mp6001dn MPS, mp6001dn Datasheet - Page 7

• Manufacturer Part Number: mp6001dn
• Description: Monolithic Flyback/forward Dc-dc Converter
• Manufacturer: MPS

Synchronize Programmable Oscillator
The MP6001 oscillating frequency is set by an
external resistor from the RT pin to ground. The
value of RT can be calculated from:
The MP6001 can be synchronized to an
external clock pulse. The frequency of the clock
pulse must be higher than the internal oscillator
frequency. The clock pulse width should be
within 50ns to 150ns. The external clock can be
coupled to the RT pin with a 100pF capacitor
and a peak level greater than 3.5V.
Duty Cycle Limiting with Line Feed Forward
The MP6001 has a D
limit at 67.5% when the LINE pin voltage is
equal to 1.3V. As V
Maximum duty cycle can be calculated by:
Limiting the duty cycle at high line voltage
protects
minimizes
transients.
MP6001 Rev. 0.91
9/21/2007
D
against
MAX
the
TM
RT
=
⎡
⎢
⎣
2
=
output
7 .
LINE
10
magnetic
V
MAX
2
MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.
k
7 .
+
Ω
increases, D
V
V
×
(maximum duty cycle)
LINE
550
sensitivity
f
⎤
⎥
⎦
KHz
S
×
MP6001 – MONOLITHIC FLYBACK/FORWARD DC-DC CONVERTER
saturation
100
MAX
%
© 2007 MPS. All Rights Reserved.
to
reduces.
www.MonolithicPower.com
and
line
Auto-Restart
When V
and an open loop condition occurs, the voltage
at the VCC pin increases to 6.5V. When V
crosses the threshold voltage, the auto-restart
circuit turns off the power switch and puts the
controller in standby mode. When V
4.5V, the startup switch turns on to charge V
up again. When V
turns off and the standby current discharges
V
cycles between the two threshold voltages 15
times, the auto-restart circuit is disabled and the
controller begins soft-start.
CC
back to 4.5V. After repeating the ramp
CC
is biased from an auxiliary winding
CC
crosses 6.0V, the switch
CC
drops to
CC
CC
7