a us t ria
m i c r o
s y s t e m s
AS1351
Programmable Dual LDO
P ro du c t B ri e f
1 General Description
The AS1351 is a high-performance dual CMOS low-
dropout voltage regulator in a single 3x3 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 as well
as full-production in the field. Factory trimmed versions
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 AS1351 is available in a 12-pin QFN 3x3 package
or in a wafer bumping package.
2 Key Features
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2 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: 125µA (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
Wafer Bumping
QFN12 3x3, Pitch 0.8mm Package
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3 Applications
The AS1351 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.
Figure 1. Pinout Assignments (Top View)
N/C
12
N/C
11
REF
10
EN2
1
9
V
DD
EN1
2
AS1351
8
N/C
GND
3
7
V
DD
4
TRIM
5
6
13
GND (Exposed Pad)
V
OUT1
V
OUT2
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