MC44605P ON Semiconductor, MC44605P Datasheet - Page 17

• Manufacturer Part Number: MC44605P
• Description: IC CTRLR PWM FREQ LATCH 16DIP
• Manufacturer: ON Semiconductor
• Series: GreenLine™r
• Type: High Performance Latched Mode PWM Contollerr

Specifications of MC44605P

• Pwm Type: Current Mode
• Number Of Outputs: 1
• Frequency - Max: 250kHz
• Duty Cycle: 80%
• Voltage - Supply: 10 V ~ 15 V
• Buck: No
• Boost: No
• Flyback: Yes
• Inverting: No
• Doubler: No
• Divider: No
• Cuk: No
• Isolated: Yes
• Operating Temperature: -25°C ~ 85°C
• Package / Case: 16-DIP (0.300", 7.62mm)
• Frequency-max: 250kHz
• Output Voltage Range: 2.4 V to 2.6 V
• Input Voltage Range: + 14.5 V to + 18 V
• Mounting Style: Through Hole
• Lead Free Status / RoHS Status: Contains lead / RoHS non-compliant
• Other names: MC44605POS

value) in the last equation, the value R
deducted:
where: (p
Disabling Block Section
(directly supplied by the V
output is forced to zero).
circuit when one of the following faults is detected:
— a Winding Short Circuit
— too high synchronization pulses
— a too high input power
— a too high power switch (MOSFET) heating
fault is detected (for instance, when the input power is
detected as too high, Dis
current source charges C
when its voltage becomes higher than V
inhibition latch is activated. Thus, the circuit gets
definitively disabled after a delay depending on C
C
— 260 mA for EHTOVP and WSCD
— 8.5 mA for OHD and MPL
when R
ext
Consequently, by replacing V
This section consists of a “definitive inhibition latch”
In effect, this block aims at definitively disabling the
The signals corresponding to these faults are high when a
When one (or several) of these four faults is detected, a
According to the detected fault, the current that charges
The typical values are:
is not the same:
acceptable.
ref
R
on
is equal to 10 kW.
OHD
)
max
+
are the maximum on time losses
3
Γ
2.5
MPL
ext
OHD
cc
(with a certain duty cycle) and
) that disables the output (the
is high).
R
ref
OHD
R 2
S
R
by 2.5 V (threshold
OHD
dson
(p on ) max
ref
, the definitive
to use, can be
ext
that are
http://onsemi.com
.
17
In this case, if a new startup is performed, the circuit will
work normally (until this fault or another one is detected).
circuit, the converter must be turned off for a time long
enough to enable the V
Note: As V
necessary to add a latch and a delay to build a 4 ms width
pulse when V
This latch is reset when the V
Practically, to re−start after a fault has shutdown the
Pin 12
1
WSCD
V
ref
WSCD
Figure 15. Disabling Block
0
3.4% I
2.5 V
is generally a really narrow pulse, it is
becomes high.
ref
cc
Dis
Dis
capacitor discharge (repair time...).
OHD
MPL
MC44605
Definitive
Inhibition
Output
cc
1
V
Buffer
Latch
V
ref
CC
falls down to about 3.0 V.
0
104% I
ref
E.H.T.
Delay
Q S
4mS
R
OVP
V
WSCD