XC6216_2 Datasheet, PDF (20/41 Pages) Torex Semiconductor – Voltage Regulators with Stand-by Function - Input Voltage: 28V

XC6216/XE6216 Series
˙çOPERATIONAL EXPLANATION
<Output Voltage Control>
ç The voltage divided by resistors R11 & R12 is compared with the internal reference voltage by the error amplifier. The
P-channel MOSFET which is connected to the VOUT pin is then driven by the subsequent output signal. The output
voltage at the VOUT pin is controlled and stabilized by a system of negative feedback. The current limit circuit and short
protect circuit operate in relation to the level of output current and heat dissipation. Further, the IC’s internal circuitry
can be shutdown via the CE pin’s signal.
<Short-Circuit Protection>
The XC6216/XE6216 series includes a current fold-back circuit as a short circuit protection. When the load current reaches
the current limit level, the current fold-back circuit operates and output voltage drops. The output voltage drops further and
output current decreases. When the output pin is shorted, a current of about 30mA flows.
<CE Pin>
The IC’s internal circuitry can be shutdown via the signal from the CE pin with the XC6216/XE6216 series. In shutdown
mode, output at the VOUT pin will be pulled down by R11 and R12 to the VSS level. Note that as the XC6216/XE6216 series
is ‘High Active/No pull down’, operations will become unstable with the CE pin open. We suggest that you use this IC with
either a VIN voltage or a VSS voltage input at the CE pin. If this IC is used with the correct specifications for the CE pin, the
operational logic is fixed and the IC will operate normally. However, supply current may increase as a result of through
current in the IC’s internal circuitry if a medium voltage is applied.
<Thermal Shutdown>
When the junction temperature of the built-in driver transistor reaches the temperature limit level (150ˆ TYP.), the thermal
shutdown circuit operates and the driver transistor will be set to OFF. The IC resumes its operation when the thermal
shutdown function is released and the IC’s operation is automatically restored because the junction temperature drops to the
level of the thermal shutdown release voltage.
<Minimum Operating Voltage>
For the stable operation of the IC, over 2.0V of input voltage is necessary. The output voltage may not be generated
normally if the input voltage is less than 2.0V.
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