Conceptual
5V/12V Synchronous-Rectified Buck Controller
uP9305
Features
General Description
The uP9305 is a compact synchronous-rectified buck ꢀ Operates from 5V or 12V Supply Voltage
controller specifically designed to operate from 5V or 12V
supply voltage and to deliver high quality output voltage
as low as 0.6V for uP9305S/W (linear OCP).
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3.3V to 12V VIN Input Range
VREF with 1.0% Accuracy:
uP9305S/W: 0.6V VREF
uP9305T/Q: 0.8V VREF
The uP9305 adopts constant frequency, voltage mode
control scheme, featuring easy-to-use, low external
component count, and fast transient response. Fixed
300kHz operation provides an optimal level of integration
to reduce size and cost of the power supply.
ꢀ Stand Alone Mode Operation
ꢀ Simple Single-Loop Control Design
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Voltage-Mode PWM Control
Fast Transient Response
This controller integrates internal MOSFET drivers that
support 12V+12V bootstrapped voltage for high efficiency
power conversion. The bootstrap diode is built-in to simplify
the circuit design and minimize external part count.
Fixed 300kHz Switching Frequency
ꢀ High-Bandwidth Error Amplifier
0% to 90% Duty Cycle
ꢀ Lossless, Adjuatable Over Current Protection
Other features include internal soft start, over/under
voltage protection, over current protection and shutdown
function. With aforementioned functions, this part provides
customers a compact, high efficiency, well-protected and
cost-effective solutions. This part is available in PSOP-8L
package.
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Uses Lower MOSFET RDS(ON)
uP9305S/W: Linear OCP
uP9305T/Q: Fixed OCP
Pin Configuration
ꢀ Internal Soft Start
ꢀ Integrated Boot Diode
ꢀ PSOP-8L Package
BOOT
UG
PH
1
2
3
4
8
7
6
5
COMP/EN
FB
9
GND
OCS
LG
ꢀ RoHS Compliant and Halogen Free
VCC
Applications
PSOP-8L (uP9305S/W)
ꢀ Power Supplies for Microprocessors or Subsystem
Power Supplies
BOOT
UG
PH
1
2
3
4
8
7
6
5
ꢀ Cable Modems, Set Top Boxes, and DSL Modems
COMP/EN
FB
9
ꢀ Industrial Power Supplies; General Purpose
GND
GND
LG
Supplies
VCC
ꢀ 5V or 12V Input DC-DC Regulators
PSOP-8L (uP9305Q/T)
ꢀ Low-Voltage Distributed Power Supplies
uP9305-DS-C3000, Aug. 2015
www.upi-semi.com
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