LED Driver. RT8463 Datasheet

RT8463 Driver. Datasheet pdf. Equivalent

RT8463 Datasheet
Recommendation RT8463 Datasheet
Part RT8463
Description High Voltage Multi-Topology LED Driver
Feature RT8463; .
Manufacture Richtek
Datasheet
Download RT8463 Datasheet




Richtek RT8463
®
RT8463
High Voltage Multi-Topology LED Driver
General Description
The RT8463 is a current mode PWM regulator for LED
driving applications. With a 2A power switch, wide input
voltage (4.5V to 50V) and output voltage (up to 50V)
ranges, the RT8463 can operate in any of the three
common topologies : Buck, Boost or Buck-Boost.
With 470kHz operating frequency, the size of the external
PWM inductor and input/output capacitors can be
minimized. High efficiency is achieved by a 100mV current
sensing control.
Brightness dimming can be controlled from either analog
or PWM signal. A unique built-in clamping comparator
and filtering resistor allow easy low noise analog dimming
conversion from PWM signal with only one external
capacitor.
The RT8463 is available in the TSSOP-14 (Exposed pad)
and WDFN-12L 3x3 packages.
Ordering Information
RT8463
Package Type
CP : TSSOP-14 (Exposed Pad)
QW : WDFN-12L 3x3 (W-Type)
(Exposed Pad-Option 1)
Lead Plating System
G : Green (Halogen Free and Pb Free)
Note :
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.
Features
High Voltage : VIN Up to 50V, VOUT Up to 50V
Buck, Boost or Buck-Boost Operation
Built-In 2A Power Switch
Current Mode PWM Control
470kHz Fixed Switching Frequency
Easy Dimming : Analog, PWM Digital or PWM
Converting to Analog with One External Capacitor
Adjustable Soft-Start to Avoid Inrush Current
Adjustable Over Voltage Protection to Limit Output
Voltage
Thermal Shutdown
Under Voltage Lockout
RoHS Compliant and Halogen Free
Applications
GPS, Portable DVD Backlight
Desk Lights and Room Lighting
Industrial Display Backlight
Marking Information
RT8463GCP
RT8463GCP : Product Number
RT8463
GCPYMDNN
YMDNN : Date Code
RT8463GQW
98=YM
DNN
98 = : Product Code
YMDNN : Date Code
Simplified Application Circuit
L
VIN
C1
RT8463
VCC
SW
5V EN ISP
PWM
Dimming Control
DCTL
VC
ISN
OVP
R1 C3
SS
ACTL
CREG
C2 C4 GND
D1
R2
R3
R4
C5
VOUT
C6
VOUT
Copyright ©2014 Richtek Technology Corporation. All rights reserved.
DS8463-01 August 2014
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
1



Richtek RT8463
RT8463
Pin Configurations
ISP
ISN
VC
ACTL
DCTL
EN
GND
14
2 13
3 12
4 GND 11
5 10
6 15 9
78
VCC
CREG
SW
GND
SS
OVP
GND
TSSOP-14 (Exposed Pad)
(TOP VIEW)
ISP 1
ISN 2
VC 3
ACTL 4
DCTL 5
EN 6
GND
13
12 VCC
11 CREG
10 SW
9 GND
8 SS
7 OVP
WDFN-12L 3x3
Functional Pin Description
Pin No.
TSSOP-14
(Exposed Pad)
WDFN-12L 3x3
Pin Name
Pin Function
1 1 ISP Positive Current Sense Input.
2
2
ISN
Negative Current Sense Input. Voltage threshold between ISP and
ISN is 100mV.
3 3 VC Compensation Node for PWM Boost Converter Loop.
4
4
ACTL
Analog Dimming Control Input. Effective programming range is
between 0.2V and 1.2V.
Digital Dimming Control Input. By adding a 0.47F filtering
5
5
DCTL
capacitor on the ACTL pin, the PWM dimming signal on DCTL pin
will be averaged and converted into analog dimming signal on the
ACTL pin. VACTL = 1.2V x PWM dimming duty cycle.
6
6
EN
Enable Control Input (Active High). When this pin is low, the chip is
in shutdown mode.
7, 8, 11, 15
(Exposed Pad)
9,
13 (Exposed Pad)
GND
Ground. The exposed pad must be soldered to a large PCB and
connected to GND for maximum power dissipation.
9
7
OVP
Over Voltage Protection Sense Input. The PWM Boost converter
turns off when VOVP goes higher than 1.2V.
10
8
SS
Soft-Start Time Setting. A minimum 10nF capacitor is required for
soft-start.
12 10 SW Switch Node of PWM Boost Converter.
13
11
CREG
Regulator Output for Internal Circuit. Placed a 1F capacitor to
stabilize the 5V output regulator.
14
12
VCC
Power Supply Voltage Input. For good bypass, a low ESR
capacitor is required.
Copyright ©2014 Richtek Technology Corporation. All rights reserved.
www.richtek.com
2
is a registered trademark of Richtek Technology Corporation.
DS8463-01 August 2014



Richtek RT8463
Function Block Diagram
VCC
OVP
EN
VC
SS
DCTL
4.5V
1.2V
1.4V
-
+
+
-
+
-
OSC
Shutdown
S
R
R
5µA
1.2V
+
-
-
GM
+
+
-
RT8463
SW
5V
LDO
CREG
ISN
ISP
GND
VISP – VISN
(mV)
100
ACTL
0 0.2
1.2
Figure 1
VACTL (V)
Operation
The RT8463 is specifically designed to be operated in
Buck, Boost and Buck-Boost converter applications. This
device uses a fixed frequency, current mode control
scheme to provide excellent line and load regulations. The
control loop has a current sense amplifier to sense the
voltage between the ISP and ISN pins and provides an
output voltage at the VC pin. A PWM comparator then
turns off the internal power switch when the sensed power
switch current exceeds the compensated VC pin voltage.
The power switch will not reset by the oscillator clock in
each cycle. If the comparator does not turn off the switch
in a cycle, the power switch is on for more than a full
switching period until the comparator is tripped. In this
manner, the programmed voltage across the sense
resistor is regulated by the control loop.
The current through the sense resistor is set by the
programmed voltage and the sense resistance. The voltage
across the sense resistor can be programmed by either
the analog or PWM signals at the ACTL pin, or the PWM
signal at the DCTL pin.
The RT8463 provides protection functions which include
over temperature, input voltage under voltage, output
voltage over voltage, and switch current limit.
Copyright ©2014 Richtek Technology Corporation. All rights reserved.
DS8463-01 August 2014
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
3







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