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 PFETs 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.
|Part number||Order||Vin (Min) (V)||Vin (Max) (V)||Vout (Min) (V)||Vout (Max) (V)||Iout (Max) (A)||Regulated outputs (#)||Number of Phases||Switching frequency (Min) (kHz)||Switching frequency (Max) (kHz)||Iq (Typ) (mA)||Features||Duty cycle (Max) (%)||Operating temperature range (C)||Rating||Package Group||Type||Control mode|
||4.5||35||1.239||35||4||1||1||50||1400||0.28||Enable||100||-40 to 125||Automotive||VSSOP | 8||Controller||Hysteretic|
||4.5||35||1.239||35||4||1||1||50||1400||0.28||Enable||100||-40 to 125||Catalog||VSSOP | 8||Controller||Hysteretic|