LM22677 SIMPLE SWITCHER® 5A, Step-Down DC/DC Switching Reg. with Frequency Synchronization | TI.com

LM22677 (ACTIVE)

SIMPLE SWITCHER® 5A, Step-Down DC/DC Switching Reg. with Frequency Synchronization


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The LM22677 switching regulator provides all of the functions necessary to implement an efficient high-voltage step-down (buck) regulator using a minimum of external components. This easy-to-use regulator incorporates a 42-V N-channel MOSFET switch that can provide up to 5 A of load current. Excellent line and load regulation along with high efficiency (> 90%) are featured. Voltage mode control offers short minimum on-time, allowing the widest ratio between input and output voltages. Internal loop compensation means that the user is free from the tedious task of calculating the loop compensation components. Fixed 5-V output and adjustable output voltage options are available. The default switching frequency is set at 500 kHz, thus allowing for small external components and good transient response. In addition, the frequency can be adjusted over a range of 200 kHz to 1 MHz with a single external resistor. The internal oscillator can be synchronized to a system clock or to the oscillator of another regulator. A precision enable input allows simplification of regulator control and system power sequencing. In shutdown mode the regulator draws only 25 µA (typical). The LM22677 also has built-in thermal shutdown, and current limiting to protect against accidental overloads.

The LM22677 device is a member of Texas Instruments’ SIMPLE SWITCHER family. The SIMPLE SWITCHER® concept provides for an easy-to-use complete design using a minimum number of external components and the TI WEBENCH design tool. TI's WEBENCH tool includes features such as external component calculation, electrical simulation, thermal simulation, and Build-It boards for easy design-in.


  • Wide Input Voltage Range: 4.5 V to 42 V
  • Internally Compensated Voltage Mode Control
  • Stable With Low ESR Ceramic Capacitors
  • 100-mΩ N-Channel MOSFET
  • Output Voltage Options:
    • -ADJ (Outputs as Low as 1.285 V)
    • -5.0 (Output Fixed to 5 V)
  • ±1.5% Feedback Reference Accuracy
  • 500-kHz Default Switching Frequency
  • Adjustable Switching Frequency and
  • –40°C to +125°C Operating Junction Temperature
  • Precision Enable Input
  • Integrated Boot-Strap Diode
  • Integrated Soft-Start
  • Fully WEBENCH® Enabled
  • LM22677-Q1 is an Automotive-Grade Product
    that is AEC-Q100 Grade 1 Qualified (–40°C to
    +125°C Operating Junction Temperature)
  • NDR (Exposed Pad)

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Parametrics Compare all products in Buck converters (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)
Control mode
Duty cycle (Max) (%)
Operating temperature range (C)
Package Group
Package size: mm2:W x L (PKG)
LM22677 LM22675 LM22678 LM22679
4.5     4.5     4.5     4.5    
42     42     42     42    
1.285     1.285     1.285     1.285    
37     37     37     37    
5     1     5     5    
1     1     1     1    
200     500     500     500    
1000     500     500     500    
3.4     3.4     3.4     3.4    
Frequency Synchronization
Over Current Protection    
Over Current Protection    
Over Current Protection    
Adjustable Current Limit
Over Current Protection    
Voltage Mode     Voltage Mode     Voltage Mode     Voltage Mode    
90     90     90     90    
-40 to 125     -40 to 125     -40 to 125     -40 to 125    
Catalog     Catalog     Catalog     Catalog    
TO-263 | 7     SO PowerPAD | 8     TO-263 | 7     TO-263 | 7    
Converter     Converter     Converter     Converter    
7TO-263: 142 mm2: 14.01 x 10.16 (TO-263 | 7)     8SO PowerPAD: 19 mm2: 3.9 x 4.89 (SO PowerPAD | 8)     7TO-263: 142 mm2: 14.01 x 10.16 (TO-263 | 7)     7TO-263: 142 mm2: 14.01 x 10.16 (TO-263 | 7)    

Design tool

WEBENCH® Designer LM22677

  Min   Max Range
Vin  V 4.5 to 42.0V
Vout  V 1.28 to 37V
Iout  A ≤ 5A
Ambient Temp  °C -40 to 125°C