NCP3121
Dual 3.0 A, Step-Down
DC/DC Switching Regulator
The NCP3121 is a dual buck converter designed for low voltage
applications requiring high efficiency. This device is capable of
producing an output voltage as low as 0.8 V. The NCP3121 provides
dual 3.0 A switching regulators with an adjustable 200 kHz
−
750 kHz
switching frequency. The switching frequency is set by an external
resistor. The NCP3121 also incorporates an auto−tracking and
sequencing feature. Protection features include cycle−by−cycle
current limit and undervoltage lockout (UVLO). The NCP3121 comes
in a 32−pin QFN package.
Features
http://onsemi.com
MARKING DIAGRAM
1
1
32
NCP3121
AWLYYWWG
G
•
•
•
•
•
•
•
•
•
•
•
Input Voltage Range from 4.5 V to 13.2 V
12 V
in
to 5.0 V
out
= 85% Efficiency Min @ 3.0 A
200−750 kHz Operation
Stable with Low ESR Ceramic Output Capacitor
0.8
±1.5%
FB Reference Voltage
External Soft−Start
Out of Phase Operation of OUT1 & OUT2
Auto−Tracking and Sequencing
Enable/Disable Capability
Hiccup Overload Protection
Low Shutdown Power (I
q
< 100
mA)
QFN32
CASE 488AM
NCP3121 = Specific Device Code
A
= Assembly Location
WL
= Wafer Lot
YY
= Year
WW
= Work Week
G
= Pb−Free Package
(Note: Microdot may be in either location)
ORDERING INFORMATION
See detailed ordering and shipping information in the package
dimensions section on page 40 of this data sheet.
Typical Applications
•
Set−Top Boxes, Portable Applications, Networking and
Telecommunications
•
DSP/mP/FPGA Core
VIN
RVIN
FB1
R_TRACK
PG1
Enable
Disable
Enable
Disable
EN2
PG2
EN1
R14
R24
C3
AVIN
GND
PG1
PG2
EN1
SEQ1
EN2
SEQ2
COMP2
COMP1
AGND
AGND
TRACK1,2
FB2
RT
SW2
SS1
OUT1
SW1
L11
D11
R11
C11
NCP3121
GND
VIN
R12
C1
GND
L21
D21
C12
GND
R22
R13
C13
GND
GND
GND
C2
GND
GND
OUT2
GND
GND
SS2
R21
C21
RT
C22
R23
GND
C23
GND
GND
Figure 1. Typical Application Circuit
©
Semiconductor Components Industries, LLC, 2008
October, 2008
−
Rev. 1
1
Publication Order Number:
NCP3121/D