19-0224; Rev 3; 7/00
NUAL
KIT MA
UATION TA SHEET
EVAL
WS DA
FOLLO
5V-to-3.3V, Synchronous, Step-Down
Power-Supply Controller
____________________________Features
The MAX767 is a high-efficiency, synchronous buck
controller IC dedicated to converting a fixed 5V supply
into a tightly regulated 3.3V output. Two key features set
this device apart from similar, low-voltage step-down
switching regulators: high operating frequency and all
N-channel construction in the application circuit. The
300kHz operating frequency results in very small, lowcost external surface-mount components.
The inductor, at 3.3µH for 5A, is physically at least five
times smaller than inductors found in competing solutions. All N-channel construction and synchronous rectification result in reduced cost and highest efficiency.
Efficiency exceeds 90% over a wide range of loading,
eliminating the need for heatsinking. Output capacitance
requirements are low, reducing board space and cost.
The MAX767 is a monolithic BiCMOS IC available in
20-pin SSOP packages. For other fixed output voltages
and package options, please consult the factory.
o
o
o
o
o
o
o
o
o
>90% Efficiency
700µA Quiescent Supply Current
120µA Standby Supply Current
4.5V-to-5.5V Input Range
Low-Cost Application Circuit
All N-Channel Switches
Small External Components
Tiny Shrink-Small-Outline Package (SSOP)
Predesigned Applications:
Standard 5V to 3.3V DC-DC Converters up to 10A
High-Accuracy Pentium P54C VR-Spec Supply
o Fixed Output Voltages Available:
3.3V (Standard)
3.45V (High-Speed Pentium™)
3.6V (PowerPC™)
_______________Ordering Information
PINPACKAGE
REF
TOL
0°C to +70°C
20 SSOP
±1.8% 3.3
0°C to +70°C
20 SSOP
±1.8% 3.45
MAX767SCAP
0°C to +70°C
20 SSOP
±1.8% 3.6
MAX767TCAP
0°C to +70°C
20 SSOP
±1.2% 3.3
MAX767C/D
________________________Applications
0°C to +70°C
Dice*
PART
TEMP. RANGE
Local 5V-to-3.3V DC-DC Conversion
MAX767CAP
Microprocessor Daughterboards
MAX767RCAP
Power Supplies up to 10A or More
_________Typical Application Circuit
—
VOUT
(V)
—
Ordering Information continued at end of data sheet.
* Contact factory for dice specifications.
__________________Pin Configuration
INPUT
4.5V TO 5.5V
TOP VIEW
VCC
ON
BST
DH
3.3µH
OUTPUT
3.3V
AT 5A
LX
MAX767
CS 1
20 FB
SS 2
19 DH
ON 3
18 LX
GND 4
DL
MAX767
17 BST
GND 5
16 DL
PGND
GND 6
15 VCC
CS
GND 7
14 VCC
FB
REF 8
13 PGND
SYNC 9
GND
12 N.C.
VCC 10
REF
11 GND
SSOP
Pentium is a trademark of Intel. PowerPC is a trademark of IBM.
________________________________________________________________ Maxim Integrated Products
1
For price, delivery, and to place orders, please contact Maxim Distribution at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
MAX767
________________General Description
