Data Sheet

ADPL42001

analog.com

Rev. 0

8 of 17

Thermal Protection

When the junction temperature exceeds +165°C, an internal thermal sensor turns the pass transistor off, allowing the

device to cool. The thermal sensor turns the pass transistor on again after the junction temperature cools by 15°C.

This results in a cycled output during continuous thermal-overload conditions. Thermal protection protects the

ADPL42001 in the event of fault conditions.

Output Short-Circuit Current Limit

The ADPL42001 features a 140mA (typ) current limit. The output can be shorted to GND for an indefinite period

without damage to the device. During a short-circuit event, the power dissipated across the internal pass transistor

can quickly heat the device. When the die temperature reaches +165°C, the ADPL42001 shuts down and automatically

restarts once the die temperature cools by 15°C.

APPLICATIONS INFORMATION

Output Voltage Setting

The output voltage can be programmed from 0.6V to 18V. Set the output voltage by connecting a resistor divider

from output to FB to GND. Choose R2 = 59kΩ, then calculate R1 with the following equation:

R1 = 98.3 x (VOUT - 0.6)kΩ

Output Capacitor Selection

If the output voltage is less than 1.8V, use a low-ESR 10µF(min) 0805 ceramic output capacitor for good load transient

response. If the output voltage is greater than or equal to 1.8V, use a low-ESR 4.7µF(min) 0805 ceramic output

capacitor.

VOUT

R1

R2

FB

GND

Figure 2. Setting the Output Voltage

Available Output Current Calculation

At a particular operating condition, the power loss that leads to the temperature rise of the part is estimated as

follows:

PLOSS = (VIN - VOUT) x ILOAD

where VIN is the input voltage, VOUT is the output voltage, and ILOAD is the load current.

For a multilayer board, the thermal performance metrics for the packages are given in Table 4.

The junction temperature of the ADPL42001 can be estimated at any given maximum ambient temperature (TA_MAX)

from the equation below:

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