cs2843aln8 ON Semiconductor, cs2843aln8 Datasheet - Page 7

• Manufacturer Part Number: cs2843aln8
• Description: Off?line Current Mode Pwm Control Circuit With Undervoltage Lockout
• Manufacturer: ON Semiconductor

above formulas:
determined using the Typical Performance Characteristic
graphs.
Grounding
necessitate careful grounding techniques. Timing and
bypass capacitors should be connected close to GND pin in
a single point ground.
circuit, are used to sample the oscillator waveform and apply
and adjustable ramp to Sense.
Substituting in typical values for the parameters in the
V
V
V
I
t
The frequency and maximum duty cycle can be
High peak currents associated with capacitive loads
The transistor and 5.0 kΩ potentiometer, shown in the test
c
d
upper
REF
lower
≈ 0.5534R
= 8.3 mA
= 5.0 V
t d + R T C T ln
= 2.7 V
= 1.0 V
t c + R T C T ln
t d + R T C T ln
T
C
T
V REF * I d R T * V upper
V REF * I d R T * V lower
V REF * V upper
V REF * V lower
2.3 * 0.0083R T
4.0 * 0.0083R T
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7
Timing Parameters
Sawtooth Mode
Triangular Mode
Figure 7. Oscillator Timing Network and
V
V
upper
lower
Large R
Small R
V
GND
OSC
REF
T
T
(≈ 700 kΩ)
(≈ 10 kΩ)
Parameters
t
c
R
C
T
t
T
d
V
Internal Clock
V
Internal Clock
OSC
OSC