锂电池3.3-4.3V升压5V1A，96高效率，低成本方案.pdf-资料库

PS7516 PS7516 Description Description The PS7516 is a high efficiency, fixed frequency The PS7516 is a high efficiency, fixed frequency 1MHz, current mode PWM boost DC/DC converter 1MHz, current mode PWM boost DC/DC converter which could operate battery such as input voltage which could operate battery such as input voltage down to 2.5V. The converter output voltage can be down to 2.5V. The converter output voltage can be adjusted to a maximum of 5.25V by an external adjusted to a maximum of 5.25V by an external resistor divider. Besides the converter includes a resistor divider. Besides the converter includes a 0.08Ω N-channel MOSFET switch and 0.12Ω 0.08Ω N-channel MOSFET switch and 0.12Ω P-channel synchronous rectifier. So no external P-channel synchronous rectifier. So no external Schottky diode is required and could get better Schottky diode is required and could get better efficiency near 93%. efficiency near 93%. The converter is based on a fixed frequency, current The converter is based on a fixed frequency, current mode, pulse-width-modulation PWM controller that mode, pulse-width-modulation PWM controller that goes automatically into PSM mode at light load. goes automatically into PSM mode at light load. When converter operation into discontinuous mode, When converter operation into discontinuous mode, the reduce the reduce interference and radiated electromagnetic energy. interference and radiated electromagnetic energy. internal anti-ringing internal anti-ringing switch will switch will The PS7516 is available in a space-saving SOT-23-6 The PS7516 is available in a space-saving SOT-23-6 package for portable application. package for portable application. Pin Assignments Pin Assignments SOT SOT 23- 6 23- 6 - - . . Features Features Fixed 1MHz Switching Frequency  High Efficiency up to 93%  High Efficiency up to 93%  Low RDS(ON) Integrated Power MOSFET  Low RDS(ON) Integrated Power MOSFET  NMOS 80mΩ / PMOS120mΩ  NMOS 80mΩ / PMOS120mΩ  Wide Input Voltage Range: 2.5V to 5.5V  Wide Input Voltage Range: 2.5V to 5.5V  Fixed 1MHz Switching Frequency   Low-Power Mode for Light Load Conditions  Low-Power Mode for Light Load Conditions  ±2.0% Voltage Reference Accuracy  ±2.0% Voltage Reference Accuracy  PMOS Current Limit for Short Circuit Protection  PMOS Current Limit for Short Circuit Protection  Low Quiescent Current  Low Quiescent Current  Output Ripple under 200mV. (Scope Full  Output Ripple under 200mV. (Scope Full Bandwidth) Bandwidth)  Fast Transient Response  Fast Transient Response  Built-In Soft Start Function  Built-In Soft Start Function  Over-Temperature Protection with Auto Recovery  Over-Temperature Protection with Auto Recovery  Output Overvoltage Protection  Output Overvoltage Protection  Space-Saving SOT-23-6 Package  Space-Saving SOT-23-6 Package Applications Applications  Portable Power Bank  Portable Power Bank  Wireless Equipment  Wireless Equipment  Handheld Instrument  Handheld Instrument  GPS Receiver  GPS Receiver VIN VIN OUT EN OUT EN 6 6 1 1 5 5 2 2 4 4 3 3 LX LX GND GND FB FB Figure 1. Pin Assignment of PS7516 Figure 1. Pin Assignment of PS7516 Functional Pin Description Functional Pin Description Pin Name Pin Name Pin No. Pin No. Pin Function Pin Function EN EN GND GND LX LX VIN VIN OUT OUT FB FB 4 4 2 2 1 1 6 6 5 5 3 3 Logic Controlled Shutdown Input. Logic Controlled Shutdown Input. Ground Pin. Ground Pin. Power Switching Connection. Connect LX to the inductor and output rectifier. Power Switching Connection. Connect LX to the inductor and output rectifier. Power Supply Input Pin. Power Supply Input Pin. Output of the Synchronous Rectifier. Output of the Synchronous Rectifier. Voltage Feedback Input Pin. Voltage Feedback Input Pin. 1 1

PS7516 PS7516 . . 85T 85T Block Diagram Block Diagram VIN VIN LX LX EN EN On/Off On/Off Control Control ANTI-RING ANTI-RING PMOS PMOS NMOS NMOS OUT OUT Body-Diode Body-Diode Switch Switch Isense/Current Limit Isense/Current Limit Slope Comp. Slope Comp. Anti-Reverse Anti-Reverse Comparator Comparator COMP COMP OTP OTP Error Error Amp Amp Bandgap Bandgap Reference Reference FB FB PWM PWM Control Control Logic Logic PFM PFM Control Control OSC OSC OVP OVP UVLO UVLO VIN VIN GND GND Figure 3. Block Diagram of PS7516 Figure 3. Block Diagram of PS7516 85T 85T 2 2

PS7516 PS7516 Typical Application Circuit Typical Application Circuit VIN VIN 2.5V to 5.5V 2.5V to 5.5V C1 C1 10μF 10μF C2 C2 0.1μF 0.1μF L1 L1 10μH 10μH 6 6 2 2 4 4 VIN VIN LX LX PS7516 PS7516 GND GND OUT OUT EN EN FB FB 1 1 5 5 3 3 C4, C6 C6 0.1μF 0.1μF C5 C , C5 22μF 22μF ON ON OFF OFF Figure 2. Typical Application Circuit Figure 2. Typical Application Circuit VOUT VOUT 5V/1A 5V/1A R1 R1 525K 525K R2 R2 100K 100K 85T 85T Absolute Maximum Ratings (Note 1) Absolute Maximum Ratings (Note 1) ● Supply Voltage VIN --------------------------------------------------------------------------------------------- -0.3V to +6.5V ● Supply Voltage VIN --------------------------------------------------------------------------------------------- -0.3V to +6.5V ● LX Voltage VLX -------------------------------------------------------------------------------------------------- -0.3V to +6.5V ● LX Voltage VLX -------------------------------------------------------------------------------------------------- -0.3V to +6.5V ● All Other Pins Voltage ----------------------------------------------------------------------------------------- -0.3V to +6.5V ● All Other Pins Voltage ----------------------------------------------------------------------------------------- -0.3V to +6.5V ● Maximum Junction Temperature (TJ) --------------------------------------------------------------------- +150°C ● Maximum Junction Temperature (TJ) --------------------------------------------------------------------- +150°C ● Storage Temperature (TS) ----------------------------------------------------------------------------------- -65°C to +150°C ● Storage Temperature (TS) ----------------------------------------------------------------------------------- -65°C to +150°C ● Lead Temperature (Soldering, 10sec.) ------------------------------------------------------------------- +260°C ● Lead Temperature (Soldering, 10sec.) ------------------------------------------------------------------- +260°C ● Package Thermal Resistance (θJA) ● Package Thermal Resistance (θJA) SOT-23-6 ---------------------------------------------------------------------------------------------- +250°C/W SOT-23-6 ---------------------------------------------------------------------------------------------- +250°C/W ● Package Thermal Resistance (θJC) ● Package Thermal Resistance (θJC) SOT-23-6 ---------------------------------------------------------------------------------------------- +130°C/W SOT-23-6 ---------------------------------------------------------------------------------------------- +130°C/W Note 1：Stresses beyond this listed under “Absolute Maximum Ratings" may cause permanent damage to the device. Note 1：Stresses beyond this listed under “Absolute Maximum Ratings" may cause permanent damage to the device. Recommended Operating Conditions Recommended Operating Conditions ● Supply Voltage VIN --------------------------------------------------------------------------------------------- +2.5V to +5.5V ● Supply Voltage VIN --------------------------------------------------------------------------------------------- +2.5V to +5.5V ● Output Voltage Range ---------------------------------------------------------------------------------------- up to +5.25V ● Output Voltage Range ---------------------------------------------------------------------------------------- up to +5.25V ● Operation Temperature Range ------------------------------------------------------------------------------ -40°C to +85°C ● Operation Temperature Range ------------------------------------------------------------------------------ -40°C to +85°C 3 3

PS7516 PS7516 Electrical Characteristics Electrical Characteristics (VIN=3.3V, TA=25°C, unless otherwise specified.) (VIN=3.3V, TA=25°C, unless otherwise specified.) 85T 85T Parameter Parameter Symbol Symbol Conditions Conditions Min Min Typ Typ Max Max Unit Unit VIN Input Supply Voltage VIN Input Supply Voltage VIN VIN 2.5 2.5 5.5 5.5 Input UVLO Threshold Input UVLO Threshold Under Voltage Lockout Threshold Under Voltage Lockout Threshold Hysteresis Hysteresis VIN Supply Current (Switching) VIN Supply Current (Switching) VIN Supply Current (No switching) VIN Supply Current (No switching) VIN Rising VIN Rising VIN Falling VIN Falling VIN=3.3V, VFB=0.8V VIN=3.3V, VFB=0.8V Measure VIN Measure VIN VFB=1V VFB=1V 1.85 1.85 0.2 0.2 300 300 500 500 25 25 V V V V V V μA μA μA μA Feedback Voltage Feedback Voltage VFB VFB 2.5V≦VIN≦5.5V 2.5V≦VIN≦5.5V 0.784 0.784 0.8 0.8 0.816 0.816 V V High-Side PMOSFET RDS(ON) High-Side PMOSFET RDS(ON) Low-Side NMOSFET RDS(ON) Low-Side NMOSFET RDS(ON) High-Side MOSFET Leakage High-Side MOSFET Leakage Current Current ILX(leak) ILX(leak) VLX=5.5V, VOUT=0V VLX=5.5V, VOUT=0V Low-Side MOSFET Leakage Current Low-Side MOSFET Leakage Current VLX=5.5V VLX=5.5V Oscillation Frequency Oscillation Frequency FOSC FOSC Switch Current Limit Switch Current Limit Short Circuit Trip Point Short Circuit Trip Point Short Circuit Current Limit Short Circuit Current Limit VIN=3.3V VIN=3.3V Monitored FB voltage Monitored FB voltage VIN = 3.3V VIN = 3.3V Maximum Duty Cycle Maximum Duty Cycle DMAX DMAX VIN=3.3V VIN=3.3V Line Regulation Line Regulation Load Regulation Load Regulation OVP Threshold Voltage on OUT Pin OVP Threshold Voltage on OUT Pin OVP Threshold Hysteresis OVP Threshold Hysteresis Internal Soft-Start Time Internal Soft-Start Time EN Input Low Voltage EN Input Low Voltage EN Input High Voltage EN Input High Voltage VEN (L) VEN (L) VEN (H) VEN (H) VIN=2.5V to 5.5V, IOUT=100mA VIN=2.5V to 5.5V, IOUT=100mA IOUT=0A to 1A IOUT=0A to 1A EN Input Current EN Input Current IEN IEN VIN=3.3V VIN=3.3V Thermal Shutdown Threshold Thermal Shutdown Threshold (Note 2) (Note 2) Thermal Shutdown Hysteresis Thermal Shutdown Hysteresis Note 2：Not production tested. Note 2：Not production tested. TSD TSD 450 2.5 2.5 85 85 1.4 1.4 1000 KHz KHz 120 120 80 80 0.3 0.3 50 50 90 90 0.5 0.5 6 6 500 500 1 1 2 2 150 150 30 30 10 10 10 10 mΩ mΩ mΩ mΩ μA μA μA μA 1 1 3 3 0.4 0.4 A A V V mA mA % % % % % % V V mV mV ms ms V V V V μA μA °C °C °C °C 4 4

PS7516 PS7516 Application Information Application Information Controller Circuit Controller Circuit Device Enable Device Enable 85T 85T constant constant to regulate to regulate The device is based on a current-mode control The device is based on a current-mode control topology and uses a topology and uses a frequency frequency pulse-width modulator the output the output pulse-width modulator voltage. The controller limits the current through voltage. The controller limits the current through the power switch on a pulse by pulse basis. The the power switch on a pulse by pulse basis. The current sensing circuit is integrated in the device; current sensing circuit is integrated in the device; therefore, no additional components are required. therefore, no additional components are required. Due to the nature of the boost converter topology Due to the nature of the boost converter topology used here, the peak switch current is the same as used here, the peak switch current is the same as the peak inductor current, which will be limited by the peak inductor current, which will be limited by the integrated current limiting circuits under normal the integrated current limiting circuits under normal operating conditions. operating conditions. Synchronous Rectifier Synchronous Rectifier transistor transistor The device integrates an N-channel and a P- The device integrates an N-channel and a P- channel MOSFET realize a channel MOSFET realize a synchronous rectifier. There is no additional synchronous rectifier. There is no additional Schottky diode required. Because the device Schottky diode required. Because the device uses a integrated low RDS(ON) PMOS switch for uses a integrated low RDS(ON) PMOS switch for rectification, the power conversion efficiency rectification, the power conversion efficiency reaches 93%. reaches 93%. to to A special circuit is applied to disconnect the load A special circuit is applied to disconnect the load from the input during shutdown of the converter. from the input during shutdown of the converter. In conventional synchronous rectifier circuits, the In conventional synchronous rectifier circuits, the backgate diode of the high-side PMOS is forward backgate diode of the high-side PMOS is forward biased in shutdown and allows current flowing from biased in shutdown and allows current flowing from the battery to the output. This device, however, the battery to the output. This device, however, uses a special circuit to disconnect the backgate uses a special circuit to disconnect the backgate diode of the high-side PMOS and so, disconnects diode of the high-side PMOS and so, disconnects the output circuitry from the source when the the output circuitry from the source when the regulator is not enabled (EN=low). regulator is not enabled (EN=low). PSM Mode PSM Mode The PS7516 is designed for high efficiency over The PS7516 is designed for high efficiency over wide output current range. Even at light load, the wide output current range. Even at light load, the efficiency stays high because the switching losses efficiency stays high because the switching losses of the converter are minimized by effectively of the converter are minimized by effectively reducing the switching frequency. The controller reducing the switching frequency. The controller will enter a power saving mode if certain conditions will enter a power saving mode if certain conditions are met. In this mode, the controller only switches are met. In this mode, the controller only switches on the transistor if the output voltage trips below a on the transistor if the output voltage trips below a set threshold voltage. It ramps up the output set threshold voltage. It ramps up the output voltage with one or several pulses, and goes again voltage with one or several pulses, and goes again into PSM mode once the output voltage exceeds a into PSM mode once the output voltage exceeds a set threshold voltage. set threshold voltage. The device will be shut down when EN is set to The device will be shut down when EN is set to GND. In this mode, the regulator stops switching, GND. In this mode, the regulator stops switching, all internal control circuitry including the low-battery all internal control circuitry including the low-battery comparator will be switched off, and the load will be comparator will be switched off, and the load will be disconnected from the input (as described in above disconnected from the input (as described in above synchronous rectifier section). This also means synchronous rectifier section). This also means that the output voltage may drop below the input that the output voltage may drop below the input voltage during shutdown. voltage during shutdown. The device is put into operation when EN is set The device is put into operation when EN is set high. During start-up of the converter, the duty high. During start-up of the converter, the duty cycle is limited in order to avoid high peak currents cycle is limited in order to avoid high peak currents drawn from the battery. The limit is set internally drawn from the battery. The limit is set internally by the current limit circuit. by the current limit circuit. Anti-Ringing Switch Anti-Ringing Switch The device integrates a circuit which removes The device integrates a circuit which removes the ringing that typically appears on the SW node the ringing that typically appears on the SW node when the converter enters the discontinuous when the converter enters the discontinuous current mode. In this case, the current through current mode. In this case, the current through the inductor ramps to zero and the integrated the inductor ramps to zero and the integrated PMOS switch turns off to prevent a reverse PMOS switch turns off to prevent a reverse current from the output capacitors back to the current from the output capacitors back to the battery. Due to remaining energy that is stored battery. Due to remaining energy that is stored in parasitic components of the semiconductors in parasitic components of the semiconductors and the inductor, a ringing on the SW pin is and the inductor, a ringing on the SW pin is induced. The integrated anti-ringing switch induced. The integrated anti-ringing switch clamps this voltage internally to VIN; therefore, clamps this voltage internally to VIN; therefore, dampens this ringing. dampens this ringing. Adjustable Output Voltage Adjustable Output Voltage The accuracy of the output voltage is determined by The accuracy of the output voltage is determined by the accuracy of the internal voltage reference, the the accuracy of the internal voltage reference, the controller topology, and the accuracy of the external controller topology, and the accuracy of the external resistor. The reference voltage has an accuracy of resistor. The reference voltage has an accuracy of ± 2%. The controller switches between fixed ± 2%. The controller switches between fixed frequency and PSM mode, depending on load frequency and PSM mode, depending on load current. The tolerance of the resistors in the current. The tolerance of the resistors in the feedback divider determines feedback divider determines total system total system accuracy. accuracy. the the Design Procedure Design Procedure The PS7516 boost converter family is intended for The PS7516 boost converter family is intended for systems that are powered by a single-cell Ion systems that are powered by a single-cell Ion battery with a typical terminal voltage between 3V battery with a typical terminal voltage between 3V to 4.2V. to 4.2V. 5 5

PS7516 PS7516 Application Information (Continued) Application Information (Continued) (1) Programming the Output Voltage (1) Programming the Output Voltage (3) Capacitor Selection (3) Capacitor Selection 85T 85T The output voltage of the PS7516 can be The output voltage of the PS7516 can be adjusted with an external resistor divider. The adjusted with an external resistor divider. The typical value of the voltage on the FB pin is typical value of the voltage on the FB pin is 800mV in fixed frequency operation. The 800mV in fixed frequency operation. The maximum allowed value for the output voltage is maximum allowed value for the output voltage is 5.5V. The current through the resistive divider 5.5V. The current through the resistive divider should be about 100 times greater than the should be about 100 times greater than the current into the FB pin. The typical current into current into the FB pin. The typical current into the FB pin is 0.01µA, and the voltage across R2 the FB pin is 0.01µA, and the voltage across R2 is typically 800mV. Based on those two values, is typically 800mV. Based on those two values, the recommended value for R2 is in the range of the recommended value for R2 is in the range of 800kΩ in order to set the divider current at 1µA. 800kΩ in order to set the divider current at 1µA. From that, the value of resistor R1, depending From that, the value of resistor R1, depending on the needed output voltage (VO), can be on the needed output voltage (VO), can be calculated using Equation 1. calculated using Equation 1. R1 R2 O T R1 R2 O T F F -1 800kΩ O T -1 800kΩ O T 800m 800m -1 …..(1) -1 …..(1) (2) Inductor Selection (2) Inductor Selection A boost converter normally requires two main A boost converter normally requires two main passive components for storing energy during passive components for storing energy during the conversion. A boost inductor is required the conversion. A boost inductor is required and a storage capacitor at the output. To select and a storage capacitor at the output. To select the boost inductor, it is recommended to keep the boost inductor, it is recommended to keep the possible peak inductor current below the the possible peak inductor current below the current limit threshold of the power switch in the current limit threshold of the power switch in the chosen configuration. chosen configuration. The second parameter for choosing the inductor The second parameter for choosing the inductor is the desired current ripple in the inductor. is the desired current ripple in the inductor. Normally, it is advisable to work with a ripple of Normally, it is advisable to work with a ripple of less than 20% of the average inductor current. less than 20% of the average inductor current. A smaller ripple reduces the magnetic hysteresis A smaller ripple reduces the magnetic hysteresis losses in the inductor, as well as output voltage losses in the inductor, as well as output voltage ripple and EMI. But in the same way, regulation ripple and EMI. But in the same way, regulation time at load changes rises. In addition, a larger time at load changes rises. In addition, a larger inductor increases the total system cost. With inductor increases the total system cost. With those parameters, it is possible to calculate the those parameters, it is possible to calculate the value for the inductor by using Equation 2. value for the inductor by using Equation 2. N O T- N N O T- N O T O T …..(2) …..(2) Parameter is the switching requency and Δ L is Parameter is the switching requency and Δ L is the ripple current in the inductor, i.e, 20% x IL. the ripple current in the inductor, i.e, 20% x IL. With this calculated value and currents, it is With this calculated value and currents, it is possible to choose a suitable inductor. Care must possible to choose a suitable inductor. Care must be taken that load transients and losses in the be taken that load transients and losses in the circuit can lead to higher currents. Also, the circuit can lead to higher currents. Also, the losses losses inductor caused by magnetic inductor caused by magnetic hysteresis losses and copper losses are a major hysteresis losses and copper losses are a major parameter for total circuit efficiency. parameter for total circuit efficiency. the the in in The major parameter necessary to define the The major parameter necessary to define the output capacitor is the maximum allowed output output capacitor is the maximum allowed output voltage ripple of the converter. This ripple is voltage ripple of the converter. This ripple is determined by two parameters of the capacitor, determined by two parameters of the capacitor, the capacitance and the ESR. It is possible to the capacitance and the ESR. It is possible to calculate the minimum capacitance needed for calculate the minimum capacitance needed for the defined ripple, supposing that the ESR is zero, the defined ripple, supposing that the ESR is zero, by using Equation 3. by using Equation 3. M N M N O T O T- N O T O T- N O T O T …..(3) …..(3) Parameter f is the switching frequency and △V is Parameter f is the switching frequency and △V is the maximum allowed ripple. the maximum allowed ripple. The total ripple is larger due to the ESR of the The total ripple is larger due to the ESR of the output capacitor. This additional component of output capacitor. This additional component of the ripple can be calculated using Equation 4. the ripple can be calculated using Equation 4. ESR O T RESR …..(4) ESR O T RESR …..(4) The total ripple is the sum of the ripple caused by The total ripple is the sum of the ripple caused by the capacitance and the ripple caused by the ESR the capacitance and the ripple caused by the ESR of the capacitor. It is possible to improve the of the capacitor. It is possible to improve the design by enlarging the capacitor or using smaller design by enlarging the capacitor or using smaller capacitors in parallel to reduce the ESR or by using capacitors in parallel to reduce the ESR or by using better capacitors with lower ESR, like ceramics. better capacitors with lower ESR, like ceramics. Tradeoffs must be made between performance and Tradeoffs must be made between performance and costs of the converter circuit. costs of the converter circuit. A 10µF input capacitor A 10µF input capacitor is recommended to is recommended to improve transient behavior of the regulator. A improve transient behavior of the regulator. A ceramic or tantalum capacitor with a 100nF in ceramic or tantalum capacitor with a 100nF in parallel placed close to the IC is recommended. parallel placed close to the IC is recommended. 6

85T 85T PS7516 PS7516 . . Application Information (Continued) Application Information (Continued) Layout Considerations Layout Considerations As for all switching power supplies, the layout is an As for all switching power supplies, the layout is an important step in the design, especially at high peak important step in the design, especially at high peak currents and high switching frequencies. If the currents and high switching frequencies. If the layout is not carefully done, the regulator could layout is not carefully done, the regulator could show stability problems as well as EMI problems. show stability problems as well as EMI problems. Therefore, use wide and short traces for the main Therefore, use wide and short traces for the main current path as indicated in bold in Figure 4. The current path as indicated in bold in Figure 4. The input capacitor, output capacitor and the inductor input capacitor, output capacitor and the inductor should be placed as close to the IC as possible. should be placed as close to the IC as possible. Use a common ground node as shown in Figure 4 Use a common ground node as shown in Figure 4 to minimize the effects of ground noise. The to minimize the effects of ground noise. The feedback divider should be placed as close to the IC feedback divider should be placed as close to the IC as possible. as possible. VIN VIN VOUT VOUT C1 C1 C C 2 2 6 6 5 5 4 4 C C 4 4 C C 6 6 C3 C3 C5 C5 L1 L1 GND GND GND GND LX LX 1 1 2 2 3 3 R2 R2 R1 R1 Figure 4. Layout Diagram Figure 4. Layout Diagram 7 7

PS7516 PS7516 Outline Information Outline Information SOT-23-6 Package (Unit: mm) SOT-23-6 Package (Unit: mm) 85T 85T SYMBOLS SYMBOLS UNIT UNIT A A A1 A1 A2 A2 B B D D E E E1 E1 e e e1 e1 L L DIMENSION IN MILLIMETER DIMENSION IN MILLIMETER MIN MIN 0.90 0.90 0.00 0.00 0.90 0.90 0.30 0.30 2.80 2.80 2.60 2.60 1.50 1.50 0.90 0.90 1.80 1.80 0.30 0.30 MAX MAX 1.45 1.45 0.15 0.15 1.30 1.30 0.50 0.50 3.00 3.00 3.00 3.00 1.70 1.70 1.00 1.00 2.00 2.00 0.60 0.60 Note：Followed From JEDEC MO-178-C. Note：Followed From JEDEC MO-178-C. Carrier Dimensions Carrier Dimensions 8 8

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