BH15LB1WG 데이터 시트보기 (PDF) - ROHM Semiconductor
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BH15LB1WG Datasheet PDF : 9 Pages
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BH □□FB1WG series, BH□□FB1WHFV series,
BH □□LB1WG series, BH□□LB1WHFV series, BH □□MA3WHFV series
Technical Note
Input capacitor
It is recommended to insert bypass capacitors between input and GND pins, positioning them as close to the pins as
possible. These capacitors will be used when the power supply impedance increases or when long wiring routes are used, so
they should be checked once the IC has been mounted.
Ceramic capacitors generally have temperature and DC bias characteristics. When selecting ceramic capacitors, use X5R or
X7R or better models that offer good temperature and DC bias characteristics and high torelant voltages.
Examples of ceramic capacitor characteristics
120
100
100
95
50V torelance
80
90
60
85
10V torelance 16V torelance
40
80
50V torelance
16V torelance
10V torelance
120
100
80
X7R
X5R
60
Y5V
40
20
75
20
0
0
1
2
3
4
70
0
1
2
3
4
0
-25
0
25
50
75
DC bias Vdc (V)
Fig. 29: Capacitance -bias characteristics (Y5V)
DC bias Vdc (V)
Fig. 30: Capacitance -bias characteristics (X5R, X7R)
Temperature (°C)
Fig. 31: Capacitance–temperature characteristics
(X5R, X7R, Y5V)
Output capacitor
To prevent oscillation at the output, it is recommended that the IC be operated at the stable region show in below Fig. It
operates at the capacitance of more than 1.0μF. As capacitance is larger, stability becomes more stable and characteristic of
output load fluctuation is also improved.
BHŜŜLB1WHFV/WG
BHŜŜFB1WHFV/WG
BHŜŜMA3WHFV
Cout=1.0μF Ta=+25°C
100
Cout=2.2μF Ta=+25°C
100
100 Cout=1.0μF Cin=1.0μF
Ta=+25°C
10
10
10
1
Stable region
0.1
1
Stable region
0.1
1
Stable region
0.1
0.01
0
0.01
50
100
150
0
Output current IOUT(mA)
50
100
150
Output current IOUT(mA)
Fig. 32 BHŜŜLB1WHFV/WG
Stable operating region characteristics (Example)
Fig. 33 BHŜŜFB1WHFV/WG
Stable operating region characteristics (Example)
0.01
0
100
200
300
Output current IOUT(mA)
Fig. 34 BHŜŜMA3WHFV
Stable operating region characteristics (Example)
Other precautions
• Over current protection circuit
The IC incorporates a built-in over current 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 circuits use fold-back type current limiting and
are designed to limit current flow by not latching up 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.
• Thermal shutdown circuit
This system has a built-in thermal shutdown circuit for the purpose of protecting the IC from thermal damage. As shown
above, this must be used within the range of power dissipation, but if the power dissipation happens to be continuously
exceeded, the chip temperature increases, causing the thermal shutdown circuit to operate. When the thermal shutdown
circuit operates, the operation of the circuit is suspended. The circuit resumes operation immediately after the chip
temperature decreases, so the output repeats the ON and OFF states. There are cases in which the IC is destroyed due to
thermal runaway when it is left in the overloaded state. Be sure to avoid leaving the IC in the overloaded state.
• Actions in strong magnetic fields
Use caution when using the IC in the presence of a strong magnetic field as such environments may occasionally cause the chip
to malfunction.
• Back current
In applications where the IC may be exposed to back current flow, it is recommended to create a route t dissipate this current
by inserting a bypass diode between the VIN and VOUT pins.
• GND potential
Ensure a minimum GND pin potential in all operating conditions.
In addition, ensure that no pins other than the GND pin carry a voltage less than or equal to the GND pin, including during
actual transient phenomena.
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2010.07 - Rev. C
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