MAX1623EAP+ Maxim Integrated Products, MAX1623EAP+ Datasheet

IC REG LV SYNC 3A STEPDWN 20SSOP

MAX1623EAP+

Manufacturer Part Number
MAX1623EAP+
Description
IC REG LV SYNC 3A STEPDWN 20SSOP
Manufacturer
Maxim Integrated Products
Type
Step-Down (Buck)r
Datasheet

Specifications of MAX1623EAP+

Internal Switch(s)
Yes
Synchronous Rectifier
Yes
Number Of Outputs
1
Voltage - Output
1.1 ~ 3.8 V
Current - Output
3A
Frequency - Switching
Up to 350kHz
Voltage - Input
4.5 ~ 5.5 V
Operating Temperature
-40°C ~ 85°C
Mounting Type
Surface Mount
Package / Case
20-SSOP
Power - Output
1.3W
Output Voltage
1.1 V to 3.8 V
Input Voltage
4.5 V to 5.5 V
Supply Current
400 uA
Switching Frequency
350 KHz
Maximum Operating Temperature
+ 85 C
Minimum Operating Temperature
- 40 C
Lead Free Status / RoHS Status
Lead free / RoHS Compliant
19-1436; Rev 2; 3/02
The MAX1623 switch-mode buck regulator with syn-
chronous rectification provides local CPU and bus-ter-
mination power in notebook and desktop computers.
An internal 55mΩ (typ), 3A PMOS power switch and
60mΩ (typ), 3A NMOS synchronous-rectifier switch
deliver continuous load currents up to 3A from a 5V
supply with 95% typical efficiency. Output accuracy is
±1%, including line and load regulation.
The MAX1623 features constant-off-time, current-mode
pulse-width-modulation (PWM) control with switching
frequencies as high as 350kHz. An external resistor at
the TOFF pin sets the off-time, allowing optimum design
flexibility in terms of switching frequency, output switch-
ing noise, and inductor size. This device is available in
a space-saving 20-pin SSOP package.
Idle Mode is a trademark of Maxim Integrated Products.
________________________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.
Synchronous Rectification and Internal Switches
INPUT
5V
5V to 3.3V Conversion
Notebook Computer CPU I/O Supply
Desktop Computer Bus-Termination Supply
CPU Daughter Card Supply
DSP Supply
3A, Low-Voltage, Step-Down Regulator with
Typical Operating Circuit
________________________________________________________________ Maxim Integrated Products
General Description
SHDN
TOFF
IN
V
FBSEL
COMP
CC
MAX1623
REF
PGND
GND
LX
FB
OUTPUT
2.5V
o ±1% Output Accuracy, Including Line and Load
o 94% Efficiency
o Internal Switches
o Guaranteed 3A Load Capability
o Minimal External Components
o Pin-Selectable Fixed 3.3V, 2.5V, or
o 4.5V to 5.5V Input Voltage Range
o 400µA (typ) Supply Current
o <1µA Shutdown Supply Current
o Constant-Off-Time PWM Operation
o Switching Frequencies Up to 350kHz
o Idle Mode™ Operation at Light Loads
o Thermal Shutdown Protection
o Available in 20-Pin SSOP
____________________________Features
MAX1623EAP
Regulation
Adjustable (1.1V to 3.8V) Output Voltage
TOP VIEW
55mΩ PMOS Power Switch
60mΩ NMOS Synchronous-Rectifier Switch
PART
FBSEL
SHDN
TOFF
LX
LX
LX
FB
IN
IN
IN
10
1
2
3
4
5
6
7
8
9
TEMP RANGE
-40°C to +85°C
Ordering Information
MAX1623
SSOP
Pin Configuration
20
19
18
17
16
15
14
13
12
11
20 SSOP
PIN-PACKAGE
LX
LX
PGND
LX
PGND
V
COMP
REF
GND
PGND
CC
1

Related parts for MAX1623EAP+

MAX1623EAP+ Summary of contents

Page 1

... FB SHDN TOFF GND COMP REF Idle Mode is a trademark of Maxim Integrated Products. ________________________________________________________________ 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. ____________________________Features o ±1% Output Accuracy, Including Line and Load Regulation ...

Page 2

Low-Voltage, Step-Down Regulator with Synchronous Rectification and Internal Switches ABSOLUTE MAXIMUM RATINGS IN to PGND ..................................................................... GND ................................................................-0. PGND to GND.....................................................................±0. .............................................................................±0. Current (Note 1).............................................................±5.5A SHDN to ...

Page 3

Low-Voltage, Step-Down Regulator with Synchronous Rectification and Internal Switches ELECTRICAL CHARACTERISTICS ( 5V, FBSEL unconnected PARAMETER Input Voltage Range Output Voltage Output Adjustment Range Reference Output Voltage Current-Limit Threshold PMOS Switch On-Resistance NMOS ...

Page 4

Low-Voltage, Step-Down Regulator with Synchronous Rectification and Internal Switches __________________________________________Typical Operating Characteristics (Circuit of Figure +25°C, unless otherwise noted.) A EFFICIENCY vs. OUTPUT CURRENT 100 3.3V 110kΩ OUT TOFF ...

Page 5

Low-Voltage, Step-Down Regulator with Synchronous Rectification and Internal Switches ____________________________ Typical Operating Characteristics (continued) (Circuit of Figure +25°C, unless otherwise noted.) A START-UP AND SHUTDOWN TRANSIENT 1ms/div 3.3V, ...

Page 6

Low-Voltage, Step-Down Regulator with Synchronous Rectification and Internal Switches PIN NAME Connection to the internal power switches. 16,18 Power Input. Internally connected to the PMOS switch source. Connect to 5V. ...

Page 7

Low-Voltage, Step-Down Regulator with Synchronous Rectification and Internal Switches V IN 4.5V TO 5.5V COMP REF SHDN REF NOTE: HEAVY LINES DENOTE HIGH SWITCHING CURRENT PATHS. Figure 1. Functional Diagram At light loads, the device ...

Page 8

Low-Voltage, Step-Down Regulator with Synchronous Rectification and Internal Switches INPUT 4.5V TO 5.5V 10Ω NOTE: HEAVY LINES DENOTE HIGH SWITCHING CURRENT PATHS. Figure 2. Standard 3.3V/3A Application Circuit Setting the AC Loop Gain The internal integrator amplifier effectively eliminates ...

Page 9

Low-Voltage, Step-Down Regulator with Synchronous Rectification and Internal Switches LX MAX1623 PGND GND 10kΩ to 500kΩ R1 OUT REF V = 1.1V REF Figure 3. Adjustable Output Voltage A high capacitor value ...

Page 10

Low-Voltage, Step-Down Regulator with Synchronous Rectification and Internal Switches 2 flow. A copper area of 0.4in showed thermal resis- tance of 60°C/W. Airflow over the IC can significantly reduce θ Power Dissipation The MAX1623’s power dissipation consists mostly of ...

Page 11

Low-Voltage, Step-Down Regulator with Synchronous Rectification and Internal Switches Stable operation requires the right output filter capaci- tor. When choosing the output capacitor, ensure the fol- lowing conditions are met: ≥ × OFF and 10mΩ ...

Page 12

... 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. 12 ____________________Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 © 2002 Maxim Integrated Products Printed USA is a registered trademark of Maxim Integrated Products ...

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