Preliminary
RT9256
Actively Alternative Mode Two-Phase / Dual Switching
PWM Controller
General Description
The RT9256 is an analogous current mode design and is
specifically promoted for high power density consideration
platform with MLCC capacitor attached, such as high-end
add-on graphic card core power and DDR SDRAM core
power, etc. A highlight for RT9256 is the RichTek’ s new
innovation of actively alternative mode operation two-phase
power conversion or dual PWM controller operation. Based
on above innovation architecture, the RT9256 provides more
flexibility and higher performance to customer application.
The part is implemented specially for multiple power
sourcing with power budget limitation. The part comes to
small footprint package VQFN-32L 5x5.
Features
Analogous Current Mode Design
Innovative Design for Actively Alternative Mode
Operation :
Two-Phase Power Conversion
Dual PWM Controllers
2.5V to 12V Switching Source Power
0.8V to 3.3V Output Voltage Regulation
Multiple Power Sourcing for Power Budget Limitation
Adjustable V
IN
Feed-Forward Ramp Slope
Adjustable Operation Frequency
Precision Core Voltage Regulation
Precision DCR Current Sensing (with High Quality
Capacitor, X7R)
±
1% V
REF
Accuracy
Input Voltage : 12V or 5V Bias
Enable and PGOOD Function for Sequencing-
Concerned Power
Over Current Protection
Over Voltage Protection
External Soft Start Setting
Operation Frequency Up to 1.0MHz Per Channel
32-Lead VQFN Package
RoHS Compliant and 100% Lead (Pb)-Free
Ordering Information
RT9256
Package Type
QV : VQFN-32L 5x5 (V-Type)
Operating Temperature Range
P : Pb Free with Commercial Standard
G : Green (Halogen Free with Commer-
cial Standard)
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.
Pin Configurations
(TOP VIEW)
UGATE1
25
24
23
22
21
20
19
33
18
17
9
10
11
12
13
14
15
16
PGOOD
27
Add-on graphic core power card
DDR SDRAM core power
Gaming Console
High power density consideration platform
Desktop/motherboard high power devices
Power sequencing-concerned power application
32
31
30
VCC
RR1
SS1
Applications
CSN1
CSP1
COMP1
FB1
FB2
COMP2
CSP2
CSN2
1
2
3
4
5
6
7
8
29
28
BOOT1
26
IMAX1
VCC5
PHASE1
PGND
LGATE1
PVCC
PVCC
LGATE2
PGND
PHASE2
BOOT2
IMAX2
SS2
RR2
RT
VQFN-32L 5x5
DS9256-07 August 2007
UGATE2
GND
EN
www.richtek.com
1
RICHTEK [ RICHTEK TECHNOLOGY CORPORATION ]
