RT8800A Datasheet, PDF (1/21 Pages) Richtek Technology Corporation – General Purpose 3-Phase PWM Controller for High-Density Power Supply

RT8800A
General Purpose 3-Phase PWM Controller for High-Density
Power Supply
General Description
Features
The RT8800A is a general-purposed multi-phase
synchronous buck controller dedicating for high power
density applications. The RT8800A operates with 2 or 3
synchronous buck switching stages in interleaved phase
set automatically. The multiphase architecture provides
high output current while maintaining low power dissipation
on power devices and low stress on input and output
capacitors.
The output voltage is precisely regulated to the external
reference voltage at PI pin. The RT8800A can provide Intel^®
VRD10.x or AMD^® K8 compliant output voltage when
companioned with DAC generator RT9401A/B.
The RT8800A adopts innovative time-sharing DCR current
sensing technique for channel current balance, droop
tuning, and over current protection. Using one common
GM amplifier for current sensing eliminates offset errors
and linearity variation between GMs. As sub-milli-ohm-
grade inductors are widely used in modern mother boards,
slight mismatch of GM amplifiers offset and linearity results
in considerable current shift between phases. The time-
sharing DCR current sensing technique is extremely
important to guarantee phase current balance at mass
production.
Other features include overvoltage protection, undervoltage
protection and internal softstart. The RT8800A comes to
a VQFN-16L 3x3 package.
Ordering Information
RT8800A
Package Type
QV : VQFN-16L 3x3 (V-Type)
Operating Temperature Range
P : Pb Free with Commercial Standard
G : Green (Halogen Free with Commer-
cial Standard)
z 5V Power Supply Voltage
z 2/3-Phase Power Conversion with Automatic Phase
Selection
z Output Voltage Controlled by External Reference
Voltage
z Precise Core Voltage Regulation
z Power Stage Thermal Balance by DCR Current
Sensing
z Extreme Low-Cost, Lossless Time Sharing Current
Sensing
z Internal Soft-Start
z Hiccup Mode Over-Current Protection
z Over-Voltage Protection
z Adjustable Operating Frequency and Typical at
300kHz Per Phase
z Power Good Indication
z Small 16-Lead VQFN Package
z RoHS Compliant and 100% Lead (Pb)-Free
Applications
z Desktop CPU Core Power
z Low Output Voltage, High Power Density DC-DC
Converters
z Voltage Regulator Modules
Marking Information
For marking information, contact our sales representative
directly or through a Richtek distributor located in your
area, otherwise visit our website for detail.
Note :
Richtek Pb-free and Green products are :
`RoHS compliant and compatible with the current require-
ments of IPC/JEDEC J-STD-020.
`Suitable for use in SnPb or Pb-free soldering processes.
`100% matte tin (Sn) plating.
All brand name or trademark belong to their owner respectively
DS8800A-04 August 2007
www.richtek.com
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