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Hysteretic PFET Buck Controller with Enable Pin


Package | PIN: DGK | 8
Temp: Q (-40 to 125)
Carrier: Cut Tape
Qty Price
1-9 $1.28
10-24 $1.15
25-99 $1.06
100-249 $0.93
250-499 $0.86
500-749 $0.72
750-999 $0.59
1000+ $0.54


  • Qualified for Automotive Parts
  • AEC-Q100 Qualified With the Following Results:
    • Device Temperature Grade 1: –40°C to 125°C Ambient Operating Temperature Range
    • Device HBM ESD Classification Level 2
    • Device CDM ESD Classification Level C5
  • Easy-to-Use Control Methodology
  • No Control Loop Compensation Required
  • Wide 4.5-V to 35-V Input Range
  • 1.239 V to VIN Adjustable Output Range
  • High Efficiency: 93%
  • ±1.3% (±2% Over Temperature) Internal Reference
  • 100% Duty Cycle Operation
  • Maximum Operation Frequency > 1 MHz
  • Current Limit Protection
  • Dedicated Enable Pin (on if Unconnected)
  • Shutdown Mode Draws Only 7-µA Supply Current
  • 8-Pin VSSOP Package

Texas Instruments  LM3489MMX/NOPB

The LM3489 device is a high-efficiency PFET switching regulator controller that can be used to quickly and easily develop a small, cost-effective, switching buck regulator for a wide range of applications. The hysteretic control architecture provides for simple design without any control loop stability concerns using a wide variety of external components. The PFET architecture also allows for low component count as well as ultra-low dropout, 100% duty cycle operation. Another benefit is high efficiency operation at light loads without an increase in output ripple. A dedicated enable pin provides a shutdown mode drawing only 7 µA. Leaving the enable pin unconnected defaults to on.

Current limit protection can be implemented by measuring the voltage across the PFET’s RDS(ON), thus eliminating the need for a sense resistor. A sense resistor may be used to improve current limit accuracy if desired. The cycle-by-cycle current limit can be adjusted with a single resistor, ensuring safe operation over a range of output currents.