AP2202

Document number: DS38214 Rev. 6 - 2

20 of 26

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August 2022

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AP2202

Application Information

Input Capacitor

A 1µF minimum capacitor is recommended to be placed between VIN and GND.

Output Capacitor

An output capacitor is required to prevent oscillation. A 1.0µF minimum is recommended when CBYP is unused. A 2.2µF minimum is

recommended when CBYP is 100pF. The output capacitor may be increased to improve transient response.

Noise Bypass Capacitor

A bypass capacitor is connected to the internal voltage reference. A 100pF capacitor connected from BYP to GND makes this reference quiet,

resulting in a significant reduction in output noise, but the ESR stable area will be narrowed.

The start-up speed of the AP2202 is inversely proportional to the value of the reference bypass capacitor. In some cases, if output noise is not a

major concern and rapid turn-on is necessary, omit CBYP and leave BYP open.

Power Dissipation

Thermal shutdown may take place if the maximum power dissipation is exceeded in application. Under all possible operating conditions, the

junction temperature must be within the range specified under absolute maximum ratings to avoid thermal shutdown.

To determine if the power dissipated in the regulator reaches the maximum power dissipation (see Figures Power Dissipation vs. Ambient

Temperature (SOT-23-5 package and SOT-89 package)), use:

TJ = PD*θJA + TA

PD = (VIN-VOUT)*IOUT+VIN*IGND

Where: TJ ≤ TJ(max), TJ(max) is absolute maximum ratings for the junction temperature; VIN*IGND can be ignored due to its small value.

TJ(max) is +150°C, θJA is 200°C/W for SOT-23-5 package; and 165°C/W for SOT-89 package. No heatsink is required since the package alone will

dissipate enough heat to satisfy these requirements, unless the calculated value for power dissipation exceeds the limit.

Example: For 2.8V version packaged in SOT-23-5, IOUT = 150mA, TA = +50°C, VIN(Max) is:

(150°C-50°C)/(0.15A*200°C/W)+2.8V = 6.133V

Therefore, for good performance, please make sure that input voltage is less than 6.133V without heatsink when TA = +50°C.