NCV898031(2012) 查看數據表（PDF） - ON Semiconductor

零件编号

产品描述 (功能)

生产厂家

NCV898031
(Rev.:2012)

2 MHz Non-Synchronous SEPIC/Boost Controller

ON Semiconductor 

NCV898031

The total feedback resistance (Rupper + Rlower) should be

in the range of 1 kW – 100 kW.

Select Compensator Components

Current Mode control method employed by the

NCV898031 allows the use of a simple, Type II

compensation to optimize the dynamic response according

to system requirements.

Select MOSFET(s)

In order to ensure the gate drive voltage does not drop out

the MOSFET(s) chosen must not violate the following

inequality:

Qg(total)

v

Idrv

fs

Where: Qg(total): Total Gate Charge of MOSFET(s) [C]

Idrv: Drive voltage current [A]

fs: Switching Frequency [Hz]

The maximum RMS Current can be calculated as follows:

Ǹ ǒ Ǔ ID(max) +

DWC

IQ(peak)

2

)

ǒDIL1

)

3

DIL2Ǔ2

*

IQ(peak)ǒDIL1

)

DI

Ǔ

L2

where

IQ(peak) + IL1_peak ) IL2_peak

The maximum voltage across the MOSFET will be the

maximum output voltage, which is the higher of the

maximum input voltage and the regulated output voltaged:

VQ(max) + VOUT(max)

Select Diode

The output diode rectifies the output current. The average

current through diode will be equal to the output current:

ID(avg) + IOUT(max)

Additionally, the diode must block voltage equal to the

higher of the output voltage and the maximum input voltage:

VD(max) + VOUT(max)

The maximum power dissipation in the diode can be

calculated as follows:

PD + Vf (max) IOUT(max)

Where: Pd: Power dissipation in the diode [W]

Vf(max): Maximum forward voltage of the diode [V]

Oscillator

PWM Comparator S Q

R

GDRV

L

Gate

Drive

ISNS

+

CSA

Slope

Compensation

VFB

Voltage Error

VIN

VOUT

CO

RL

NCV898031

VEA

Compensation

Figure 11. Boost Current Mode Schematic

http://onsemi.com

10

Share Link: