RT8108
5V to 12V Single Synchronous Buck PWM Controller
General Description
Features
z Single IC Supply Voltage ( 5V to 12V)
The RT8108 series are single-phase synchronous buck
PWM DC/DC controllers designed to drive two
N-MOSFETs. They provide a highly accurate,
programmable output voltage precisely regulated to low
voltage requirement with an internal 0.6V or 0.8V reference.
z Drive Two N-MOSFETs
z Fixed Operating Frequency at 200kHz, 300kHz and
500kHz
z Voltage Mode PWM Control with External
Feedback Loop Compensation
The RT8108 series use a single feedback loop voltage mode
PWM control for fast transient response. The high driving
capability makes it suitable for large output current
applications. An oscillator with fixed frequency 200kHz /
300kHz / 500kHz reduces the component size of the
external inductor and capacitor for saving PCB board area
and cost.
z Over Current Protection by Sensing MOSFET RDS(ON)
z Hardware Pin for On/Off Control
z Full 0 to 90% Duty Cycle
z Fast Transient Response
z RoHS Compliant and Halogen Free
Applications
z Mother Boards andDesktop Servers
The RT8108 series integrate complete protection functions
such as OCP, OVP and OTP UVP into SOP-8 and SOP-8
(Exposed Pad) surface mount packages.
z Graphic Cards
z Switching Power Supply
z GenericDC/DC Power Regulator
Ordering Information
RT8108
Pin Configurations
Package Type
S : SOP-8
(TOP VIEW)
SP : SOP-8 (Exposed Pad-Option 1)
8
BOOT
UGATE
PHASE
COMP/SD
FB
Lead Plating System
G : Green (Halogen Free and Pb Free)
2
3
4
7
6
5
GND
LGATE/OCSET
VCC
Frequency / VREF Options
A : 300k / 0.6V
SOP-8
B : 300k / 0.8V
C : 200k / 0.6V
D : 200k / 0.8V
E : 500k / 0.6V
8
BOOT
UGATE
PHASE
COMP/SD
FB
2
7
6
5
GND
F : 500k / 0.8V
3
4
GND
9
LGATE/OCSET
Note :
VCC
Richtek products are :
SOP-8 (Exposed Pad)
` RoHS compliant and compatible with the current require-
ments of IPC/JEDEC J-STD-020.
` Suitable for use in SnPb or Pb-free soldering processes.
DS8108-03 September 2011
www.richtek.com
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