LM43603 (ACTIVE)

3.5V to 36V, 3A Synchronous Step-Down Voltage Converter

 

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Description

The LM43603 regulator is an easy-to-use synchronous step-down DC-DC converter capable of driving up to 3 A of load current from an input voltage ranging from 3.5 V to 36 V (42 V abs max). The LM43603 provides exceptional efficiency, output accuracy and dropout voltage in a very small solution size. An extended family is available in 0.5-A, 1-A, and 2-A load current options in pin to pin compatible packages. Peak current mode control is employed to achieve simple control loop compensation and cycle-by-cycle current limiting. Optional features such as programmable switching frequency, synchronization, power-good flag, precision enable, internal soft-start, extendable soft-start, and tracking provide a flexible and easy to use platform for a wide range of applications. Discontinuous conduction and automatic frequency modulation at light loads improve light load efficiency. The family requires few external components and pin arrangement allows simple, optimum PCB layout. Protection features include thermal shutdown, VCC undervoltage lockout, cycle-by-cycle current limit, and output short circuit protection. The LM43603 device is available in the HTSSOP / PWP 16 leaded package (5.1 mm × 6.6 mm × 1.2 mm) and VSON-16 package with wettable flanks. HTSSOP package is pin-to-pin compatible with LM43600, LM43601, LM43602, LM46000, LM46001, LM46002. VSON-16 package is only pin-to-pin compatible with LM43602.

Features

  • 27-µA Quiescent Current in Regulation
  • High Efficiency at Light Load (DCM and PFM)
  • Meets EN55022/CISPR 22 EMI standards
  • Integrated Synchronous Rectification
  • Adjustable Frequency Range: 200 kHz to 2.2 MHz (500 kHz default)
  • Frequency Synchronization to External Clock
  • Internal Compensation
  • Stable with Almost Any Combination of Ceramic, Polymer, Tantalum, and Aluminum Capacitors
  • Power-Good Flag
  • Soft Start into a Pre-Biased Load
  • Internal Soft-Start: 4.1 ms
  • Extendable Soft-Start Time by External Capacitor
  • Output Voltage Tracking Capability
  • Precision Enable to a Program System UVLO
  • Output Short Circuit Protection with Hiccup Mode
  • Overtemperature Thermal Shutdown Protection
  • Create a Custom Design Using the LM43603 with the WEBENCH® Power Designer

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Parametrics Compare all products in Buck Converter (Integrated Switch)

 
Vin (Min) (V)
Vin (Max) (V)
Vout (Min) (V)
Vout (Max) (V)
Iout (Max) (A)
Regulated Outputs (#)
Switching Frequency (Min) (kHz)
Switching Frequency (Max) (kHz)
Iq (Typ) (mA)
Features
Control Mode
Duty Cycle (Max) (%)
Operating Temperature Range (C)
Rating
Package Group
LM43603 LM25576 LM2678 LM2679 LM53603 LM53635-Q1 LM73605 LM73606 LMR14030 LMR14050 LMR23610 LMR23625 LMR23630 LMR33630 LMS3655 TPS54540
3.5    6    8    8    3.5    3.5    3.5    3.5    4    4    4.5    4.5    4.5    3.8    3.5    4.5   
36    42    40    40    42    42    36    36    40    40    36    36    36    36    42    42   
1    1.23    1.23    1.23    3.2    3.2    1    1    1    1    1    1    1      1    0.8   
28    40    37    37    9.9    10    34    34    36    36    30    30    30    34    15    41.1   
3    3    5    5    3    3.5    5    6    3.5    5    1    2.5    3    3    5.5    5   
1    1    1    1    1    1    1    1    1    1    1    1    1    1    1    1   
200    50    260    260    1850    1850    350    350    200    200    200    200    200    400    250    100   
2200    1000    260    260    2350    2350    2200    2200    2500    2500    2200    2200    2200    2100    500    2500   
0.027    1    4.2    4.2    0.023    0.018    0.015    0.015    0.04    0.04    0.075    0.075    0.075    0.024    0.015    0.146   
Enable
Frequency Synchronization
Light Load Efficiency
Power Good
Synchronous Rectification
Tracking   
Frequency Synchronization    Frequency Synchronization    Frequency Synchronization    Enable
Frequency Synchronization
Light Load Efficiency
Power Good
Synchronous Rectification   
Enable
Forced Pulse Width Modulation (FPWM) Mode
Frequency Synchronization
Light Load Efficiency
Power Good
Pre-Bias Start-Up
Synchronous Rectification
Wettable Flanks Package   
Enable
Forced Pulse Width Modulation (FPWM) Mode
Frequency Synchronization
Light Load Efficiency
Over Current Protection
Power Good
Pre-Bias Start-Up
Synchronous Rectification
UVLO Fixed
Wettable Flanks Package   
Enable
Forced Pulse Width Modulation (FPWM) Mode
Frequency Synchronization
Light Load Efficiency
Over Current Protection
Power Good
Pre-Bias Start-Up
Synchronous Rectification
UVLO Fixed
Wettable Flanks Package   
Enable
Frequency Synchronization
Light Load Efficiency
Power Good
Pre-Bias Start-Up
Tracking
UVLO Adjustable   
Enable
Frequency Synchronization
Light Load Efficiency
Power Good
Pre-Bias Start-Up
Tracking
UVLO Adjustable   
Enable
Frequency Synchronization
Light Load Efficiency
Pre-Bias Start-Up
Synchronous Rectification
UVLO Adjustable   
Enable
Frequency Synchronization
Light Load Efficiency
Pre-Bias Start-Up
Synchronous Rectification
UVLO Adjustable   
Enable
Frequency Synchronization
Light Load Efficiency
Pre-Bias Start-Up
Synchronous Rectification
UVLO Adjustable   
Enable
Light Load Efficiency
Power Good
Pre-Bias Start-Up
Synchronous Rectification   
Enable
Frequency Synchronization
Light Load Efficiency
Power Good
Pre-Bias Start-Up
Synchronous Rectification   
Enable
Frequency Synchronization
Light Load Efficiency
UVLO Adjustable   
Current Mode    Current Mode    Voltage Mode    Voltage Mode    Current Mode    Current Mode    Current Mode    Current Mode    Current Mode    Current Mode    Current Mode    Current Mode    Current Mode    Current Mode    Current Mode    Current Mode   
99    95    91    91    98    98    96    95    98    98    97    97    97    98    98    98   
-40 to 125    -40 to 125    -40 to 125    -40 to 125    -40 to 125    -40 to 150    -40 to 125    -40 to 125    -40 to 125    -40 to 125    -40 to 125    -40 to 125    -40 to 125    -40 to 125    -40 to 125    -40 to 125   
Catalog    Catalog    Catalog    Catalog    Catalog    Automotive    Catalog    Catalog    Catalog    Catalog    Catalog    Catalog    Catalog    Catalog    Catalog    Catalog   
HTSSOP
SON   
HTSSOP    DDPAK/TO-263
TO-220
VSON   
DDPAK/TO-263
TO-220
VSON   
HTSSOP    VQFN-HR    WQFN    WQFN    SO PowerPAD    SO PowerPAD    SO PowerPAD    SO PowerPAD
SON   
SO PowerPAD
SON   
SO PowerPAD    VQFN-HR    SO PowerPAD   

Other qualified versions of LM43603

Version Part Number Definition
Automotive LM43603-Q1 Q100 devices qualified for high-reliability automotive applications targeting zero defects

WEBENCH® Designer LM43603

  Min   Max Range
Vin  V 3.5 to 36.0V
Vout  V 1.01 to 28.0V
Iout  A ≤ 3A
Ambient Temp  °C -40 to 125°C
Package