NX2142A MICROSEMI [Microsemi Corporation], NX2142A Datasheet - Page 18

• Manufacturer Part Number: NX2142A
• Description: SINGLE CHANNEL PWM CONTROLLER WITH FEEDFORWARD AND 5V BIAS REGULATOR
• Manufacturer: MICROSEMI [Microsemi Corporation]

to reduce the EMI radiated by the power loop due to
the high switching currents through them.
RMS ripple current and a high frequency decoupling
ceramic cap which usually is 1uF
cally
plane connection is a must.
as to the load as possible and plane connection is re-
quired.
the high-side MOSFET need to be connected thru a
plane ans as close as possible. A snubber nedds to be
placed as close to this junction as possible.
nected to the GND plane with multiple vias. One is not
enough. This is very important. The same applies to
the output capacitors and input capacitors.
MOSFET gate as possible. The gate traces should be
wide and short. A place for gate drv resistors is needed
to fine tune noise if needed.
passing capacitor needs to be placed first around the
IC and as close as possible. The capacitor on comp to
GND or comp back to FB needs to be place as close to
the pin as well as resistor divider.
back to the resistor divider should not go through high
frequency signals.
plane.
kept away from the inductor and other noise sources,
and be placed close to the IC.
analog ground. These two grounds must be connected
together on the PC board layout at a single point. The
goal is to localize the high current path to a separate
loop that does not interfere with the more sensitive ana-
log control function.
Rev. 1.1
10/28/07
2. Low ESR capacitor which can handle input
3. The output capacitors should be placed as close
4. Drain of the low-side MOSFET and source of
5. Source of the lower MOSFET needs to be con-
6. Hdrv and Ldrv pins should be as close to
7. Vcc capacitor, BST capacitor or any other by-
8. The output sense line which is sensing output
9. All GNDs need to go directly thru via to GND
10. The feedback part of the system should be
11. In multilayer PCB, separate power ground and
touching the drain pin of the upper MOSFET, a
need to be practi-
NX2142/2142A
18