RT9210 Datasheet, PDF (1/17 Pages) Richtek Technology Corporation – Dual 5V Synchronous Buck DC-DC PWM Controller for DDR Memory VDDQ and VTT Termination

Preliminary
RT9210
Dual 5V Synchronous Buck DC-DC PWM Controller
for DDR Memory V_DDQ and V_TT Termination
General Description
The RT9210 is a dual high power, high efficiency
synchronous buck DC-DC controller optimized for high
performance double data rate (DDR) memory applications.
It is designed to convert voltage supplies ranging from
4.5V to 5.5V into efficiently 2.5V_DDQ for powering DDR
memory, V_TT for signal termination and a buffered amplifier
for V_REF reference. V_TT tracks (V_DDQ/2) to ±30mV, and
V_TT accurately tracks V_REF. The RT9210 integrates all of
the control, output adjustment, monitoring and protection
functions into a single package.
The V_TT supply can be turned off independently of V_DDQ
during S3 sleep mode, the V_TT output is maintained by a
low power window regulator when V2_SD pin being
triggered high.
The RT9210 provides simple, single feedback loop, voltage
mode control with fast transient response for V_DDQ
regulator. The V_TT regulator features internal compensation
that eases the circuitry design. It includes two phase-
locked 300kHz sawtooth-wave oscillators which are placed
90° to minimize interference between the two PWM
regulators.
The RT9210 protects against over-current conditions by
inhibiting PWM operation. It also monitors the current in
the V_DDQ regulator by using the R_DS(ON) of the upper
MOSFET which eliminates the need for a current sensing
resistor.
Ordering Information
RT9210
Note :
Package Type
C : TSSOP-24
S : SOP-24
Operating Temperature Range
P : Pb Free with Commercial Standard
G : Green (Halogen Free with Commer-
cial Standard)
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.
DS9210-05 March 2007
Features
z Operating with Single 5V Supply Voltage
z High Power V_DDQ, V_TT and V_REF for DDR Memory
z V_TT Tracks (V_DDQ/2) to ±30mV
z V_TT Regulator Internally Compensated
z Support “S3” Sleep Mode
z Drives All Low Cost N-MOSFETs
z Voltage Mode PWM Control
z 300kHz Fixed Frequency Oscillator
z Fast Transient Response :
Full 0% to 100% Duty Ratio
z Internal Soft-Start
z Adaptive Non-Overlapping Gate Driver
z Over-Current Fault Monitor on V_CC, No Current
Sense Resistor Required
z RoHS Compliant and 100% Lead (Pb)-Free
Applications
z DDR Memory Termination Supply
z SSTL_2 and SSTL_3 Interfaces
z Graph Card, Motherboard, Desktop Servers
z High Power Tracking DC-DC Regulators
Pin Configurations
UGATE1
BOOT1
PHASE1
VREF
FB1
COMP1
SENSE1
VREF_IN
GNDA
NC
BOOT2
UGATE2
(TOP VIEW)
24
2
23
3
22
4
21
5
20
6
19
7
18
8
17
9
16
10
15
11
14
12
13
PGND1
LGATE1
PVCC1
OCSET/SD
V2_SD
PGOOD
NC
SENSE2
NC
VCC
LGATE2
PGND2
TSSOP-24 & SOP-24
www.richtek.com
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