© 2015 Exar Corporation

THEORY OF OPERATION

The XRP6275’s ultra low input voltage allow

single rail operation from 2.625V down

1.045V without requiring any extra biasing

voltage.

This

single

input

voltage

range

provides

easy

conversions

from

industry

standard 1.1V, 1.2V, 1.35V, 1.5V, 1.8V and

2.5V power rails.

The dropout voltage is the input

differential

voltage

at

which

the

ceases to regulate against further reductions

in input voltage; this point occurs when the

input voltage approaches the output voltage.

The

XRP6275

provides

ultra

low

leading dropout voltage performance making it

the perfect solution for high current extremely

tight input/output voltage conversions. T

extremely low dropout voltage allows high

efficiencies conversions.

Below

tables

illustrate

the

achievable

conversions for different load requirements

the XRP6275.

3A

VIN (V)

1.80

1.50

1.35

1.20

1.10

1.00

0.90

2.50

Yes

Yes

Yes

Yes

Yes

Yes

Yes

1.80

Yes

Yes

Yes

Yes

Yes

Yes

1.50

No

Yes

Yes

Yes

Yes

1.35

No

Yes

Yes

Yes

1.20

No

Yes

Yes

1.10

No

Yes

2A

VIN (V)

1.80

1.50

1.35

1.20

1.10

1.00

0.90

2.50

Yes

Yes

Yes

Yes

Yes

Yes

Yes

1.80

Yes

Yes

Yes

Yes

Yes

Yes

1.50

Yes

Yes

Yes

Yes

Yes

1.35

Yes

Yes

Yes

Yes

1.20

No

Yes

Yes

1.10

No

Yes

1A

VIN (V)

1.80

1.50

1.35

1.20

1.10

1.00

0.90

2.50

Yes

Yes

Yes

Yes

Yes

Yes

Yes

1.80

Yes

Yes

Yes

Yes

Yes

Yes

1.50

Yes

Yes

Yes

Yes

Yes

1.35

Yes

Yes

Yes

Yes

1.20

Yes

Yes

Yes

1.10

Yes

Yes

Output Voltage

Output Voltage

Output Voltage

Note: Yellow indicates conversions that may be thermally

limited

The maximum output current available for a

given

conversion

is

dependent

o

operating conditions and thermal performance

of DFN10/PCB (see note 1 on page 3)

3A Ultra Low Dropout Voltage Regulator

7/11

ra low input voltage allows

5V down to

1.045V without requiring any extra biasing

voltage.

This

single

input

voltage

range

easy

conversions

from

industry

standard 1.1V, 1.2V, 1.35V, 1.5V, 1.8V and

The dropout voltage is the input-to-output

differential

voltage

at

which

the

XR6275

ceases to regulate against further reductions

voltage; this point occurs when the

input voltage approaches the output voltage.

ultra

low

industry

leading dropout voltage performance making it

the perfect solution for high current extremely

tight input/output voltage conversions. This

extremely low dropout voltage allows high

Below

tables

illustrate

the

achievable

conversions for different load requirements for

0.90

0.80

0.60

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

0.90

0.80

0.60

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

0.90

0.80

0.60

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

Yes

conversions that may be thermally

The maximum output current available for a

given

conversion

is

dependent

on

the

and thermal performance

(see note 1 on page 3).

The XRP6275 is an adjustable regulator that

can be programmed to any value between

0.6V and 2.4V using 2 external resistors, R1

and R2. The relationship between the resistors

and the output voltage is:

0.6

Sum of resistors R1 and R2 must meet the

following requirement:

1 2 20

The XRP6275 is designed to be stable for all

available types and values of output capacitors

greater than 4.7µF.

The required capacitance on

pins strongly depends on the input supply

source

impedance;

the

minimum

recommended capacitor for VIN is 4.7µF. Low

ESR ceramic X5R and X7R capacitors are

recommended and should be placed as close

as

possible

to

the

pins

for

optimal

performance.

Because of the low voltages and high currents

supported by this device, typical values of

47uF for both input and output capacitors are

recommended

when

powering

high

speed

digital circuits.

The enable pin (EN) can be used

the XRP6275. Connecting this pin to ground

signal or to a voltage less than typical

will completely turn off the regulator.

the EN above 0.67V enables the XRP6275.

Where EN is derived from VIN it must be

sequenced with respect to VIN as shown in the

application

circuit.

Where

an

independent

control signal is applied to EN, it must be

asserted high after VIN reaches its minimum

operating range.

The enable pin is a high impedance MOS input.

In order to allow the EN pin compatibili

5V or 3.3V control signals, there is an internal

XRP6275

3A Ultra Low Dropout Voltage Regulator

Rev. 2.0.0

OLTAGE

table regulator that

can be programmed to any value between

V using 2 external resistors, R1

and R2. The relationship between the resistors

6 1

is the desired output voltage.

Sum of resistors R1 and R2 must meet the

20

APACITORS

designed to be stable for all

available types and values of output capacitors

pins strongly depends on the input supply

source

impedance;

the

minimum

recommended capacitor for VIN is 4.7µF. Low

ESR ceramic X5R and X7R capacitors are

recommended and should be placed as close

as

possible

to

the

pins

for

optimal

Because of the low voltages and high currents

supported by this device, typical values of

47uF for both input and output capacitors are

recommended

when

powering

high

speed

HUTDOWN

The enable pin (EN) can be used to shut down

. Connecting this pin to ground

signal or to a voltage less than typical 0.55V

will completely turn off the regulator. Pulling

the EN above 0.67V enables the XRP6275.

Where EN is derived from VIN it must be

o VIN as shown in the

application

circuit.

Where

an

independent

control signal is applied to EN, it must be

asserted high after VIN reaches its minimum

is a high impedance MOS input.

In order to allow the EN pin compatibility with

5V or 3.3V control signals, there is an internal