NDP1331KC

业务联系：１３６０２６３２４２７李先生 NDP1331KC 2.8A,34V High Efficiency Synchronous Step-Down DC/DC Converter Features Description NDP1331KC is a high  Wide VIN Range : 7V to 32V efficiency, Z monolithic synchronous step-down DC/DC  2.8A Continuous Output Current converter utilizing a constant frequency,  Up to 93% Efficiency  CC/CV Mode Control average current mode control architecture.  100% Max Duty Cycle Capable of delivering up to 2.8A continuous  Built in Adjustable Line-Compensation load with excellent line and load regulation.  Adjustable Output Voltages The device operates from an input voltage  +/-1.5% Output Voltage Accuracy range of 7V to 32V and provides an 子  +/- 5% Current Limit Accuracy. adjustable output voltage from 3.6V to 25V.  Integrated 75mΩ High Side Switch The NDP1331KC features short circuit system reliability. The internal soft-start  Programable Frequency(130KHz~300KHz)  Burst Mode Operation at Light Load  Internal loop Compensation 微 avoids input inrush current during startup.  Integrated 35mΩ Low Side Switch 电 and thermal protection circuits to increase The NDP1331KC require a minimum number of external components. and a wide 思 reliability 成 array of protection features to enhance  Internal Soft Start  Available in SOP8 Package Applications  Car Charger  Rechargeable Portable Devices  Networking Systems  Distributed Power Systems Typical Application Note: When using a solid or ceramic input Cap, It is recommended to parallel a TVS diode. Nanjing Deep-Pool Microelectronics Co., Ltd. May-2020 Rev1.4 Page1-9 业务联系：１３６０２６３２４２７李先生 NDP1331KC Absolute Maximum Ratings (at TA = 25°C) Characteristics VIN to GND SW to GND FB, FS to GND CSP, CSN to GND Junction to Ambient Thermal Resistance Operating Junction Temperature Storage Junction Temperature Thermal Resistance from Junction to case Thermal Resistance from Junction to ambient Symbol Rating Unit θJC θJA -0.3 to 34 -0.3 to VIN+0.3 -0.3 to +6 -0.3 to 25 105 -40 to 150 -55 to 150 45 90 V V V V °C/W °C °C °C/W °C/W Pin Function And Descriptions VFB 2 CSP 3 CSN 4 VIN 5,6 SW 7 FS 8 GND 电 1 Description Feedback Of Output Voltage Positive Pole of Current Sense Negative Pole1 of Current Sense Power Input Positive Pole Switching, Connected With a Inductor Connect a Resistor to GND for Frequency Config Ground Top Marking 思 NDP1331 K C 成 Order information Order Information 子 NAME 微 PIN Pin NO. C:8 Package K: SOP Product Number Nanjing Deep-Pool Microelectronics Co., Ltd. DY: Year (D8=2018,D9=2019,…) WW: Weekly (01-53) X : Internal ID Code May-2020 Rev1.4 Page2-9 业务联系：１３６０２６３２４２７李先生 NDP1331KC Electrical Characteristics TJ = 25°C. VIN = 12V, unless otherwise noted Characteristics Symbol Input Voltage VIN UVLO Voltage VUVLO Conditions Min Typ Max 7 - 32 UVLO Hysteresis Input over voltage Vovp protect Units V 5.8 V 1.4 V 32 V ICCQ VFB = 1.2V, no switch - 1300 - uA Standby Current ISB No Load - 1.7 2.2 mA FB Reference Voltage VFB 0.985 1 1.015 V VFB bias Current IFB 0.2 uA Current Sense AMP VCS 63 mV Switching Frequency FSW FS Shut down VFSEN Minimum On-Time ILIM VFB short protect VFBSCP Hicup Interval 电 connect 470K resister - 60 130 KHz 300 KHz 0.3 0.4 V 100 - % 250 - ns 3.5 Thiccup Tss 思 Soft start Time 57 成 Current Limit FS Floating 微 Maximum Duty Cycle CSP-CSN 子 Quiescent Current A 0.6 V 500 mS 2 mS RDSON Of Power High side Temp=25℃ 75 mΩ MOS Low side Temp=25℃ 35 mΩ 150 °C Thermal Regulation Thermal shutdown Temp Thermal Shutdown Hysteresis TTR TSD - 165 - °C TSH - 30 - °C Nanjing Deep-Pool Microelectronics Co., Ltd. May-2020 Rev1.4 Page3-9 业务联系：１３６０２６３２４２７李先生 NDP1331KC 微 电 子 Block Diagram Operation monolithic, converter 成 The NDP1331KC is a high efficiency, synchronous utilizing a step-down constant DC/DC frequency, 思 average current mode control architecture. Average current mode control enables fast and precise control of the output current. It operates through a wide VIN range and regulates with low quiescent current. An error amplifier compares the output voltage with a internal reference voltage of 1.0V and adjusts the peak inductor current accordingly. overvoltage and undervoltage comparators will turn off the regulator. Main Control Loop During normal operation, the internal top power switch (P-channel MOSFET) is turned on at the beginning of each clock cycle, causing the Nanjing Deep-Pool Microelectronics Co., Ltd. inductor current to increase. The sensed inductor current is then delivered to the average current amplifier, whose output is compared with a saw-tooth ramp. When the exceeds the vduty voltage, voltage the PWM comparator trips and turns off the top power MOSFET. After the top power MOSFET turns off, the synchronous power switch (N-channel MOSFET) turns on, causing the inductor current to decrease. The bottom switch stays on until the beginning of the next clock cycle, unless the reverse current limit is reached and the reverse current comparator trips. In closed-loop operation, the average current amplifier creates an average current loop that forces the average sensed current signal to be equal to the internal ITH voltage. Note that the DC gain and compensation of this average current loop is automatically adjusted to maintain an optimum May-2020 Rev1.4 Page4-9 业务联系：１３６０２６３２４２７李先生 NDP1331KC current-loop response. The error amplifier adjusts the ITH voltage by comparing the divided-down output voltage (VFB) with a 1.0V reference voltage. If the load current changes, the error amplifier adjusts the average inductor current as needed to keep the output voltage in regulation. Low Current operation Rlow（K） 100 160 360 470 820 1200 25 39 91 120 200 300 table 1 Cable Drop compensation (mV) 130 200 500 680 1200 1800 Frequency Selection and Shutdown discontinuous-conduction modes (DCMs) are available to control the operation of the NDP1331KC at low currents. Burst Mode operation automatically switch from continuous operation to the Burst Mode operation when the The switching frequency of the NDP1331KC can be programmed through an external resistor between 130kHz and 300 kHz，Floating this pin set the switching frequency to 130K, an external 子 The RFB(UPER)（K） resistor can set the frequency up to 300KHz。the load current is low switching frequency is set using the FS pins as 电 VIN Overvoltage Protections In order to protect the internal power MOSFET devices against transient voltage 微 spikes, the NDP1331KC constantly monitors the VIN pin for an overvoltage condition. When VIN rises above 32V, the regulator suspends 成 operation by shutting off both power MOSFETs. Once VIN drops below 31V, the regulator 思 immediately resumes normal operation. The regulator executes its soft-start function when exiting an overvoltage condition. Cable Drop Compensation shown in Table 1: FS Resistor(KΩ) Frequency(KHz) Floating 130K 2000 180K 1000 220K 470 300K When the FS pin is below 0.3V, the NDP1331KC enters a low current shutdown state, reducing the DC supply current to 1.3mA. Applications Information Input Capacitor (CIN) Selection The input capacitance CIN is needed to filter the Due to the resistive of charger’s output square wave current at the drain of the top Cable, The NDP1331KC built in a simple user power MOSFET. To prevent large voltage programmable cable voltage drop compensation transients from occurring, a low ESR input using the impedance at the FB pin. Choose the capacitor sized for the maximum RMS current proper resistance values for charger’s output should be used. The maximum RMS current is cable as show in table 1: given by: Rup is the upper resistor the resistors divider net Rlow is the lower resistor the resistors divider net This formula has a maximum at VIN = 2VOUT, where: IRMS ≅ IOUT/2 Nanjing Deep-Pool Microelectronics Co., Ltd. May-2020 Rev1.4 Page5-9 业务联系：１３６０２６３２４２７李先生 NDP1331KC This simple worst-case condition is commonly density than other types. Tantalum capacitors used for design because even significant have the highest capacitance density but it is deviations do not offer much relief. Note that important to only use types that have been ripple surge tested for use in switching power supplies. current ratings from capacitor manufacturers are often based on only 2000 Aluminum hours of life which makes it advisable to further significantly higher ESR, but can be used derate the capacitor, or choose a capacitor in cost-sensitive applications provided that rated at a higher temperature than required. consideration is given to ripple current ratings Several capacitors may also be paralleled to and long-term reliability. Ceramic capacitors meet size or height requirements in the design. have excellent low ESR characteristics and For low input voltage applications, sufficient bulk small footprints. input capacitance is needed to minimize capacitors have Inductor Selection 子 transient effects during output load changes. electrolytic Given the desired input and output voltages, the Output Capacitor (COUT) Selection inductor The selection of COUT is determined by the determine the ripple current: and operating frequency 电 value effective series resistance (ESR) that is required to minimize voltage ripple and load step 微 transients as well as the amount of bulk capacitance that is necessary to ensure that the control loop is stable. Loop stability can be 成 checked by viewing the load transient response. 思 The output ripple, △VOUT, is determined by: The output ripple is highest at maximum input voltage since △IL increases with input Lower ripple current reduces power losses in the inductor, ESR losses in the output capacitors and output voltage ripple. Highest efficiency operation is obtained at low frequency with small ripple current. However, achieving this requires a large inductor. There is a trade-off between component size, efficiency and operating frequency. A reasonable starting point is to choose a ripple current that is about voltage. Multiple capacitors placed in parallel 40% of IOUT(MAX). To guarantee that ripple may be needed to meet the ESR and RMS current does not exceed a specified maximum, current handling requirements. Dry tantalum, the inductance should be chosen according to: special polymer, aluminum electrolytic, and ceramic capacitors are all available in surface mount packages. Special polymer capacitors are very low ESR but have lower capacitance Once the value for L is known, the type of selected. As the inductance or frequency inductor must be selected. Actual core loss is increases, core losses decrease. Unfortunately, independent of core size for a fixed inductor increased inductance requires more turns of value, but is very dependent on the inductance wire and therefore copper losses will increase. Nanjing Deep-Pool Microelectronics Co., Ltd. May-2020 Rev1.4 Page6-9 业务联系：１３６０２６３２４２７李先生 NDP1331KC Efficiency Considerations increases Ferrite designs have very low core The percent efficiency of a switching regulator is losses and are preferred at high switching equal to the output power divided by the input frequencies, so design goals can concentrate power times 100%. It is often useful to analyze on copper loss and preventing saturation. individual losses to determine what is limiting Ferrite core material saturates “hard”, which the efficiency and which change would produce means that inductance collapses abruptly when the most improvement. Percent efficiency can the peak design current is exceeded. This be expressed as: % Efficiency = 100% – (Loss1 results in an abrupt increase in inductor ripple + Loss2 + …) where Loss1, Loss2, etc. are the current and consequent output voltage ripple. individual losses as a percentage of input power. Do not allow the core to saturate! Although all dissipative elements in the circuit Different core materials and shapes will change produce losses, three main sources usually the size/current and price/current relationship of account for most of the losses in NDP1331KC an inductor. Toroid or shielded pot cores in circuits: 1) I2R losses, 2) switching and biasing ferrite or permalloy materials are small and don’t losses, 3) other losses. 电 子 Copper losses also increase as frequency Thermal Conditions than powdered iron core inductors with similar In a majority of applications, the NDP1331KC characteristics. The choice of which style does not dissipate much heat due to its high inductor to use mainly depends on the price efficiency and low thermal resistance. However, versus size requirements and any radiated in applications where the NDP1331KC is field/EMI requirements. New designs for surface running at high ambient temperature, high VIN, mount inductors are available from Coilcraft, and maximum output current load, the heat Toko, Vishay, NEC/Tokin, TDK and Würth dissipated may exceed the maximum junction temperature 思 Electronik. 成 微 radiate much energy, but generally cost more of the part. If the junction analysis is to determine whether the power temperature reaches approximately 165°C, both dissipated exceeds the maximum junction power switches will be turned off until the temperature of the part. If the application calls temperature drops about 30°C cooler To avoid for a higher ambient temperature and/or higher the NDP1331KC from exceeding the maximum switching frequency, care should be taken to junction temperature, the user will need to do reduce the temperature rise of the part by using some thermal analysis. The goal of the thermal a heat sink or forced air flow. Nanjing Deep-Pool Microelectronics Co., Ltd. May-2020 Rev1.4 Page7-9 业务联系：１３６０２６３２４２７李先生 NDP1331KC 思 成 微 电 子 Typical Applications Nanjing Deep-Pool Microelectronics Co., Ltd. May-2020 Rev1.4 Page8-9 业务联系：１３６０２６３２４２７李先生 NDP1331KC Package Description A A1 A2 b c D E E1 e L θ Dimensions In Millimeters Min Max 1.350 1.750 0.050 0.250 1.250 1.650 0.310 0.510 0.170 0.250 4.700 5.150 3.800 4.000 5.800 6.200 1.270 (BSC) 0.400 1.270 0º 8º 思 Symbol 成 微 电 子 8-Lead Standard Small Outline Package [SOP-8] Nanjing Deep-Pool Microelectronics Co., Ltd. Dimensions In Inches Min Max 0.053 0.069 0.002 0.010 0.049 0.065 0.012 0.020 0.006 0.010 0.185 0.203 0.157 0.15 0.228 0.244 0.05 (BSC) 0.016 0.050 0º 8º May-2020 Rev1.4 Page9-9