| Vin (Min) (V) | 4.5 |
| Vin (Max) (V) | 35 |
| Vout (Min) (V) | 1.239 |
| Vout (Max) (V) | 35 |
| Iout (Max) (A) | 4 |
| Iq (Typ) (uA) | 280 |
| Switching frequency (Min) (kHz) | 50 |
| Switching frequency (Max) (kHz) | 1400 |
| Features | Enable |
| Regulated outputs (#) | 1 |
| Number of phases | 1 |
| Rating | Catalog |
- 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
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.
