AP1516 150KHz, 3A PWM Buck DC/DC Converter + 1A Ultra Low Drop Regulator Features General Description * Channel 1: simple switch - Adjustable version output voltage range, 1.23V to 18V+4% & Fixed 3.3V version - 150KHz +20% fixed switching frequency - Voltage mode non-synchronous PWM control - ON/OFF shutdown control input - Operating voltage can be up to 20V - Output load current: 3A - Low power standby mode * Channel 2: ultra low drop regulator - Adjustable output voltage - 0.6V Maximum Dropout voltage at 1.0A Load current - Fast transient response - Good noise rejection * Channel 1 & Channel 2 - SOP-16L Pb-free package - Built-in switching transistor on chip - Thermal-shutdown and current-limit protection of each channel The Channel 1 is a step-down DC/DC converter, and own the ability of driving a 3A load without additional transistor component. Due to reducing the number of external component, the board space can be saved easily. The external shutdown function can be controlled by logic level and then come into standby mode. The internal compensation makes feedback control have good line and load regulation without external design. Regarding protected function, thermal shutdown is to prevent over temperature operating from damage, and current limit is against over current operating of the output switch. If current limit function occurred and VFB is down to 0.5V below, the switching frequency will be reduced. The switching frequency of 150KHz thus allowing smaller sized filter components than what would be needed with lower frequency switching regulators. Other features include a guaranteed +4% tolerance on output voltage under specified input voltage and output load conditions, and +20% on the oscillator frequency. The channel 2 is a 1A regulator with extremely low dropout voltage. This product is specifically designed to provide well regulated supply for applications requiring 2.8V or lower voltages from 3.3V power supplies where high efficiency of a switcher can be achieved without the cost and complexity associated with switching regulator. Applications - PC Motherboard - LCD Monitor - Graphic Card - DVD-Video Player - NIC/Switch - Telecom Equipment - ADSL Modem - Printer and other Peripheral Equipment Pin Assignments Pin Descriptions ( Top View ) Name GND 1 16 GND VOUT1 2 15 3 14 FB1 SD1 VIN2 VOUT2 VOUT2 4 13 GND GND VIN1 VB VIN2 VOUT1 VOUT2 FB1 FB2 SD1 VSENSE2 GND VIN1 VB 12 VSENSE2 11 FB2 10 V OUT2 5 6 7 8 9 VOUT2 SOP-16L Description Operating voltage input of channel 1 Channel 2 bias voltage Main power source of channel 2 Channel 1 switching output Channel 2 output Output1 voltage feedback control Output2 voltage feedback control Channel 1 ON/OFF shutdown Channel 2 output sense pin Ground This datasheet contains new product information. Anachip Corp. reserves the rights to modify the product specification without notice. No liability is assumed as a result of the use of this product. No rights under any patent accompany the sale of the product. Rev.1.1 May 23, 2005 1/10 AP1516 150KHz, 3A PWM Buck DC/DC Converter + 1A Ultra Low Drop Regulator Ordering Information AP1516 XX X X Output version Package Packing Ch1: Blank : Adjustable -33 : 3.3V S: SOP-16L Blank : Tube A : Taping Block Diagram SD VIN1 200mV Current Source bias 1.235V Reference 2.5V Regulator 220mV Start up + Comp _ _ Comp + Frequecy compensation _ FB1 + _Amp Comp + Pre-driver 3A Switch VOUT1 150kHz OSC. Thermal Limit VIN2 GND VOUT2 VB VSENSE2 + 1.25V _ + + + CURRENT LIMIT _ THERMAL SHUTDOWN FB2 Anachip Corp. www.anachip.com.tw Rev.1.1 May 23, 2005 2/10 AP1516 150KHz, 3A PWM Buck DC/DC Converter + 1A Ultra Low Drop Regulator Absolute Maximum Ratings Symbol VIN1, B VIN2 VSD VFB1 VOUT1 PD TST TOP VOP Parameter Supply Voltage Supply Voltage ON/OFF Pin Input Voltage Feedback Pin Voltage Output Voltage to Ground Power Dissipation Storage Temperature Operating Temperature Operating Voltage Rating +22 +14 -0.3 to +18 -0.3 to +18 -1 Internally limited -65 to +150 -40 to +125 +4.5 to +22 Unit V V V V V W o C o C V Electrical Characteristics (All Output Voltage Versions) Unless otherwise specified, VIN2=12V for 3.3V, ILOAD = 0.5A Sym. IB1 Parameter Feedback Bias Current FOSC Oscillator Frequency FSCP Oscillator Frequency of Short Circuit Protect VSAT1 Saturation Voltage DC Max. Duty Cycle (ON) Min. Duty Cycle (OFF) ICL1 Current Limit IL IQ ISTBY VIL VIH IH IL Output Leakage Output = -1 Current Quiescent Current Standby Quiescent Current ON/OFF Pin Logic Input Threshold Voltage ON/OFF Pin Logic Input Current ON/OFF Pin Input Current Output = 0 Conditions VFB1=1.3V (Adjustable version only) When current limit occurred and VFB1 < 0.5V, Ta=25 oC IOUT1=2A No outside circuit VFB1=0V force driver on VFB=0V force driver on VFB=12V force driver off Peak current No outside circuit VFB1=0V force driver on No outside circuit VFB1=12V force driver off VIN1=22V VFB1=12V force driver off ON/OFF pin=5V VIN1=22V Low (regulator ON) High (regulator OFF) Min. Typ. -10 127 110 150 5 15 θJC Thermal Resistance θJA Thermal Resistance with Junction to Copper Area of Approximately SOP-16L ambient 2 2 15 in + 15 in Unit 25 KHz nA KHz 1.4 1.25 V 1.5 100 0 % 3.5 A -200 -5 5 70 2.0 1.3 VLOGIC=2.5V (OFF) VLOGIC=0.5V (ON) Junction to SOP-16L case Max. -50 -100 173 173 uA mA mA 10 150 200 0.6 - uA V -0.01 -0.1 uA -1 10 o 40 o C/W C/W Anachip Corp. www.anachip.com.tw Rev.1.1 May 23, 2005 3/10 AP1516 150KHz, 3A PWM Buck DC/DC Converter + 1A Ultra Low Drop Regulator Electrical Characteristics (Continued) o o Unless otherwise specified, these specifications apply over, CIN=1uF, COUT=10uF, and TJ=0 to 150 C. Typical value refer to TJ=25 C. VOUT = VSENSE. Sym. VREF Parameter Test Condition o TJ=25 C,(VIN2-VOUT2)=0.5V, Reference Voltage IO=10mA VB =VIN2+1V IO2=10mA, VOUT2+0.5V<VIN2<12V Line Regulation VB =VIN2+1V 0mA< IO2<1.0A, TJ=25oC, (VIN2 – VOUT2) = 2V, Load Regulation VB = VIN2 + 1V VFB2 =0V for all conditions Dropout Voltage (VB-VOUT2) below. VIN2 =2.05V, IO2=1.0A VFB2 =0V for all conditions Dropout Voltage (VIN2-VOUT2) below. VB =3V, IO2=1.0A VB =3V, VIN2 =2.05V, Current Limit ∆VO=100mV, VFB2=0V VB =5V, VIN2 =3.3V, Minimum Load Current VFB2 =0V Thermal Regulation 30ms Pulse VB =5V, VIN2 =5V, IO2=1.0A, VFB2 =0V, TJ =25, Ripple Rejection VRIPPLE=1Vpp at 120Hz VFB2 =0V for all conditions below. VB =2.75V, Control Pin Current VIN2 =2.05V, IO2=1.0A Adjust Pin Current VB =2.75V, VIN2=2.05,VFB2=0 Symbol AP1516-ADJ AP1516-3.3V Typ. Max. Unit 1.225 1.250 1.275 V 0.2 % 1 % 1.5 1.7 V 0.5 0.6 V 1.1 60 VFB1 Output Feedback η Efficiency Conditions 4.5V < VIN1 < 22V 0.2A < ILOAD1 < 3A VOUT programmed for 3V VIN1 = 12V, ILOAD1=3A Output voltage 4.75V < VIN1 < 22V 0.2A < ILOAD1 < 3A 3.3 Efficiency VIN1 = 12V, ILOAD1=3A 76 VOUT1 η Parameter Min. A 5 10 mA 0.01 0.02 %W 70 dB 6 10 mA 50 120 µA Typ. Limit 1.23 1.193/1.18 1.267/1.28 74 3.168/3.135 3.432/3.465 Unit V VMIN VMAX % V VMIN VMAX % Specifications with boldface type are for full operating temperature range, the other type are for TJ=25ºC. Anachip Corp. www.anachip.com.tw Rev.1.1 May 23, 2005 4/10 AP1516 150KHz, 3A PWM Buck DC/DC Converter + 1A Ultra Low Drop Regulator Typical Application Circuit (1) AP1516-3.3 Fix Version VB 12V VCC1 330u VOUT1 3.3/3A VIN1 VOUT1 7/8/9/10 AP1516-3.3 4 FB1 33u VIN2 6 14 13 3 1/2/15/16 5 SR360 GND SD1 680uF VOUT2 VOUT2 12 V SENSE2 2.5V/1A R1 121 11 FB2 470uF 121 R2 IFB2 * R1 & R2 =100 ~200 ohm * VOUT2=1.235(1+R2/R1)+IFB2 *R2 (2) AP1516-ADJ Version VB VCC1 330u VOUT1 2.5/3A 680uF 33u 1K R3 1K R4 VIN1 FB1 VOUT1 SR360 14 13 4 VIN2 6 7/8/9/10 AP1516 VOUT2 12 V SENSE2 1/2/15/16 SD1 GND 1.8V/1A R1 220 3 5 VOUT2 470uF 11 FB2 R2 100 * R1 = 200 ~ 300 ohm * R4 = 1K ~ 2K * VOUT1 = 1.235*(1+R3/R4) Anachip Corp. www.anachip.com.tw Rev.1.1 May 23, 2005 5/10 AP1516 150KHz, 3A PWM Buck DC/DC Converter + 1A Ultra Low Drop Regulator Typical Performance Characteristics AP1516 Efficiency v.s. Temperature (VIN1=12V, VOUT1=3.3V, IO1=3A) 83 82 81 80 79 78 77 76 75 74 73 72 -50 -30 -10 10 30 50 70 90 110 130 150 Temperature (TA) (°C) 78 77 76 Efficiency (%) Efficiency (%) AP1516 Efficiency v.s. Temperature (VIN1=12V, VOUT1=5V, IO1=3A) 74 73 72 71 70 -50 -30 -10 10 30 50 70 90 110 130 150 Temperature (TA) (°C) AP1516 Saturation Voltage v.s. Temperature (VIN1=12V, VFB1=0V, VSD1=0) AP1516 Switch Current Limit v.s. Temperature (VIN1=12V, VFB1=0V) 1.6 Switch Current Limit (A) 5.5 1.5 Saturation Voltage (V) 75 3A 1.4 1.3 2A 1.2 1A 1.1 0.5A 1 0.9 0.8 0.7 -50 -25 0 25 50 75 100 5 4.5 4 3.5 3 -50 125 Temperature (TA) (°C) -30 -10 10 30 50 70 90 Temperature (TA) (°C) 15 14 13 12 11 10 9 8 7 6 5 60 Supply Current (uA) Supply Current (mA) AP1516 Supply Current v.s. Temperature (VIN1=12V, No Load , VSD1=0V(Switch ON), VSD1=5V(Switch OFF)) Switch ON -50 -30 -10 10 30 50 70 90 110 130 150 55 50 45 Switch OFF 40 35 30 -50 -30 -10 10 30 50 70 90 110 130 150 Temperature (TA) (°C) Temperature (TA) (°C) Anachip Corp. www.anachip.com.tw Rev.1.1 May 23, 2005 6/10 AP1516 150KHz, 3A PWM Buck DC/DC Converter + 1A Ultra Low Drop Regulator Typical Performance Characteristics (Continued) AP1516 Threshold Voltage v.s. Temperature (VIN1=12V, IO1=100mA) AP1516 ON/OFF Current v.s. ON/OFF Voltage (VIN1=12V) 1.7 10 0 -10 -20 -30 -40 -50 -60 -70 -80 -90 -100 1.6 ON/OFF Current (nA) Threshold Voltage (V) 1.5 1.4 1.3 1.2 1.1 1 0.9 Temperature (TA) (°C) 6 9 12 ON/OFF Voltage (V) AP1516 Frequency v.s. Temperature (VIN1=12V, IO1=500mA, VOUT1=5V) AP1516 Feedback Current v.s. Temperature (VIN1=12V, VOUT1=5V, VFB1=1.3V) 30 50 70 0 90 110 130 150 170 10 165 0 Feedback Current (nA) Frequency (KHz) 0.8 -50 -30 -10 10 160 155 150 145 140 -50 -30 -10 10 30 50 70 3 15 18 21 -10 -20 -30 -40 -50 -50 -30 -10 10 30 50 70 90 110 130 150 Temperature (TA) (°C) 90 110 130 150 Temperature (TA) (°C) Vout (V) AP1516 Output Voltage v.s. Temperature (VIN1=12V, IO1=3A) 3.5 3.45 3.4 3.35 3.3 3.25 3.2 3.15 3.1 3.05 3 2.95 2.9 -40 -20 0 20 40 60 80 100 120 140 160 Temperature (TA) (°C) Anachip Corp. www.anachip.com.tw Rev.1.1 May 23, 2005 7/10 AP1516 150KHz, 3A PWM Buck DC/DC Converter + 1A Ultra Low Drop Regulator Function Description of two external resistors to any voltages within the range of 1.25V to 15.5V. Another major requirement of these graphic chips is the need to switch the load current from zero to several amps in tens of nanoseconds at the processor pins, which translates to an approximately 300 to 500ns of current step at the regulator. In addition, the output voltage tolerances are also extremely tight and they include the transient response as part of the specification. The channel 2 is specifically designed to meet the fast current transient needs as well as providing an accurate initial voltage, reducing the overall system cost with the need for fewer number of output capacitors. Another feature of the device is its true remote sensing capability that allows accurate voltage setting at the load rather than at the device. Pin Functions +VIN, B This is the positive input supply for the IC switching regulator. A suitable input bypass capacitor must be present at this pin to minimize voltage transients and to supply the switching currents needed by the regulator. Ground Circuit ground. VOUT1 Internal switch. The voltage at this pin switches between (+VIN1 – VSAT) and approximately – 0.5V, with a duty cycle of approximately VOUT1 / VIN1. To minimize coupling to sensitive circuitry, the PC board copper area connected to this pin should be kept a minimum. Feedback Senses the regulated output voltage to complete the feedback loop. Output Voltage Setting The channel 2 can be programmed to any voltages in the range of 1.25V to 15.5V with the addition of R1 and R2 external resistors according to the following formula: SD Allows the switching regulator circuit to be shutdown using logic level signals thus dropping the total input supply current to approximately 150uA. Pulling this pin below a threshold voltage of approximately 1.3V turns the regulator on, and pulling this pin above 1.3V (up to a maximum of 18V) shuts the regulator down. If this shutdown feature is not needed, the SD pin can be wired to the ground pin. Vout = Vref (1+R2/R1) + IFB2 * R2 where : Vref = 1.25V & IFB2=50uA Typically Vin3 Vout2 Channel 2-ADJ Vsense2 Vin2 FB IFB2=50uA Introduction The channel 2 regulator is a extremely low dropout voltages comparable to the PNP type without the disadvantage of the extra power dissipation due to the base current associated with PNP regulators. This is done by bringing out the control pin of the regulator that provides the base current to the power NPN and connecting it to a voltage that is greater than the voltage present at the VIN2 pin. This flexibility makes the channel 2 ideal for applications where dual inputs are available such as a computer motherboard with an ATX style power supply that provides 5V and 3.3V to the board. One such application is the new graphic chip sets that require anywhere from 2.4V to 2.7V supply. The channel 2-ADJ can easily be programmed with the addition Vref R1+ R2+ The channel 2 keeps a constant 1.25V between the VSENSE pin and the FB2 pin. By placing a resistor R1 across these two pins and connecting the VSENSE and VOUT pin together, a constant current flows through R1, adding to the IFB2 current and into the R2 resistor producing a voltage equal to the (1.25/R1)*R2 + IFB2*R2. This voltage is then added to the 1.25V to set the output voltage. This is summarized in the above equation. Anachip Corp. www.anachip.com.tw Rev.1.1 May 23, 2005 8/10 AP1516 150KHz, 3A PWM Buck DC/DC Converter + 1A Ultra Low Drop Regulator Function Description (Continued) Since the minimum load current requirement of the channel 2 is 10mA, R1 is typically selected to be a 121Ω resistor so that it automatically satisfies this condition. Notice that since the IFB2 is typically in the range of 50uA it only adds a small error to the output voltage and should be considered when very precise output voltage setting is required. Thermal Considerations The SOP-16 package needs a heat sink under most conditions. The size of the heatsink depends on the input voltage, the output voltage, the load current and the ambient temperature. The AP1516 junction temperature rises above ambient temperature for a 3A load and different input and output voltages. Load Regulation Since the channel 2 has separate pins for the output (VOUT2) and the sense (VSENSE2), it is ideal for providing true remote sensing of the output voltage at the load. This means that the voltage drops due to parasitic resistance such as PCB traces between the regulator and the load are compensated for using remote sensing. Figure following shows a typical application of the channel 2 with remote sensing. Vin3 Vin2 Vout2 Vin3 Channel 2-ADJ Vsense2 Vin2 FB2 R1 For the best thermal performance, wide copper traces and generous amounts of printed circuit board copper should be used in the board layout. (Once exception to this is the output (switch) pin, which should not have large areas of copper.) Large areas of copper provide the best transfer of heat (lower thermal resistance) to the surrounding air, and moving air lowers the thermal resistance even further. RL R2 Stability The channel 2 requires the use of an output capacitor as part of the frequency compensation in order to make the regulator stable. Typical designs for the microprocessor applications use standard electrolytic capacitors with typical ESR in the range of 50 to 100mΩ and an output capacitance of 100uF to 1000uF. Fortunately as the capacitance increases, the ESR decreases resulting in a fixed RC time constant. The channel 2 takes advantage of the phenomena in making the overall regulator loop stable. For most applications a minimum of 100uF aluminum electrolytic capacitor insures both stability and good transient response. Package thermal resistance and junction temperature rise numbers are all approximate, and there are many factors that will affect these numbers. Some of these factors include board size, shape, thickness, position, location, and even board temperature. Other factors are, trace width, total printed circuit copper area, copper thickness, single or double-sided, multi-layer board and the amount of solder on the board. The effectiveness of the PC board to dissipate heat also depends on the size, quantity and spacing of other components on the board, as well as whether the surrounding air is still or moving. Furthermore, some of these components such as the catch diode will add heat to the PC board and the heat can vary as the input voltage changes. For the inductor, depending on the physical size, type of core material and the DC resistance, it could either act as a heat sink taking heat away from the board, or it could add heat to the board. Anachip Corp. www.anachip.com.tw Rev.1.1 May 23, 2005 9/10 AP1516 150KHz, 3A PWM Buck DC/DC Converter + 1A Ultra Low Drop Regulator Marking Information ( Top View ) 9 16 Logo Date Code X: Internal code WW: Xth week:01~52 YY: Year: "01" = 2001 "02" = 2002 AP1516-XX YY WW X Part No. Output Type: Blank: Adjustable 33:3.3V 1 8 ~ SOP-16L Package Information E H Package Type: SOP-16L ? L VIEW "A" D 7o(4X) y Symbol A A1 A2 B C D E e H L Θ Dimensions In Millimeters Min. Nom. Max. 1.40 1.60 1.75 0.10 0.25 1.30 1.45 1.50 0.33 0.41 0.51 0.19 0.20 0.25 9.80 9.90 10.00 3.80 3.90 4.00 1.27 5.80 6.00 6.20 0.38 0.71 1.27 0 8 C B A1 e 7o(4X) A A2 0.015x45o VIEW "A" Dimensions In Inches Min. Nom. Max. 0.055 0.063 0.069 0.040 0.010 0.051 0.057 0.059 0.013 0.016 0.020 0.0075 0.008 0.0098 0.386 0.390 0.394 0.150 0.154 0.157 0.050 0.228 0.236 0.244 0.015 0.028 0.050 0 8 Anachip Corp. www.anachip.com.tw Rev.1.1 May 23, 2005 10/10