AIC2363 3.2A 550k/1.1MHz Synchronous PWM/PSM Step-Down Converter with High Light-load Efficiency FEATURES DESCRIPTION 2.5V to 6V Input Voltage Range Adjustable Output Voltage from 0.8V to Vin 3.2A Guaranteed Output Current 88% Efficiency at Heavy Load (Vin=5V, Vout=3.3V, Iout=3.2A) 95% Efficiency at Moderate Load (Vin=5V, Vout=3.3V, Iout=1.5A) 91% Efficiency at Light Load (Vin=5V, Vout=3.3V, Iout=50mA) Low RDS(ON) Internal Switches: 110mΩ No Schottky Diode Required 100% Duty Cycle in Low Dropout Operation Fixed 550k/1.1MHz Operating Frequency Optional Soft-Start Internal Fixed 1ms SoftStart (in SOP-8) The AIC2363 is a low-noise, pulse-widthmodulated (PWM), DC-DC step-down converter. The device features an internal synchronous rectifier for high efficiency; it requires no external Schottky diode. The AIC2363 is ideally suited for Li-Ion battery applications. Automatic PWM/PSM mode extends battery life and enhance efficiency by switching to a pulse-skippingmodulated mode during light load. Shutdown mode places the device in standby, reducing supply current to under 2µA. Other features of the AIC2363 include high efficiency for all load range, low dropout voltage, short circuit protection, and over temperature protection. APPLICATIONS LCD TV Portable Products Wireless and DSL Modems Solid-State Drives Battery-Operated Devices (1 Li-Ion or 3 NiMH/ NiCd) Analog Integrations Corporation Si-Soft Research Center DS-2363G-04 20140219 st 3A1, 1 Li-Hsin 1 Rd., Science Park , Hsinchu 300, Taiwan , R.O.C. TEL: 886-3-5772500 FAX: 886-3-5772510 www.analog.com.tw 1 AIC2363 APPLICATIONS CIRCUIT 1 VIN 5V R4 100KΩ R1 10Ω ON 8 OFF 7 PG 2 C1 10uF 9 C2 0.1uF VIN EN PGOOD VCC PGND AIC2363 L1 10 LX 2.2uH FB VOUT 3.3V R2 50KΩ 5 3 REF 6 SS 4 GND C5 0.22uF C3 22uF C4 0.1uF R3 16KΩ Fig. 1 Typical Application Circuit for DFN-10 Package 8 VIN R1 10Ω 5V 1 ON C1 10uF C2 0.1uF 5 OFF 6 VIN LX VCC FB EN REF PGND AIC2363 GND 7 L1 2.2uH 4 VOUT R2 50kΩ 3.3V 2 3 C4 0.1uF R3 16kΩ C3 22uF Fig. 2 Typical Application Circuit for SOP-8 Package 2 AIC2363 PIN CONFIGURATION PIN CONFIGURATION AIC2363XXXXXX PACKING TYPE TR: TAPE & REEL TB: TUBE(For SOP-8 Package) BG: BAG(For DFN-10 Package) PACKAGE TYPE R8: SOP-8 with Exposed Pad DC: DFN-10 with Exposed Pad G: Green Package A: 1.1MHz B: 550kHz DFN-10 (3x3) with Exposed Pad (heat sink) TOP VIEW VIN 1 VCC 2 REF 3 GND 4 7 PGOOD FB 5 6 SS 10 LX 9 PGND Exposed Pad 8 EN Note: The exposed pad must be connected with GND pin. SOP-8 with Exposed Pad (heat sink) TOP VIEW Example: AIC2363AGDCTR Fixed 1.1MHz Operating Frequency in Green DFN-10 with Exposed Pad VCC 1 Package and Tape & Reel Packing Type REF 2 GN D 3 FB 4 8 VIN Exposed Pad 7 LX 6 PGND 5 EN Note: The exposed pad must be connected with GND pin. 3 AIC2363 ABSOLUTE MAXIMUM RATINGS Supply Input Volatge, VCC, VIN -0.3V to 6.5V LX Pin Switch Voltage -0.3V to (VIN + 0.3V) Other I/O Pin Voltage -0.3V to (VCC + 0.3V) +/-0.3 V PGND to GND -40C to 85C Operating Ambient Temperature Range TA Operating Maximum Junction Temperature TJ 150C -65C to 150C Storage Temperature Range TSTG 260C Lead Temperature (Soldering 10 Sec.) Thermal Resistance Junction to Case SOP-8 (Exposed Pad) * 15C/W Thermal Resistance Junction to Case DFN 10L (Exposed Pad)* 20C/W Thermal Resistance Junction to Ambient SOP-8 (Exposed Pad)* 60C/W Thermal Resistance Junction to Ambient DFN 10L (Exposed Pad)* 50C/W Latch-Up HBM (Human Body Mode) 200mA 4KV (Assume no Ambient Airflow) Absolute Maximum Ratings are those values beyond which the life of a device may be impaired. * The package is placed on a two layers PCB with 2 ounces copper and 2 square inch, connected by 8 vias. 4 AIC2363 ELECTRICAL CHARACTERISTICS (TA=25C, VIN=3.3V, unless otherwise specified.) (Note1) PARAMETER CONDITIONS Input Voltage Range Under Voltage Lockout Threshold VCC Rising VCC Falling Output Adjustment Range Shutdown Current Quiescent Current (SOP-8 Package) Quiescent Current (DFN-10 Package) VEN = 0V IOUT = 0A, VFB = 1V No Switching IOUT = 0A, VFB = 1V No Switching Standby Current IOUT = 0A, Switching Feedback Reference Voltage VOUT Line Regulation VIN = 2.5V to 5.5V SYMBOL MIN VIN VUVLO(R) 2.5 VUVLO(F) VOUT ISD TYP MAX UNITS 6 V V 2.3 2.1 1 VIN 2 V V A IQ 200 380 A IQ 300 480 A ISB 600 900 A 0.8 0.816 V 0.8 VREF 0.784 ΔVOUT -2 FB Leakage Current IFB 0.1 EN Supply Current IEN 3.5 2 % 0.2 A A En Logic High 1.5 VCC V EN Logic Low 0 0.5 V P-Channel On-Resistance ILX = 0.2A RDSH(ON) 110 m N-Channel On-Resistance ILX = 0.2A RDSL(ON) 80 m Switch Leakage Current VEN = 0V, VIN = 5.5V Peak Inductor Current 0.1 1 A IPK 4 5 Oscillator Frequency (A Version) fOSCA 920 1100 1280 kHz Oscillator Frequency (B Version) fOSCB 468 550 632 kHz Maximum Duty Cycle DMAX 100 Thermal Shutdown Trip Point TOTP 150 °C Thermal Shutdown Hysteresis TOTP_HYS 25 °C PGood Leakage Current PGOOD=5V IPGOOD PGood Voltage Low IPGOOD=1mA VPGL PGood High Window With respect to nominal output, TA=TJ=25°C PGood Delay Time Vout Rising or Vout Falling A % 1 0.2 ±5 ±10 1024 A V ±15 % clks Soft-Start Charge Current ISS 4 A Note 1: Specifications are production tested at TA=25C. Specifications over the -40C to 85C operating temperature range are assured by design, characterization and correlation with Statistical Quality Controls (SQC). 5 AIC2363 TYPICAL PERFORMANCE CHARACTERISTICS (C1=10μF,C3=22μF,L1=2.2μH,TA=25℃,unless otherwise noted) y( ) 100.00 95.00 90.00 85.00 80.00 75.00 70.00 65.00 60.00 55.00 50.00 3.3VOUT 1.8VOUT (VCC=VIN=5V) 0 500 1000 1500 2000 2500 3000 Fig. 3 Efficiency vs load Current Fig. 4 Output Voltage Deviation vs Input Voltage VIN=VCC=3.3V,VOUT=1.8V,ILOAD=1.5A VIN=VCC=3.3V,VOUT=1.8V,ILOAD=1.5A ILX VLX VOUT OUT Ripple VEN Fig. 5 Switching Waveform Fig. 6 Soft Start Waveform VIN=VCC=3.3V,VOUT=0.8V,ILOAD=1.5A VEN VOUT VLX VEN VOUT Fig. 7 Soft Start Waveform Fig. 8 Shoutdown Waveform 6 AIC2363 TYPICAL PERFORMANCE CHARACTERISTICS (Continued) VIN=VCC=5V,VOUT=1.5V,ILOAD=0.5A to 1A VIN=VCC=5V,VOUT=2.5V,ILOAD=0.5A to 1A OUT Ripple OUT Ripple ILOAD ILOAD Fig. 9 Load Transient Response Fig. 10 Load Transient Response Fig. 11 Switching Frequence vs Input Voltage Fig. 12 Output Voltage Deviation vs Load Current 7 AIC2363 BLOCK DIAGRAM Functional Block Diagram of AIC2363 8 AIC2363 PIN DESCRIPTIONS (For DFN-10 PACKAGE) Pin No. 1 2 3 4 5 6 7 8 9 10 Pin Name Pin Function VIN Power Input Supply. Decouple this pin to PGND with a capacitor. VCC Signal Input Supply. Decouple this pin to GND with a capacitor. Normally VCC is equal to VIN. REF Internal Reference Voltage. Decouple this pin to GND with a capacitor. GND Signal Ground. All small-signal components and compensation components should connect to this ground, which in turn connects to PGND at one point. FB Feedback Pin. This pin receives the feedback voltage from a resistive divider connect across the output. SS Soft-Start Control Input. SS Controls the soft-start period. Connect a capacitor from SS to GND to set the soft-start period. PGOOD Power good indicator. It is an open drain output. Low when the output is out of the power good high window. EN Enable Pin. Connect to logic high in normal operation. Forcing this ping to GND cause the device to be shutdown. PGND Power Ground. Connect this pin to the negative terminal of CIN and COUT. LX Internal Power MOSFET Switches Output. Connect this pin to the inductor. (For SOP-8 PACKAGE) Pin No. 1 2 3 4 5 6 7 8 Pin Name Pin Function VCC Signal Input Supply. Decouple this pin to GND with a capacitor. Normally VCC is equal to VIN. REF Internal Reference Voltage. Decouple this pin to GND with a capacitor. GND Signal Ground. All small-signal components and compensation components should connect to this ground, which in turn connects to PGND at one point. FB Feedback Pin. This pin receives the feedback voltage from a resistive divider connect across the output. EN Enable Pin. Connect to logic high in normal operation. Forcing this pin to GND cause the device to be shutdown. PGND Power Ground. Connect this pin to the negative terminal of CIN and COUT. LX Internal Power MOSFET Switches Output. Connect this pin to the inductor. VIN Power Input Supply. Decouple this pin to PGND with a capacitor. 9 AIC2363 APPLICATION INFORMATION Operation Short Circuit Protection The AIC2363 is a low-noise step-down DC/DC While the output is shorted to ground, the switching converter control frequency of AIC2363 will be reduced to one fourth of architecture. It features an internal synchronous the normal switching frequency. This lower switching rectifier, which eliminates the external Schottky diode frequency ensures the inductor current has more time and increases efficiency. During normal operation, the to discharge, thereby preventing inductor current AIC2363 can regulate its output voltage through a runaway. The switching frequency will automatically feedback control circuit, which is composed of an error return to its designed value while short circuit condition amplifier; a current comparator and several control is released. with current-mode PWM/PSM signal generators. By comparing the feedback voltage to the reference voltage of 0.8V, the error amplifier varies its output voltage. The output voltage of the error amplifier is compared with the summing signal of current sensing signal and slope compensation signal to determine the duty cycle of internal main power Shutdown By connecting the EN pin to GND, the AIC2363 can be shut down to reduce the supply current to 2A (typical). At this operation mode, the output voltage of stepdown converter is equal to 0V. switch (P-channel MOSFET). While the main power 100% Duty Cycle Operation switch is turned on, the synchronous power switch (N- When the input voltage approaches the output voltage, channel MOSFET) will be turned off through anti-short- the AIC2363 smoothly transits to 100% duty cycle through block. Similarly, when the main power switch operation. This allows AIC2363 to regulate the output is turned off, the synchronous power switch will be voltage until AIC2363 completely enters 100% duty turned on until the inductor current starts to reverse or cycle operation. In 100% duty cycle mode, the output the beginning of the next switching cycle. In order to voltage is equal to the input voltage minus the voltage, achieve better efficiency and prevent overcharging the which is the drop across the main power switch. output capacitor, AIC2363 will enter pulse-skipping- The AIC2363 achieves 100% duty cycle operation by modulated mode (PSM) operation while working at extending the turn-on time of the main power switch. If light load conditions. the summing signal of current sensing signal and slope Current Limitation The AIC2363 provides current limit function by using an internal sensing resistor. When the main power switch turns on, current follows through the internal sensing resistor. And current amplifier senses the voltage, which crosses the resistor, and amplifies it. While the sensed voltage gets higher than reference voltage, the current limitation function is activated. While the current limitation function is activated, the duty cycle will be reduced to limit the output power to protect the internal power switches. compensation signal does not reach the output voltage level of the error amplifier at the end of 90% switching period, the main power switch is continuously turned on and the oscillator remains off until the summing signal of current sensing signal and slope compensation signal reaches the output voltage level of the error amplifier. After the summing signal of current sensing signal and slope compensation signal reaches the output voltage level of the error amplifier, the main power switch is turned off and the synchronous power switch is turned on for a constant off time. At the end of the constant off time, the next 10 AIC2363 switching cycle is begun. While the input voltage The selection of output capacitor depends on the approaches required output voltage ripple. The output voltage the output voltage, the switching frequency decreases gradually to smoothly transit to ripple can be expressed as: 100% duty cycle operation. VOUT If input voltage is very close to output voltage, the switching mode goes from pure PWM mode to 100% duty cycle operation. During this transient state mentioned above, large output ripple voltage may appear on output terminal. IL ESR IL 8 fOSC COUT For lower output voltage ripple, the use of low ESR ceramic capacitor is recommended. The tantalum capacitor can also be used well, but its ERS is larger than that of ceramic capacitor. Components Selection When Inductor The inductor selection depends on the current ripple of capacitors, X5R and X7R types are recommended inductor, the input voltage and the output voltage. ranges of voltage and temperature than other types. L VOUT fOSC IL VOUT 1 VIN Accepting a large current ripple of inductor allows the use of a smaller inductance. However, higher current choosing the input and output ceramic because they retain their capacitance over wider Output Voltage Programming By connecting a resistive divider R2 and R3, the output voltage of AIC2363 step-down converter can be set. VOUT can be calculated as: voltage and large core loss. By setting an acceptable R VOUT 0.8 1 2 R3 current ripple of inductor, a suitable inductance can be The resistive divider should sit as close to VFB pin as obtained from above equation. possible. ripple of inductor can cause higher output ripple In addition, it is important to ensure the inductor saturation current exceeds the peak value of inductor Layout Consideration current in application to prevent core saturation. The In order to ensure a proper operation of AIC2363, the peak value of inductor current can be calculated following points should be managed comprehensively. according to the following equation. 1. The input capacitor and VIN should be placed as IPEAK VOUT VOUT 1 IOUT max 2 fOSC L VIN close as possible to each other to reduce the input voltage ripple and noise. 2. The output loop, which is consisted of the inductor, the internal main power switch, the internal Input Capacitor and Output Capacitor To prevent the high input voltage ripple and noise synchronous power switch and the output capaci- resulted from high frequency switching, the use of low tor, should be kept as small as possible. ESR ceramic capacitor for the maximum RMS current is recommended. The approximated RMS current of the input capacitor can be calculated according to the following equation. 2 ICINRMS IOUT ( MAX ) 3. The routes with large current should be kept short and wide. 4. Logically the large current on the converter should flow at the same direction. VOUT VIN VOUT IL2 VIN2 12 5. The VFB pin should be connected to the feedback resistors directly and the route should be away from the noise sources. 11 AIC2363 PHYSICAL DIMENSIONS (unit: mm) SOP-8 Exposed Pad (Heat Sink) D D1 EXPOSED THERMAL PAD(Heat Sink) (BOTTOM CENTER OF PACKAGE) h X 45° A A SEE VIEW B A e H E E1 WITH PLATING 0.25 C A1 B GAUGE PLANE SEATING PLANE S Y M B O L SOP-8 Exposed Pad(Heat Sink) MILLIMETERS MIN. MAX. A 1.35 1.75 A1 0.00 0.15 B 0.31 0.51 C 0.17 0.25 D 4.80 5.00 D1 1.50 3.50 L VIEW B BASE METAL SECTION A-A Note : 1. Refer to JEDEC MS-012E. 2. Dimension "D" does not include mold flash, protrusions or gate burrs. Mold flash, protrusion or gate burrs shall not exceed 6 mil per side . 3. Dimension "E" does not include inter-lead flash or protrusions. 4. Controlling dimension is millimeter, converted inch dimensions are not necessarily exact. E 3.80 4.00 E1 1.0 2.55 e 1.27 BSC H 5.80 6.20 h 0.25 0.50 L 0.40 1.27 θ 0° 8° 12 AIC2363 DFN-10L-3X3 PACKAGE D2 D 6 E E2 L 10 5 A3 A S Y M B O L A DFN 10L-3x3x0.75-0.5mm MILLIMETERS MIN. MAX. 0.70 0.80 A3 b SEATING PLANE 1 e PIN#1 0.20 BSC b 0.18 0.30 D 2.90 3.10 D2 2.20 2.70 E 2.90 3.10 E2 1.40 1.80 0.5 BSC e L 0.30 0.50 Note : 1. DIMENSION AND TOLERANCING CONFORM TO ASME Y14.5M-1994. 2.CONTROLLING DIMENSIONS：MILLIMETER，CONVERTED INCH DIMENSION ARE NOT NECESSARILY EXACT. Note: Information provided by AIC is believed to be accurate and reliable. However, we cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in an AIC product; nor for any infringement of patents or other rights of third parties that may result from its use. We reserve the right to change the circuitry and specifications without notice. Life Support Policy: AIC does not authorize any AIC product for use in life support devices and/or systems. Life support devices or systems are devices or systems which, (I) are intended for surgical implant into the body or (ii) support or sustain life, and whose failure to perform, when properly used in accordance with instructions for use provided in the labeling, can be reasonably expected to result in a significant injury to the user. 13