Rainbow Electronics MAX789 User Manual
Applications, Pin configuration, Typical operating circuit
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___________Product Selection Guide
_______________General Description
The MAX787/MAX788/MAX789 are monolithic, bipolar,
pulse-width modulation (PWM), switch-mode, step-down
DC-DC regulators. Each is rated at 5A. 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.
The MAX787/MAX788/MAX789 have excellent dynamic
and transient response characteristics, while featuring
cycle-by-cycle current 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 6.5A. See the MAX724/
MAX726 data sheet for more applications information.
_______________________Applications
Distributed Power from High-Voltage Buses
High-Current, High-Voltage Step-Down
Multiple-Output Buck Converter
MAX787/MAX788/MAX789
5V/3.3V/3V 5A Step-Down, PWM,
Switch-Mode DC-DC Regulators
________________________________________________________________
Maxim Integrated Products
1
V
IN
V
SW
GND
V
C
SENSE
CASE IS CONNECTED TO GROUND. STANDARD PACKAGE HAS STAGGERED LEADS.
CONTACT FACTORY FOR STRAIGHT LEADS.
5-PIN TO-220
FRONT VIEW
MAX787
MAX788
MAX789
1
2
3
4
5
__________________Pin Configuration
VIN
VC
VSW
220
µ
F
GND
2.7k
0.01
µ
F
OUTPUT
5V AT 5A
SENSE
50
µ
H
MBR745
470
µ
F
INPUT
8V TO 40V
MAX787
STEP-DOWN CONVERTER
__________Typical Operating Circuit
Call toll free 1-800-998-8800 for free samples or literature.
19-0182; Rev 3; 9/95
___________________________Features
♦
Input Range: Up to 40V
♦
5A On-Chip Power Switch
♦
Fixed Outputs: 5V (MAX787)
3.3V (MAX788)
3V (MAX789)
♦
100kHz Switching Frequency
♦
Excellent Dynamic Characteristics
♦
Few External Components
♦
8.5mA Quiescent Current
♦
TO-220 Package
______________Ordering Information
PART
V
OUT
(V)
I
OUT
MAX (A)
MAX724
Adjustable
5
MAX728
3.3
2
MAX726
Adjustable
2
MAX727
5
2
MAX787
5
5
MAX788
3.3
5
MAX789
3
5
MAX729
3
2
PART
MAX787
CCK
MAX787ECK
MAX788
CCK
MAX788ECK
-40°C to +85°C
0°C to +70°C
TEMP. RANGE
PIN-PACKAGE
5 TO-220
5 TO-220
-40°C to +85°C
0°C to +70°C
5 TO-220
5 TO-220
MAX789
CCK
MAX789ECK
-40°C to +85°C
0°C to +70°C
5 TO-220
5 TO-220