UCD9240 Datasheet, PDF (1/21 Pages) Texas Instruments – UCD9240 Digital Point of Load System Controller

UCD9240 Digital Point of Load
System Controller
FEATURES
• Controls up to 8 power stages and up to 4
voltage feedback control loops.
• Supports PMBus version 1.1.
• Flexible configuration, device can control:
o Four single or dual power stages,
o Two 4-phase power stages, or
o One 2,4,6, or 8-phase power stage.
• Supports switching frequencies up to 2MHz.
• Supports conversion ratio of 12 to 1 at 2MHz
with 250 psec duty-cycle resolution.
• +/-1mV feed-back resolution.
• Hardware accelerated digital 3-pole/3-zero
compensator.
• Internal regulator drives an external pass
element, giving a wide supply voltage range.
• 12-bit digital monitoring of power supply
parameters, including:
o Vin,
o Vout, each rail,
o Iout, each power stage (phase),
o External Temperature, each stage.
• Multiple levels of current fault protection:
o External current fault inputs,
o Fast analog comparators monitor
current sense voltage,
o Digital current sense monitor of
average current.
• Eight Synchronous Rectifier Enable (SRE)
outputs.
• Able to synchronize PWM clocks between
multiple UCD9240 devices.
• Enhanced non-volatile memory with ECC
• Programmable soft start and soft stop ramps
under closed loop control.
• Supports multiple soft-start and soft-stop
configuration including pre-bias start-up.
• Supports voltage tracking.
• Supports current sharing on multi-phase
power stages.
• Supports phase shedding on multi-phase
power stages based on average current.
• Programmable fan control outputs.
• Programmable margining and sequencing.
• Power+ Designer, a full featured PC based
design tool to simulate, configure, and
monitor power supply performance.
UCD9240
SLUS766 – APRIL 2007
APPLICATIONS
• Industrial / ATE
• Networking Equipment
• Servers
• Storage Systems
• Telecommunications Equipment
DESCRIPTION
The UCD9240 is a digital synchronous buck PWM
controller that can control up to 8 power stages in
multi-phase configuration or up to 4 feedback
outputs with two phases per output. This device
provides enhanced configurability and control for
point of load (POL) applications. The device is
configured via PMBus with the Power+ Designer
GUI.
The switching frequency, output configuration and
feedback compensation are programmed through
the Power+ Designer. This allows the UCD9240 to
support multiple converter arrangements and to meet
dynamic converter performance for a broad range of
POL applications.
Each high speed digital control loop has a dedicated
3-pole/3-zero compensator and 250ps PWMs. This
architecture enables wide input to output voltage
conversion ratio’s at switching frequency of up to
2MHz.
Additionally, the UCD9240 is able to monitor and
manage power supply operating conditions and
report the status to the host system through the
PMBus. The management parameters are
configurable through the Power+ Designer. The
design tool allows the power supply designer to
easily configure the control loop characteristics and
generate the expected performance by displaying
Bode plots for each controlled power stage.
On multi-phase power stage outputs, the UCD9240
incorporates current balancing. The average current
in each phase is monitored and the duty cycle for
each phase adjusted to balance the average current.
In addition, the UCD9240 supports "shedding" one or
more phases (ganged power stages) commanded
through PMBus or by average current demand.
When a phase is dropped or added the UCD9240
automatically adjusts the phase of each PWM output
to minimize output ripple as well as any needed
change in loop compensation.
PRODUCT PREVIEW information concerns products in the
formative or design phase of development. Characteristic data
and other specifications are design goals. Texas Instruments
reserves the right to change or discontinue these products
without notice.
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Copyright © 2007, Texas Instruments Incorporated
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