RT9239 Ver la hoja de datos (PDF) - Richtek Technology
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RT9239 Datasheet PDF : 6 Pages
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Preliminary
RT9239
Synchronous PWM Step-down DC/DC Converter Controller
General Description
Features
The RT9239 is a low cost, high-efficiency voltage-
mode PWM controller for motherboard power supply
application. Synchronous N-channel MOSFET driver,
short-circuit protection, and soft start function are
integrated in a single chip. A simple high power buck
regulator with shutdown function can be
implemented with minimum external components.
The RT9239 provides current-limit protection by
monitoring the voltage drop across N-channel
MOSFET in over current condition, therefore,
eliminates the current sensing resistor and minimizes
the efficiency loss. The soft start function reduces the
stress on power supply and components in power on
duration. The 200 kHz operating frequency and high
speed PWM control loop with Synchronous N-
channel MOSFET driver provide optimized
compromise between efficiency, cost, and response
speed.
Ordering Information
RT9239
Package type
S : SOP-14
Operating temperature range
C: Commercial standard
z Synchronous N-channel MOSFET Driver
z High Efficiency
z Fast Response with 200kHz Operating
Frequency
z Adjustable Current Limit by Sensing MOSFET
RDS(ON), without Extra Current Sensing
Resistor
z Shutdown Function
Applications
z Low Cost CPU Power Supply
z Motherboard I/O Power Supply
z Add-On Card Power Supply
z DDR SDRAM Bus Terminator Power Supply
Pin Configurations
Part Number
Pin Configurations
RT9239CS
(Plastic SOP-14)
TOP VIEW
NC 1
OCSET 2
SS 3
NC 4
FB 5
EN 6
GND 7
14 VCC
13 PVCCL
12 LGATE
11 PGNDL
10 PVCCH
9 UGATE
8 PHASE
Typical Application Circuit
12V
R1
10Ω
D1 C1
13 10
C2; 1000pF
15V
1µF
14
PVCCL PVCCH
VCC OCSET
2
Low Shutdown
6 EN
R2; 2.4k
UGATE 9
Q1
C3
0.1µF
3 SS
PHASE 8
11 PGNDL
7 GND
LGATE 12
FB 5
Q2
L1
C6
1µF
+
-
1µH
C4
1000µF×2
L2
D2 7µH + C5
1N5817 - 1000µF×6
RT9239
R4
1K 1%
R3
1K 1%
VIN 5V
VOU T
2.5V/10A
C4, C5: Each 1000µF 6.3WV DC, Sanyo MV-GX or Equivalent.
L1: Core: Micrometals T50-52; Winding: 5 turns of 18 AWG.
L2: Core: Micrometals T60-52; Winding: 14 turns of 17 AWG.
Q1, Q2: PHB83N03LT, PHB95N03LT
DS9239-00 June 2001
www.richtek-ic.com.tw
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