LM61440 3-V to 36-V, 4-A, low-noise synchronous step-down converter | TI.com

LM61440 (PREVIEW) 3-V to 36-V, 4-A, low-noise synchronous step-down converter

 

More information and sample availability

Full datasheet and other design resources are available. Request now

LM61460EVM evaluation module (EVM) is available. Request now

Alternate preproduction samples are available (PLM61460AASQRJRTQ1). This device has the same functionality, pinout and package as the LM61440 but is not an exact equivalent. Request now

Description

The LM61440 is a general-purpose synchronous step-down buck converter providing adjustable output voltage and 0 to 4 A DC load current from a supply voltage ranging from 3.0 V to 36 V. The LM61440 is designed to achieve high efficiency and high performance. Auto-mode enables frequency foldback when operating with light loads, allowing an unloaded current consumption of only 8 µA (typical) and high efficiency with light loads. Together with very low MOSFET ON resistances and optional external bias input, exceptional efficiency is achieved over entire load range. It also targets minimal EMI by adjustable SW node rise time and VQFN-HR package featuring low ringing and optimal-layout-friendly pinout. Switching frequency can be set or synchronized between 200 kHz and 2.2 MHz to avoid noise sensitive frequency bands, and for improved efficiency at low operating frequency or smaller solution size at high frequency. The device also provides an open-drain PGood output and comprehensive protection features. Electrical characteristics are specified over a junction temperature range of –40°C to +150°C.

Features

  • High efficiency power conversion at all loads
    • Synchronous Rectification
    • 8-µA standby current with VIN=13.5 V, VOUT=3.3 V, no load
    • Frequency foldback in light load for improved efficiency with Auto Mode
    • Low MOSFET ON-Resistance
      RDS_ON_HS = 41 mΩ (typical)
      RDS_ON_LS = 21 mΩ (typical)
    • Optional external bias input
  • Low EMI
    • Adjustable SW node rise time
    • Frequency adjust or synchronize over 200 kHz – 2.2 MHz range
    • FPWM when synchronized for constant frequency at light loads
    • 4 mm × 3.5 mm low-EMI VQFN-HR package (with wettable flanks) and pinout
  • Wide Conversion Range
    • Input voltage: 3 V to 36 V
    • Output voltage adjustable from 1 V to 95% of VIN
    • DC load current: 0 A to 4 A
    • tON_MIN = 50 ns (typical)
    • tOFF_MIN = 70 ns (typical)
  • PGood output with filter and delayed release
  • Built-in compensation, soft start, current limits, hiccup protection, thermal shutdown, and UVLO

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Parametrics

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Part number Order 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 Type Package size: mm2:W x L (PKG)
LM61440 Order now 3     36     1     34     4     1     200     2200     0.009     Enable
Frequency Synchronization
Light Load Efficiency
Over Current Protection
Power Good
Soft Start Adjustable
Spread Spectrum
Synchronous Rectification
Wettable Flanks Package    
Current Mode     98     -40 to 150     Catalog     VQFN-HR | 14     Converter     14VQFN-HR: 14 mm2: 3.5 x 4 (VQFN-HR | 14)    
LM61460 Samples not available 3     36     1     34     6     1     200     2200     0.009     Enable
Frequency Synchronization
Light Load Efficiency
Over Current Protection
Power Good
Soft Start Adjustable
Spread Spectrum
Synchronous Rectification
Wettable Flanks Package    
Current Mode     98     -40 to 150     Catalog     VQFN-HR | 14     Converter     14VQFN-HR: 14 mm2: 3.5 x 4 (VQFN-HR | 14)    
LM73605 Order now 3.5     36     1     34     5     1     350     2200     0.015     Enable
Forced PWM
Frequency Synchronization
Light Load Efficiency
Over Current Protection
Power Good
Pre-Bias Start-Up
Synchronous Rectification
Tracking
UVLO Fixed
Wettable Flanks Package
Soft Start Adjustable    
Current Mode     96     -40 to 125     Catalog     WQFN | 30     Converter     30WQFN: 24 mm2: 4 x 6 (WQFN | 30)    
LM73606 Order now 3.5     36     1     34     6     1     350     2200     0.015     Enable
Forced PWM
Frequency Synchronization
Light Load Efficiency
Over Current Protection
Power Good
Pre-Bias Start-Up
Synchronous Rectification
Tracking
UVLO Fixed
Wettable Flanks Package    
Current Mode     95     -40 to 125     Catalog     WQFN | 30     Converter     30WQFN: 24 mm2: 4 x 6 (WQFN | 30)    
LMS3655 Order now 3.5     42     1     15     5.5     1     250     500     0.015     Enable
Forced PWM
Frequency Synchronization
Light Load Efficiency
Over Current Protection
Power Good
Pre-Bias Start-Up
Spread Spectrum
Synchronous Rectification
Wettable Flanks Package    
Current Mode     98     -40 to 125     Catalog     VQFN-HR | 22     Converter