BD9134MUV_14 Datasheet, PDF (10/25 Pages) Rohm – Synchronous Buck Converter with Integrated FET

BD9134MUV
3. Information on Advantages
Advantage 1：Offers fast transient response by using current mode control system.
Conventional product (Load response IO=1A to 3A)
BD9134MUV (Load response IO=1A to 3A)
VOUT
572mV
VOUT
328mV
IOUT
IOUT
Voltage drop due to sudden change in load was reduced.
Figure 24. Comparison of Transient Response
Advantage 2： Offers High Efficiency for all Load Ranges.
(a) For lighter load:
This IC utilizes the current mode control called SLLM^TM, which reduces various dissipations such as switching
dissipation (PSW), gate charge/discharge dissipation (PGATE), ESR dissipation of output capacitor (PESR) and
ON-Resistance dissipation (PRON) that may otherwise cause reduction in efficiency.
Achieves Efficiency Improvement for Lighter Load.
(b) For heavier load:
This IC utilizes the synchronous rectifying mode and uses low ON-Resistance power MOSFETs.
ON-Resistance of High Side MOSFET : 82mΩ(Typ)
ON-Resistance of Low Side MOSFET : 70mΩ(Typ)
Achieves Efficiency Improvement for Heavier Load.
Offers high efficiency for all load range with the improvements mentioned above.
100
SLLM^TM
②
50 _{① PWM}
①improvement by SLLM^TM system
②improvement by synchronous rectifier
0
0.001 0.01
0.1
1
Output current IOUT[A]
Figure 25. Efficiency
Advantage 3：・Supplied in smaller package due to small-sized power MOSFET.
・Output capacitor Co required for current mode control: 22µF ceramic capacitor
・Inductance L required for the operating frequency of 1 MHz: 2.2µH inductor
・Incorporates FET + Boot strap diode
Reduces mounting area requirement.
EN
VCC
VREF
Gm Amp
+
Current
Comp
+ _RQ
S
SLOPE
CLK
OSC
VCC
Soft
UVLO
Start
TSD
SCP
Current
Sense/
Protect
+
Driver
Logic
PVCC
VCC
BST
PVCC
SW
PGND
GND
3.3V
Input
Output
VOUT
ITH
RITH CITH
20mm
Cf
R2
CBST
Rf
L
15mm
R1
CIN
RITH
CITH
Co
Figure 26. Example Application
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TSZ22111・15・001
10/21
TSZ02201-0J3J0AJ00150-1-2
03.Oct.2014 Rev.002