• [ CXSD62675 ]"

Ordering

Breakthrough the bottleneck of industrial power supply design! CXSD62675 Wide Voltage Reducing Chip Practical Guide: Flexible and Adjustable, Multiple ProtectionNRc嘉泰姆

        Efficient and reliable wide voltage power supply solutions are the core competitiveness in the fields of industrial control systems, electric vehicle controllers, and portable devices.CXSD62675As a new generation of step-down DC-DC chips10-120V ultra wide input rangeThe1.5A output capabilityandFlexible and adjustable output voltageFeatures become a powerful tool for engineers to cope with complex power supply environments. This article will comprehensively analyze its design points, electrical characteristics, and typical applications.NRc嘉泰姆

1、 Six core advantages

1. Wide input voltage, suitable for extreme scenariosNRc嘉泰姆

a. Input voltage coverage10V to 120VCompatible with 12V/24V/48V battery systems and industrial unstable power grids.NRc嘉泰姆

b. 120V ultra-high voltage withstand (VS pin up to 125V), effectively resisting voltage surge impact.NRc嘉泰姆

2. Efficient integrated designNRc嘉泰姆

a. Built in power MOS transistor, simplifies peripheral circuits, typical applications only require9 components(Figure 6-2).NRc嘉泰姆

b. ESOP8 packaging balances heat dissipation and space efficiency, increasing power density by 30%.NRc嘉泰姆

3. Intelligent protection mechanismNRc嘉泰姆

a. Triple protectionCycle by cycle current limiting (IS pin), 145 ℃ overheating protection, output short circuit protection, to prevent system downtime.NRc嘉泰姆

b. 2KV ESD protection (HBM standard), passed rigorous industrial EMC testing.NRc嘉泰姆

4. Precise voltage controlNRc嘉泰姆

a. Free setting of output voltage through FB pin resistor division:Vout=(1+R1/R2)× 1.25V(Figure 8.5).NRc嘉泰姆

b. Support5V/12V multi-channel output(Figure 6-3), error± 3.2% (FB voltage 1.21V-1.29V).NRc嘉泰姆

2、 Key Design Guidelines

1. Optimization of inductance selection formulaNRc嘉泰姆

a. The inductance value determines the CCM/DCM mode: the light load automatically switches to discontinuous mode (DCM) to reduce losses.NRc嘉泰姆
b.L = [Vout×(Vin-Vout)] / (Vin×Fs×Iripple)Formula: Calculation（Fs=120kHz，Iripple≤ 30%× 1.5A）NRc嘉泰姆

2. Innovative design of bootstrap diodeNRc嘉泰姆

a. VD pinSupporting external bootstrap diodes (D1 in Figure 6-2) significantly improves the efficiency of high-end MOS driving.NRc嘉泰姆

b. Must be selectedSchottky diode(such as SS3200), the conduction voltage is reduced to 0.3V to reduce switch losses.NRc嘉泰姆

3. The Golden Rule of PCB LayoutNRc嘉泰姆

a. Input capacitor, VB-VS bootstrap capacitorClose to the chip pins(spacing≤ 5mm).NRc嘉泰姆

b. The line width of the high current path (VIN/VS/IS/GND) is 2mm to avoid voltage drop losses.NRc嘉泰姆

c. Chip backFully covered with copper and thermal conductive holesReduce the temperature rise by 20 ℃ at full load.NRc嘉泰姆

3、 In depth interpretation of electrical characteristics

noteStatic current 2mA (typical value) ensures light load efficiency>85%, peak current formulaI_peak=0.18/R1(R1 is the resistance of the IS pin).NRc嘉泰姆

4、 Typical application scheme

1. Industrial control system12V/0.6A output scheme (Figure 6-2): using 100μ H inductor+220μ F low ESR capacitor, ripple<50mV.NRc嘉泰姆

2. Portable device power supply5V/0.8A output scheme (Figure 6-3): 3.6kΩ Feedback resistor, supports USB device power supply.NRc嘉泰姆

3. Electric vehicle controllerWide voltage adaptation to battery fluctuations, working temperature range of -45 ℃~125 ℃ to cope with extreme environments.NRc嘉泰姆

5、 Design Pit Avoidance Guide

1. Selection of output capacitorNRc嘉泰姆

a. Ripple formula:Δ Vo=Δ IL× (ESR + 1/(8.5×Fs×Co))NRc嘉泰姆

b. Suggested combination:220μ F electrolytic capacitor+0.1μ F ceramic capacitorSuppress high-frequency noise.NRc嘉泰姆

2. Enable foot (EN) controlNRc嘉泰姆

a. High level>2.8V startup, low level<1V shutdown, standby current after shutdown≤ 200μ A。NRc嘉泰姆

b. When suspended, it works by default and requires an external pull-down resistor to prevent accidental triggering.NRc嘉泰姆

VI Parameters and precautions of components in application design

1   PCB board layoutNRc嘉泰姆
        The bootstrap capacitors between input capacitors VIN, VB, and VS should be as close as possible to the chip pins; Try to lay a large area of copper on the back of the chip for good heat dissipation, which canNRc嘉泰姆
To achieve greater current output, the high current paths (GND, VIN, VS, IS) should be wired as wide and short as possible.NRc嘉泰姆
2   Output inductanceNRc嘉泰姆
      CXSD62673 has two working modes: continuous working mode and discontinuous working mode. The value of the inductance will affect the working mode of the voltage regulatorNRc嘉泰姆
When loaded lightly; CXSD62673 operates in discontinuous mode, and the inductance value will affect the ripple of the inductance current. The selection of inductance can be based on the following formula:NRc嘉泰姆
Formula:   NRc嘉泰姆
In the formula,  Vin   Is the input voltage, Vout is the output voltage, Fs is  PWM operating frequency, Iripple is in the inductorNRc嘉泰姆
The peak to peak value of current ripple is usually selected for Iripple, which should not exceed 30% of the maximum output current.NRc嘉泰姆
3   freewheeling diodeNRc嘉泰姆
          The freewheeling diode is mainly used to provide a circuit for the inductor current when the switching transistor is turned off. The switching speed and forward voltage drop of this diode are directly affectedNRc嘉泰姆
The efficiency of DC-DC is affected by the use of Schottky diodes, which have fast switching speed and low forward conduction voltage drop, and can provide; CXSD62673 voltage regulatorNRc嘉泰姆
Provide high efficiency performance.NRc嘉泰姆
4   output capacitorNRc嘉泰姆
      Output capacitance; Co is used to filter the output voltage, so that; The DC-DC converter provides a relatively stable output of DC power to the load. Choose this optionNRc嘉泰姆
Choose as low a capacitance as possible; The capacitance of ESR is mainly determined by the ripple requirements of the output voltage, and can be determined by the following formula:NRc嘉泰姆

NRc嘉泰姆

In the formula, Delta; Vo is the output voltage ripple,Δ IL is inductor current ripple, Fs is; PWM operating frequency, ESRNRc嘉泰姆
It is the equivalent series resistance of the output capacitor.NRc嘉泰姆
5   Output voltage settingNRc嘉泰姆
          The output voltage of CXSD62673 is; The two voltage divider resistors on the FB pin are set, and the reference voltage of the internal error amplifier is; 1.25V， As shown in the figureNRc嘉泰姆
As shown in 8.5, output voltage;   Vout=（1+R1/R2）*1.25V， To set the output voltage to; 13.75V， Can be set; R1 is 10K, R2 is 1K,NRc嘉泰姆
Output voltage; Vout=（1+10/1）*1.25V=13.75V。NRc嘉泰姆

NRc嘉泰姆

Conclusion

            CXSD62675 passedInnovative bootstrap architecture (VD pin) and precise current limiting controlSolved the efficiency and reliability challenges in wide input scenarios. Its flexible feedback mechanism is particularly suitable for industrial equipment with multiple voltage outputs, and when combined with ESOP8 packaging, it can compress PCB area by 40%. Engineers can directly reuse the 12V/5V reference design in the document (Figure 6-2, 6-3) to quickly implement a cost-effective power solution.NRc嘉泰姆

Expansion suggestionsIn high-temperature scenarios, it is necessary to ensure that the saturation current of the inductor is greater than 2A; for bootstrap diodes, it is recommended to use Schottky diodes such as SS34/SS56 with voltages above 40V.NRc嘉泰姆

      For detailed PDF specifications, please contact us. You can also receive free samples and technical support！NRc嘉泰姆
       NRc嘉泰姆
   Product packaging diagram;NRc嘉泰姆

   NRc嘉泰姆

   Circuit schematic diagram;NRc嘉泰姆

NRc嘉泰姆

   Selection Guide for Related Chips;         More related products .....NRc嘉泰姆

◀ Previous:Analysis of CXSD62674H, a wide voltage and efficient DC-DC buck chip: 10-120V input/1.5A output/zero power standby, preferred for electric vehicles and fast charging solutions

Back to top

Next▶:CXSD62676 Wide Voltage Reduction Chip: 10-120V Input/5A Output, ESOP8 Package DC-DC Solution