Datasheet AS1331 300mA Buck-Boost Synchronous DC/DC Converters 1 General Description 2 Key Features This special device is a synchronous buck-boost DC/DC converter which can handle input voltages above, below, or equal to the output voltage. Due to the internal structure of the AS1331 which is working continuously through all operation modes this device is ideal for dual or triple cell alkaline/NiCad/NiMH as well as single cell Li-Ion battery applications. Because of the implemented Power Save Mode, the solution footprint and the component count is minimized and also over a wide range of load currents a high conversion efficiency is provided. The device includes two N-channel MOSFET switches and two P-channel switches. Also following features are implemented: a quiescent current of typically 22µA (ideal for battery power applications), a shutdown current less than 1µA, current limiting, thermal shutdown and output disconnect. The AS1331 is available in a 10-pin 3x3mm TDFN package with fixed and adjustable output voltage. ! Input Voltage Range: 1.8V to 5.5V ! Output Voltages: - Fixed: 2.5V, 3.0V, 3.3V - Adjustable: 2.5V to 3.3V ! Output Current: 300mA @ 3.3V ! Up to 90% efficiency ! Power Good ! Output Disconnection in Shutdown ! Automatic transition between Buck and Boost mode ! Ultra Low Quiescent Current: 22µA, Shutdown Current <1µA (Active Low) ! Short-Circuit Protection ! Low Battery detection ! Over Temperature Protection ! 10-pin 3x3mm TDFN package 3 Applications The AS1331 is an ideal solution for handheld computers, handheld instruments, portable music players and PDA’s. Two and three cell Alkaline, NiCd or NiMH or single cell Li battery powered products. Figure 1. AS1331 - Typical Application Diagram L1 6.8µH 4 SW1 2 SW2 5 1.8 to 5.5V 8 VIN C1 10µF 7 LBI On Off LBO AS1331-AD R3 1 VOUT R1 10 6 C2 22µF VOUT 2.5V to 3.3V FB EN R2 3 PGND www.austriamicrosystems.com Low Battery Detect 9 GND Revision 1.03 1 - 16 AS1331 Datasheet - P i n A s s i g n m e n t s 4 Pin Assignments Figure 2. Pin Assignments (Top View) VOUT 1 10 FB 9 GND SW2 2 PGND 3 AS1331 SW1 4 VIN 5 8 LBO 7 LBI 11 6 EN Pin Descriptions Table 1. Pin Descriptions Pin Name VOUT SW1 PGND Pin Number 1 2 3 SW2 4 VIN 5 EN 6 LBI 7 LBO 8 GND 9 FB 10 NC www.austriamicrosystems.com 11 Description Output of the Buck/Boost Converter. Buck/Boost Switch Pin. Connect the inductor from SW1 to SW2 Power Ground. Both GND pins must be connected. Buck/Boost Switch Pin. Connect the inductor from SW1 to SW2. An optional Schottky diode can be connected between this pin and VOUT to increase efficiency. Input Supply Pin. A minimum 2.2µF capacitor should be placed between VIN and GND. Enable Pin. Logic controlled shutdown input. 1 = Normal operation; 0 = Shutdown; quiescent current <1µA. Low Battery Comperator Input. 1.25V Threshold. May not be left floating. If connected to GND LBO is working as Output Power okay. Low Battery Comperator Output. This open-drain output is low when the voltage on LBI is less than 1.25V. Ground. Both GND pins must be connected. Feedback Pin. Feedback input for the adjustable version. Connect a resistor divider tap to this pin. The output voltage can be adjusted from 2.5V to 3.3V by: VOUT = 1.25V[1 + (R1/R2)] Note: For the fixed Output Voltage Version contact this pin to VOUT. Exposed Pad. This pad is not connected internally. It can be used for ground connection between GND and PGND. Revision 1.03 2 - 16 AS1331 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 Electrical Characteristics on page 4 is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Table 2. Absolute Maximum Ratings Parameter Min Max Units SW1, SW2, VIN, VOUT, EN -0.3 +7 V PGND to GND -0.3 +0.3 V SW1, SW2 -0.3 +7 V ESD 4 kV Thermal Resistance θJA +33 ºC/W Junction Temperature +150 ºC Operating Temperature Range -40 85 ºC Storage Temperature Range -65 +125 ºC Package Body Temperature www.austriamicrosystems.com +260 Revision 1.03 ºC Notes HBM MIL-Std. 883E 3015.7 methods The reflow peak soldering temperature (body temperature) specified is in accordance with IPC/JEDEC J-STD020D “Moisture/Reflow Sensitivity Classification for Non-Hermetic Solid State Surface Mount Devices”. The lead finish for Pb-free leaded packages is matte tin (100% Sn). 3 - 16 AS1331 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 VIN = 3.6V, VOUT = 3.3V, TAMB = -40°C to +85ºC. Typical values are at TAMB = +25ºC. Unless otherwise specified. Table 3. Electrical Characteristics Symbol Parameter Conditions Min Typ Max Units 5.5 V 1.6 1.8 V 1.6 1.7 V 3.30 V Input VIN Input Voltage Range 1.8 Minimum Startup Voltage Undervoltage Lockout VUV ILOAD < 1mA VIN decreasing 1 Threshold 1.5 Regulation VOUT Output Voltage Adjustable Version 2.50 Output Voltage 3.3V 3.201 3.3 3.399 V 2.910 3.0 3.090 V 2.425 2.5 2.575 V 1.212 1.25 1.288 V 1 100 nA 2.15 2.3 V Output Voltage 3.0V No Load Output Voltage 2.5V VFB FB Voltage Adjustable version No Load IFB FB Input Current Adjustable Version VFB = 1.3V, TAMB = 25°C 2 VOUT Lockout Threshold Rising Edge 2.0 Operating Current IQ ISHDN Quiescent Current VIN VIN = 5V 2 6 µA Quiescent Current VOUT VIN = 5V, VOUT = 3.6V, VFB = 1.3V 20 32 µA Shutdown Current EN = 0V, VOUT = 0V, TAMB = +25ºC 0.01 1 µA MOS Switch Leakage VIN = 5V, TAMB=25°C, Switches A-D 0.01 1 µA NMOS B, C VIN = 5V 0.13 Ω PMOS A VIN = 5V 0.17 Ω PMOS D VOUT = 3.3V 0.21 Ω Peak Current Limit L = 6.8µH, VIN = 5V Switches IMOS RON IPEAK 450 600 750 mA Enable VENH EN Input High VENL EN Input Low IEN 1.4 EN Input Current EN = 5.5V, TAMB = 25°C V 0.4 V 1 100 nA 1.25 1.288 Low Battery & Power-OK LBI Threshold Falling Edge 1.212 LBI Hysteresis 10 LBI Leakage Current LBO Voltage Low 3 LBI = 5.5V, TAMB = 25°C ILBO = 1mA LBO Leakage Current LBO = 5.5V, TAMB = 25°C Power-OK Threshold LBI = 0V, Falling Edge www.austriamicrosystems.com Revision 1.03 90 V mV 1 100 nA 0.05 0.2 V 1 100 nA 92.5 95 % 4 - 16 AS1331 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 Table 3. Electrical Characteristics Symbol Parameter Conditions Min Typ Max Units Thermal Protection Thermal Shutdown 10°C Hysteresis 145 °C 1. If the input voltage falls below this value during normal operation the device goes in startup mode. 2. The regulator is in startup mode until this voltage is reached. Caution: Do not apply full load current until the device output > 2.3V 3. LBO goes low in startup mode as well as during normal operation if: 1) The voltage at the LBI pin is below LBI threshold. 2) The voltage at the LBI pin is below 0.1V and VOUT is below 92.5% of its nominal value. www.austriamicrosystems.com Revision 1.03 5 - 16 AS1331 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 Circuit of Figure 24 on page 12, VIN = 2.4V, VOUT = 3.3V, TAMB = +25°C, unless otherwise specified. Figure 4. Efficiency vs. Output Current; VOUT = 3.0V 100 100 90 90 80 80 Efficiency (%) Efficiency (%) Figure 3. Efficiency vs. Output Current; VOUT = 2.5V 70 60 50 70 60 50 Vi n = 1.8V 40 Vi n = 1.8V 40 Vi n = 3.6V Vi n = 3.6V Vi n = 5.5V Vi n = 5.5V 30 30 0.1 1 10 100 1000 0.1 Output Current (mA) 10 100 1000 Output Current (mA) Figure 5. Efficiency vs. Output Current; VOUT = 3.3V Figure 6. Efficiency vs. Input Voltage 100 100 90 90 80 80 Efficiency (%) Efficiency (%) 1 70 60 50 70 60 50 Iout = 10mA Vi n = 1.8V 40 40 Vi n = 3.6V Iout = 100mA Vi n = 5.5V Iout = 300mA 30 30 0.1 1 10 100 1000 1.8 2.2 2.6 3.0 3.4 3.8 4.2 4.6 5.0 5.4 Output Current (mA) Figure 7. IOUT max vs. Input Voltage Input Voltage (V) Figure 8. Sleep Currents vs. Input Voltage 30 25 400 Sleep Current (µA) Output Current max (mA) 500 300 200 100 IVOUT 20 15 10 5 IVIN 0 0 1.8 2.2 2.6 3.0 3.4 3.8 4.2 4.6 5.0 5.4 1.8 2.2 2.6 3.0 3.4 3.8 4.2 4.6 5.0 5.4 Input Voltage (V) www.austriamicrosystems.com Input Voltage (V) Revision 1.03 6 - 16 AS1331 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. IIN Short Circuit vs. Input Voltage Figure 10. VOUT Ripple vs. Input Voltage 250 30 Vout Ripple Voltage (mV) Input Current (mA) 25 20 15 10 5 200 150 100 50 10uF / Vpp 22uF / Vpp 47uF / Vpp 0 0 1.8 2.2 2.6 3.0 3.4 3.8 4.2 4.6 5.0 5.4 1.5 2 2.5 Input Voltage (V) 3 3.5 4 4.5 5 5.5 75 90 Input Voltage (V) Figure 11. Load Regulation vs. Load Current Figure 12. VOUT Regulation vs. Temperature 3.38 3.5 VOUT = 3.3V 3.25 Output Voltage (V) Output Voltage (V) 3.36 3.34 3.32 3.3 3.28 3.26 VOUT = 3.0V 3 2.75 VOUT = 2.5V 2.5 2.25 Vout - 10uF Vout - 22uF Vout - 47uF 3.24 0.1 1 10 100 2 -45 -30 -15 1000 Load Current (mA) 0 15 30 45 60 Temperature (°C) Figure 13. IFB vs. Temperature; VIN = 5V Figure 14. EN Pin Threshold 1 0.4 3.6V 5.0V 5.5V Threshold Voltage (V) FB Input Current (µA) 0.3 0.2 0.1 0 0.9 0.8 0.7 -0.1 up-ON down-OFF -0.2 -45 -30 -15 0 15 30 45 60 75 90 0.6 -45 -30 -15 Temperature (°C) www.austriamicrosystems.com 0 15 30 45 60 75 90 Temperature (°C) Revision 1.03 7 - 16 AS1331 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 SW2 SW1 VOUT 5µs/Div SW2 SW1 VOUT 5µs/Div SW2 SW1 200mA/Div VOUT ICOIL 200mA/Div 200mV/Div 5V/Div 5V/Div Figure 20. VIN = 2.5V, VOUT = 3.3V, IOUT = 50mA 200mV/Div 5V/Div 5V/Div Figure 19. VIN = 2.5V, VOUT = 3.3V, IOUT = 200mA SW2 SW1 200mA/Div 200mA/Div ICOIL SW2 SW1 VOUT ICOIL 5µs/Div VOUT 200mV/Div 5V/Div 5V/Div Figure 18. VIN = 3.6V, VOUT = 3.3V, IOUT = 50mA 200mV/Div 5V/Div 5V/Div Figure 17. VIN = 3.6V, VOUT = 3.3V, IOUT = 200mA ICOIL 200mA/Div 200mA/Div ICOIL SW2 SW1 VOUT ICOIL 5µs/Div 5µs/Div www.austriamicrosystems.com 200mV/Div 5V/Div 5V/Div Figure 16. VIN = 4.4V, VOUT = 3.3V, IOUT = 50mA 200mV/Div 5V/Div 5V/Div Figure 15. VIN = 4.4V, VOUT = 3.3V, IOUT = 200mA 5µs/Div Revision 1.03 8 - 16 AS1331 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 2V/Div 5V/Div SW2 SW1 200mA/Div VOUT ICOIL 200mA/Div 200mV/Div VOUT SW2 SW1 ICOIL 1µs/Div www.austriamicrosystems.com 5V/Div Figure 22. Startup; VIN = 3.6V, Rload = 3.3kΩ 5V/Div 5V/Div Figure 21. Shorted Output; VIN = 3.6V 500µs/Div Revision 1.03 9 - 16 AS1331 Datasheet - D e t a i l e d D e s c r i p t i o n 8 Detailed Description The synchronous buck-boost converter AS1331 uses a Power Save Mode control technique to reach a high efficiency over a wide dynamic range of load currents. The output voltage is monitored by a comparator with 3% accuracy. The Power Save Mode puts the device into “sleep mode” when VOUT is above its programmed reference threshold. Meaning, the switching is stopped and only quiescent current is drawn from the power source. The switching is started again when VOUT drops below the reference threshold and the output capacitor is charged again. The numbers of current pulses which are necessary to load the output capacitor are set by the value of the output capacitor, the load current, and the comparator hysteresis (~1%). Figure 23. AS1331 - Block Diagram - Fixed Output Voltage SW2 SW1 SW A VIN SW D Gate Drivers and Anticross Conduction SW B AS1331 Peak Current 600mA Limit IZERO Detect SW C VBEST VIN VBEST State Machine and Logic VIN VOUT FB UVLO 1.25V VOUT Comp 1.6V EN Shutdown VOUT R2 R1 Thermal Shutdown PGND GND Modes of Operation When VOUT drops below the reference threshold, the AS1331 switches on the transistors SW A and SW C until the inductor current reaches approximately 400mA. In the next step SW A and SW D are closed and depending on the difference between VIN and VOUT the inductor current raises, falls or stays constant. VIN > VOUT: The inductor current is going up to 600mA. VIN ~ VOUT: The device stops after 2µs. VIN < VOUT: The inductor current falls down to 0mA. If the inductor current is not 0mA, the transistors SW B and SW D are closed to ramp down the current to zero. If VOUT is still below the threshold voltage the next cycle is started. If IMAX (600mA) wasn’t reached in the previous cycle, SW A and SW D are closed until the inductor current is 600mA. Note: The 4-switch-mode (SW A+SW C => SW B+SW D => SW A + SW C...) and also the buck-mode (SW A+SW D => SW B+SW D => SW A+SW D...) are never used. www.austriamicrosystems.com Revision 1.03 10 - 16 AS1331 Datasheet - D e t a i l e d D e s c r i p t i o n Start-Up Mode At start-up the switch SW D is disabled and its diode is used to transfer current to the output capacitor until VOUT reaches approximately 2.15V. The inductor current is controlled by an alternate algorithm during start-up. Note: Do not apply loads >1mA until VOUT = 2.3V is reached. Other AS1331 Features Shutdown The part is in shutdown mode while the voltage at pin EN is below 0.4V and is active when the voltage is higher than 1.4V. Note: EN can be driven above VIN or VOUT, as long as it is limited to less than 5.5V. Output Disconnect and Inrush Limiting During shutdown VOUT is going to 0V so that no current from the input source is running thru the device. The inrush current is also limited at turn-on mode to minimize the surge currents seen by the input supply. These features of the AS1331 are realized by opening both P-channel MOSFETs of the rectifiers, allowing a true output disconnect. Power-OK and Low-Battery-Detect Functionality LBO goes low in startup mode as well as during normal operation if: 1) The voltage at the LBI pin is below LBI threshold (1.25V). This can be used to monitor the battery voltage. 2) LBI pin is connected to GND and VOUT is below 92.5% of its nominal value. LBO works as a power-OK signal in this case. The LBI pin can be connected to a resistive-divider to monitor a particular definable voltage and compare it with a 1.25V internal reference. If LBI is connected to GND an internal resistive-divider is activated and connected to the output. Therefore, the Power-OK functionality can be realised with no additional external components. The Power-OK feature is not active during shutdown and provides a power-on-reset function that can operate down to VIN = 1.8V. A capacitor to GND may be added to generate a power-on-reset delay. To obtain a logic-level output, connect a pull-up resistor from pin LBO to pin VOUT. Larger values for this resistor will help to minimize current consumption; a 100kΩ resistor is perfect for most applications (see Figure 25 on page 12). For the circuit shown in the left of Figure 24 on page 12, the input bias current into LBI is very low, permitting largevalue resistor-divider networks while maintaining accuracy. Place the resistor-divider network as close to the device as possible. Use a defined resistor for R2 and then calculate R1 as: V IN (EQ 1) R 1 = R 2 ⋅ ⎛⎝ -------------------- – 1⎞⎠ V SENSE Where: VSENSE (the internal sense reference voltage) is 1.25V. R2 (the predefined resistor in the resistor devider) has to be ≤ 270kΩ. In case of the LBI pin is connected to GND, an internal resistor-devider network is activated and compares the output voltage with a 92.5% voltage threshold. For this particular Power-OK application, no external resistive components are necessary. Thermal Shutdown To prevent the AS1331 from short-term misuse and overload conditions the chip includes a thermal overload protection. To block the normal operation mode all switches will be turned off. The device is in thermal shutdown when the junction temperature exceeds 145°C. To resume the normal operation the temperature has to drop below 135°C. A good thermal path has to be provided to dissipate the heat generated within the package. Otherwise it’s not possible to operate the AS1331 at its useable maximal power. To dissipate as much heat as possible away from the package into a copper plane with as much area as possible, it’s recommended to use multiple vias in the printed circuit board. It’s also recommended to solder the Exposed Pad (pin 11) to the GND plane. Note: Continuing operation in thermal overload conditions may damage the device and is considered bad practice. www.austriamicrosystems.com Revision 1.03 11 - 16 AS1331 Datasheet - D e t a i l e d D e s c r i p t i o n Output Voltage Selection The AS1331 is available in two versions (see Ordering Information on page 15). One version can only operate at one fixed output voltage (see Figure 25) and the other version can operate with user-adjustable output voltages from 2.5V to 3.3V by connecting a voltage divider between the pins VOUT and FB (see Figure 24). Figure 24. LiIon to Adjustable Output Voltage L1 6.8µH 4 SW1 2 SW2 5 LiIon 8 VIN C1 10µF LBO 7 AS1331-AD LBI On Off R3 VOUT 2.5V to 3.3V 1 VOUT R1 10 6 C2 22µF FB EN R2 3 PGND 9 GND The output voltage can be adjusted by selecting different values for R1 and R2. Calculate VOUT by: R1 V OUT = V FB × ⎛ 1 + ------⎞ ⎝ R 2⎠ (EQ 2) Where: VFB = 1.25V, VOUT = 2.5V to 3.3V; Figure 25. LiIon to 3.3V with POK - Fixed Output Voltage L1 6.8µH 4 SW1 2 SW2 5 LiIon 8 VIN C1 10µF 7 LBI On Off LBO AS13313.3V C2 22µF VOUT 3.3V 300mA FB EN 3 PGND www.austriamicrosystems.com VOUT 10 6 R3 1 9 GND Revision 1.03 12 - 16 AS1331 Datasheet - A p p l i c a t i o n I n f o r m a t i o n 9 Application Information Component Selection Only three power components are required to complete the design of the buck-boost converter. For the adjustable version VOUT programming resistors are needed. The high operating frequency and low peak currents of the AS1331 allow the use of low value, low profile inductors and tiny external ceramic capacitors. Inductor Selection For best efficiency, choose an inductor with high frequency core material, such as ferrite, to reduce core losses. The inductor should have low DCR (DC resistance) to reduce the I²R losses, and must be able to handle the peak inductor current without saturating. A 6.8µH inductor with a >600mA current rating and <400mΩ DCR is recommended. Table 4. Recommended Inductors Part Number L DCR Current Rating Dimensions (L/W/T) LPS3015-682M 6.8µH 300mΩ 0.89A 3.0x3.0x1.5mm EPL2014-682M 6.8µH 287mΩ 0.80A 2.0x2.0x1.4mm XPL2010-682M 6.8µH 336mΩ 0.73A 2.0x1.9x1.0mm Manufacturer Coilcraft www.coilcraft.com Capacitor Selection The buck-boost convertor requires two capacitors. Ceramic X5R or X7R types will minimize ESL and ESR while maintaining capacitance at rated voltage over temperature. The VIN capacitor should be at least 2.2µF. The VOUT capacitor should be between 10µF and 47µF. A larger output capacitor should be used if lower peak to peak output voltage ripple is desired. A larger output capacitor will also improve load regulation on VOUT. See Table 5 for a list of capacitors for input and output capacitor selection. Table 5. Recommended Input Capacitor Part Number C TC Code Rated Voltage Dimensions (L/W/T) GRM188R61A225KE34 2.2µF X5R 10V 0603, T=0.87mm GRM188R60J475KE19 4.7µF X5R 6.3V 0603, T=0.87mm GRM219R60J106KE19 10µF X5R 6.3V 0805, T=0.95mm Manufacturer Murata www.murata.com Table 6. Recommended Output Capacitor Part Number C TC Code Rated Voltage Dimensions (L/W/T) GRM21BR61A106KE19 10µF X5R 10V 0805, T=1.35mm GRM319R61A106KE19 10µF X5R 10V 1206, T=0.95mm GRM319R61A106KE19 10µF X5R 10V 1210, T=0.95mm GRM31CR61C226KE15 22µF X5R 16V 1206, T=1.8mm GRM31CR60J475ME19 47µF X5R 6.3V 1206, T=1.75mm www.austriamicrosystems.com Revision 1.03 Manufacturer Murata www.murata.com 13 - 16 AS1331 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 The device is available in a 10-pin 3x3mm TDFN package. Figure 26. 10-pin 3x3mm TDFN package Diagram D2 SEE DETAIL B A D D2/2 B 2x E E2 E2/2 L aaa C PIN 1 INDEX AREA (D/2 xE/2) K PIN 1 INDEX AREA (D/2 xE/2) aaa C N N-1 2x TOP VIEW e b e (ND-1) X e ddd bbb C C A B BTM VIEW Terminal Tip DETAIL B A3 ccc C A C SEATING PLANE SIDE VIEW A1 0.08 C Min Typ 3.00 3.00 Datum A or B ODD TERMINAL SIDE Table 7. 10-pin 3x3mm TDFN package Dimensions Symbol Min Typ Max A 0.70 0.75 0.80 A1 0.00 0.02 0.05 A3 0.20 REF L1 0.03 0.15 L2 0.13 aaa 0.15 bbb 0.10 ccc 0.10 ddd 0.05 eee 0.08 ggg 0.10 Symbol D BSC E BSC D2 E2 L K b e N ND θ 2.20 1.40 0.30 0.20 0.18 0° 0.40 0.25 0.50 10 5 Max 2.70 1.75 0.50 0.30 14° Note: 1. 2. 3. 4. 5. Figure 26 is shown for illustration only. All dimensions are in millimeters, angle is in degrees. Dimensioning and tolerancing conform to ASME Y14.5M-1994. N is the total number of terminals. Terminal #1 identifier and terminal numbering convention shall conform to JESD 95-1 SPP-012. Details of terminal #1 identifier are optional, but must be located within the area indicated. The terminal #1 identifier may be either a mold, embedded metal or mark feature. 6. Dimension b applies to metallized terminal and is measured between 0.15 and 0.30mm from terminal tip. 7. ND refers to the maximum number of terminals on D side. 8. Unilateral coplanarity zone applies to the exposed heat sink slug as well as the terminals. www.austriamicrosystems.com Revision 1.03 14 - 16 AS1331 Datasheet - O r d e r i n g I n f o r m a t i o n 11 Ordering Information The device is available as the standard products shown in Table 8. Table 8. Ordering Information Ordering Code Marking AS1331-BTDT-AD ASRP AS1331-BTDT-25* ASRR AS1331-BTDT-30* ASRT AS1331-BTDT-33 ASRU Output Description 300mA Buck-Boost adjustable Synchronous DC/DC Converters 300mA Buck-Boost 2.5V Synchronous DC/DC Converters 300mA Buck-Boost 3.0V Synchronous DC/DC Converters 300mA Buck-Boost 3.3V Synchronous DC/DC Converters Delivery Form Package Tape and Reel 10-pin 3x3mm TDFN Tape and Reel 10-pin 3x3mm TDFN Tape and Reel 10-pin 3x3mm TDFN Tape and Reel 10-pin 3x3mm TDFN * on request Note: All products are RoHS compliant and Pb-free. Buy our products or get free samples online at ICdirect: http://www.austriamicrosystems.com/ICdirect For further information and requests, please contact us mailto:[email protected] or find your local distributor at http://www.austriamicrosystems.com/distributor www.austriamicrosystems.com Revision 1.03 15 - 16 AS1331 Datasheet Copyrights Copyright © 1997-2009, 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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