AS1355

300mA, Triple LDO

www.ams.com/LDOs/AS1355

Revision 1.3

1 - 12

1 General Description

The AS1355 is a high-performance triple CMOS low-dropout voltage

regulator in a single QFN package. The efficient set of

programmable power supplies is optimized to deliver the best

compromise between quiescent current and regulator performance

for mobile phones, PDAs, MP3 players, and other battery powered

devices.

Stability is guaranteed with ceramic output capacitors of only 1µF

(±20% – X5R) up to 4.7µF (±20% – X5R). The low equivalent series

resistance (ESR) of these capacitors ensures low output impedance

at high frequencies.

Regulation performance is excellent even under low dropout

conditions, when the power transistor has to operate in linear mode.

The low-noise performance allows direct connection of noise

sensitive circuits without additional filtering networks.

The AS1355 is available in a 16-pin QFN 3x3 package.

2 Key Features



3 Independent Voltage Regulators with Shutdown



Output Current: 300mA each LDO



Programmable Output Voltage Range: 1.25V to 3.6V in 50mV

Steps

Figure 1. AS1355 - Typical Application Diagram



Accuracy: ±1.0%



PSRR: 70dB at 1kHz, 60dB at 100kHz



Load Regulation: 3mV (0 to 300mA)



Supply Range: 2.3V to 5.5V



0.1V Dropout Voltage @ Iload = 200mA



Shutdown Current: 1µA



Supply Current Without Load: 160µA



Softstart for Low Inrush Current



Stable with low ESR Ceramic Capacitors from 1µF to 4.7µF



Low Noise: 40µV rms @10Hz to 100kHz Bandwidth



Thermal Protection



Over-Current Protection



Temperature Range: -40°C to +85°C



Packages:

- 16-pin QFN 3x3

- 16-pin TQFN 3x3

3 Applications

The AS1355 is ideal for cordless and mobile phones, MP3 players,

CD and DVD players, PDAs, hand-held computers, digital cameras,

and any other hand-held battery-powered device.

1µF

3.3V

(Improved Noise Performance)

µP

AS1355

VOUT1

VDD1

EN1

EN2

EN3

GND

REF

+5V

1µF

VDD2

VDD3

1µF

1.8V

VOUT2

1µF

1.5V

VOUT3

VDDA