AS1357
Programmable Triple LDO
www.austriamicrosystems.com Revision 1.07 1 - 10
Data Sheet
1 General Description
The AS1357 is a high-performance triple CMOS low-
dropout voltage regulator in a single QFN package. The
efficient set of programmable power supplies is opti-
mized to deliver the best compromise between quies-
cent current and regulator performance for mobile
phones, PDAs, MP3 players, and other battery powered
devices.
The one-time-programmable (OTP) function provides
greater design flexibility by allowing for independent pro-
gramming of the output voltage for each regulator on-
site. The OTP function allows for fast prototyping reduc-
ing development times and costs significant. Factory
trimmed versions for full-production are also available.
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 capaci-
tors 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 net-
works.
The AS1357 is available in a 12-pin QFN 4x4 or 16-pin
QFN 3x3 package.
Figure 1. Pinout Assignments (Top View)
2 Key Features
! 3 Independent Voltage Regulators with Shutdown
! Output Current: 200mA each LDO
! One Time Programmable Output Voltage
(User- or Factory-Trimmed)
! Programmable Output Voltage Range: 1.8 to 3.3V in
0.1V Steps
! Accuracy: ±1.5%
! PSRR: 70dB at 1kHz, 40dB at 100kHz
! Line Regulation: ±2mV
! Load Regulation: ±0.6mV
! Supply Range: 3 to 5.5V
! 0.2V Dropout Voltage @ I = 200mA
! Shutdown Current: ≤1µA
! Supply Current Without Load: 175µA (typ)
! Softstart for Low Inrush Current
! Stable with low ESR Ceramic Capacitors from 1 to
4.7µF
! Low Noise: 40µV rms @10Hz to 100kHz Bandwidth
! Thermal Protection
! Over-Current Protection
! Temperature Range: -40 to +85°C
! Package Types: 12-pin QFN 4x4 and
16-pin QFN 3x3
3 Applications
The AS1357 is ideal for cordless and mobile phones,
MP3 players, CD and DVD players, PDAs, handheld
computers, digital cameras, and any other hand-held
battery-powered device.
GND
V
OUT2VOUT1
EN3 N/C REF
13
6
12
VDD
10
5
1415
EN1
1
VDD
2
VDD
4
AS1357
16-pin QFN
3x3
VDD
3
VOUT3
7
N/C
8
VDD
9
GND
11
EN2
16
AS1357
12-pin QFN
4x4
GND
V
OUT3VOUT2VOUT1
EN3 N/C REF
10
6
9
(Exposed Pad)
VDD
8
N/C
7
54
1112
EN2
1
EN1
2
VDD
3
GND
13
