AS1355
300mA, Triple LDO
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
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.
Figure 1. AS1355 - Typical Application Diagram
1µF
+5V
VDD1
VDD2
VDD3
µP
VDDA
EN1
EN2
EN3
AS1355
VOUT1
VOUT2
1µF
1µF
VOUT3
1µF
REF
3.3V
1.8V
1.5V
C
REF
= 100nF
(Improved Noise Performance)
GND www.ams.com/LDOs/AS1355 Revision 1.3
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AS1355
Datasheet - P i n A s s i g n m e n t s
4 Pin Assignments
Figure 2. Pin Assignments (Top View)
EN1 1
EN2
16
EN3
15
NC
14
REF
13
12
GND
VDDA
2
AS1355
11
GND
VDD1
3 10
NC
17
VDD2
4
5 6 7
VOUT1 VOUT2 VOUT3
8
NC
9
VDD3
4.1 Pin Descriptions
Table 1. Pin Descriptions
Pin Number
1
2
3
6
7
4
5
8
9
10
Pin Name
EN1
VDDA
VDD1
VDD2
VOUT1
VOUT2
VOUT3
NC
VDD3
NC
11, 12 GND
13
14
15
16
17
REF
NC
EN3
EN2
NC
Description
Active-High Enable Input 1. Pull this pin to GND to disable the regulated output voltage V
OUT1
.
Analog Power Supply Voltage
Unregulated Input Voltage 1
Unregulated Input Voltage 2
Regulated Output Voltage 1
Regulated Output Voltage 2
Regulated Output Voltage 3
Not Connected
Unregulated Input Voltage 3
Not Connected
Ground.
Note:
All GND pins must be connected together externally.
Reference Voltage.
Note:
Connect to a 100nF capacitor during normal operation.
Not Connected
Active-High Enable Input 3. Pull this pin to GND to disable the regulated output voltage V
OUT3
.
Active-High Enable Input 2. Pull this pin to GND to disable the regulated output voltage V
OUT2
.
Exposed Pad. This pad is not connected internally, it can be connected to GND.
www.ams.com/LDOs/AS1355 Revision 1.3
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AS1355
Datasheet - A b s o l u t e M a x i m u m R a t i n g s
5 Absolute Maximum Ratings
Stresses beyond those listed in
Table 2 may cause permanent damage to the device. These are stress ratings only, and functional operation of
the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability.
Table 2. Absolute Maximum Ratings
Parameter
Electrical Parameters
VDDx, ENx to GND
VOUTx to GND
All other pins to GND
Electrostatic Discharge
Electrostatic Discharge HBM
Temperature Ranges and Storage Conditions
Thermal Resistance Θ
JA
Junction Temperature
Storage Temperature Range
Min
-0.3
-0.3
7
5
-0.3
V
DD
+ 0.3
-55
2
Max
33
+125
+125
Units
V
V
V kV
ºC/W
ºC
ºC
Comments
Norm: MIL 883 E method 3015 on PCB
Package Body Temperature
+260
ºC
The reflow peak soldering temperature (body temperature) specified is in accordance with IPC/
JEDEC J-STD-020“Moisture/Reflow Sensitivity
Classification for Non-Hermetic Solid State Surface
Mount Devices”.
Humidity non-condensing
Moisture Sensitive Level
5
3
85 %
Represents a max. floor life time of 168h www.ams.com/LDOs/AS1355 Revision 1.3
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AS1355
Datasheet - E l e c t r i c a l C h a r a c t e r i s t i c s
6 Electrical Characteristics
V
DD
= 4V, C
OUT
= 1µF, typical values are for T
AMB
= 25°C (unless otherwise specified);
Table 3. Electrical Characteristics
Symbol
T
AMB
V
DD
V
OUT
R
ON
Parameter
Operating Temperature Range
Supply Voltage Range
Output Voltage Range
On Resistance
Conditions
PSRR t
I
I
OFF
VDD set
1
1
Power Supply
Rejection Ratio
Shut Down Current
Supply Current
Output Voltage
Settling Time
I f = 1kHz, C
REF
= 100nF f = 100kHz, C
REF
= 100nF
ENx = Low, T
AMB
= +25°C
Without Load
LOAD
Switched from 0 to 100mA
V
V t start
V
1
OUT
LINEREG
LOADREG 1
Start-up Time 2
Output Voltage Tolerance
Line Regulation, Static
Load Regulation, Static
C
REF
= 100nF Pre-charged
C
REF
= 0nF Uncharged
C
REF
= 100nF Uncharged
I
LOAD
= 0mA, T
AMB
= 25°C
I
LOAD
= 0mA
V
OUT(NOM)
+0.3V to 5.4V
I
LOAD
= 0 to 50 mA
I
LOAD
= 0 to 300 mA
I
I
V
V
V
IH
IL
LOAD
LIMIT
Noise
Enable Input Voltage High
Enable Input Voltage Low
Output Current
Output Current Limitation
Output Noise Voltage
Thermal Protection
1. Guaranteed by design and verified by lab evaluation.
2. Startup is performed if any EN pin goes high.
10Hz to 100kHz, C
REF
= 100nF
-1
-2
-1
Min
-40
2.3
1.25
1.5
0
450
40
150
0.5
70
60
160
Typ
200
15
0.5
3
1
2.5
1
2
10
1
240
50
300
Max
85
5.5
3.6
0.4
300
Unit
°C
V
V
Ω dB
µA
µA
µs
% mV mV
V
V mA mA
µV
RMS
°C
µs
µs ms
%
%
Note:
All limits are guaranteed. The parameters with min and max values are guaranteed with production tests or SQC (Statistical Quality
Control) methods. www.ams.com/LDOs/AS1355 Revision 1.3
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AS1355
Datasheet - Ty p i c a l O p e r a t i n g C h a r a c t e r i s t i c s
7 Typical Operating Characteristics
V
DD
= 4V, V
OUT
= 3.3V, C
OUT
= 1µF, T
AMB
= +25°C (unless otherwise specified);
Figure 3. Load Regulation; V
3.36
3.34
3.32
3.3
3.28
3.26
3.24
OUT
vs. I
-45 -30 -15 0 15 30 45 60 75 90
Temperature (°C)
Figure 7. Startup; no Load, no C
REF
OUT
3.24
0 50 100 150 200
Output Current (mA)
250
Figure 5. Output Voltage vs. Temp.; I
OUT
= 1mA
3.36
300
3.34
3.32
3.3
3.28
3.26
Figure 4. Line Regulation; V
OUT
vs. V
IN
1.84
1.83
1.82
1.81
1.8
1.79
1.78
1.77
1.76
2 2.5
3 3.5
4
Input Voltage (V)
4.5
Figure 6. Quiescent Current vs. Temperature
240
220
5 5.5
200
180
160
140
120
100
80
-45 -30 -15 0 15 30 45 60 75 90
Temperature (°C)
Figure 8. Startup; R
LOAD
= 11
Ω, no C
REF
www.ams.com/LDOs/AS1355
50µs/Div
Revision 1.3
50µs/Div
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AS1355
Datasheet - Ty p i c a l O p e r a t i n g C h a r a c t e r i s t i c s
Figure 9. Startup; no Load, C
REF
= 100nF Figure 10. Startup; R
LOAD
= 11
Ω, C
REF
= 100nF
2ms/Div
Figure 11. Startup; no Load, C
REF
= 100nF (pre-charged)
2ms/Div
Figure 12. Startup; R
LOAD
= 11
Ω, C
REF
= 100nF (pre-charged)
20µs/Div 20µs/Div
Figure 13. Load Transient Response; I
OUT
= 0 to
300mA
Figure 14. Load Transient Response; I
OUT
= 300 to
0mA
www.ams.com/LDOs/AS1355
10µs/Div
Revision 1.3
500µs/Div
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AS1355
Datasheet - D e t a i l e d D e s c r i p t i o n
8 Detailed Description
Figure 15. AS1355 - Block Diagram
VDD1
EN1
VDD2
EN2
VDD3
EN3
VDDA
VOUT1
Thermal
Overcurrent
Softstart
Control
V
REF
Thermal
Overcurrent
Softstart
Control
V
REF
VOUT2
VOUT3
Thermal
Overcurrent
Softstart
Control
V
REF
Reference
Voltage
AS1355
REF
GND www.ams.com/LDOs/AS1355 Revision 1.3
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AS1355
Datasheet - Ty p i c a l A p p l i c a t i o n
9 Typical Application
Figure 16. Typical Application
+5V
VDD1
VDD2
1µF
VDD3
Microprocessor
VDDA
EN1
EN2
EN3
AS1355
VOUT1
1µF
3.3V
VOUT2
1µF
1.8V
VOUT3
1µF
REF
1.5V
C
REF
= 100nF
(Improved Noise Performance)
GND www.ams.com/LDOs/AS1355 Revision 1.3
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AS1355
Datasheet - P a c k a g e D r a w i n g s a n d M a r k i n g s
10 Package Drawings and Markings
Figure 17. 16-pin QFN 3x3 Package
Marking: YYWWIZZ.
YY
last two digits of the current year www.ams.com/LDOs/AS1355
WW
manufacturing week
Revision 1.3
X
plant identifier
ZZ
free choice / traceability code
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AS1355
Datasheet - P a c k a g e D r a w i n g s a n d M a r k i n g s
Figure 18. 16-pin TQFN 3x3 Package
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AS1355
Datasheet - O r d e r i n g I n f o r m a t i o n
11 Ordering Information
The devices are available as the standard products shown in
Table 4 .
Table 4. Ordering Information
Ordering Code
AS1355-BQFT-WGD
AS1355-BQFT-WWW
AS1355-BQFT-WWD2
AS1355-BQFT-xyz*
Marking
ASSG
ASSV
ASTD
____
Output
V
OUT1
= 3.3V
V
OUT2
= 1.8V
V
OUT3
= 1.5V
V
OUT1
= 3.3V
V
OUT2
= 3.3V
V
OUT3
= 3.3V
V
OUT1
= 3.3V
V
OUT2
= 3.3V
V
OUT3
= 1.5V
V
OUT1
*
V
OUT2
*
V
OUT3
*
Description
300mA, Triple LDO
300mA, Triple LDO
300mA, Triple LDO
300mA, Triple LDO
Delivery Form
Tape and Reel
Tape and Reel
Tape and Reel
Tape and Reel
Package
16-pin QFN 3x3
16-pin QFN 3x3
16-pin TQFN 3x3
16-pin QFN 3x3
*
These devices are available in factory-set output voltages from 1.25V to 3.6V in 100mV increments. Choose the desired V
OUT
suffix from
Table 5 and insert it instead of “xyz” in the part number.
On request also non-standard devices with output voltages between 1.25V and 3.6V in 50mV steps are available.
Table 5. Output Voltage Suffix Guide
Min
F
G
D
E
Suffix
A
B
C
H
I
1.5
1.6
1.7
1.8
Typ
1.25
1.3
1.4
1.9
2.0
Max
O
P
M
N
Suffix
J
K
L
Q
R
Min
2.4
2.5
2.6
2.7
Typ
2.1
2.2
2.3
2.8
2.9
Max
Y
Z
W
X
2
Suffix
S
T
V
Min Typ
3.0
3.1
3.2
3.3
3.4
3.5
3.6
thin QFN
Max
Note:
All products are RoHS compliant and ams green.
Buy our products or get free samples online at www.ams.com/ICdirect
Technical Support is available at www.ams.com/Technical-Support
For further information and requests, email us at [email protected]
(or) find your local distributor at www.ams.com/distributor www.ams.com/LDOs/AS1355 Revision 1.3
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AS1355
Datasheet - O r d e r i n g I n f o r m a t i o n
Copyrights
Copyright © 1997-2013, ams AG, Tobelbaderstrasse 30, 8141 Unterpremstaetten, Austria-Europe. Trademarks Registered ®. All rights reserved. The material herein may not be reproduced, adapted, merged, translated, stored, or used without the prior written consent of the copyright owner.
All products and companies mentioned are trademarks or registered trademarks of their respective companies.
Disclaimer
Devices sold by ams AG are covered by the warranty and patent indemnification provisions appearing in its Term of Sale. ams AG makes no warranty, express, statutory, implied, or by description regarding the information set forth herein or regarding the freedom of the described devices from patent infringement. ams AG reserves the right to change specifications and prices at any time and without notice. Therefore, prior to designing this product into a system, it is necessary to check with ams AG for current information. This product is intended for use in normal commercial applications. Applications requiring extended temperature range, unusual environmental requirements, or high reliability applications, such as military, medical life-support or life-sustaining equipment are specifically not recommended without additional processing by ams AG for each application. For shipments of less than 100 parts the manufacturing flow might show deviations from the standard production flow, such as test flow or test location.
The information furnished here by ams AG is believed to be correct and accurate. However, ams AG shall not be liable to recipient or any third party for any damages, including but not limited to personal injury, property damage, loss of profits, loss of use, interruption of business or indirect, special, incidental or consequential damages, of any kind, in connection with or arising out of the furnishing, performance or use of the technical data herein. No obligation or liability to recipient or any third party shall arise or flow out of ams AG rendering of technical or other services.
Contact Information
Headquarters
ams AG
Tobelbaderstrasse 30
A-8141 Unterpremstaetten, Austria
Tel : +43 (0) 3136 500 0
Fax : +43 (0) 3136 525 01
For Sales Offices, Distributors and Representatives, please visit: http://www.ams.com/contact www.ams.com/LDOs/AS1355 Revision 1.3
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