RT8477A Datasheet, PDF (5/13 Pages) Richtek Technology Corporation – High Voltage High Multiple-Topology Current LED Driver

RT8477A
Parameter
Symbol
Test Conditions
Min Typ Max Unit
PWM Converter
Switch Frequency
Maximum Duty Cycle
Minimum On-Time
f_SW
D_MAX
(Note 6)
330 380 430 kHz
--
--
100
%
--
200
--
ns
Gate High Voltage
Gate Driver Source
V_{GATE_H} I_GATE = 20mA
4.5
5
5.5
V
1
2.5
--
A
Gate Driver Sink
1
3.5
--
A
Soft-Start Time
(Note 7)
--
2
--
ms
Sense Current Limit Threshold
Over-Temperature Protection
I_{SE NS_LI M}
100 150
--
mV
Thermal Shutdown Temperature
Thermal Shutdown Hysteresis
T_{S D}
T_SD
--
150
--
C
--
20
--
C
Note 1. Stresses beyond those listed “Absolute Maximum Ratings” may cause permanent damage to the device. These are
stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in
the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions may
affect device reliability.
Note 2. If connected with a 20kΩ serial resistor, CTL can go up to 40V.
Note 3. θJA is measured at TA = 25°C on a high effective thermal conductivity four-layer test board per JEDEC 51-7. θJC is
measured at the exposed pad of the package.
Note 4. Devices are ESD sensitive. Handling precaution is recommended.
Note 5. The device is not guaranteed to function outside its operating conditions.
Note 6. When the natural maximum duty cycle of the switching frequency is reached, the switching cycle will be skipped (not
reset) as the operating condition requires to effectively stretch and achieve higher on cycle than the natural maximum
duty cycle set by the switching frequency.
Note 7. Guaranteed by design, not subjected to production test.
Copyright ©2015 Richtek Technology Corporation. All rights reserved.
DS8477A-02 April 2015
is a registered trademark of Richtek Technology Corporation.
www.richtek.com
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