operate over a 2.6V to 16.5V input voltage range. The
controllers deliver load current from 1mA to more than
2A. The MAX1626 has pin-selectable 3.3V and 5V out-
puts. The MAX1627 supports adjustable outputs from
1.3V to 16V.
A unique current-limited, pulse-frequency-modulation
(PFM) control scheme operates up to 100% duty cycle,
resulting in very low dropout voltage. This control
scheme eliminates minimum load requirements and
reduces supply current under light loads to 90µA
(versus 2mA to 10mA for common pulse-width modula-
tion controllers).
The devices are available in a 8-pin SOIC package
(-40°C to +85°C) and dice (0°C to +70°C).
•
Reduce Power Dissipation
•
> 90% Efficiency from 3mA to 2A Loads
•
Low Dropout Voltage
•
100% Maximum Duty Cycle
•
Reduce Number of DC-DC Controllers to Stock
•
Wide 2.6V to 16.5V Input Voltage Options
•
Selectable 3.3V and 5V or Adjustable 1.3V to 16V
Applications
• 5V to 3.3V Green PC Applications
• Battery-Powered Applications
• Handheld Computers
• High-Efficiency Step-Down Regulation
• Low-Cost Notebook Computer Supplies
• Minimum Component DC-DC Converters
• PCMCIA Power Supplies
• PDAs and Other Handheld Devices
• Portable Terminals
Output Voltage Options
•
Reduce System Power Consumption
•
90µA Max Quiescent Current
•
1µA Max Shutdown Current
•
Operates Reliably in Adverse Environment
•
Soft-Start Limits Startup Current
•
Current-Limited Control Scheme
•
Increase Design Flexibility
•
External P-Channel MOSFET Allows Output Power
of > 12.5W
Ordering Information
PART
MAX1626C/D
TEMP RANGE
0°C to +70°C
PIN-PACKAGE
Dice*
8 SO
Dice*
8 SO
MAX1626ESA
-40°C to +85°C
MAX1627C/D
0°C to +70°C
MAX1627ESA
-40°C to +85°C
* Dice are tested at T
A
= +25°C.
Pin Configuration
TOP VIEW
Typical Operating Circuit
INPUT
3.3V to 16.5V
V+
OUT
3/5 (FB)
1
2
8
GND
EXT
CS
V+
MAX1626
ON/OFF
SHDN
CS
EXT
3/5
REF
GND
OUT
P
OUTPUT
3.3V
SHDN 3
REF 4
MAX1626
MAX1627
7
6
5
SO
( ) ARE FOR MAX1627
19-1075; Rev 1; 5/15
MAX1626/MAX1627
5V/3.3V or Adjustable,
100% Duty-Cycle, High-Efficiency,
Step-Down DC-DC Controllers
Supply Voltage, V+ to GND.......................................-0.3V, +17V
OUT, FB,
3/5,
SHDN, REF, CS, EXT to GND ...-0.3V, (V+ + 0.3V)
Maximum Current at REF (I
REF
) ..........................................15mA
Maximum Current at EXT (I
EXT
) ..........................................50mA
Continuous Power Dissipation (T
A
= +70°C)
SO (derate 5.88mW/°C above +70°C) ..........................471mW
Operating Temperature Range
MAX1626ESA/MAX1627ESA ............................-40°C to +85°C
Storage Temperature Range .............................-65°C to +160°C
Lead Temperature (soldering, 10sec) .............................+300°C
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.
Electrical Characteristics
PARAMETER
Input Voltage Range
Supply Current into V+
Undervoltage Lockout
Output Voltage
OUT Input Current
FB Threshold Voltage
FB Leakage Current
CS Input Current
CS Threshold Voltage
SHDN Input Voltage High
SHDN Input Voltage Low
SHDN Input Current
3/5
Input Voltage High
3/5
Input Voltage Low
3/5
Leakage Current
EXT Resistance
Minimum EXT Off Time
EXT Duty-Cycle Limit
Line Regulation
Load Regulation
Reference Voltage
REF Load Regulation
REF Line Regulation
V
REF
6.0V < V+ < 12.0V, I
LOAD
= 1A
30mA < I
LOAD
< 2.0A, V+ = 8V
I
LOAD
= 0µA
0µA
≤
I
REF
≤
100µA
V+ = 3V to 16.5V, I
LOAD
= 0µA
1.27
3/5
= 0V or V+
V+ = 5V
Output forced to 0V
Output in regulation
8
1.5
100
5
15
1.30
4
10
1.33
10
100
10
10
2.0
12
2.5
SHDN = 0V or V+
V+ - 0.5
0.5
±1
V
CS
V
OUT
I
OUT
Circuit of Figure 1,
3/5
= V+ (Note 1)
Circuit of Figure 1,
3/5
= 0V (Note 1)
MAX1626,
3/5
= V+, output forced to 5V
MAX1627, includes hysteresis
MAX1627
4.85
3.20
24
1.27
0
0
85
1.6
0.4
±1
100
SYMBOL
V+
I+
Operating, no load
V+ = SHDN = 16.5V (shutdown)
2.7
5.00
3.30
37
1.30
CONDITIONS
MIN
3.0
70
TYP
MAX
16.5
90
1
2.8
5.15
3.40
50
1.33
35
10
115
UNITS
V
µA
V
V
µA
V
nA
µA
mV
V
V
µA
V
V
µA
Ω
µs
%
mV/V
mV/A
V
mV
µV/V
www.maximintegrated.com
Maxim Integrated | 2
MAX1626/MAX1627
5V/3.3V or Adjustable,
100% Duty-Cycle, High-Efficiency,
Step-Down DC-DC Controllers
Electrical Characteristics
PARAMETER
Input Voltage
Supply Current into V+
Undervoltage Lockout
Output Voltage
OUT Input Current
FB Threshold Voltage
FB Leakage Current
CS Threshold Voltage
Reference
I
LOAD
= 0µA
V
OUT
I
OUT
Circuit of Figure 1,
3/5
= V+
Circuit of Figure 1,
3/5
= 0V
MAX1626,
3/5
= V+, output forced to 5V
MAX1627, includes hysteresis
MAX1627
4.80
3.16
24
1.25
0
80
1.25
SYMBOL
V+
I
OUT
Operating, no load
V+ = SHDN = 16.5V (shutdown)
CONDITIONS
MIN
3.0
TYP
MAX
16.5
100
2
2.9
5.20
3.44
50
1.35
50
120
1.35
UNITS
V
µA
V
V
µA
V
nA
mV
V
Note 1:
V+ must exceed V
OUT
to maintain regulation.
Note 2:
Specifications from 0°C to -40°C are guaranteed by design, not production tested.
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