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Fig.2. Auxiliary voltage waveform
Via a resistor divider connected between the auxiliary winding and INV (pin 3), the auxiliary voltage is sampled at the end of
消磁,这是保持到下一次采样。
采样电压与V相比,
REF
(2.0V) and the error is amplified. The error amplifier output COMP reflects the
负载状态,并控制PWM开关频率来调节输出电压,从而输出电压一定能
来实现。
当采样电压低于V
REF
和误差放大器的输出COMP达到其最大值时,开关频率是
由采样的电压从而输出电压控制来调节输出电流,从而在恒定的输出电流
可以实现的。
可调恒流点和输出功率
In RS2135, the CC point and maximum output power can be externally adjusted by external current sense resistor R
S
在CS引脚
如图中的典型应用电路。的输出功率通过恒流点变化进行调整。大ř
S
中,
smaller CC point is, and the smaller output power becomes, and vice versa as shown in Fig.3.
Fig.3. Adjustable output power by changing R
S
操作开关频率
The switching frequency of RS2135 is adaptively controlled according to the load conditions and the operation modes. No
外部频率设定元件。在最大输出功率的操作开关频率被设定为
60KHz internally.
对于反激的DCM操作,最大输出功率由下式给出
1
P
O
最大
= ×
L
P
×
F
SW
×
I
P
2
2
其中,L
P
表明初级电感线圈和我
P
是初级绕组的峰值电流。
DS‐RS2135‐03
九月
2009
www.Orister.com