APW7073AKE-TRG Ver la hoja de datos (PDF) - Anpec Electronics
Número de pieza
componentes Descripción
Fabricante
APW7073AKE-TRG Datasheet PDF : 20 Pages
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APW7073A
Function Description (Cont.)
Over-Current Protection (Cont.)
An over current condition will shut down the device and
discharge the CSS with a 30µA sink current and then
initiate the soft-start sequence. After two over-current
events are counted, the device turns off both high-side
and low-side MOSFETs and the converter output is latched
to be floating. It requires a POR of VCC to restart.
Switching Frequency
The APW7073A provides the oscillator switching fre-
quency adjustment. The device includes a 200kHz free-
running triangle wave oscillator. If operating in higher
frequency than 200kHz, connect a resistor from RT pin
to the ground to increase the switching frequency.
Conversely, if operating in lower frequency than 200kHz,
connect a resistor from RT to the VCC to decrease the
switching frequency.
Figure 2. shows how to select the resistor for the desired
frequency. Figure 3 shows more detail for the higher
frequencies and Figure 4 shows the lower frequency
detail.
1000
900
800
700
600
500
400
300
200
100
0
10
Frequency (kHz)
1000
Figure 2. Oscillator Frequency vs. RT Resistance
1000
900
800
700
600
500
400
300
200
100
0
200 300 400 500 600 700 800 900 1000
Frequency (kHz)
Figure 3. Oscillator Frequency vs. RT Resistance
(High Frequency)
1000
900
800
700
600
500
400
300
200
50 70 90 110 130 150 170
Frequency (kHz)
Figure 4. Oscillator Frequency vs. RT Resistance
(Low Frequency)
Copyright © ANPEC Electronics Corp.
11
Rev. A.5 - Nov., 2012
www.anpec.com.tw
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