Datasheet
MAX639/MAX640/MAX653
5V/3.3V/3V/Adjustable, High-Efficiency,
Low I
Q
, Step-Down DC-DC Converters
2 _______________________________________________________________________________________
ABSOLUTE MAXIMUM RATINGS
ELECTRICAL CHARACTERISTICS
(V+ = 9V for the MAX639, V+ = 5V for the MAX640/MAX653, I
LOAD
= 0mA, T
A
= T
MIN
to T
MAX
, typical values are at T
A
= +25°C,
unless otherwise noted.)
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
PARAMETER MIN TYP MAX UNITS
91
Dropout Voltage 0.5 V
Output Voltage (Note 2)
2.88 3.00 3.12
V
3.17 3.30 3.43
94
87
91
85
Supply Current
Supply Voltage 4.0 11.5 V
10 20 µA
4.80 5.00 5.20
Efficiency
89
%
CONDITIONS
MAX653
I
OUT
= 100mA, L = 100µH
MAX653, V+ = 4.0V to 11.5V, 0mA < I
OUT
< 100mA
MAX640, V+ = 4.0V to 11.5V, 0mA < I
OUT
< 100mA
MAX639
MAX640
SHDN = V+, no load
MAX639, V+ = 6.0V to 11.5V, 0mA < I
OUT
< 100mA
V+...........................................................................................12V
LX .........................................................(V+ - 12V) to (V+ + 0.3V)
LBI, LBO, VFB, SHDN, VOUT........................-0.3V to (V+ + 0.3V)
LX Output Current (Note 1) ......................................................1A
LBO Output Current ............................................................10mA
Continuous Power Dissipation (T
A
= +70°C)
Plastic DIP (derate 9.09mW/°C above +70°C) .............727mW
SO (derate 5.88mW/°C above +70°C)..........................471mW
CERDIP (derate 8.00mW/°C above +70°C)..................640mW
Operating Temperature Ranges:
MAX639C_ _ .......................................................0°C to +70°C
MAX639E_ _ ....................................................-40°C to +85°C
MAX639MJA ..................................................-55°C to +125°C
Storage Temperature Range .............................-65°C to +160°C
Lead Temperature (soldering, 10s) .................................+300°C
I
OUT
= 100mA, L = 100µH
I
OUT
= 25mA, L = 470µH
I
OUT
= 100mA, L = 100µH
I
OUT
= 25mA, L = 470µH
I
OUT
= 100mA, L = 100µH
I
OUT
= 25mA, L = 470µH
Switch On-Time
V+ = 9V, V
OUT
= 5V
V+ = 6V, V
OUT
= 3V
42.5 50.0 57.5
V+ = 9V, V
OUT
= 3.3V
V+ = 4V, V
OUT
= 3.3V
µs
10.6 12.5 14.4
V+ = 9V, V
OUT
= 3V
V+ = 4V, V
OUT
= 3V
14.2 16.7 19.2
7.5 8.8 10.1
60.7 71.4 82.1
7.1 8.3 9.5
MAX653
MAX639
MAX640
Switch Off-Time
V+ = 9V, V
OUT
= 5V
V+ = 6V, V
OUT
= 3V
14.6 17.2 19.8
V+ = 9V, V
OUT
= 3.3V
V+ = 4V, V
OUT
= 3.3V
µs
9.0 11.7 13.5
V+ = 9V, V
OUT
= 3V
V+ = 4V, V
OUT
= 3V
16.6 19.5 22.4
13.3 15.6 17.9
13.3 15.6 17.9
14.6 17.2 19.8
MAX653
MAX639
MAX640
Note 1: Peak inductor current must be limited to 600mA by using an inductor of 100µH or greater.