BD9111NV_09 Datasheet, PDF (5/14 Pages) Rohm – Output 2A or More High Efficiency Step-down Switching Regulator with Built-in Power MOSFET

BD9111NV
Technical Note
●Information on advantages
Advantage 1：Offers fast transient response with current mode control system.
Conventional product (Load response IO=0.1A→0.6A)
BD9111NV (Load response IO=1A→2A)
VOUT
160mV
VOUT
100mV
IOUT
IOUT
Voltage drop due to sudden change in load was reduced by about 50%.
Fig.18 Comparison of transient response
Advantage 2： Offers high efficiency for all load range.
・For lighter load:
Utilizes the current mode control mode called SLLM for lighter load, which reduces various dissipation such as switching
dissipation (P_SW), gate charge/discharge dissipation, ESR dissipation of output capacitor (P_ESR) and on-resistance
dissipation (P_RON) that may otherwise cause degradation in efficiency for lighter load.
Achieves efficiency improvement for lighter load.
・For heavier load:
Utilizes the synchronous rectifying mode and the low on-resistance
MOS FETs incorporated as power transistor.
ON resistance of P-channel MOS FET : 200mΩ(Typ.)
ON resistance of N-channel MOS FET : 160mΩ(Typ.)
Achieves efficiency improvement for heavier load.
Offers high efficiency for all load range with the improvements mentioned above.
100
SLLM
②
50 _{① PWM}
①inprovement by SLLM system
②improvement by synchronous rectifier
0
0.001 0.01
0.1
1
Output current Io[A]
Fig.19 Efficiency
Advantage 3：・Supplied in smaller package due to small-sized power MOS FET incorporated.
・Output capacitor Co required for current mode control: 22μF ceramic capacitor
・Inductance L required for the operating frequency of 1 MHz: 2.2μH inductor
(BD9111NV:Co=22μF, L=2.2μH)
Reduces a mounting area required.
VCC
RITH
CITH
DC/DC
Convertor
Controller
Cin
L
VOUT
Co
15mm
CIN
RITH
L
10mm
CITH
CO
Fig.20 Example application
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5/13
2009.05 - Rev.A