MC33368DG ON Semiconductor, MC33368DG Datasheet - Page 10

• Manufacturer Part Number: MC33368DG
• Description: IC PFC CONTROLLER CRM 16SOIC
• Manufacturer: ON Semiconductor
• Series: GreenLine™r

Specifications of MC33368DG

• Mode: Critical Conduction (CRM)
• Current - Startup: 16mA
• Voltage - Supply: 10 V ~ 16 V
• Operating Temperature: -25°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 16-SOIC (3.9mm Width)
• Maximum Operating Temperature: + 125 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 25 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Frequency - Switching: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

NOTE:
Table 1. Design Equations
Converter Output Power
Peak Indicator Current
Inductance
Switch On--Time
Switch Off--Time
Minimum Switch
Off--Time
Delay Time
Switching Frequency
Peak Switch Current
Multiplier Input Voltage
Converter Output
Voltage
Converter Output
Peak--to--Peak
Ripple Voltage
Error Amplifier
Bandwidth
Calculation
The following converter characteristics must be chosen:
V
I
Vac = AC RMS operating line voltage.
O
O
= Desired output current.
= Desired output voltage.
ΔV
O(pp)
L
P
t
d
V
=
t
= I
(off)
O
= – R10 C7 ln
t
= V
t
L(pk)

(off)
I
t
=
L(pk)
(on)
V

f =
V
O
BW =
2
M
ref
P
min

R7 =

O
2
–Vac
Formula
=
=
Vac
ΔV
=
t
(on)

= V
Vac
=
 V
R2
R1


O
V
2
η Vac
(LL)
2 P
η Vac 2
Vac
R5
R3
2 π C1
(LL)
t
2 π f ac C3
2 2
I
O
(on)
= Converter output peak--to--peak ripple voltage.
+ t
L(pk)
V
+ 1

L
Sin θ
g m
O

1
 P
O
P
CS
+ 1
= AC RMS minimum required operating line voltage for output regulation.
O
V

http://onsemi.com
I
V
(off)
1
P
I

O
(LL)
O

L(pk)
L
V
CC
2
η Vac
O

O
P
– I

CC
–1
IB
– 2

2
R1
(LL)

+ ESR 2
10
2
Calculate the maximum required output power.
Calculated at the minimum required ac line voltage for
output regulation. Let the efficiency  = 0.92 for low line
operation.
Let the switching cycle t = 40 ms for universal input (85
to 265 Vac) operation and 20 ms for fixed input (92 to
138 Vac, or 184 to 276 Vac) operation.
In theory, the on--time t
tends to increase at the ac line zero crossings due to
the charge on capacitor C5. Let Vac = Vac
t
The off--time t
voltage and approaches zero at the ac line zero
crossings. Theta (θ) represents the angle of the ac line
voltage.
The off--time is at a minimum at ac line crossings. This
equation is used to calculate t
zero.
The delay time is used to override the minimum
off--time at the ac line zero crossings by programming
the Frequency Clamp with C7 and R10.
The minimum switching frequency occurs at the peak of
the ac line voltage. As the ac line voltage traverses
from peak to zero, t
increase in switching frequency.
Set the current sense threshold V
universal input (85 to 265 Vac) operation and to 0.5 V
for fixed input (92 to 138 Vac, or 184 to 276 Vac)
operation. Note that V
Set the multiplier input voltage V
Empirically adjust V
ac line voltage range while guaranteeing startup at
minimum line.
The I
current in excess of 100 mA.
The calculated peak--to--peak ripple must be less than
16% of the average dc output voltage to prevent false
tripping of the Overvoltage Comparator. Refer to the
Overvoltage Comparator Text. ESR is the equivalent
series resistance of C3.
The bandwidth is typically set to 20 Hz. When operating
at high ac line, the value of C1 may need to be
increased.
(on)
and t
IB
R1 error term can be minimized with a divider
(off)
calculations.
(off)
is greatest at the peak of the ac line
(off)
M
for the lowest distortion over the
CS
(on)
approaches zero producing an
Notes
must be less than 1.4 V.
is constant. In practice, t
(off)
M
as Theta approaches
CS
to 3.0 V at high line.
to 1.0 V for
(LL)
for initial
(on)