MAX727 Datasheet, PDF (1/4 Pages) Maxim Integrated Products – 5V/3.3V/3V 2A Step-Down, PWM, Switch-Mode DC-DC Regulators

19-0149; Rev 2; 9/95
5V/3.3V/3V 2A Step-Down, PWM,
Switch-Mode DC-DC Regulators
_______________General Description
The MAX727/MAX728/MAX729 are monolithic, bipolar,
pulse-width modulation (PWM), switch-mode, step-down
DC-DC regulators. Each is rated at 2A. Very few external
components are needed for standard operation because
the power switch, oscillator, feedback, and control circuitry
are all on-chip. Employing a classic buck topology, these
regulators perform high-current step-down functions.
These regulators have excellent dynamic and transient
response characteristics, while featuring cycle-by-cycle cur-
rent limiting to protect against overcurrent faults and short-
circuit output faults. They also have a wide 8V to 40V input
range.
Each regulator is available in a 5-pin TO-220 package.
These devices have a preset 100kHz oscillator frequency
and a preset current limit of 2.6A. See the MAX724/
MAX726 data sheet for more applications information.
_______________________Applications
Distributed Power from High-Voltage Buses
High-Current, High-Voltage Step-Down Applications
Multiple-Output Buck Converter
___________________________Features
o Input Range: Up to 40V
o 2A On-Chip Power Switch
o Fixed Outputs: 5V (MAX727)
3.3V (MAX728)
3V (MAX729)
o 100kHz Switching Frequency
o Excellent Dynamic Characteristics
o Few External Components
o 8.5mA Quiescent Current
o TO-220 Package
______________Ordering Information
PART
MAX727CCK
MAX727ECK
MAX728CCK
MAX728ECK
MAX729CCK
MAX729ECK
TEMP. RANGE
0°C to +70°C
-40°C to +85°C
0°C to +70°C
-40°C to +85°C
0°C to +70°C
-40°C to +85°C
PIN-PACKAGE
5 TO-220
5 TO-220
5 TO-220
5 TO-220
5 TO-220
5 TO-220
__________Typical Operating Circuit ^{__________________Pin Configuration}
INPUT
8V TO 40V
220µF
VIN
VSW
MAX727
VC
SENSE
2.7k
GND
0.01µF
100µH
OUTPUT
5V AT 2A
MBR745
470µF
STEP-DOWN CONVERTER
FRONT VIEW
5
MAX727
MAX728
4
MAX729 ³
2
1
5-PIN TO-220
VIN
VSW
GND
VC
SENSE
CASE IS CONNECTED TO GROUND. STANDARD PACKAGE HAS STAGGERED LEADS.
CONTACT FACTORY FOR STRAIGHT LEADS.
________________________________________________________________ Maxim Integrated Products 1
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