Rainbow Electronics MAX767 - Manual

________________General Description
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, low-
cost external surface-mount components.
The inductor, at 3.3µH for 5A, is physically at least five
times smaller than inductors found in competing solu-
tions. All N-channel construction and synchronous rectifi-
cation 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.
________________________Applications
Local 5V-to-3.3V DC-DC Conversion
Microprocessor Daughterboards
Power Supplies up to 10A or More
____________________________Features
♦ >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
♦ Fixed Output Voltages Available:
3.3V (Standard)
3.45V (High-Speed Pentium™)
3.6V (PowerPC™)
_______________Ordering Information
MAX767
5V-to-3.3V, Synchronous, Step-Down
Power-Supply Controller
________________________________________________________________ Maxim Integrated Products 1
20
19
18
17
16
15
14
13
12
11
1
2
3
4
5
6
7
8
9
10
FB
DH
LX
BST GND
ON
SS
CS
TOP VIEW
MAX767
DL
V CC
V CC
PGND REF
GND
GND
GND
N.C.
GND V CC
SYNC
SSOP
__________________Pin Configuration
OUTPUT
3.3V
AT 5A
INPUT
4.5V TO 5.5V
LX
DL
GND
MAX767
V CC
REF
3.3 µH
BST
DH
PGND
CS
FB
ON
_________Typical Application Circuit
19-0224; Rev 3; 7/00
PART TEMP. RANGE
PIN-
PACKAGE
MAX767CAP 0°C to +70°C 20 SSOP
MAX767RCAP 0°C to +70°C 20 SSOP
MAX767SCAP 0°C to +70°C 20 SSOP
Pentium is a trademark of Intel. PowerPC is a trademark of IBM.
MAX767C/D 0°C to +70°C Dice*
REF
TOL
±1.8%
±1.8%
±1.8%
—
Ordering Information continued at end of data sheet.
* Contact factory for dice specifications.
V OUT
(V)
3.3
3.45
3.6
—
MAX767TCAP 0°C to +70°C 20 SSOP ±1.2% 3.3
EVALUATION KIT MANUAL
FOLLOWS DATA SHEET
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.