NX2154A MICROSEMI [Microsemi Corporation], NX2154A Datasheet - Page 14

• Manufacturer Part Number: NX2154A
• Description: 300kHz SYNCHRONOUS PWM CONTROLLER
• Manufacturer: MICROSEMI [Microsemi Corporation]

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.
TYPICAL APPLICATION FOR HIGH CURRENT
Rev.1.2
02/26/07
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
+5V
+12V
Vin
Vin
33uF
C3
HI=SD
Figure 9 - High output current application of 2154
M3
220pF
C1
800
R2
5k
C2
15nF
R4
C6
1uF
L2 1uH
7
6
Comp
Fb
Vcc
5
Gnd
3
R1
1k
BST
1
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.
Hdrv
Ldrv
SW
D1 MBR0530T1
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
2
8
4
C7 4.7nF
C4
0.1uF
M1 IRF3706
M2
2 x IRF3706
C5
1uF
L1 1uH
NX2154/2154A
Cin
2 x 16SP180M
2 x (1500uF,13mohm)
Co
Vout
+1.8V,20A
14