Datasheet

IGBT Driver Control
Protection
TPS65563A
www.ti.com ......................................................................................................................................................... SLVS858A – JULY 2008 – REVISED AUGUST 2008
Typical usages of this function are:
• Setting the peak charging currents based on the battery voltage. The easiest way is to connect a resistive
divider with battery voltage. This saves battery life.
• Reducing peak current at the primary side when the system powers a zoom-lens motor. This avoids
inadvertent shutdowns due to a large current from the battery.
In Figure 1 , three optional connections to I_PEAK are shown:
1. Use the controller to input PWM signal with RC filter.
2. Use a digital-to-analog converter (DAC).
3. Use a resistive divider to input a fixed value into I_PEAK.
Methods 1 and 2 make it possible to delicately control peak current at the primary side. For example, set higher
current during initial charging, but set lower current just before complete charging. This effectively saves the
battery life.
The TPS65563A integrates an IGBT driver for flashing the xenon tube. After charge completion, the xenon tube
allows turnon with the IGBT driver. If the earlier flashing is needed before charge completion, the confirmation of
the lowest allowable flashing voltage to apply to the xenon tube is required.
G_IGBT should be connected to the gate of IGBT as close as possible to avoid the misoperation of flashing or
breaking the gate of IGBT. The output voltage of G_IGBT voltage depends on IGBT_VCC. The rise time and fall
time of G_IGBT are almost the same because the TPS65563A does not include a pullup/pulldown resistor for the
IGBT driver. The rise time and fall time should be met with the value specified in the data sheet of the IGBT to
avoid breaking the IGBT.
The IGBT drive has two logic inputs, one is flash acceptable (F_EN) and the other is flash enable (F_ON). To
turn on the xenon tube, high-level signal should be inputted into both F_EN and F_ON. It is acceptable to
connect both F_EN and F_ON if simple control is preferred.
The TPS65563A provides two protection mechanisms; thermal shutdown and overcurrent protection.
Thermal Shutdown (TSD)
Once the TPS65563A die temperature reaches a specific temperature, the operation is immediately latched off.
To recover the operation, the TPS65563A die temperature should be lower than a specific temperature and
forced to a low level at CHG if protection is needed.
Overcurrent Protection (OCP)
The TPS65563A has OCP at the SW pin. The TPS65563A is latched off if the SW pin is dropped to compare
VBAT pin voltage during the switch ON time. The threshold is specified in Overcurrent Protection Trigger Voltage
at SW in Electrical Characteristics. To recover the operation, the CHG level is forced to a low level after
protection occurs and peak current is less than threshold.
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