Datasheet > RP500N171A-TR

RP500N171A-TR

更新时间： 2023-01-02 20:28:25

品牌	Logo	应用领域
理光 - RICOH		光电二极管
页数	文件大小	规格书
22页	472K
描述
Switching Regulator, 0.9A, 1440kHz Switching Freq-Max, CMOS, PDSO6, SOT-23, 6 PIN

阅读下载

获取价格

如果您发现信息不准确，欢迎纠错

RP500N171A-TR 数据手册

RP500X

OPERATION OF THE BUCK CONVERTER AND THE OUTPUT CURRENT

The DC/DC converter charges energy in the inductor when LX transistor is ON, and discharges the energy from

the inductor when LX transistor is OFF and controls with less energy loss, so that a lower output voltage than the

input voltage is obtained. The operation will be explained with reference to the following diagrams:

ILmax

V^OUT

GND

ILmin

Pch Tr

Nch Tr

topen

V^IN

ton

toff

T=1/fosc

Step 1: P-channel Tr. turns on and current IL (=i1) flows, and energy is charged into CL. At this moment, IL

increases from ILmin (=0) to reach ILmax in proportion to the on-time period (ton) of P-channel Tr.

Step 2: When P-channel Tr. turns off, Synchronous rectifier N-channel Tr. turns on in order that L maintains IL

at ILmax, and current IL (=i2) flows.

Step 3: IL (=i2) decreases gradually and reaches IL=ILmin=0 after a time period of topen, and N-channel Tr.

Turns off. Provided that in the continuous mode, next cycle starts before IL becomes to 0 because toff

time is not enough. In this case, IL value increases from this ILmin (>0).

In the case of PWM control system, the output voltage is maintained by controlling the on-time period (ton), with

the oscillator frequency (fosc) being maintained constant.

The maximum value (ILmax) and the minimum value (ILmin) of the current flowing through the inductor are the

same as those when P-channel Tr. turns on and off.

The difference between ILmax and ILmin, which is represented by ∆I:

∆I = ILmax – ILmin = VOUT x topen / L = (VIN - VOUT) x ton / L ..................................Equation 1

wherein,

T = 1 / fosc = ton + toff

duty (%) = ton / T x 100 = ton x fosc x 100

topen≦toff

In Equation 1, VOUT×topen/L and (VIN − VOUT) ×ton/L respectively show the change of the current at "ON", and

the change of the current at "OFF".

1...4 5 678 9 10...22

下载PDF

型号	品牌	描述	获取价格	数据表
RP500N171A-TR-F	RICOH	Switching Regulator, Current-mode, 0.9A, 1440kHz Switching Freq-Max, CMOS, PDSO6, LEAD FRE	获取价格
RP500N171A-TR-FE	RICOH	Switching Regulator, 1440kHz Switching Freq-Max, CMOS, PDSO6, HALOGEN FREE AND ROHS COMPLI	获取价格
RP500N172A-TR	RICOH	Switching Regulator, 0.9A, 1440kHz Switching Freq-Max, CMOS, PDSO6, SOT-23, 6 PIN	获取价格
RP500N172A-TR-FE	RICOH	Switching Regulator, 1440kHz Switching Freq-Max, CMOS, PDSO6, HALOGEN FREE AND ROHS COMPLI	获取价格
RP500N174A-TR-FE	RICOH	Switching Regulator, 1440kHz Switching Freq-Max, CMOS, PDSO6, HALOGEN FREE AND ROHS COMPLI	获取价格
RP500N181A-TR	RICOH	Switching Regulator, 0.9A, 1440kHz Switching Freq-Max, CMOS, PDSO6, SOT-23, 6 PIN	获取价格