W83301R
Preliminary
7.Functional Description
7.1 Mode Selection
The W83301R supports two modes for customer’s multi-applications, as shown as
Table1, the mode A and mode B can selected via VSET0 pin. If this pin connects to 5V,
the chip will operate under mode A, otherwise the chip will operate under mode B when
VSET0 connects to ground.
Both mode A and B supports a linear switch to generate an ACPI-compliant 5V
DL
voltage from ATX power supply 5V/5V
SB
according to S5# and S3# signals. And user
also can turn off the whole 5V
DL
output in S5 state via 5V
DLEN
# pin if needed.
Under the mode A operation, the chip provide a linear controller STR1 that drives a
N-channel MOSFET Q3 (refer to figure) to generate a regulated voltage 2.5V
DUAL
from an
external power source 3.3V
DUAL
, the 2.5 V
DUAL
is provide for RDRAM/DDRAM ACPI
suspend to RAM application. And In order to simply the circuit design and reduce
customer’s cost, the W83301R also integrate a bus termination controller BT driving two
external N-channel MOSFETs (Q4, Q5) to generate a specific ACPI-compliant voltage
according to a half of STR1 output for sourcing and sinking bus redundant current.
Under the mode B operation, the chip provide three linear controllers, that is STR1-
2.5V
DUAL
, STR2- 3.3 V
DUAL
, and STR3- 1.8V
DUAL
, all of the three outputs drive a N-
channel MOSFET (Q3, Q4, and Q5) to generate an ACPI-compliant voltage by different
applications. Such as STR1- 2.5V
DUAL
for clock generator application, STR2- 3.3 V
DUAL
for SDRAM application, and STR3- 1.8V
DUAL
chipset application.
Besides, as shown in Table 1 the W83301R also provide a tri-state pin VSET1 to bias
an extra voltage up to 0.2V in each output for more performance but under mode A
operation, the BT output voltage will generated according to a half of STR1 output set by
VSET1.
Table 1.
W83301R Control Table
Mode VSET0
0V
A
0V
0V
Mode VSET0
5V
B
5V
5V
VSET1
0V
NC
5V
VSET1
5V
NC
0V
STR1
2.5V
DUAL
2.6V
DUAL
2.7V
DUAL
STR1
2.5V
DUAL
2.6V
DUAL
2.7V
DUAL
Bus Termination Controller
1.25V
DUAL
1.30V
DUAL
1.35V
DUAL
STR2
3.3V
DUAL
3.4V
DUAL
3.5V
DUAL
STR3
1.8V
DUAL
1.8V
DUAL
1.8V
DUAL
Remark
-STR1 output for RDRAM/DDRAM voltage
-Bus Termination Controller for memory bus
redundant current sinking and sourcing.
Remark
-STR1 output for Clock Gen. voltage
-STR2 output for SDRAM voltage
-STR3 output for Chipset voltage
Confidential
Revision 0.6
7
WINBOND [ WINBOND ]
