TS19460CS RLG Taiwan Semiconductor, TS19460CS RLG Datasheet - Page 4

• Manufacturer Part Number: TS19460CS RLG
• Description: LED Lighting Drivers WLED Driver with External Mosfet
• Manufacturer: Taiwan Semiconductor

Specifications of TS19460CS RLG

• Rohs: yes

Application Information
The TS19460 is optimized to drive buck LED drivers using average current mode control. This method of control
enables fairly accurate LED current control without the need for high side current sensing or the design of any
closed loop controllers. The IC uses very few external components and enables both linear and PWM dimming of
the LED current.
A resistor connected to the RT pin programs the frequency of operation (or the off-time). Constant frequency of
average current mode control is used for stability and to improve the LED current regulation over a wide range of
input voltages.
The current through the switching MOSFET source is averaged and used to give constant-current feedback. This
current is detected from a sense resistor at the CS pin, the feedback operates is a fast open-loop mode, there are
no compensation is required, the output current is programmed as
When the Voltage at the LD input >1.5V, otherwise
When application to design the inductor witching ripple current in it is 40% of average peak to peak, full load
current, the inductance can be calculated as follow:
The duty cycle range of current control feedback is limited to <0.75%, when the LED string voltage is greater than
75% of input voltage, the LED current will be reduced.
When output LED voltage is below
the loss of regulation of LED current. This condition will cause an increase in LED current and can be possible to
trip the short circuit protection comparator when the voltage at CS exceeds 0.44V, the Gate off time (
400uS) is generated to prevent stair casing of inductor current. the leading edge blanking delay is provide at CS to
prevent false triggering of current feedback and short circuit protection, both of output open or short condition is
required to recycle the
Input Voltage Regulator
The TS19460 can be powered directly from its VIN pin and can work from 8.0V~450VDC at its VIN pin. When a
voltage is applied at the VIN pin, the TS19460 maintains a constant 7.5V at the VDD pin. This voltage is used to
power the IC and any external resistor dividers needed to control the IC. The VDD pin must be bypassed by a low
ESR capacitor to provide a low impedance path for the high frequency current of the output GATE driver. The
TS19460 can be also operated by supplying a voltage at the VDD pin greater than the internally regulated voltage.
Please note that this external voltage at the VDD pin should not exceed 12V.
Although the VIN pin of the TS19460 is rated up to 450V, the actual maximum voltage that can be applied is limited
by the power dissipation in the IC. For example, if an SOP-8 (junction to ambient thermal resistance Rθ
W) TS19460 draws about I
junction temperature limited to about the maximum voltage at the VIN pin would be:
In these cases, to operate the TS19460 from higher input voltages, a Zener diode can be added in series with the
VIN pin to divert some of the power loss from the TS19460 to the Zener diode. In the above example, using a 100V
zener diode will allow the circuit to easily work up to 490V.
I
I
L
V
LED
LED
OUT
IN(MAX)
= 0.25V / R
= ( V
= ( V
V
DD
= ( T
LD
to restore to operate in normally.
OUT(max)
IN
= 2.0mA from the VIN pin, and has a maximum allowable temperature rise of the
* 0.181 ) / R
J(MAX)
CS
V
* T
OUT(MIN)
– T
OFF
A
AC/DC WLED Driver with External MOSFET
CS
) / ( Rθ
) / ( 0.4 * I
= V
IN
* D
JA
(MIN)
* I
OUT
4/7
IN
, where
) = 390V
)
D
(MIN)
Universal High Brightness
= 1uS / (T
OFF
+ 1uS)
TS19460
, it also occurred
Version: A12
JA
T
= 128°C/
HICCUP
=