AS1340 5 0 V, M i c r o p o w e r, D C - D C B o o s t C o n v e r t e r 1 General Description 2 Key Features The AS1340 boost converter contains a 1.4A internal switch in a tiny TDFN-8 3x3mm package. The device operates from a 2.7 to 5.5V supply, and can boost voltages up to 50V output. The output voltage can easily be adjusted by an external resistor divider. 2.7V to 50V Adjustable Output Voltage 2.7V to 50V Input Voltage Range 2.7V to 5.5V Supply Voltage Range High Output Currents: The AS1340 uses a unique control scheme providing the highest efficiency over a wide range of load conditions. An internal 1.4A MOSFET reduces external component count, and a fixed high switching frequency (1MHz) allows for tiny surface-mount components. - 100mA @ 12V from 3.3V VIN - 50mA @ 24V from 3.3V VIN - 30mA @ 36V from 3.3V VIN Efficiency: Up to 93% The AS1340 also features power-OK circuitry which monitors the output voltage. Switching Frequency: 1MHz Additionally the AS1340 features a low quiescent supply current and a shutdown mode to save power. During shutdown an output disconnect switch separates the input from the output. The AS1340 is ideal for LCD or OLED panels with low current requirements and can also be used in a wide range of other applications. Output Disconnect Power-OK Output Operating Supply Current: 30µA Shutdown Current: 0.1µA TDFN-8 3x3mm Package The device is available in a low-profile TDFN-8 3x3mm package. 3 Applications The device is ideal for OLED display power supply, LED power supply, LCD bias generators, mobile/cordless phones, palmtop computers, PDAs and organizers, handy terminals or any other portable, battery-powered device. Figure 1. AS1340 - Typical Application Diagram L1 4.7µH 3 VIN = 2.7V to 5.5V CIN SWVIN 5 AS1340 1 EN R1 COUT 8 FB R2 7, 9 6 VOUT LX VCC VOUT = > VIN to 50V LX POK On Off SWOUT VCC 3 VIN = 2.7V to 5.5V 6 2 4 L1 VIN = 2.7V to ~VOUT L1 3 VIN = 2.7V to 5.5V VCC GND 6 VOUT LX If not needed the output disconnect switch can be left unconnected which will also increase the efficiency. Additionally the supply of the chip can be split to allow higher supply voltages for the coil. In this case the output disconnect switch must not be used. www.ams.com/DC-DC_Step-Up/AS1340 Revision 1.20 1 - 17 AS1340 Datasheet - P i n A s s i g n m e n t s 4 Pin Assignments Figure 2. Pin Assignments (Top View) EN 1 8 FB VCC 2 7 GND AS1340 SWVIN 3 POK 4 6 SWOUT GND 9 5 LX 4.1 Pin Descriptions Table 1. Pin Descriptions Pin Number Pin Name 1 EN 2 3 VCC SWVIN 4 POK 5 LX 6 7 SWOUT GND 8 FB 9 GND www.ams.com/DC-DC_Step-Up/AS1340 Description Active-High Enable Input. A logic low on this pin shuts down the device and reduces the supply current to 0.1µA. Note: Connect to VCC for normal operation. +2.7V to +5.5V Supply Voltage. Bypass this pin to GND with a 1µF capacitor. Shutdown Disconnect Switch In Power-OK. 0 = VOUT < 90% of VOUTNOM. 1 = VOUT > 90% of VOUTNOM. Inductor. The drain of the internal N-channel MOSFET. Note: This pin is high impedance in shutdown. Shutdown Disconnect Switch Out. Disconnects the input from the output during shutdown. Ground. This pin and pin 9 must be connected to GND to ensure normal operation. Feedback Pin. Feedback input to the gm error amplifier. Connect a resistor divider tap to this pin. The output voltage can be adjusted from VIN to 50V by: VOUT = 1.25V[1 + (R1/R2)] Ground. This pin and pin 7 must be connected to GND to ensure normal operation. Revision 1.20 2 - 17 AS1340 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 VCC, FB, EN to GND -0.3 7 SWVIN, SWOUT to GND -0.3 7 Units Comments Electrical Parameters LX to GND Input Current (latch-up immunity) V 55 -100 100 mA Norm: JEDEC 78 1.5 kV Norm: MIL 883 E method 3015 36.7 ºC/W on PCB Electrostatic Discharge Electrostatic Discharge HBM Temperature Ranges and Storage Conditions Thermal Resistance JA Junction Temperature Storage Temperature Range -55 Package Body Temperature Humidity non-condensing Moisture Sensitive Level www.ams.com/DC-DC_Step-Up/AS1340 5 +150 ºC +125 ºC +260 ºC 85 % 1 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”. The lead finish for Pb-free leaded packages is matte tin (100% Sn). Represents a max. floor life time of unlimited Revision 1.20 3 - 17 AS1340 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 VCC = EN = 2.7V, TAMB = -40 to +85ºC (unless otherwise specified). Typical values are at TAMB = +25ºC. Table 3. Electrical Characteristics Symbol Parameter TAMB Operating Temperature Range VCC Max Unit -40 +85 °C Supply Voltage 2.7 5.5 V VIN Inductor Input Voltage Range 2.7 50 V VOUT Output Voltage Range 2.7 50 V ICC Quiescent Supply Current VFB = 1.3V, VIN = 5V 30 50 µA Enable Supply Current EN = GND 0.1 1 µA VCC Line Regulation VOUT = 18V, ILOAD = 1mA, VIN = 5.5V, VCC = 2.7 to 5.5V 0.3 %/V VIN Line Regulation VOUT = 18V, ILOAD = 1mA, VCC = 5V, VIN = 2.7 to 5.5V 0.25 %/V VLDR Load Regulation VOUT = 18V, VCC = VIN = 5V, ILOAD = 0 to 20mA 0.02 %/mA Efficiency L1 = 10µH, VIN = 5.5V, VOUT = 20V, ILOAD = 100mA 88 % VFB Feedback Set Point IFB Feedback Input Bias Current VLNR Condition Min 1.225 Typ 1.25 1.275 V VFB = 1.3V 5 100 nA VOUT max VIN = 5.5V, ILOAD = 0mA 50 V ILX(MAX) LX Switch Current Limit VIN = 5.5V, ILOAD > 20mA 1.41 A RLX LX On-Resistance VCC = 5.5V, ILX = 100mA 0.6 RP_ON Switch On-Resistance VIN = 5.5V, PMOS 0.2 ILX_LEAK LX Leakage Current VLX = 50V 2 IP_LEAK Switch Leakage Current VIN = 5.5V, PMOS 0.5 DC-DC Switches µA Control Inputs VIH EN Input Threshold 2.7V VCC 5.5V EN Input Bias Current VCC = 5.5V, VEN = 0 to 5.5V POK Output Low Voltage POK sinking 1mA POK Output High Leakage Current POK = 5.5V POK Threshold Rising edge, referenced to VOUT(NOM) 0.8 x VCC 0.2 x VCC VIL IEN -1 V +1 µA 0.01 0.2 V 100 500 nA 87 90 93 % Oscillator Frequency 0.85 1 1.15 MHz Maximum Duty Cycle 85 90 95 % POK Output VOL Oscillator fCLK 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/DC-DC_Step-Up/AS1340 Revision 1.20 4 - 17 AS1340 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 Parts used for measurements: 4.7µH (LPS4018-472ML) Inductor, 10µF (GRM32DR71C106KA01) CIN and 1µF (GRM31MR71H105KA88) COUT. Figure 4. Efficiency vs. Output Current; VOUT = 24V 100 100 90 90 80 80 70 70 Efficiency (%) Efficiency (%) Figure 3. Efficiency vs. Output Current; VOUT = 36V 60 50 40 30 60 50 40 30 20 20 Vi n = 2.7V 10 Vi n = 2.7V Vi n = 3.3V Vi n = 3.3V 10 Vi n = 5.5V 0 Vi n = 5.5V 0 0.1 1 10 100 0.1 1 Output Current (mA) Figure 5. Efficiency vs. Output Current; VOUT = 12V 100 90 90 80 80 70 70 60 50 40 30 60 50 40 30 20 20 Vi n = 2.7V Vi n = 2.7V Vi n = 3.3V 10 Vi n = 3.3V 10 Vi n = 5.5V 0 Vi n = 5.5V 0 0.1 1 10 100 0.1 1 Output Current (mA) 100 Figure 8. Efficiency vs. VIN; IOUT = 10mA 100 90 90 Efficiency (%) 100 80 70 60 50 10 Output Current (mA) Figure 7. Efficiency vs. VIN; VOUT=18V, Split Supplies Efficiency (%) 100 Figure 6. Efficiency vs. Output Current; VOUT = 6V 100 Efficiency (%) Efficiency (%) 10 Output Current (mA) Iout = 1mA Iout = 5mA Iout = 10mA Iout = 20mA 80 70 60 50 Iout = 50mA Vout = 6V Vout = 12V Vout = 18V Vout = 24V Vout = 30V Vout = 36V Vout = 48V 40 40 2 4 6 8 10 12 2.7 Input Voltage (V) www.ams.com/DC-DC_Step-Up/AS1340 3.1 3.5 3.9 4.3 4.7 5.1 5.5 Input Voltage (V) Revision 1.20 5 - 17 AS1340 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. Output Voltage vs. Temperature; VOUT = 18V Figure 10. Output Voltage vs. Load Current; VOUT = 18V, VIN = 3.3V 18.5 18.5 Iout=1mA 18.4 Iout=5mA Iout=10mA 18.3 18.3 Iout=20mA 18.2 Output Voltage (V) . Output Voltage (V) . 18.4 Iout=50mA 18.1 18 17.9 17.8 18.2 18.1 18 17.9 17.8 17.7 17.7 17.6 17.6 17.5 -45 -30 -15 17.5 0 15 30 45 60 75 90 0 Temperature (C°) 20 30 Figure 12. Output Voltage vs. Input Voltage; VOUT = 18V 18.5 18.4 18.4 18.3 18.3 Output Voltage (V) 18.5 18.2 18.1 18 17.9 17.8 17.7 Iout = 1mA 17.6 Iout = 10mA Iout = 5mA 18.2 18.1 18 17.9 17.8 17.7 Iout = 1mA 17.6 Iout = 10mA Iout = 5mA Iout = 20mA Iout = 20mA 17.5 17.5 2 3 4 5 6 7 8 9 10 11 12 2.7 3.1 3.5 Input Voltage (V) 3.9 4.3 4.7 5.1 5.5 5.1 5.5 Input Voltage (V) Figure 13. Output Current vs. VIN; Split Supplies Figure 14. Output Current vs. VIN 500 500 450 Vout = 12V Vout = 18V Vout = 24V Vout = 30V 450 Vout = 36V Vout = 12V Vout = 18V Vout = 24V Vout = 30V Vout = 36V 400 Output Current (mA) Output Current (mA) 40 Output Current (mA) Figure 11. Output Voltage vs. Input Voltage; VOUT = 18V, Split Supplies Output Voltage (V) 10 350 300 250 200 150 400 350 300 250 200 150 100 100 50 50 0 0 2 3 4 5 6 7 8 9 10 11 12 2.7 Input Voltage (V) www.ams.com/DC-DC_Step-Up/AS1340 3.1 3.5 3.9 4.3 4.7 Input Voltage (V) Revision 1.20 6 - 17 AS1340 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 16. Input Current vs. Input Voltage; IOUT = 0mA, switching 5.5 1 5 0.9 4.5 0.8 Vout = 6V Vout = 12V Input Current (mA) 4 3.5 3 2.5 2 1.5 1 0.5 Vout = 6V Vout = 12V Vout = 18V Vout = 24V Vout = 30V Vout = 36V Vout = 18V Vout = 24V 0.7 Vout = 30V 0.6 0.5 0.4 0.3 0.2 0.1 0 0 0 5 10 15 20 25 30 35 40 45 50 2.7 3.1 3.5 Output Current (mA) Figure 17. Input Current vs. Output Current; VOUT = 12V 4.3 4.7 5.1 5.5 60 70 Figure 18. Input Current vs. Output Current; VOUT = 18V 600 600 Vi n = 2.4V Vi n = 2.4V Vi n = 2.7V 500 Vi n = 2.7V 500 Vi n = 3.3V Vi n = 5.5V Input Current (mA) 400 300 200 100 Vi n = 3.3V Vi n = 5.5V 400 300 200 100 0 0 10 20 30 40 50 60 70 0 Output Current (mA) 30 40 50 VOUT POK EN 500mA/DIV 5V/Div Figure 20. Startup Waveform - POK 10V/Div EN LX VOUT 20 Output Current (mA) Figure 19. Startup Waveform 200µs/Div www.ams.com/DC-DC_Step-Up/AS1340 10 5V/Div 0 5V/DIV Input Current (mA) 3.9 Input Voltage (V) 2V/Div Start-Up Voltage (V) Figure 15. Startup Voltage vs. Output Current; VIN = 2.7 to 5.5V 50µs/Div Revision 1.20 7 - 17 AS1340 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 500µs/Div Figure 23. Output Voltage Ripple; VOUT = 18V, IOUT = 1mA Figure 24. Output Voltage Ripple; VOUT = 18V, IOUT = 20mA VIN = 2.7V VIN = 2.7V 2ms/Div 1µs/Div 1mA 20mA VOUT(AC) IOUT 1mA 20mA VOUT(AC) IOUT 200mV/Div Figure 26. Fixed Frequency vs. Powersave Operation; VIN = 2.7V, VOUT = 18V 200mV/Div Figure 25. Load Transient Response; VIN = 5.5V, VOUT = 18V 2ms/Div www.ams.com/DC-DC_Step-Up/AS1340 VIN = 3.3V 200mV/Div VOUT VIN = 5.5V 200mV/Div VOUT VIN = 5.5V VIN = 3.3V 200mV/Div VOUT(AC) VIN 500µs/Div 2V/DIV 200mV/Div Figure 22. Transient Line Regulation; VOUT = 18V, ILOAD = 20mA 2V/DIV VIN VOUT(AC) Figure 21. Transient Line Regulation; VOUT = 18V, ILOAD = 1mA 2ms/Div Revision 1.20 8 - 17 AS1340 Datasheet - D e t a i l e d D e s c r i p t i o n 8 Detailed Description The AS1340 features a current limiting circuitry, a fixed-frequency PWM architecture, power-OK circuitry, thermal protection, and an automatic powersave mode in a tiny package, and maintains high efficiency at light loads. Figure 27. AS1340 - Block Diagram with Shutdown Disconnect Switch 3 VIN = 2.7V to 5.5V SWVIN 6 L1 4.7µH SWOUT 4 POK 5 LX 2 – VOUT Good VCC CIN 1µF PWM Control Sync Drive Control 1 MHz Spread Spectrum Ramp Generator Slope Compensator 1 Shutdown Control Powersave Shutdown Powersave Operation Control VIN to 50V + 0.9 CFF* Current Sense R1 AS1340 + PWM – Comp – EN 1.13V VC RC COUT 8 – gm Error Amp + FB CP2 CC 1.25V Ref R2 7,9 GND * Optional Automatic powersave mode regulates the output and also reduces average current flow into the device, resulting in high efficiency at light loads. When the output increases sufficiently, the powersave comparator output remains high, resulting in continuous operation. For each oscillator cycle, the power switch is enabled. A voltage proportional to switch current is added to a stabilizing ramp and the resulting sum is delivered to the positive terminal of the PWM comparator. The error amplifier compares the voltage at FB with the internal 1.25V reference and generates an error signal (VC). When VC is below the powersave mode threshold voltage the automatic powersave-mode is activated and the hysteretic comparator disables the power circuitry, with only the low-power circuitry still active (total current consumption is minimized). When a load is applied, VFB decreases; VC increases and enables the power circuitry and the device starts switching. In light loads, the output voltage (and the voltage at FB) will increase until the powersave comparator disables the power circuitry, causing the output voltage to decrease again. This cycle is repeated resulting in low-frequency ripple at the output. The POK output indicates whether the output voltage is within 90% of the nominal output voltage level or not. When EN is low, the circuit is not active and POK gives a high signal when connected to VCC by a pull-up resistor. When EN goes high, POK goes low after approximately 50µs and will go high when the output reaches 90% of the nominal output voltage (see Figure 20 on page 7). When input and output voltage are almost the same, it may happen that the POK Signal does not go low because VOUT reaches 90% before the delay has expired. The open-drain POK output sinks current, when EN is high and the output voltage is below 90% of the nominal output voltage. Thermal protection circuitry shuts down the device when its temperature reaches 145ºC. www.ams.com/DC-DC_Step-Up/AS1340 Revision 1.20 9 - 17 AS1340 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 9.1 Power Supply Concept The AS1340 has an operating voltage range from 2.7 to 5.5V. If the inductor is supplied from the same source the battery disconnect switch can be used as well (see Figure 1 on page 1). In case that a input voltage source is higher than 5.5V, the inductor can be supplied separately up to 50V (see Figure 28), but then the battery disconnect switch cannot be used, because its operating voltage range is limited to 5.5V. 9.2 Shutdown A logic low on pin EN shuts down the AS1340 and a logic high on EN powers on the device. In shutdown mode the supply current drops to below 1µA to maximize battery life. In case that the battery disconnect switch is used, the battery is disconnected from the output during shutdown. Note: Pin EN should not be left floating. If the shutdown feature is not used, connect EN to VIN. 9.3 Battery Disconnect The AS1340 has an integrated switch that can be used to disconnect the battery during shutdown. The operation voltage of this switch is limited to 5.5V. When EN is high, the switch is closed and supplies the inductor. Due to the RON resistance the efficiency is slightly lower if the battery disconnect switch is used. PLOSS = IIN² x RON (EQ 1) 9.4 Setting Output Voltage Output voltage can be adjusted by connecting a voltage divider between pins LX and FB (see Figure 28). Figure 28. Typical Application (SWVIN and SWOUT not in use) Supply 2.7V to VOUT L1 4.7µH CIN 10µF 3 2 VIN = 2.7V to 5.5V C1 0.1µF SWVIN 6 SWOUT 5 VCC D1 VOUT = 18V LX R1 2.2M 4 AS1340 POK On 1 Off EN COUT 1µF 8 FB R2 165k 7,9 GND The output voltage can be adjusted by selecting different values for R1 and R2. For R2, select a value between 10k and 200k. Calculate R1 by: V OUT R 1 = R 2 ------------- – 1 V FB (EQ 2) Where: VOUT = VIN to 50V, VFB = 1.25V The input bias current of FB has a maximum value of 100nA which allows for large-value resistors. For less than 1% error, the current through R2 should be 100 times the feedback input bias current (IFB). www.ams.com/DC-DC_Step-Up/AS1340 Revision 1.20 10 - 17 AS1340 Datasheet - A p p l i c a t i o n I n f o r m a t i o n 9.5 LED Power Supply Application The AS1340 can also be used for driving LEDs. Just simply connect the LEDs between the pins LX and FB. (see Figure 29). Figure 29. LED Supply Application L1 4.7µH 3 VIN = 2.7V to 5.5V 2 C1 0.1µF SWVIN 6 SWOUT 5 VCC 4 LX AS1340 POK On 1 Off EN D1 COUT 1µF 8 FB ILED R2 100 7,9 GND The output voltage is adjusted automatically to the required voltage of the LEDs. This voltage depends on the forward voltage (VF) of the used LEDs and the Feedback Voltage VFB. Calculate VOUT by: V OUT = V F I LED n + V FB (EQ 3) Note: The brightness of the LEDs can directly be adjusted by setting the current ILED via the corresponding R2. Calculate R2 by: V FB I LED = ---------R2 (EQ 4) Where: VFB = 1.25V n .... number of LED’s www.ams.com/DC-DC_Step-Up/AS1340 Revision 1.20 11 - 17 AS1340 Datasheet - A p p l i c a t i o n I n f o r m a t i o n 9.6 Inductor Selection For the external inductor, a 6.8µH inductor is recommended. Minimum inductor size is dependant on the desired efficiency and output current. Inductors with low core losses and small DCR at 1MHz are recommended. Table 4. Recommended Inductors Part Number LPS4018-472ML_ L 4.7µH DCR Current Rating 0.125 Dimensions (L/W/T) 1.9A 4.4x4.4x1.7mm ME3220-472ML_ 4.7µH 0.190 1.5A 3.2x2.8x2mm MOS6020-472ML_ 4.7µH 0.050 1.94A 6.8x6x2.4mm MSS6122-472ML_ 4.7µH 0.065 1.82A 6.1x6.1x6mm LPS4018-682ML_ 6.8µH 0.150 1.3A 4.4x4.4x1.7mm ME3220-682ML_ 6.8µH 0.270 1.2A 3.2x2.8x2mm MOS6020-682ML_ 6.8µH 0.078 1.72A 6.8x6x2.4mm MSS6122-682ML_ 6.8µH 0.100 1.50A 6.1x6.1x6mm Manufacturer Coilcraft www.coilcraft.com 100 100 90 90 80 80 70 70 Efficiency (%) . Efficiency (%) . Figure 30. Efficiency Comparison of Different Inductors, VIN = 3.3V, VOUT = 18V 60 50 40 30 20 LPS4018-472 10 ME3220-472 LPS4018-682 ME3220-682 0 60 50 40 30 20 MOS6020-472 10 MSS6122-472 MOS6020-682 MSS6122-682 0 1 10 100 1 Output Current (mA) 10 100 Output Current (mA) 100 100 90 90 80 80 70 70 Efficiency (%) . Efficiency (%) . Figure 31. Efficiency Comparison of Different Inductors, VIN = 5.5V, VOUT = 18V 60 50 40 30 20 LPS4018-472 10 ME3220-472 LPS4018-682 ME3220-682 0 60 50 40 30 20 MOS6020-472 10 MSS6122-472 MOS6020-682 MSS6122-472 0 1 10 100 1 Output Current (mA) www.ams.com/DC-DC_Step-Up/AS1340 10 100 Output Current (mA) Revision 1.20 12 - 17 AS1340 Datasheet - A p p l i c a t i o n I n f o r m a t i o n 9.7 Capacitor Selection A 4.7µF capacitor is recommended for CIN as well as a 2µF for COUT. Small-sized ceramic capacitors are recommended. X5R and X7R ceramic capacitors are recommend as they retain capacitance over wide ranges of voltages and temperatures. 9.7.1 Output Capacitor Selection Low ESR capacitors should be used to minimize VOUT ripple. Multi-layer ceramic capacitors are recommended since they have extremely low ESR and are available in small footprints. A 2.2 to 10µF output capacitor is sufficient for most applications. Larger values up to 22µF may be used to obtain extremely low output voltage ripple and improve transient response. X5R and X7R dielectric materials are recommended due to their ability to maintain capacitance over wide voltage and temperature ranges. Table 5. Recommended Output Capacitor Part Number C TC Code Rated Voltage GRM31MR71H105KA88 1µF GRM32ER71H475KA88 4.7µF X7R 50V C1210 C1206C105K5RAC 1µF X7R 50V C1206 C1206C225K5RAC 2.2µF X7R 50V C1210 1206C105KAT2A 1µF X7R 50V C1206 9.7.2 X7R 50V Dimensions (L/W/T) C1206 Manufacturer Murata www.murata.com Kemet www.kemet.com AVX www.avx.com Input Capacitor Selection Low ESR input capacitors reduce input switching noise and reduce the peak current drawn from the battery. Ceramic capacitors are recommended for input decoupling and should be located as close to the device as is practical. A 4.7µF input capacitor is sufficient for most applications. Larger values may be used without limitations. Table 6. Recommended Input Capacitor Part Number C TC Code Rated Voltage Dimensions (L/W/T) GRM21BR71C105KA01 1µF X7R 16V C0805 GRM21BR61C225KA88 2.2µF X7R 16V C0805 GRM32DR71C106KA01 10µF X7R 16V C1210 9.7.3 Manufacturer Murata www.murata.com Diode Selection A Schottky diode must be used to carry the output current for the time it takes the PMOS synchronous rectifier to switch on. Note: Do not use ordinary rectifier diodes, since the slow recovery times will compromise efficiency. Table 7. Recommended Diodes Part Number Reverse Voltage Forward Current Package Manufacturer PMEG4010BEA 40V 1A SOD123 Philips www.nxp.com MBR0540 40V 500mA SOD123 MBR0560 60V 500mA SOD123 MCC www.mccsemi.com 9.8 Thermal Protection To protect the device from short circuit or excessive power dissipation of the auxiliary NPNs, the integrated thermal protection switches off the device when the junction temperature (TJ) reaches 145ºC (typ). When TJ decreases to approximately 125ºC, the device will resume normal operation. If the thermal overload condition is not corrected, the device will switch on and off while maintaining TJ within the range between 125ºC and 145ºC. www.ams.com/DC-DC_Step-Up/AS1340 Revision 1.20 13 - 17 AS1340 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 32. TDFN-8 3x3mm Marking Package Code: XXXX - encoded Datecode www.ams.com/DC-DC_Step-Up/AS1340 Revision 1.20 14 - 17 AS1340 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 33. TDFN-8 3x3mm Package www.ams.com/DC-DC_Step-Up/AS1340 Revision 1.20 15 - 17 AS1340 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 Description Delivery Form Package AS1340A-BTDT-10 ASM3 50V, Micropower, DC-DC Boost Converter, Automatic Power Save, 1MHz Tape and Reel TDFN-8 3x3mm Note: All products are RoHS compliant. Buy our products or get free samples online at ICdirect: http://www.ams.com/ICdirect Technical Support is found at http://www.ams.com/Technical-Support For further information and requests, please contact us mailto:[email protected] or find your local distributor at http://www.ams.com/distributor www.ams.com/DC-DC_Step-Up/AS1340 Revision 1.20 16 - 17 AS1340 Datasheet Copyrights Copyright © 1997-2010, 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. 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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/DC-DC_Step-Up/AS1340 Revision 1.20 17 - 17