AS1330 AMSCO
Document overview
- Manufacturer or author: Provided By digicamel.com
- PDF pages: 16
Technical content
1 General Description
including all external components. ideal for application powered by a single cell battery. features a power save mode for light loads. pin) or report the status of the output voltage (POK).
2 Key Features
3 Applications
ers, GPS receivers, and PC or Memory cards. Figure 1. AS1330 - Typical Application Diagram
4 Pin Assignments
Figure 2. Pin Assignments (Top View) Table 1. Pin Descriptions
1 SENSE
to GND the POK output is related to VOUT. If the fixed output voltage version ist used, connect this pin to VOUT. 3 EN Active-High Enable Input. A logic LOW reduces the supply current to < 1µA. Connect to pin VIN for normal operation.
4 POK
pin unconnected if the Power-OK feature is not used. the negative side of the output capacitor(s). switch is connected from this pin to VIN to minimize EMI. Note: An optional Schottky diode can be connected between this pin and VOUT.
7 VOUT
level and the internal series resistance of the supply. connection to the PCB to achieve optimal thermal performance.
8 VIN
5 GND
5 Absolute Maximum Ratings
Table 2. Absolute Maximum Ratings State Surface Mount Devices”. packages is matte tin (100% Sn).
6 Electrical Characteristics
Table 3. Electrical Characteristics
- Guaranteed by design and verified in lab characterisation.
- External Schottky diode is mandatory for output voltages higher than 3V.
- VOUT is forced to 3.6V in production test.
- Internal pull-down resistor.
- The POK parameters are tested with proprietary test modes.
SQC (Statistical Quality Control) methods.
7 Typical Operating Characteristics
Figure 7. Efficiency vs. IOUT, Coil Comparision Figure 8. Efficiency vs. I OUT, Coil Comparision
8 Detailed Description
and PMOS switches, the device maintains high-efficiency from light to heavy loads. conversion efficiency over a wide output power range, thus increasing battery life in these types of devices. falls below a factory programmed threshold. Figure 19. AS1330 - Block Diagram allowing the devices to start up into an output load. supply sufficient energy to the output.
www.austriamicrosystems.com/DC-DC_Step-Up/AS1330 Revision 1.04 9 - 16 AS1330 Datasheet - Detailed Description Low-Noise Fixed-Frequency Operation Oscillator The AS1330 switching frequency is internally fixed at 4MHz allowing the use of very small external components. Current Sensing A signal representing the internal NMOS-switch current is summed with the slope compensator. The summed signal is compared to the error amplifier output to provide a peak current control command for the PWM. Peak switch current is limited to approximately 650mA independent of V IN or VOUT. Zero Current Comparator The zero current comparator monitors the inductor current to the output and shuts off the PMOS synchronous rectifier once this current drops to 20mA (approx.). This prevents the inductor current from reversing polarity and results in improved converter efficiency at light loads. Anti-Ringing Control Anti-ringing control circuitry prevents high-frequency ringing on pin SW as the inductor current approaches zero. This is accomplished by damping the resonant circuit formed by the inductor and the capacitance on pin SW (C SW). Powersave Operation In light load conditions, the integrated powersave feature removes power from all circuitry not required to monitor VOUT. When VOUT has dropped approximately 1% from nominal, the device powers up and begins normal PWM oper- ation. C2 recharges, causing the AS1330 to re-enter powersave mode as long as the output load remains below the power- save threshold. The frequency of this intermittent PWM is proportional to load current; i.e., as the load current drops further below the powersave threshold, the AS1330 turns on less frequently. When the load current increases above the powersave threshold, the AS1330 will resume continuous, seamless PWM operation. Notes: 1. An optional capacitor (CFF) between pins VOUT and FB in some applications can reduce VOUTp-p ripple and input quiescent current during powersave mode. Typical values for CFF range from 15 to 220pF. 2. In powersave mode the AS1330 draws only 30µA from the output capacitor(s), greatly improving converter effi- ciency. Shutdown When pin EN is low the AS1330 is switched off and <1µA current is drawn from the battery; when pin EN is high the device is switched on. If EN is driven from a logic-level output, the logic high-level (on) should be referenced to VOUT to avoid intermittently switching the device on. In shutdown the battery input is disconnected from the output. Thermal Overload Protection To prevent the AS1330 from short-term misuse and overload conditions the chip includes a thermal overload protection. To block the normal operation mode the device is turning the PFET and the NFET off in PWM mode as soon as the junction temperature exceeds 150°C. To resume the normal operation the temperature has to drop below 140°C. Note: Continuing operation in thermal overload conditions may damage the device and is considered bad practice.
9 Application Information
hand-held instruments, digital cameras, MP3 players, GPS receivers, and PC or Memory cards. which the AS1330 converters are perfectly suited.
- SENSE to GND: The POK is related to VOUT (see Figure 22 on page 11).
SENSE is below 0.8V (see Figure 21 on page 11). Figure 20. AS1330 - Boost Converter, Single AA Cell to 3.0V fixed Output Voltage
DC system requieres only 6.6x6.6mm of PCB space (see Figure 23). Figure 23. Layout Consideration
the use of low value, low profile inductors and tiny external ceramic capacitors. compared to less expensive powdered iron types, which result in improved converter efficiency. a concern, a toroidal or shielded inductor can be used. X7R ceramic capacitors are recommended as they retain capacitance over wide ranges of voltages and temperatures. wide voltage and temperature ranges. input capacitor is sufficient for most applications. Larger values may be used without limitations. on the other hand the output disconnect function is no longer working. Note: Do not use ordinary rectifier diodes, since the slow recovery times will compromise efficiency. Table 4. Recommended External Components
The device is available in a TDFN (2x2mm) 8-pin package. Figure 24. TDFN (2x2mm) 8-pin package Diagram
- Dimensioning and tolerancing conform to ASME Y14.5M-1994.
- All dimensions are in millimeters, angle is in degrees.
- Terminal #1 identifier and terminal numbering convention shall conform to JESD 95-1 SPP-012. Details of ter-
either a mold, embedded metal or mark feature. b applies to metallized terminal and is measured between 0.15 and 0.30mm from terminal tip. Table 5. TDFN (2x2mm) 8-pin package Dimensions
The device is available as the standard products listed in Table 6. Note: All products are RoHS compliant and Pb-free. Table 6. Ordering Information
www.austriamicrosystems.com/DC-DC_Step-Up/AS1330 Revision 1.04 16 - 16 AS1330 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. Disclaimer Devices sold by austriamicrosystems AG are covered by the warranty and patent indemnification provisions appearing in its Term of Sale. austriamicrosystems 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. austriamicrosystems 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 austriamicrosystems 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 austriamicrosystems 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 austriamicrosystems AG is believed to be correct and accurate. However, austriamicrosystems 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 tech- nical data herein. No obligation or liability to recipient or any third party shall arise or flow out of austriamicrosystems AG rendering of technical or other services. Contact Information Headquarters austriamicrosystems 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.austriamicrosystems.com/contact