MAX639CSA+ Maxim, MAX639CSA+ Datasheet

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MAX639CSA+

Manufacturer Part Number
MAX639CSA+
Description
DC-DC Converter, Step-Down, 4 to 11.5 Vin, 5 Vout, 225 mA Iout, 0 to 70 C, SOIC8
Manufacturer
Maxim
Datasheet

Specifications of MAX639CSA+

Lead Free Status / Rohs Status
RoHS Compliant part Electrostatic Device
19-4505; Rev 4; 7/05
The MAX639/MAX640/MAX653 step-down switching
regulators provide high efficiency over a wide range of
load currents, delivering up to 225mA. A current-limiting
pulse-frequency-modulated (PFM) control scheme gives
the devices the benefits of pulse-width-modulated
(PWM) converters (high efficiency at heavy loads), while
using only 10µA of supply current (vs. 2mA to 10mA for
PWM converters). The result is high efficiency over a
wide range of loads.
The MAX639/MAX640/MAX653 input range is 4V to
11.5V, and the devices provide lower preset output volt-
ages of 5V, 3.3V, and 3V, respectively. Or, the output
can be user-adjusted to any voltage from 1.3V to the
input voltage.
The MAX639/MAX640/MAX653 have an internal 1A power
MOSFET switch, making them ideal for minimum-compo-
nent, low- and medium-power applications. For increased
output drive capability, use the MAX649/MAX651/MAX652
step-down controllers, which drive an external P-channel
FET to deliver up to 5W.
________________________Applications
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
__________Typical Operating Circuit
_______________General Description
LOW-BATTERY
DETECTOR
ON/OFF
INPUT
9V Battery to 5V, 3.3V, or 3V Conversion
High-Efficiency Linear Regulator Replacement
Portable Instruments and Handy-Terminals
5V-to-3.3V Converters
5.5V TO 11.5V
INPUT
LBI
SHDN
________________________________________________________________ Maxim Integrated Products
VFB
MAX639
5V/3.3V/3V/Adjustable, High-Efficiency,
V+
GND
Low I
VOUT
LBO
LX
LOW-BATTERY
DETECTOR
OUTPUT
Q
, Step-Down DC-DC Converters
OUTPUT
225mA
5V
♦ High Efficiency for a Wide Range of Load Currents
♦ 10µA Quiescent Current
♦ Output Currents Up to 225mA
♦ Preset or Adjustable Output Voltage:
♦ Low-Battery Detection Comparator
♦ Current-Limiting PFM Control Scheme
Ordering Information continued on last page.
*Contact factory for dice specifications.
____________________________Features
__________________Pin Configuration
______________Ordering Information
MAX639CPA
MAX639CSA
MAX639C/D
MAX639EPA
MAX639ESA
MAX639MJA
TOP VIEW
PART
5.0V (MAX639)
3.3V (MAX640)
3.0V (MAX653)
VOUT
GND
LBO
LBI
-40°C to +85°C
-40°C to +85°C
-55°C to +125°C
1
2
3
4
TEMP RANGE
0°C to +70°C
0°C to +70°C
0°C to +70°C
MAX639
MAX640
MAX653
DIP/SO
8
7
6
5
PIN-PACKAGE
8 Plastic DIP
8 SO
Dice*
8 Plastic DIP
8 SO
8 CERDIP
SHDN
VFB
V+
LX
1

Related parts for MAX639CSA+

MAX639CSA+ Summary of contents

Page 1

... LBO DETECTOR INPUT VFB GND ________________________________________________________________ Maxim Integrated Products For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at 1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com. , Step-Down DC-DC Converters Q ____________________________Features ♦ High Efficiency for a Wide Range of Load Currents ♦ 10µA Quiescent Current ♦ ...

Page 2

... Note 1: Peak inductor current must be limited to 600mA by using an inductor of 100µH or greater. 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 ...

Page 3

High-Efficiency, Low I ELECTRICAL CHARACTERISTICS (continued) ( for the MAX639 for the MAX640/MAX653, I unless otherwise noted.) PARAMETER Switch On-Resistance ...

Page 4

... L = 220µ (V) 4 _______________________________________________________________________________________ = +25°C, unless otherwise noted.) A EFFICIENCY vs. INPUT VOLTAGE 100 I = 100mA OUT MAX639 95 90 MAX640 85 MAX653 (V) MAXIMUM OUTPUT CURRENT vs. INPUT VOLTAGE 470µH 65 MAX639 55 MAX640 45 MAX653 (V) 150 I = 25mA OUT 125 100 470µ EFFICIENCY vs. INPUT VOLTAGE 100 L = 470µH ...

Page 5

High-Efficiency, Low I _____________________________Typical Operating Characteristics (continued) (Circuit of Figure 3, internal feedback 100µH, T MAX639 START-UP TIME vs. OUTPUT CURRENT 12 MEASURED FROM THE RISING EDGE SHDN 5V). OUT 10 ...

Page 6

High-Efficiency, Low I , Step-Down DC-DC Converters Q _____________________________Typical Operating Characteristics (continued) (Circuit of Figure 3, internal feedback 100µH, T MAX653 LOAD-TRANSIENT RESPONSE 1ms/div A: I 0mA TO 100mA, 50mA/div LOAD 100mV/div, AC COUPLED ...

Page 7

High-Efficiency, Low I ______________________________________________________________Pin Description PIN NAME Sense Input for regulated-output operation. Internally connected to an on-chip voltage divider and to 1 VOUT the variable duty-cycle, on-demand oscillator. It must be connected to the external regulated output. Low-Battery Output. ...

Page 8

High-Efficiency, Low I , Step-Down DC-DC Converters Q Figure 2 shows what happens to the ideal circuit of Figure 1 if the switch turns on with a 66% duty cycle and The inductor current ...

Page 9

... PART NUMBER SE014 SE024 Collmer Semiconductor 14368 Proton Road Dallas, TX 75244 (214) 233-1589 . NOTE: This list does not constitute an endorsement by Maxim Integrated Products and is not intended comprehensive list of all manufacturers of these components. INDUCTORS — THROUGH HOLE SIZE VALUE I MAX (inches) (µH) (A) 0 ...

Page 10

... For low-power circuits with peak currents less than 100mA, signal diodes such as the 1N4148 perform well. The 1N5817 diode works well for high- power circuits, or for maximum efficiency at low power. 1N5817 equivalent diodes are also available in surface- mount packages (Table 1). Although the 1N4001 and ...

Page 11

... OUT Layout Figure 8. Efficiency of Figure 6 Circuit -3.3V (MAX640), or -3V (MAX653). Avoid exceeding the maximum differential voltage of 11.5V from Other negative voltages can be generated by placing a voltage divider across C point to VFB in the same manner as the normal step- down configuration. Two AA Batteries to 5V, 3.3V ...

Page 12

High-Efficiency, Low I , Step-Down DC-DC Converters Q _Ordering Information (continued) PART TEMP RANGE MAX640CPA 0°C to +70°C MAX640CSA 0°C to +70°C MAX640C/D 0°C to +70°C MAX640EPA -40°C to +85°C MAX640ESA -40°C to +85°C MAX640MJA -55°C to +125°C MAX653CPA ...

Page 13

... A1 FRONT VIEW Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are implied. Maxim reserves the right to change the circuitry and specifications without notice at any time. 13 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © ...

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