© Semiconductor Components Industries, LLC, 2013
October, 2013 − Rev. 10
1 Publication Order Number:
NCP81038/D
NCP81038
Synchronous Buck Controller
with Auto Power Saving
Mode and Built-In LDO
NCP81038 is a dual synchronous buck controller that is optimized
for converting the battery voltage or adaptor voltage into multiple
power rails required in desktop and notebook system. NCP81038
consists of two buck switching controllers with fixed 5.0 V output on
channel 2, 3.3 V on channel 1 and two on−board LDOs with three
outputs: 5 V / 60 mA and 3.3 V or 12 V / 10 mA. NCP81038 supports
high efficiency, fast transient response and provides power good
signals. ON Semiconductor proprietary adaptive−ripple control
enables seamless transition from CCM to DCM, where converter runs
at reduced switching frequency with much higher efficiency at light
load. The part operates with supply voltage ranging from 5.5 V to
28 V. NCP81038 is available in a 28−pin QFN package.
Features
• Wide Input Voltage Range: from 5.5 V to 28 V
• Built−in 5 V / 60 mA LDO
• Built−in selectable 3.3 V or 12 V / 10 mA LDO
• Three Selectable Fixed Frequency 300 KHz, 400 KHz or 600 KHz
• 180 Interleaved Operation Between the Two Channels in
Continue−Conduction−Mode (CCM)
• Selected Power−Saving Mode/Forced PWM Mode
• Transient−Response−Enhancement (TRE) Control
• Input Supply Voltage Feed Forward Control
• Resistive or Lossless Inductor’s DCR Current Sensing
• Over−Temperature Protection
• Internal Fixed 8.5 ms Soft−Start
• Fixed Output Voltages 5 V and 3.3 V
• Power Good Outputs for Both Channels
• Built−in Adaptive Gate Drivers
• Output Discharge Operation
• Built−in Over−Voltage, Under−Voltage Protection
• Accurate Over−Current Protection
• Thermal Shutdown
Applications
• Desktop / Notebook Computers
• System Power Supplies
• I/O Power Supplies
28 PIN QFN, 4x4
MN SUFFIX
CASE 485AR
Device Package Shipping
†
ORDERING INFORMATION
NCP81038MNTWG QFN−28
(Pb−Free)
4,000 /
Tape & Reel
MARKING
DIAGRAM
81038 = Specific Device Code
A = Assembly Location
L = Wafer Lot
Y = Year
W = Work Week
G = Pb−Free Package
http://onsemi.com
†For information on tape and reel specifications,
including part orientation and tape sizes, please
refer to our Tape and Reel Packaging Specification
Brochure, BRD8011/D.
PIN CONNECTIONS
(Top View)
(Note: Microdot may be in either location)
81038
ALYWG
G
1
GH1
BST1
SWN1
GL1/FSET
PGND1
CSP1
CSN1
GH2
BST2
SWN2
GL2
PGND2
CSP2
CSN2
FB2
COMP2
EN2/SS2
PG
EN1/SS1
COMP1
FB1
5V_LDOBYP
5V_LDOOUT
5V_LDOEN
SKIP
LDO2_EN
LDO2_OUT
VIN
GND
1
28
