ZHCSJN4C February 2018 – February 2020 TPS2HB16-Q1
PRODUCTION DATA.
When IOUT reaches the current limit threshold, ICL, the channel will switch off immediately. The ICL value will vary with slew rate and a fast current increase that occurs during a powered-on short circuit can temporarily go above the specified ICL value. When the switch is in the FAULT state it will output an output current ISNSFH on the SNS pin and on version F of the device, the fault will also be indicated on the corresponding FLT pin.
During a short circuit event, the device will hit the ICL value that is listed in the Electrical Characteristics table (for the given device version and RILIM) and then turn the output off to protect the device. The device will register a short circuit event when the output current exceeds ICL, however the measured maximum current may exceed the ICL value due to the TPS2HB16-Q1 deglitch filter and turn-off time. The device is specified to protect itself during a short circuit event over the nominal supple voltage range (as defined in the Electrical Characteristics table) at 125°C.
The current limit specification in the datasheet is based on the part being enabled into a short circuit condition with 5-µH inductor on the input and output and the input resistance being less than 10 mΩ and the output impedance less than 100 mΩ. When the part is enabled into this short circuit condition, the current will rise up to the threshold specified in the Electrical Characteristics table before it begins to shut off the current. The deglitch filter time for the device to react to the current threshold is 3 µs. Therefore if you take Version A/B and subtract 3 µs from the maximum current value, the current limit threshold will align with the value specified in the Electrical Characteristics table.