2 µF
Ta = +25°C
