
STMicroelectronics
Description
PM6681A is a dual step-down controller specifically designed to provide extremely high efficiency conversion, with lossless current sensing technique. The constant on-time architecture assures fast load transient response and the embedded voltage feed-forward provides nearly constant switching frequency operation. An embedded integrator control loop compensates the DC voltage error due to the output ripple. Pulse skipping technique increases efficiency at very light load. Moreover a minimum switching frequency of 33kHz is selectable to avoid audio noise issues. The PM6681A provides a selectable switching frequency, allowing three different values of switching frequencies for the two switching sections. The output voltages OUT1 and OUT2 can be adjusted from 0.9V to 5V and from 0.9V to 3.3V respectively. The device provides also 2 LDOs, 5V fixed and 0.9V-3.3V adjustable.
FEATUREs
■ 6V to 36V input voltage range
■ Adjustable output voltages
■ 0.9-3.3V LDO adjustable delivers 100mA peak current
■ 5V LDO delivers 100mA peak current
■ 1.237V ±1% reference voltage available
■ NO RSENSE current sensing using low side MOSFETs RDS(on)
■ Negative current limit
■ Soft start internally fixed at 2ms
■ Soft output discharge
■ Latched UVP
■ Not-latched OVP
■ Selectable pulse skipping at light loads
■ Selectable minimum frequency(33kHz) in pulse skip mode
■ 5mW maximum quiescent power
■ Indipendent power good signals
■ Output voltage ripple compensation
APPLICATIONs
■ Embedded computer system
■ FPGA system power
■ Industrial applications on 24V
■ High performance and high density DC/DC modules