AS1323 D a ta S he e t 1.6µA Quiescent Current, Single Cell, DC-DC Step-Up Converter 1 General Description 2 Key Features The AS1323 high-efficiency step-up DC-DC converter was designed specifically for single-cell, battery-powered devices where lowest quiescent current and high efficiency are essential. The compact device is available in three fixed-voltage variations and is perfect for a wide variety of applications where extremely-low quiescent currents and very-small form factors are critical. The devices are available as the standard products shown in Table 1. See also Ordering Information on page 12. Table 1. Standard Products Model Fixed Output Voltage Package AS1323-27 2.7V TSOT23-5 AS1323-30 3.0V TSOT23-5 AS1323-33 3.3V TSOT23-5 Integrated boot circuitry ensures start-up even with veryhigh load currents. The true output disconnect feature completely disconnects the output from the battery during shutdown. ! 1.6µA Quiescent Current ! Input Voltage Range: 0.75 to 2V ! Up to 100mA Output Current ! Fixed Output Voltages: 2.7, 3.0 and 3.3V ! Shutdown Current: 0.1µA ! Output Voltage Accuracy: ±3% ! Efficiency: Up to 85% ! No External Diode or FETs Needed ! Output Disconnect in Shutdown ! Guaranteed 0.95V Start-Up Voltage ! TSOT23-5 Package The device is available in a TSOT23-5 pin package. 3 Applications The devices are ideal for single-cell portable devices including mobile phones, MP3 players, PDAs, remote controls, personal medical devices, wireless transmitters and receivers, and any other battery-operated, portable device. Figure 1. Typical Operating Circuit 10µH 1 5 VBATT VBATT 1 VSS 2 SHDNN 3 5 LX 4 VOUT LX 10µF AS1323 3 SHDNN 2 VSS AS1323 4 VOUT 10µF www.austriamicrosystems.com Revision 1.02 1 - 13 AS1323 Data Sheet - P i n o u t 4 Pinout Pin Assignments Figure 2. Pin Assignments (Top View) VBATT 1 VSS 2 SHDNN 3 5 LX AS1323 4 VOUT Pin Descriptions Table 2. Pin Descriptions Pin Number 1 2 Pin Name VBATT VSS 3 SHDNN 4 VOUT 5 LX Description Battery Supply Input and Coil Connection Negative Supply and Ground Shutdown Input. 0 = Shutdown mode. 1 = Normal operating mode. Output. This pin also supplies bootstrap power to the device. Inductor Connection. This pin is connected to the internal N-channel MOSFET switch drain and P-channel synchronous rectifier drain. www.austriamicrosystems.com Revision 1.02 2 - 13 AS1323 Data Sheet - 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 3 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 3. Absolute Maximum Ratings Parameter Min Max Units VDD, VBATT, SHDNN, LX to VSS -0.3 +5 V Comments Maximum Current VOUT, LX 1 A Thermal Resistance ΘJA 207.4 ºC/W on PCB Electro-Static Discharge 2 kV HBM Operating Temperature Range -40 +85 ºC Storage Temperature Range -65 +150 ºC +150 ºC Junction Temperature Package Body Temperature www.austriamicrosystems.com +260 ºC Revision 1.02 The reflow peak soldering temperature (body temperature) specified is in accordance with IPC/JEDEC J-STD-020C “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 - 13 AS1323 Data Sheet - 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 DC Electrical Characteristics TAMB = -40°C to +85°C, VBATT = 1.2V, VOUT = VOUT(NOM), SHDNN = VOUT, RLOAD = ∞, unless otherwise noted. Typical values are at TA = 25°C.(unless otherwise specified). Limits are 100% production tested at TAMB = 25ºC. Limits over the operating temperature range are guaranteed by design. Table 4. Electrical Characteristics Symbol Parameter VINMIN Minimum Input Voltage VIN Operating Input Voltage TAMB = 25ºC VINSU Minimum Start-Up Input Voltage TAMB = 25ºC, RLOAD = 100Ω VOUT 0.75 0.95 Unit V 2 V 0.75 0.95 V 2.781 AS1323-30 2.91 3.0 3.09 AS1323-33 3.201 3.3 3.399 30 40 mV N-Channel On-Resistance 0.5 1.0 Ω P-Channel On-Resistance 0.75 1.5 Ω N-Channel Switch Current Limit tON VBATT = 1.5V; ILOAD = 45mA mA Switch Maximum On-Time 6 µs Synchronous Rectifier Zero-Crossing Current 10 mA 6 µA Operating Current into VBATT IQ-OUT Quiescent Current to VOUT IQ-BAT Quiescent Current into VBATT Programmed at 400mA V 400 IOP-OUT 1 Max 2.7 ILIMIT ISDI-OUT Typ 2.619 Load depended drop of VOUT RDS-ON Min AS1323-27 Output Voltage RLOAD Condition VBATT = 1.5V, VOUT = 3.3V, TAMB = 25ºC VBATT = 1.5V, TAMB = 25ºC 1.6 3 µA 0.3 1 µA 200 nA Shutdown Current to VOUT ISDI-BAT Shutdown Current into VBATT VIL SHDNN Voltage Threshold, Low VIH SHDNN Voltage Threshold, High ISDI SHDNN Input Bias Current TAMB = 25ºC, VSDI = VOUT VBATT = 1.5V, TAMB = 25ºC 100 nA 150 mV 100 900 mV 300 nA 1. VOUT is completely disconnected (0V) during shutdown. www.austriamicrosystems.com Revision 1.02 4 - 13 AS1323 Data Sheet - 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 VOUT= 3.3V; TA = 25°C; CIN = COUT = 10µF, L = 10µH, ILOAD = 10mA; VBATT = 1.5V; unless otherwise specified. Figure 3. Efficiency vs. Output Current; VOUT= 3.3V Figure 4. Efficiency vs. Output Current; VOUT= 3.0V 90 90 VIN = 1.8V VIN = 1.8V 80 VIN = 1.2V VIN = 1.5V VIN = 0.95V 70 VIN = 1.5V Efficiency (%) . Efficiency (%) . 80 60 50 40 70 VIN = 1.2V VIN = 0.95V 60 50 40 30 30 0.1 1 10 100 0.1 1 Output Current (mA) Figure 5. Efficiency vs. Output Current; VOUT= 2.7V 3.32 VIN = 1.8V 3.315 80 Output Voltage (V) . No Load VIN = 1.5V Efficiency (%) . 100 Figure 6. Output Voltage vs. Temperature 90 VIN = 1.2V 70 VIN = 0.95V 60 50 3.31 3.305 3.3 ILOAD = 10mA 3.295 3.29 ILOAD = 30mA 40 3.285 30 0.1 1 10 3.28 -50 100 -25 Output Current (mA) 25 50 75 100 125 Figure 8. Output Voltage vs. Input Voltage 3.4 3.4 3.35 3.38 Output Voltage (V) . VIN = 1.5V 3.3 0 Temperature (°C) Figure 7. Output Voltage vs. Output Current Output Voltage (V) . 10 Output Current (mA) VIN = 1.2V 3.25 3.2 3.15 3.1 3.05 3.36 3.34 3.32 3.3 3.28 3.26 3.24 3.22 3 3.2 0 10 20 30 40 50 60 70 0.9 Output Current (mA) www.austriamicrosystems.com 1 1.1 1.2 1.3 1.4 1.5 1.6 1.7 Input Voltage (V) Revision 1.02 5 - 13 AS1323 Data Sheet - 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. Minimum Input Startup Voltage vs. Temp. 0.9 Input Current (nA) . Input Voltage (V) . Figure 10. Shutdown Current vs. Temperature 1000 1 0.8 0.7 VIN = 1.5V 100 VIN = 1.2V 10 1 0.6 0.5 -50 -25 0 25 50 75 100 125 0.1 -50 www.austriamicrosystems.com -25 0 25 50 75 100 125 Temperature (°C) Temperature (°C) Revision 1.02 6 - 13 AS1323 Data Sheet - D e t a i l e d D e s c r i p t i o n 8 Detailed Description The AS1323 is a compact, high-efficiency, step-up DC-DC converter guaranteed to start up with voltages as low as 0.95V, and operate with an input voltage down to 0.75V. Consuming only 1.6µA of quiescent current, the device includes an integrated synchronous rectifier that eliminates the need for an external diode and improves overall efficiency by minimizing losses (see Synchronous Rectification on page 7). The AS1323 also features an active-low shutdown circuit that supply current to 0.1µA. Figure 11. Block Diagram L1 4 1 VOUT VBATT 0.95 to 1.6V CIN COUT Comparator Discharge Comparator Voltage Control Logic Startup System Timing 3 SHDNN AS1323 5 LX Ref Comparator Charge 2 VSS PFM Control A forced discontinuous, current-limited, pulse-frequency modulation (PFM) control scheme provides ultra-low quiescent current and high efficiency over a wide output current-range. Rather than using an integrated oscillator, the inductor current is limited by the 400mA N-channel current limit or by the 6µs switch maximum on-time. After each device-on cycle, the inductor current must ramp to zero before another cycle can start. When the error comparator senses that the output has fallen below the regulation threshold, another cycle can begin. Synchronous Rectification The integrated synchronous rectifier eliminates the need for an external Schottky diode, reducing cost and PCB space. During normal operation, while the inductor discharges, the P-channel MOSFET turns on and shunts the MOSFET body diode. Consequently the rectifier voltage drop is significantly reduced improving efficiency without the need for external components. Low-Voltage Startup Circuit The AS1323 contains a unique low-voltage startup circuit which ensures start-up even with very high load currents. The minimum start-up voltage is independent of the load current. This device is powered from pin VBATT, guaranteeing startup at input voltages as low as 0.95V. Shutdown The AS1323 enter shutdown when the SHDNN pin is driven low. During shutdown, the output is completely disconnected from the battery. Shutdown can be pulled as high as 3.6V, regardless of the voltage at pins VBATT or VOUT. For normal operation, connect SHDN to the input. www.austriamicrosystems.com Revision 1.02 7 - 13 AS1323 Data Sheet - 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 Figure 12. Typical Application 10µH 1 5 VBATT LX 10µF AS1323 3 2 VSS 4 SHDNN VOUT 10µF Inductor Selection The control scheme of the AS1323 allows for a wide range if inductor values. A 10µH inductor should be sufficient for most applications (see Figure 12). Smaller inductance values typically offer smaller physical size for a given series resistance, allowing the smallest overall circuit dimensions. Applications using larger inductance values may startup at lower battery voltages, provide higher efficiency and exhibit less ripple, but they may reduce the maximum output current. This occurs when the inductance is sufficiently large to prevent the maximum current limit (ILIMIT) from being reached before the maximum on-time (tON) expires (see Electrical Characteristics on page 4). For maximum output current, the inductor value should be chosen such that the controller reaches the current-limit before the maximum on-time is triggered: V BATT ⋅ t ON L > -------------------------------I LIMIT (EQ 1) tONMAX is 6µs (typ). ILIMIT is 400mA (typ). For larger inductor values, the peak inductor current (IPEAK) can be determined by: The inductor’s incremental saturation current rating should be greater than the peak switching current. However, it is V BATT ⋅ t ON (EQ 2) I PEAK = -------------------------------L generally advisable to bias the inductor into saturation by as much as 20%, although this will slightly reduce efficiency. Maximum Output Current The maximum output current (IOUTMAX) is a function of IPEAK, VIN, VOUT, and the overall efficiency (η) as indicated in the formula for determining IOUTMAX: 1 V BATT I OUTMAX = --- ⋅ I PEAK ⋅ ⎛ -----------------⎞ ⋅ η ⎝ V OUT ⎠ 2 www.austriamicrosystems.com Revision 1.02 (EQ 3) 8 - 13 AS1323 Data Sheet - A p p l i c a t i o n I n f o r m a t i o n Capacitor Selection Choose input and output capacitors to supply the input and output peak currents with acceptable voltage ripple. The input filter capacitor (CIN) reduces peak currents drawn from the battery and improves efficiency. Low equivalent series resistance (ESR) capacitors are recommended. Note: Ceramic capacitors have the lowest ESR, but low ESR tantalum or polymer capacitors offer a good balance between cost and performance. Output voltage ripple has two components: variations in the charge stored in the output capacitor with each COIL pulse, and the voltage drop across the capacitor’s ESR caused by the current into and out of the capacitor: VRIPPLE = VRIPPLE(C) + VRIPPLE(ESR) (EQ 4) VRIPPLE(ESR) = IPEAK RESR(COUT) (EQ 5) 2 2 1 L V RIPPLE ( C ) ≈ --- ⋅ ⎛ --------------------------------------------------------------⎞ ⋅ ( I PEAK – I OUT ) 2 ⎝ ( V OUT – V BATT ) ⋅ C OUT⎠ (EQ 6) Where: IPEAK is the peak inductor current. For ceramic capacitors, the output voltage ripple is typically dominated by VRIPPLE(C). For example, a 10µF ceramic capacitor and a 10µH inductor typically provide 75mV of output ripple when stepping up from 1.2V to 3.3V at 50mA. Low input-to-output voltage differences require higher output capacitor values. Capacitance and ESR variation of temperature should be considered for best performance in applications with wide operating temperature ranges. PC Board Layout Considerations The AS1323 has been specially designed to be tolerant to PC board parasitic inductances and resistances. However, to achieve maximum efficiency a careful PC board layout and component selection is vital. Note: For the optimal performance the IC’s VSS and the ground leads of the input and output capacitors must be kept less than 5mm apart using a ground plane. In addition, keep all connections to COIL as short as possible. The system robustness guarantees a reliable operation even if those recommendations are not fully applied. www.austriamicrosystems.com Revision 1.02 9 - 13 AS1323 Data Sheet 10 Package Drawings and Markings The device is available in an TSOT23-5 package. Figure 13. TSOT23-5 Package Symbol A A1 A2 b b1 c Min Typ 0.01 0.84 0.30 0.31 0.12 0.05 0.87 0.35 0.15 Max 1.00 0.10 0.90 0.45 0.39 0.20 c1 0.08 0.13 0.16 D E E1 e e1 2.90BSC 2.80BSC 1.60BSC 0.95BSC 1.90BSC Notes 3,4 3,4 3,4 Symbol L L1 L2 N R R1 θ θ1 aaa bbb ccc ddd Min 0.30 Typ 0.40 0.60REF 0.25BSC 5 0.10 0.10 0º Max 0.50 Notes 0.25 4º 8º 4º 10º 12º Tolerances of Form and Position 0.15 0.25 0.10 0.20 Notes: 1. Dimensioning and tolerancing conform to ASME Y14.5M - 1994. 2. Dimensions are in millimeters. 3. Dimension D does not include mold flash, protrusions, or gate burrs. Mold flash, protrusions, and gate burrs shall not exceed 0.15mm per end. Dimension E1 does not include interlead flash or protrusion. Interlead flash or protrusion shall not exceed 0.15mm per side. Dimensions D and E1 are determined at datum H. 4. The package top can be smaller than the package bottom. Dimensions D and E1 are determined at the outermost extremes of the plastic body exclusive of mold flash, tie bar burrs, gate burrs, and interlead flash, but include any mistmatches between the top of the package body and the bottom. D and E1 are determined at datum H. www.austriamicrosystems.com Revision 1.02 10 - 13 AS1323 Data Sheet - 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 Tape and Reel Pin1 Orientation Figure 14. Tape&Reel Pin1 Orientation User direction of feed Top, Through View TSOT23-5 www.austriamicrosystems.com TSOT23-5 TSOT23-5 Revision 1.02 TSOT23-5 11 - 13 AS1323 Data Sheet - 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 5. Table 5. Ordering Information Model Marking Description Delivery Form Package AS1323-BTTT-27 ASJN High-efficiency step-up DC-DC converter, 2.7V fixed output Tape and Reel TSOT23-5 AS1323-BTTT-30 ASMP High-efficiency step-up DC-DC converter, 3.0V fixed output Tape and Reel TSOT23-5 AS1323-BTTT-33 ASMQ High-efficiency step-up DC-DC converter, 3.3V fixed output Tape and Reel TSOT23-5 www.austriamicrosystems.com Revision 1.02 12 - 13 AS1323 Data Sheet - O r d e r i n g I n f o r m a t i o n Copyrights Copyright © 1997-2007, austriamicrosystems AG, Schloss Premstaetten, 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 lifesustaining equipment are specifically not recommended without additional processing by austriamicrosystems AG for each application. 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Contact Information Headquarters austriamicrosystems AG A-8141 Schloss Premstaetten, 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 www.austriamicrosystems.com Revision 1.02 13 - 13