3-20V, Voltage Mode Synchronous Buck Controller with DCR Current Sensing - LM27402

LM27402 (ACTIVE)

3-20V, Voltage Mode Synchronous Buck Controller with DCR Current Sensing

Recommended alternative parts

  • LM2748  -  Synchronous Buck Controller With Pre-bias Startup, And Optional Clock Synchronization
  • LM3743  -  High-Performance Synchronous Buck Controller With Comprehensive Fault Protection Features From The

Description

The LM27402 is a synchronous voltage mode DC/DC buck controller with inductor DCR current sense capability. Sensing the inductor current eliminates the need to add resistive powertrain elements which increases overall efficiency and facilitates accurate continuous current limit sensing. A 0.6V ±1% voltage reference enables high accuracy and low voltage capability at the output. An input operating voltage range of 3V to 20V makes the LM27402 suitable for a large variety of input rails.

The LM27402 voltage mode control loop incorporates input voltage feed-forward to maintain stability throughout the entire input voltage range. The switching frequency is adjustable from 200 kHz to 1.2 MHz. Dual high current integrated N-channel MOSFET drivers support large QG, low RDS(ON) MOSFETs. A power good indicator provides power rail sequencing capability and output fault detection. Adjustable external soft-start capability limits inrush current and provides monotonic output control during startup. Other features include external tracking of other power supplies, integrated LDO bias supply, and synchronization capability. The LM27402 is offered in a 16 pin HTSSOP package and a 4 mm x 4 mm 16 pin exposed WQFN.

Features

  • Input Operating Voltage Range of 3V to 20V
  • Continuous Inductor DCR or Shunt Resistor Current Sensing
  • 0.6V ±1% Reference (-40°C to 125°C Junction Temperature)
  • Output Voltage as High as 95% of Input Voltage
  • Integrated MOSFET Drivers
  • Internal LDO Bias Supply
  • External Clock Synchronization
  • Adjustable Soft-Start With External Capacitor
  • Pre-Biased Startup Capability
  • Power Supply Tracking
  • Input Voltage Feed-Forward
  • Power Good Indicator
  • Precision Enable With Hysteresis

All trademarks are the property of their respective owners.

View more

Parametrics Compare all products in Step-Down (Buck) Controller

 
Vin (Min) (V)
Vin (Max) (V)
Vout (Min) (V)
Vout (Max) (V)
Iout (Max) (A)
Switching Frequency (Min) (kHz)
Switching Frequency (Max) (kHz)
Iq (Typ) (mA)
Duty Cycle (Max) (%)
Regulated Outputs (#)
Topology
Market Segment
Control Mode
Special Features
Rating
Operating Temperature Range (C)
Pin/Package
Approx. Price (US$)
LM27402 LM27403 LM2748 LM3743
3     3     1     3    
20     20     14     5.5    
0.6     0.6     0.6     0.8    
18.6     19     12     4.6    
30       20     10    
200     200     50     300    
1200     1200     1000     1000    
4.5     3.5     1.7     1.8    
95     93     86     91    
1     1     1     1    
Buck     Buck     Buck     Buck    
Communications & Telecom
Computing & Multimedia    
Communications & Telecom     Consumer & Portable Electronics
Communications & Telecom
Computing & Multimedia    
Communications & Telecom
Computing & Multimedia    
Voltage Mode     Voltage Mode     Voltage Mode     Voltage Mode    
Enable
Frequency Synchronization
Power Good
Pre-Bias Start-Up
Synchronous Rectification
Tracking    
Enable
Frequency Synchronization
Power Good
Pre-Bias Start-Up
Synchronous Rectification
Tracking    
Enable
Power Good
Synchronous Rectification
Tracking    
Enable
Pre-Bias Start-Up
Tracking    
Catalog     Catalog     Catalog     Catalog    
-40 to 125     -40 to 125     -40 to 125     -40 to 125    
16HTSSOP
16WQFN    
24WQFN     14TSSOP     10VSSOP    
1.10 | 1ku     1.20 | 1ku     0.85 | 1ku     0.99 | 1ku    

Featured tools and software

WEBENCH® LM27402
    Min   Max   Range  
  Vin V    3.00 – 20.00V  
  Vout V    0.60 – 18.60V  
  Iout A    ≤ 30.00A  
  Ambient Temp °C    ≤ 100°C  
Footprint BOM Cost Efficiency
 
 
 
'U1 M1 M2 Cdd Css Cboot Dboot Rfadj Rpgood Rf Cf L1 Csby Rset Cs Rs Rfb1 Rfb2 Cout Rc1 Cc1 Cc3 Rc2 Cc2 Cin '
 
What are WEBENCH® tools?
Click Here