Step-Down Converter. RT6239B Datasheet

RT6239B Converter. Datasheet pdf. Equivalent

RT6239B Datasheet
Recommendation RT6239B Datasheet
Part RT6239B
Description Synchronous Step-Down Converter
Feature RT6239B; ® RT6239A/B 9A, 18V, 500kHz, ACOTTM Synchronous Step-Down Converter General Description The RT6239.
Manufacture Richtek
Datasheet
Download RT6239B Datasheet




Richtek RT6239B
®
RT6239A/B
9A, 18V, 500kHz, ACOTTM Synchronous Step-Down Converter
General Description
The RT6239A/B is a high-performance 500kHz, 9A step-
down regulator with internal power switches and
synchronous rectifiers. It features quick transient response
using its Advanced Constant On-Time (ACOTTM) control
architecture that provides stable operation with small
ceramic output capacitors and without complicated
external compensation, among other benefits. The input
voltage range is from 4.5V to 18V and the output is
adjustable from 0.7V to 8V. The proprietary ACOTTM control
improves upon other fast response constant on-time
architectures, achieving nearly constant switching
frequency over line, load, and output voltage ranges. Since
there is no internal clock, response to transients is nearly
instantaneous and inductor current can ramp quickly to
maintain output regulation without large bulk output
capacitance. The RT6239A/B is stable with and optimized
for ceramic output capacitors. With internal 30mΩ switches
and 12mΩ synchronous rectifiers, the RT6239A/B displays
excellent efficiency and good behavior across a range of
applications, especially for low output voltages and low
duty cycles. Cycle-by-cycle current limit provides
protection against shorted outputs, input under-voltage
lockout, externally-adjustable soft-start, output under- and
over-voltage protection, and thermal shutdown provide safe
and smooth operation in all operating conditions. The
RT6239A/B is available in the UQFN-14L 2x3 (FC)
package, with exposed thermal pad.
Features
Fast Transient Response
Advanced Constant On-Time (ACOTTM) Control
4.5V to 18V Input Voltage Range
Adjustable Output Voltage from 0.7V to 8V
9A Output Current
30mΩ Internal High-Side N-MOSFET and 12mΩ
Internal Low-Side N-MOSFET
Steady 500kHz Switching Frequency
Up to 95% Efficiency
Optimized for All Ceramic Capacitors
Externally-Adjustable, Pre-Biased Compatible Soft-
Start
Cycle-by-Cycle Current Limit
Input Under-Voltage Lockout
Output Over- and Under-Voltage Protection
Power Good Output
Thermal Shutdown
Applications
Industrial and Commercial Low Power Systems
Computer Peripherals
LCD Monitors and TVs
Green Electronics/Appliances
Point of Load Regulation for High-Performance DSPs,
FPGAs, and ASICs
Simplified Application Circuit
VIN
EN Signal
Power Good
RT6239A/B
VIN SW
BOOT
EN FB
PGOOD
PVCC
SS
GND
VOUT
Copyright ©2016 Richtek Technology Corporation. All rights reserved.
DS6239A/B-04 May 2016
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
1



Richtek RT6239B
RT6239A/B
Ordering Information
RT6239A/B
Package Type
QUF : UQFN-14L 2x3 (U-Type) (FC)
Lead Plating System
G : Green (Halogen Free and Pb Free)
UVP Option
H : Hiccup Mode UVP
L : Latched OVP & UVP
Note :
A : PSM
B : PWM
Richtek products are :
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.
Marking Information
RT6239ALGQUF
0N : Product Code
0NW
W : Date Code
RT6239BLGQUF
0C : Product Code
0CW
W : Date Code
RT6239AHGQUF
0E : Product Code
0EW
W : Date Code
Pin Configurations
(TOP VIEW)
14 13 12
AGND 1
11 GND
FB 2
10 GND
PVCC 3
9 GND
PGOOD 4
8 VIN
56 7
RT6239BHGQUF
0D : Product Code
0DW
W : Date Code
UQFN-14L 2x3 (FC)
Copyright ©2016 Richtek Technology Corporation. All rights reserved.
www.richtek.com
2
is a registered trademark of Richtek Technology Corporation.
DS6239A/B-04 May 2016



Richtek RT6239B
RT6239A/B
Functional Pin Description
Pin No.
1
Pin Name
AGND
Analog GND.
Pin Function
2 FB
Feedback Voltage Input. It is used to regulate the output of the converter to a set
value via an external resistive voltage divider. The feedback reference voltage is
0.7V typically.
3
PVCC
Internal Regulator Output. Connect a 1F capacitor to GND to stabilize output
voltage.
4
PGOOD
Power Good Indicator Open-Drain Output.
Bootstrap Supply for High-Side Gate Driver. This capacitor is needed to drive the
5
BOOT
power switch's gate above the supply voltage. It is connected between the SW and
BOOT pins to form a floating supply across the power switch driver. A 0.1F
capacitor is recommended for use.
6 SW
Switch Node. Connect this pin to an external L-C filter.
7, 8 VIN
Power Input. The input voltage range is from 4.5V to 18V. Must bypass with a
suitably large (10F x 2) ceramic capacitor.
9, 10, 11, 12 GND
Ground.
13 EN
Enable Control Input. A logic-high enables the converter; a logic-low forces the IC
into shutdown mode reducing the supply current to less than 10A.
14 SS
Soft-Start Time Setting. An external capacitor should be connected between this
pin and GND.
Function Block Diagram
PVCC
BOOT
VIN
Reg
VIBIAS
PVCC
VREF
Min.
Off
PVCC
UGATE
OC
Control
Driver
LGATE
UV & OV
GND SW
PVCC
SW
Ripple
Gen.
6µA
SS
FB
+
-
-
Comparator
0.9 VREF
FB
+
-
VIN Comparator
SW On-Time
EN
VIN
SW
GND
PGOOD
EN
Copyright ©2016 Richtek Technology Corporation. All rights reserved.
DS6239A/B-04 May 2016
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
3







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