CYT 6218
Note 5: Regulation is measured at constant junction temperature using low duty cycle pulse testing.
Parts are tested for load regulation in the load range from 10mA to 400mA. Changes in output
voltage due to heating effects are covered by the thermal regulation specification.
Note 6: Dropout voltage is defined as the input to output differential at which the output voltage drops
2% below its nominal value measured at 1V differential.
Application Hints
Like any low dropout regulator, CYT6218 requires external capacitors to ensure stability. The external
capacitors must be carefully selected to ensure performance.
Input Capacitor
An input capacitor of at least 1µF is required. Ceramic or Tantalum can be used. The value can be
increase without upper limit.
Output Capacitor
An output capacitor is required for stability. It must be placed no more than 1 cm away from the
VOUT pin, and connected directly between VOUT and GND pins. The minimum value is 1µF but may be
increase without limit.
Thermal Considerations
It is important that the thermal limit of the package is not exceeded. The CYT6218 has built-in
thermal protection. When the thermal limit is exceeded, the IC will enter protection, and VOUT will be
pulled to ground. The power dissipation for a given application can be calculated as following:
The power dissipation (PD) is
PD = IOUT * [VIN – VOUT]
The thermal limit of the package is then limited to PD(MAX) = [TJ – TA]/ΘJA where TJ is the
junction temperature, TA is the ambient temperature, and ΘJA for SOT-23-5L is around 230°C/W for
CYT6218.CYT6218 is designed to enter thermal protection at 150°C. For example, if TA is 25°C then the
maximum PD is limited to about 0.6W. In other words, if IOUT(MAX) = 400mA, then [VIN – VOUT]
cannot exceed 1.5V.
ShenZhen CYT IC Design CO ,Ltd
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