TS19730CX6
Taiwan Semiconductor
5 Version: B1601
APPLICATION INFORMATION
Start-up Current
The typical start-up current is around 45μA. Very low start-up current allows the PWM controller to increase the
value of start-up resistor and then reduce the power dissipation.
UVLO(Under Voltage Lockout)
A hysteresis UVLO comparator is implemented in TS19730. The turn-on and turn-off thresholds level are fixed at
17.5V and 8V respectively. This hysteresis shown in Fig.3 ensures that the start-up capacitor will be adequate to
supply the chip during start-up. For quick start-up of the LED driver, the start-up resistor should be matched with
the start-up capacitor.
LEB(Leading-Edge Blanking)
Each time the power MOSFET is switched on, a turn-on spike will inevitably occur at the sense resistor. To avoid
fault trigger, a 400ns leading-edge blanking time is built in. Conventional RC filtering can therefore be omitted.
During this blanking period, the current-limit comparator is disabled and cannot switch off the gate driver.
OCP(Over Current Protection)
The TS19730 has built-in cycle by cycle over current protection function on CL pin. As the CL pin voltage is larger
than V
OCP
(0.3V), the gate output will be turned off immediately to avoid the driver board to be burned out.
Application Information (Continue)
OVP (Over Voltage Protection) on V
CC
To prevent the LED driver from being damaged, the TS19730 has an implemented OVP function on V
CC
. When the
V
CC
voltage is higher than the V
OVP
(31V), the output gate driver circuit will be shut down immediately to stop the
switching of power MOSFET. The V
CC
pin OVP function is an auto recovery type protection. If the OVP condition
happens, the pulses will be stopped until the V
CC
pin voltage is down to the UVLO off level. The TS19730 is
working in an auto-recovery mode as shown in Fig. 4.
Gate Clamp
Driver is clamped to 12.5V by an internal clamping circuit to avoid the Gate of MOSFET to get damaged.
Fig. 3
Fig. 4
