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PM6680A
Dual synchronous step-down controller
with adjustable output voltages plus LDO

PM6680A Product Page

The PM6680A is a dual step-down controller, which represents the best integrated solution for providing the two main output voltages necessary for the FPGA and MCU system power. By using a lossless current sensing technique it has an extremely high efficiency conversion, up to 95%. The PM6680A is the first of a new product family that will support power management applications in the industrial environment.
PM6680A

PM6680A Functional Description

The device provides two switching controllers with adjustable outputs and a 5V LDO capable of supplying 200mA peak current. The PM6680A can guarantee high DC output accuracy over a wide input voltage range, covering the 5V, 12V and 24V bus. Thanks to the Constant ON Time (COT) architecture, the PM6680A is able to convert the 36V input voltage to an output voltage in the range of 1.2V to 2.5V. This range covers the typical core, I/O and memory voltages required by embedded systems based on FPGA and MCU. For portable equipment the efficiency and battery life can be further increased by an internal p-channel Power MOSFET that disables the LDO 5V output and the IC is supplied directly by the external 5V bus. An embedded integrator control loop compensates the DC voltage error due to the output ripple. In light load conditions, a pulse-skip technique can be selected to increase the efficiency with minimum impact on the output regulation accuracy. During pulse-skip mode, a minimum switching frequency of 33kHz is selectable to prevent audio noise issues.

Industrial Power Management Solutions

Another key benefit of the PM6680A is a selectable switching frequency, allowing either 200/300kHz,
300/400kHz or 400/500kHz operation of the Ctrl1/Ctrl2 switching sections.

PM6680A Schematics

Main internal blocks of PM6680A

P / N
# of
out
Main
application
Regulated
switching
Regulated
LDO
LDO
current
IC supply
voltage
Output
acc.
Switch.
freq.
Package
PM6680A
3
Embedded
systems
Adj from 0.9V
Fixed 5V
200mA pk
5.5V to 36V
+1%
200kHz
to
500kHz
VFQFPN
32 pin 5X5
PM6681A
4
Adj from 0.9
and fixed 5V
100mA pk 200kHz
to
750kHz
PM6675A
3
Adj from 0.6V
Adj from 0.6V
2A pk 200kHz
to
1MHz
VFQFPN
24 pin 4X4

PM6680A Features

Constant ON Time topology
No RSENSE current sensing with low side Power MOSFET’s RDS(on)
Soft START internally fixed at 2ms
Soft OFF for a controlled output discharge
Selectable minimum frequency (33kHz) in pulseskip mode
5mW maximum quiescent power
Independent power good signals
Output voltage ripple compensation
Thermal shutdown
Housed in space-saving, 32pin VFQFPN 5x5

Typical Applications

Embedded computer systems
FPGA and MCU-based systems
Industrial applications
High performance and high density DC/DC module