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AS1358/AS1359

Datasheet - D e t a i l e d D e s c r i p t i o n

Current Limit

The AS1358/AS1359 include a current limiting circuitry to monitor and control the P-channel MOSFET pass transis-

tor’s gate voltage, thus limiting the device output current to 270mA (AS1358) and 510mA (AS1359).

Note: See Table 4 on page 4 for the recommended min and max current limits. The output can be shorted to ground

indefinitely without causing damage to the device.

Thermal Protection

Integrated thermal protection circuitry limits total power dissipation in the AS1358/AS1359. When the junction temper-

transistor and allowing the device to cool down. The thermal sensor turns the pass transistor on again after the

device’s junction temperature drops by 10ºC, resulting in a pulsed output during continuous thermal-overload condi-

tions.

Note: Thermal protection is designed to protect the devices in the event of fault conditions. For continuous operation,

do not exceed the absolute maximum junction temperature rating of +150ºC.

Operating Region and Power Dissipation

The AS1358/AS1359 maximum power dissipation is dependant on the thermal resistance of the case and PCB, the

Power dissipation across the device is calculated as:

The maximum power dissipation is calculated:

Where:

Note: Pin GND of the AS1358/AS1359 provides the electrical connection to system ground and also serves as a heat

sink. Connect pin GND to the system ground using a large pad or ground plane.

Noise Reduction

The AS1358/AS1359 noise bypass circuitry dramatically reduces output noise, exhibiting 9µVRMS of output voltage

OUT (see Figure 1 on page 1).