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Axelite Confidential Materials, do not copy or distribute without written consent.

Rev.3.3 Nov.11, 2019

AX6607

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FUNCTION DESCRIPTIONS

A minimum of 1μF capacitor must be connected from VOUT to ground to insure stability.

Typically a large storage capacitor is connected from VIN to ground to ensure that the input

voltage does not sag below the minimum dropout voltage during the load transient response.

This pin must always be dropout voltage higher than VOUT in order for the device to regulate

properly.

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APPLICATION INFORMATION

Like any low-dropout regulator, the AX6607 requires input and output decoupling

capacitors. The device is specifically designed for portable applications requiring minimum

board space and smallest components. These capacitors must be correctly selected for

good performance. Please note that linear regulators with a low dropout voltage have high

internal loop gains which require care in guarding against oscillation caused by insufficient

decoupling capacitance.

Capacitor Selection

Normally, use a 1μF capacitor on the input and a 1μF capacitor on the output of the

AX6607. Larger input capacitor values and lower ESR (X5R, X7R) provide better

supply-noise rejection and transient response. A higher- value output capacitor (2.2μF) may

be necessary if large, fast transients are anticipated and the device is located several inches

from the power source.

Input-Output (Dropout) Voltage

A regulator's minimum input-to-output voltage differential (dropout voltage) determines

the lowest usable supply voltage. In battery-powered systems, this determines the useful

end-of-life battery voltage. Because the device uses a PMOS, its dropout voltage is a

function of drain-to source on-resistance, RDS (ON), multiplied by the load current:

VDROPOUT = VIN -VOUT = RDS (ON) x IOUT

Current Limit and Thermal Shutdown Protection

In order to prevent overloading or thermal condition from damaging the device,

AX6607 regulator has internal thermal and current limiting functions designed to protect the

device. It will rapidly shut off PMOS pass element during overloading or over temperature

condition.