AS1349 Austin Semiconductor, AS1349 Datasheet

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AS1349

Manufacturer Part Number
AS1349
Description
(AS1346 - AS1349) Dual Step Down Converter
Manufacturer
Austin Semiconductor
Datasheet
Datasheet
A S 1 3 4 6 , A S 1 3 4 7 , A S 1 3 4 8 , A S 1 3 4 9
D u a l St e p - D o w n C o n v e r t e r w i t h B a t t e r y M o n i t o r i n g
1 General Description
The AS1346, AS1347, AS1348, AS1349 family is a
high-efficiency, constant-frequency dual buck converter
available with fixed voltage versions. The device pro-
vides two independent DC/DC Converters with output
currents between 0.5A and 1.2A. The wide input voltage
range (2.7V to 5.5V), automatic powersave mode and
minimal external component requirements make the
AS134x family perfect for SSD and many other battery-
powered applications.
In shutdown mode the typical supply current
decreases to ≤ 1μA. The highly efficient duty cycle
(100%) provides low dropout operation, prolonging
battery life in portable systems.
An internal synchronous switching scheme increases
efficiency and eliminates the need for an external
Schottky diode. The fixed switching frequency (2.0MHz)
allows the use of small surface mount inductors.
The integrated monitoring function can be configured
that either the output voltage (Power Okay function )
or the input voltage (Battery Monitoring Function) can
be supervised.
Table 1. Available Products
The AS1346 is available in a 12-Pin TDFN 3x3mm pack-
age.
www.austriamicrosystems.com/DC-DC_Step-Down/AS1346
Figure 1. AS1346 - Typical Application Diagram with POK Function
Devices
AS1346
AS1347
AS1348
AS1349
2.7V to 5.5V
V
IN
I
1.2A
0.5A
0.5A
1.2A
OUT1
C
IN
0.95A
I
0.5A
0.5A
1.2A
OUT2
PVIN
PVIN
VDD
EN1
EN2
LBI
AS1346
Revision 1.01
PGND
2 Key Features
3 Applications
The device is ideal for SSD applications, mobile commu-
nication devices, laptops and PDAs, ultra-low-power
systems, threshold detectors/discriminators, telemetry
and remote systems, medical instruments, or any other
space-limited application with low power-consumption
requirements.
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High Efficiency: Up to 95%
Output Current:
Input Voltage Range: 2.7V to 5.5V
Output Voltage Range: 1.2V to 3.6V (available in
100mV steps)
Constant Frequency Operation: 2.0MHz
180° Out of Phase Operation
Low Battery Detection
Low Dropout Operation: 100% Duty Cycle
Shutdown Mode Supply Current: ≤1µA
No Schottky Diode Required
Output Disconnect in Shutdown
Non standard variants available within two weeks
12-Pin TDFN 3x3mm Package
SW1
FB1
SW2
FB2
LBO
AGND
L1 = 3.3µH
L2 = 3.3µH
POK Function
see Table 1
C
C
OUT2
OUT1
V
3.3V 1200mA
V
1.8V 500mA
OUT1
OUT2
www.DataSheet4U.com
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Related parts for AS1349

AS1349 Summary of contents

Page 1

... General Description The AS1346, AS1347, AS1348, AS1349 family is a high-efficiency, constant-frequency dual buck converter available with fixed voltage versions. The device pro- vides two independent DC/DC Converters with output currents between 0 ...

Page 2

... AS1346, AS1347, AS1348, AS1349 Datasheet - Pin Assignments Figure 2. Pin Assignments (Top View) Pin Descriptions Table 2. Pin Descriptions Pin Number Pin Name Switch Node1 Connection to Inductor. This pin connects to the drains of the internal 1 SW1 main and synchronous power MOSFET switches. ...

Page 3

... AS1346, AS1347, AS1348, AS1349 Datasheet - Absolute Maximum Ratings Stresses beyond those listed in Table 3 and functional operation of the device at these or any other conditions beyond those indicated in Characteristics on page 4 is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability ...

Page 4

... AS1346, AS1347, AS1348, AS1349 Datasheet - Electrical Characteristics -40ºC to +85ºC; PVIN = VDD = EN = 5V, unless otherwise noted. Typ. values are Table 4. Electrical Characteristics Symbol Parameter V Input Voltage Range ...

Page 5

... AS1346, AS1347, AS1348, AS1349 Datasheet - Table 4. Electrical Characteristics Symbol Parameter Enable V Logic high input threshold IH,EN V Logic low input threshold IH,EN Low Battery & Power-OK V LBI Threshold LBI LBI Hysteresis LBI Leakage Current ...

Page 6

... AS1346, AS1347, AS1348, AS1349 Datasheet - Typical Operating Characteristics Figure 3. AS1346 Efficiency vs OUT 100 100 Output Current (mA) Figure 5. AS1346 Efficiency vs ...

Page 7

... AS1346, AS1347, AS1348, AS1349 Datasheet - Figure 9. AS1346 Load Regulation 3.3V OUT 3.4 3.38 3.36 3.34 3.32 3.3 3.28 3.26 3.24 Vin=4.5V 3.22 Vin = 5.5 3.2 0 200 400 600 800 Output Current (mA) Figure 11. AS1346 Line Regulation, V 3.4 3.35 3.3 3.25 LDO mode 3.2 3.15 3.1 2.7 3.1 3.5 3.9 4.3 Input Voltage (V) Figure 13. AS1346 V vs. Temperature ...

Page 8

... AS1346, AS1347, AS1348, AS1349 Datasheet - Figure 15. AS1346 I vs Vout 1 on Vout 2.7 3.1 3.5 3.9 4.3 Input Voltage (V) www.austriamicrosystems.com/DC-DC_Step-Down/AS1346 Figure 16. AS1346 I 6 Vin = 4.5V Vin = 5.5V ...

Page 9

... Datasheet - Detailed Description The AS1346, AS1347, AS1348, AS1349 family is a high-efficiency buck converter that uses a constant-frequency cur- rent-mode architecture. The device contains two internal MOSFET switches and is available with a fixed output voltage (see Ordering Information on page 14) ...

Page 10

... In this state, the PMOS is always on. This is particularly useful in battery-powered applications with a 3.3V output. The AS1346, AS1347, AS1348, AS1349 allows the output to follow the input battery voltage as it drops below the reg- ulation voltage. The quiescent current in this state is reduced to a minimal value, which aids in extending battery life. ...

Page 11

... AS1346, AS1347, AS1348, AS1349 Datasheet - case of the LBI pin is connected to GND, an internal resistor-divider network is activated and compares the output voltage with a 92.5% voltage threshold this particular Power-OK application, no external resistive components (R1 and R2) are necessary. ...

Page 12

... AS1346, AS1347, AS1348, AS1349 Datasheet - Application Information Component Selection Only three power components are required to complete the design of the buck converter. For the adjustable LBI two external resistors are needed. ...

Page 13

... AS1346, AS1347, AS1348, AS1349 Datasheet - Package Drawings and Markings The devices are available in a 12-Pin TDFN 3x3mm package. Figure 19. 12-Pin TDFN 3x3mm Package D INDEX AREA (D/2 xE/2) aaa C 2x TOP VIEW ...

Page 14

... AS1346, AS1347, AS1348, AS1349 Datasheet - Ordering Information The device is available as the standard products listed below. Table 7. Ordering Information Ordering Code Marking Channel OUT1 AS1346-BTDT-3318 ASSL OUT2 OUT1 1 tbd AS1347-BTDT-xxyy OUT2 OUT1 ...

Page 15

... AS1346, AS1347, AS1348, AS1349 Datasheet Copyrights Copyright © 1997-2010, austriamicrosystems 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. ...

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