BD9132MUV_14 Datasheet, PDF (10/26 Pages) Rohm – Synchronous Buck Converter with Integrated FET

BD9132MUV
3. Information on Advantages
Advantage 1：Offers fast transient response by using current mode control system.
Conventional product (Load response IO=1A to 3A)
BD9132MUV (Load response IO=1A to 3A)
VOUT
145mV
VOUT
62mV
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
②
50 _{① PWM}
①improvement by SLLM 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
・Inductor L required for the operating frequency of 1 MHz: 2.2µH inductor
・Incorporates FET + Boot strap diode
Reduces the mounting area requirement.
VCC
EN
VREF
Gm Amp
+
Soft
Start
Current
Comp
+ ^RQ
S
SLOPE
CLK
OSC
VCC
UVLO
TSD
SCP
Current
Sense/
Protect
+
Driver
Logic
PVCC
VCC
BST
PVCC
SW
PGND
GND
3.3V
Input
Output
15mm
ADJ
R2
R1
ITH
RITH CITH
Figure 26. Example Application
R2
R1
RITH
CITH
20mm
Cf
CBST
Rf
L
CIN
Co
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TSZ22111・15・001
10/22
TSZ02201-0J3J0AJ00140-1-2
03.Oct.2014 Rev.002