MC33023DW ON Semiconductor, MC33023DW Datasheet - Page 12

• Manufacturer Part Number: MC33023DW
• Description: IC CTRLR PWM SGL END HF 16-SOIC
• Manufacturer: ON Semiconductor

Specifications of MC33023DW

• Pwm Type: Voltage/Current Mode
• Number Of Outputs: 1
• Frequency - Max: 1MHz
• Duty Cycle: 90%
• Voltage - Supply: 10 V ~ 30 V
• Buck: No
• Boost: No
• Flyback: No
• Inverting: No
• Doubler: No
• Divider: No
• Cuk: No
• Isolated: Yes
• Operating Temperature: -40°C ~ 105°C
• Package / Case: 16-SOIC (0.300", 7.5mm Width)
• Frequency-max: 1MHz
• Duty Cycle (max): 90 %
• Output Voltage: 5.05 V to 5.15 V
• Output Current: 500 mA
• Mounting Style: SMD/SMT
• Switching Frequency: 1000 KHz
• Operating Supply Voltage: 30 V
• Maximum Operating Temperature: + 105 C
• Fall Time: 30 ns
• Minimum Operating Temperature: - 40 C
• Rise Time: 30 ns
• Synchronous Pin: Yes
• Topology: Flyback, Forward
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant

slope necessary. By choosing R
R
by I
leading edge spike on the current waveform. This sense signal can also
be used at the ramp input pin for current mode control. For ramp
compensation it is necessary to know the gain of the current feedback
loop. If a transformer is used, the gain can be calculated by:
M
When only one output is used, this method of slope compensation can be used and it is relatively noise immune. Resistor R
Output
M
The addition of an RC filter will eliminate instability caused by the
can be adjusted to achieve the required slope. The diode provides a reset pulse at the ramp input at the end of every cycle. The charge current I
= C
M
S
Figure 24. Resistive Current Sensing
e
R
. Then R
M
C
Current Sense
M
Transformer
M
can be calculated by R
R
C
R
w
A
f
f
i
+
M
and C
turns ratio
9
Ramp
R Sense
Input
7
3
M
with a larger time constant than the switching frequency, you can assume that its charge is linear. First choose C
is noise sensitive. Capacitor C
signal is added to the current signal by a voltage divider consisting of
resistors R
Figure 26A. Slope Compensation (Noise Sensitive)
1.25 V
Current Sense
This method of slope compensation is easy to implement, however, it
Figure 26B. Slope Compensation (Noise Immune)
M
= V
Information
CC
1
/I
M.
and R
C
T
I
Sense
2
.
R
2
R
http://onsemi.com
1
C
Figure 26.
1
4
5
6
7
3
1
provides AC coupling. The oscillator
12
leading edge spike on the current waveform. This sense signal can also
be used at the ramp input pin for current mode control. For ramp
compensation it is necessary to know the gain of the current feedback
loop. The gain can be calculated by:
1.25 V
The addition of an RC filter will eliminate instability caused by the
Current Sense
Figure 25. Primary Side Current Sensing
Oscillator
Resistor
R
f
C
A
M
Output
i
+
9
R
C
M
turns ratio
f
M
R
Ramp
and capacitor C
w
Input
7
3
R
1.25 V
w
M
M
provide the added
can be calculated
I
Sense
M
, then