NX2154 Datasheet, PDF (1/17 Pages) Microsemi Corporation – 300kHz SYNCHRONOUS PWM CONTROLLER

Evaluation board available.
NX2154/2154A
300kHz SYNCHRONOUS PWM CONTROLLER
PRELIMINARY DATA SHEET
Pb Free Product
DESCRIPTION
FEATURES
The NX2154/2154A controller IC is a synchronous Buck ^{n Bus voltage operation from 2V to 40V}
controller IC designed for step down DC to DC con- ^{n Fixed 300kHz voltage mode controller}
verter applications. It is optimized to convert bus volt- ^{n Internal Digital Soft Start Function}
ages from 2V to 40V to outputs as low as 0.8V voltage. ^{n Prebias Startup}
The NX2154/2154A operates at fixed 300kHz. The ^{n Less than 50 nS adaptive deadband}
NX2154/2154A employs fixed loss-less current limiting ^{n Current limit triggers hiccup by sensing Rdson of}
by sensing the Rdson of synchronous MOSFET followed ^{Synchronous MOSFET}
by hiccup feature.NX2154A has higher current limit ^{n No negative spike at Vout during startup and}
threshold than NX2154. Feedback under voltage also ^shutdown
triggers hiccup.
n Pb-free and RoHS compliant
Other features of the device are: 5V gate drive, Adaptive
deadband control, Internal digital soft start, Vcc _n
undervoltage lock out and shutdown capability via the _n
comp pin.
n
APPLICATIONS
Graphic Card on board converters
Memory Vddq Supply in mother board applications
On board DC to DC such as
5V to 3.3V, 2.5V or 1.8V
n Hard Disk Drive
n Set Top Box
TYPICAL APPLICATION
Vin
+5V
MBR0530T1
HI=SD
M3
82pF
1uF
5
Vcc
7 _Comp
12nF
13.3k
1
BST
Hdrv ²
SW ⁸
0.1uF
6
Fb
Ldrv ⁴
Gnd
3
Vin
+33V
1uF
50ME180WX
M1A STM6920
15uH
M1B
Vout
+5V,3A
6ME1000WG(1000uF,30mohm)
1k
191
Figure1 - Typical application of 2154
Device
NX2154CSTR
NX2154ACSTR
Temperature
0 to 70^oC
0 to 70^o C
Package
SOIC-8L
SOIC-8L
ORDERING INFORMATION
Frequency
300kHz
300kHz
OCP Threshold
360mV
540mV
Pb-Free
Yes
Yes
Rev.1.2
1
02/26/07