NDP1335KC

业务联系：１３６０２６３２４２７李先生 NDP1335KC 3.1A,34V High Efficiency Synchronous Step-Down DC/DC Converter Features Description NDP1335KC is a high efficiency, Z  Wide VIN Range : 7V to 32V monolithic synchronous step-down DC/DC  3.1A Continuous Output Current converter utilizing a constant frequency,  Up to 93% Efficiency average current mode control architecture. Capable of delivering up to 3.1A continuous load with excellent line and load regulation. The device operates from an input voltage range of 7V to 32V and provides an adjustable output voltage from 3.6V to 25V. The NDP1335KC features short circuit and thermal protection circuits to increase  CC/CV Mode Control  100% Max Duty Cycle  Built in Adjustable Line-Compensation  Adjustable Output Voltages  +/-1.5% Output Voltage Accuracy  +/- 5% Current Limit Accuracy.  Integrated 70mΩ High Side Switch  Integrated 30mΩ Low Side Switch  Programable Frequency(130KHz~300KHz) system reliability. The internal soft-start  Burst Mode Operation at Light Load avoids input inrush current during startup.  Internal loop Compensation The NDP1335KC require a minimum number of external components. and a wide array of protection features to enhance reliability  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. Rev1.5 Page1-9 业务联系：１３６０２６３２４２７李先生 NDP1335KC 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 PIN NAME 1 VFB 2 CSP 3 CSN 4 VIN 5,6 SW 7 FS 8 GND 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 Order information Order Information Top Marking NDP1335 K C 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 Rev1.5 Page2-9 业务联系：１３６０２６３２４２７李先生 NDP1335KC 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 protect Vovp Units V 5.8 V 1.4 V 32 V Quiescent Current 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 CSP-CSN 57 60 FS Floating 130 KHz connect 470K resister 300 KHz Maximum Duty Cycle Minimum On-Time - 0.3 0.4 V 100 - % 250 - ns Current Limit ILIM VFB short protect VFBSCP 0.47 V Hicup Interval Thiccup 500 mS Soft start Time Tss 2 mS RDSON Of Power High side Temp=25℃ 70 mΩ MOS Low side Temp=25℃ 30 mΩ Thermal Regulation TTR 150 °C Thermal shutdown Temp Thermal Shutdown Hysteresis 4.5 A TSD - 165 - °C TSH - 30 - °C Nanjing Deep-Pool Microelectronics Co., Ltd. Rev1.5 Page3-9 业务联系：１３６０２６３２４２７李先生 NDP1335KC Block Diagram Typical Performance Characteristics (TJ = 25°C, unless otherwise noted) Nanjing Deep-Pool Microelectronics Co., Ltd. Rev1.5 Page4-9 业务联系：１３６０２６３２４２７李先生 NDP1335KC current-loop response. The error amplifier Operation The NDP1335KC is a high efficiency, monolithic, converter synchronous utilizing a step-down constant DC/DC frequency, 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 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 The discontinuous-conduction modes (DCMs) are available to control the operation of the NDP1335KC at low currents. Burst Mode operation automatically switch from continuous operation to the Burst Mode operation when the load current is low regulator. VIN Overvoltage Protections 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 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 adjusts the ITH voltage by comparing the the vduty voltage, the voltage PWM comparator trips and turns off the top power MOSFET. After the top power MOSFET turns off, the synchronous power switch (N-channel In order to protect the internal power MOSFET devices against transient voltage spikes, the NDP1335KC constantly monitors the VIN pin for an overvoltage condition. When VIN rises above 32V, the regulator suspends operation by shutting off both power MOSFETs. Once VIN drops below 31V, the regulator immediately resumes normal operation. The regulator executes its soft-start function when exiting an overvoltage condition. Cable Drop Compensation MOSFET) turns on, causing the inductor current Due to the resistive of charger’s output to decrease. The bottom switch stays on until Cable, The NDP1335KC built in a simple user the beginning of the next clock cycle, unless the programmable cable voltage drop compensation 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 using the impedance at the FB pin. Choose the proper resistance values for charger’s output cable as show in table 1: Rup is the upper resistor the resistors divider net Rlow is the lower resistor the resistors divider net ITH voltage. Note that the DC gain and compensation of this average current loop is automatically adjusted to maintain an optimum Nanjing Deep-Pool Microelectronics Co., Ltd. Rev1.5 Page5-9 业务联系：１３６０２６３２４２７李先生 NDP1335KC RFB(UPER)（K） 100 160 360 470 820 1200 Rlow（K） 25 39 91 120 200 300 table 1 Cable Drop compensation This simple worst-case condition is commonly (mV) 130 200 500 680 1200 1800 used for design because even significant Frequency Selection and Shutdown The switching frequency of the NDP1335KC can be programmed through an external resistor between 130kHz and 300 kHz，Floating this pin set the switching frequency to 130K, an external resistor can set the frequency up to 300KHz。the switching frequency is set using the FS pins as 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 NDP1335KC enters a low current shutdown deviations do not offer much relief. Note that ripple current ratings from capacitor manufacturers are often based on only 2000 hours of life which makes it advisable to further derate the capacitor, or choose a capacitor rated at a higher temperature than required. Several capacitors may also be paralleled to meet size or height requirements in the design. For low input voltage applications, sufficient bulk input capacitance is needed to minimize transient effects during output load changes. Output Capacitor (COUT) Selection The selection of COUT is determined by the effective series resistance (ESR) that is required to minimize voltage ripple and load step transients as well as the amount of bulk capacitance that is necessary to ensure that the control loop is stable. Loop stability can be checked by viewing the load transient response. The output ripple, △VOUT, is determined by: state, reducing the DC supply current to 1.3mA. Applications Information Input Capacitor (CIN) Selection The output ripple is highest at maximum The input capacitance CIN is needed to filter the input voltage since △IL increases with input square wave current at the drain of the top voltage. Multiple capacitors placed in parallel power MOSFET. To prevent large voltage may be needed to meet the ESR and RMS transients from occurring, a low ESR input current handling requirements. Dry tantalum, capacitor sized for the maximum RMS current special polymer, aluminum electrolytic, and should be used. The maximum RMS current is ceramic capacitors are all available in surface given by: mount packages. Special polymer capacitors are very low ESR but have lower capacitance density than other types. Tantalum capacitors This formula has a maximum at VIN = 2VOUT, have the highest capacitance density but it is where: IRMS ≅ IOUT/2 important to only use types that have been surge tested for use in switching power supplies. Nanjing Deep-Pool Microelectronics Co., Ltd. Rev1.5 Page6-9 业务联系：１３６０２６３２４２７李先生 NDP1335KC Aluminum electrolytic capacitors have Lower ripple current reduces power losses in significantly higher ESR, but can be used the inductor, ESR losses in the output in cost-sensitive applications provided that capacitors and output voltage ripple. Highest consideration is given to ripple current ratings efficiency operation is obtained at low frequency and long-term reliability. Ceramic capacitors with small ripple current. However, achieving have excellent low ESR characteristics and this requires a large inductor. There is a small footprints. trade-off between component size, efficiency and operating frequency. A reasonable starting Inductor Selection Given the desired input and output voltages, the point is to choose a ripple current that is about inductor 40% of IOUT(MAX). To guarantee that ripple value and operating frequency determine the ripple current: current does not exceed a specified maximum, the inductance should be chosen according to: Once the value for L is known, the type of radiate much energy, but generally cost more inductor must be selected. Actual core loss is than powdered iron core inductors with similar independent of core size for a fixed inductor characteristics. The choice of which style value, but is very dependent on the inductance inductor to use mainly depends on the price selected. As the inductance or frequency versus size requirements and any radiated increases, core losses decrease. Unfortunately, field/EMI requirements. New designs for surface increased inductance requires more turns of mount inductors are available from Coilcraft, wire and therefore copper losses will increase. Toko, Vishay, NEC/Tokin, TDK and Würth Copper losses also increase as frequency Electronik. increases Ferrite designs have very low core Efficiency Considerations losses and are preferred at high switching The percent efficiency of a switching regulator is frequencies, so design goals can concentrate equal to the output power divided by the input on copper loss and preventing saturation. power times 100%. It is often useful to analyze Ferrite core material saturates “hard”, which individual losses to determine what is limiting means that inductance collapses abruptly when the efficiency and which change would produce the peak design current is exceeded. This the most improvement. Percent efficiency can results in an abrupt increase in inductor ripple be expressed as: % Efficiency = 100% – (Loss1 current and consequent output voltage ripple. + Loss2 + …) where Loss1, Loss2, etc. are the Do not allow the core to saturate! individual losses as a percentage of input power. Different core materials and shapes will change Although all dissipative elements in the circuit the size/current and price/current relationship of produce losses, three main sources usually an inductor. Toroid or shielded pot cores in account for most of the losses in NDP1335KC ferrite or permalloy materials are small and don’t Nanjing Deep-Pool Microelectronics Co., Ltd. Rev1.5 Page7-9 业务联系：１３６０２６３２４２７李先生 NDP1335KC circuits: 1) I2R losses, 2) switching and biasing efficiency and low thermal resistance. However, losses, 3) other losses. in applications where the NDP1335KC is Thermal Conditions running at high ambient temperature, high VIN, In a majority of applications, the NDP1335KC and maximum output current load, the heat does not dissipate much heat due to its high dissipated may exceed the maximum junction temperature 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 NDP1335KC 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. of the part. If the Typical Applications Nanjing Deep-Pool Microelectronics Co., Ltd. Rev1.5 Page8-9 业务联系：１３６０２６３２４２７李先生 NDP1335KC Package Description 8-Lead Standard Small Outline Package [SOP-8] Symbol 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 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 Rev1.5 Page9-9