mp1010bef MPS, mp1010bef Datasheet - Page 8

• Manufacturer Part Number: mp1010bef
• Description: Cold Cathode Fluorescent Lamp Driver
• Manufacturer: MPS

Lamp Startup
The strike voltage of the lamp will always be
guaranteed at any temperature because the
MP1010B
switching the outputs. The device will continue
to switch at the resonant frequency of the tank
until the strike voltage is achieved. This
eliminates the need for external ramp timing
circuits to ensure startup.
Chip Enable
The chip has an on/off function, which is
controlled by the En pin (pin #5, cannot be left
floating). The enable signal goes directly to a
Schmitt trigger. The chip will turn ON when En is
High (>2V) and OFF when it is Low (<0.5V). It is
recommended that power be applied to the
MP1010B via the IN pins (#7 and #14) a
minimum of 3ms prior to the En pin (#5) being
switched high.
MP1010B Rev. 2.2
9/24/2007
Voltage
Voltage
Enable
Figure 2—Input Voltage vs. Enable
Input
0
0
V
V
uses
Sequence
a
3ms
MPS Proprietary Information. Unauthorized Photocopy and Duplication Prohibited.
resonant
>2V
topology
MP1010B – COLD CATHODE FLUORESCENT LAMP DRIVER
© 2007 MPS. All Rights Reserved.
www.MonolithicPower.com
t
t
for
Design Guidelines
Ccomp is the system compensation capacitor
that connects COMP and AGND. A 1.5nF or
2.2nF X7R ceramic cap is recommended. Its
value affects the lamp current soft-on rising
time and soft-off falling time in burst mode. This
capacitor must be placed as close as possible
to the related pin.
Cref is the bypass capacitor for the internal 5V
supply. Cdrv is the bypass cap for the 6.2V gate
drive supply. Cref and Cdrv should be 0.1µF,
X7R
capacitors must be placed as close as possible
to the related pin.
CbaL and CbaR are bypass capacitors for the
inverter input power. These capacitors will
absorb most of the input switching current of
the inverter and will require adequate current
ripple rating. The typical current rating for these
caps is >500mA
2.2µF, X7R (≥25V) ceramic with low ESR value.
These capacitors must be placed as close as
possible to the related pin and with wide copper
traces for the connection.
Cba1 and Cba2 are also bypass capacitors for
the inverter input power. Their major role is for
input filtering. The typical value is 2.2µF to
4.7µF. X5R or Y5U (≥25V) ceramic capacitors
can be used.
CbtR and CbtL are bootstrap capacitors for the
upper switches’ gate drive. 10nF, X7R (≥16V)
ceramic capacitors are recommended. These
capacitors must be placed as close as possible
to the related pin.
Cp is the DC blocking cap in the transformer
primary side. It conducts large winding current
(typically 0.8A
ceramic is required. The capacitance value is
typically 0.47µF to 2.2µF. The voltage rating
needs to be 16V or higher. It is better to use
two parallel caps for minimal ESR losses.
The OUTL and OUTR pins are the bridge
outputs,
current. Wide copper traces should be used for
the connections from IC pins to the transformer.
In addition, the connection loop should be
minimized to avoid the high dv/dt impact to
other circuits.
(≥16V)
which
RMS
RMS
ceramic
), so low ESR X7R/X5R
conduct
. The typical value is 1µF to
capacitors.
typically
0.8A
These
RMS
8