The TPS40009DGQ is a Buck Controller for low-voltage non-isolated synchronous buck regulators. It drives an N-channel MOSFET for the primary buck switch and an N-channel MOSFET for the synchronous rectifier switch, thereby achieving very high-efficiency power conversion. In addition, the device controls the delays from main switch off to rectifier turn-on and from rectifier turn-off to main switch turn-on in such a way as to minimize diode losses (both conduction and recovery) in the synchronous rectifier with TI's proprietary Predictive Gate Drive? technology. The reduction in these losses is significant and increases efficiency. For a given converter power level, smaller FETs can be used, or heat sinking can be reduced or even eliminated. The current-limit threshold is adjustable with a single resistor connected to the device. The TPS4000x controllers implement a closed-loop soft start function. Startup ramp time is set by a single external capacitor connected to the SS/SD pin.
1% Internal 0.7V reference
Predictive Gate Drive? N-channel MOSFET drivers for higher efficiency
Externally adjustable soft-start and overcurrent limit
Fixed-frequency voltage-mode control
Source/sink with VOUT pre-bias
Internal bootstrap diode the SS/SD pin is also used for shutdown
(EN)
