LMS3655 (ACTIVE)

5.5A, 36V Synchronous, 400kHz, Step-Down Converter

5.5A, 36V Synchronous, 400kHz, Step-Down Converter - LMS3655
 

Description

The LMS3655 synchronous buck regulators are optimized for high performance applications, providing an adjustable output of 1 V to 15 V. Seamless transition between PWM and PFM modes, along with a low quiescent current, ensures high efficiency and superior transient responses at all loads.

Advanced high-speed circuitry allows the LMS3655 to regulate an input of 24 V to an output of 3.3 V at a fixed frequency of 400 kHz while also enabling a continuous load current of 5.5 A. An innovative frequency foldback architecture allows this device to regulate a 3.3-V output from an input voltage of only 3.5 V. The input voltage can range up to 36 V, with transient tolerance up to 42 V, easing input surge protection design.

An open-drain reset output, with built-in filtering and delay, provides a true indication of system status. This feature negates the requirement for an additional supervisory component, saving cost and board space.

Features

  • 96% Peak Efficiency While Converting 12 V to 5 V
  • Low EMI and Switch Noise
    • Minimized Switch Node Ringing
    • Pseudo-Random Spread Spectrum
  • 400-kHz (±10%) Fixed Switching Frequency
  • –40°C to +150°C Junction Temperature Range
  • External Frequency Synchronization
  • RESET Output With Internal Filter and 3-ms Release Timer
  • Automatic Light Load Mode for Improved Efficiency
  • Pin-Selectable Forced PWM Mode
  • Built-In Compensation, Soft Start, Current Limit, Thermal Shutdown, and UVLO
  • 0.35-V Dropout With 3.5-A Load at 25°C (Typical)
  • 32-µA IQ_VIN: Quiescent Current at 3.3 VOUT and No Load (Typical)
  • 5.5-A Continuous Load Current
  • Adjustable Output Voltage (1 V to 15 V)
  • ±1.5% Reference Voltage Tolerance
  • 4-mm × 5-mm, 0.5-mm Pitch SON Package

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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
LMS3655 LM73605 LM73606 TPS54540
3.5    3.5    3.5    4.5   
42    36    36    42   
1    1    1    0.8   
15    34    34    41.1   
5.5    5    6    5   
1    1    1    1   
250    350    350    100   
500    2200    2200    2500   
0.015    0.015    0.015    0.146   
Enable
Frequency Synchronization
Light Load Efficiency
Power Good
Pre-Bias Start-Up
Synchronous Rectification   
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
UVLO Adjustable   
Current Mode    Current Mode    Current Mode    Current Mode   
98    96    95    98   
-40 to 125    -40 to 125    -40 to 125    -40 to 125   
Catalog    Catalog    Catalog    Catalog   
VQFN-HR    WQFN    WQFN    SO PowerPAD   

Other qualified versions of LMS3655

Version Part Number Definition
Automotive LMS3655-Q1 Q100 devices qualified for high-reliability automotive applications targeting zero defects

WEBENCH® Designer LMS3655

  Min   Max Range
Vin  V 3.8 to 36.0V
Product Option
Vout  V 3.3 to 15.0V
Iout  A ≤ 0.20 to 5.5A
Ambient Temp  °C -40 to 125°C