RT9641A_07 Datasheet, PDF (1/11 Pages) Richtek Technology Corporation – Triple Linear Regulator Controller Support ACPI Control Interface

RT9641A/B
Triple Linear Regulator Controller Support ACPI Control
Interface
General Description
Features
The RT9641A/B, paired with either the RT9230 or RT9231
simplifies the implementation of ACPI-compliant designs
in microprocessor and computer applications. The IC
integrates two linear controllers and a low-current pass
transistor, as well as the monitoring and control functions
into a 16-pin SOIC package. One linear controller generates
the 3.3V_DUAL voltage plane from an ATX power supply's
5VSB output during sleep states (S3,S4/S5), powering
the PCI slots through an external pass transistor, as
instructed by the status of the 3.3V_DUAL enable pin. An
additional pass transistor is used to switch in the ATX
3.3V output for PCI operation during S0 and S1 (active)
operating states. The second linear controller supplies
the computer system's 2.5V/3.3V memory power through
an external pass transistor in active states. During S3
state, an integrated pass transistor supplies the 2.5V/
3.3V sleep-state power. A third controller powers up a
5V_DUAL plane by switching in the ATX 5V output in active
states, or the ATX 5VSB in sleep states.
The RT9641A/B's operating mode (active-state outputs
or sleep-state outputs) is selectable through two control
pins: S3 and S5 Further control of the logic governing
activation of different power modes is offered through two
enabling pins: EN3VDL and EN5VDL. In active states, the
3.3V_DUAL linear regulator uses an external N-channel pass
MOSFET to connect the output (V_OUT1) directly to the
3.3V input supplied by an ATX (or equivalent) power supply,
while incurring minimal losses. In sleep state, the 3.3V_DUAL
output is supplied from the ATX 5VSB through a NPN
transistor, also external to the controller. Active state power
delivery for the 2.5V/3.3V or 2.6V/3.43V V_MEM output is
done through an external NPN or a NMOS transistor. In
sleep states, conduction on this output is transferred to
an internal pass transistor. The 5V_DUAL output is powered
through two external MOS transistors. In sleep states, a
PMOS (or PNP) transistor conducts the current from the
ATX 5VSB output, while in active states, current flow is
transferred to a NMOS transistor connected to the ATX
5V output. Similar to the 3.3V_DUAL output, the operation
of the 5V_DUAL output is dictated not only by the status of
the S3 and S5 pins, but that of the EN5VDL pin as well.
Provides 3 ACPI-Controlled Voltages
`5V Active/Sleep(5VDUAL)
`3.3V Active/Sleep(3.3VDUAL)
`2.5V/3.3V Active/Sleep(VMEM) with RT9641A
`2V/3.43V Active and 2.5V/3.3V Sleep(VMEM) with
RT9641B
Simple Control Design
`No Compensation Required
Excellent Output Voltage Accuracy
`3.3VDUALOutput : ± 2.0% ; Sleep States Only
` 2.5V/3.3V (2.6V/3.43V) Output : ±2.0% ; Both
Operational States
Fixed Output Voltages Require No Precision
External Resistors
Small Size
`Small External Component Count
Selectable 2.5V/3.3V (2.6/3.43) V_(MEM) Output Voltage
via FAULT/MSEL Pin
`2.5V/2.6V for RDRAM Memory
`3.3V/3.43V for SDRAM Memory
Under-Voltage Monitoring of All Outputs with
Centralized FAULT Reporting
Adjustable Soft-start Function Eliminates
5VSB Perturbations
RoHS Compliant and 100% Lead (Pb)-Free
Ordering Information
RT9641A/B
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Package Type
S : SOP-16
Operating Temperature Range
P : Pb Free with Commercial Standard
G : Green (Halogen Free with Commer-
cial Standard)
V_MEM Voltage
A : 2.5V/3.3V
B : 2.6V/3.43V
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.
DS9641A/B-11 March 2007
www.richtek.com
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