Advanced I/O Controller with Motherboard GLUE Logic
Datasheet
Chapter 5 Power and Clock Functionality
The LPC47M182 has three power planes: VCC, VTR and V5P0_STBY.
5.1
3 Volt Operation / 5 Volt Tolerance
The LPC47M182 is a 3.3 Volt part. It is intended solely for 3.3V applications. Non-LPC bus pins are 5V
tolerant; that is, the operating input voltage is 5.5V max, and the I/O buffer output pads are backdrive
protected (they do not impose a load on any external VCC powered circuitry).
The LPC interface pins are 3.3 V only. These signals meet PCI DC specifications for 3.3V signaling. The
nRSMRST pin is also 3.3V only.
The following lists the pins that are 3.3V only (not 5V tolerant):
LAD[3:0]
nLFRAME
nLDRQ
nLPCPD
nRSMRST
The input voltage for all other pins is 5.5V max. These pins include all non-LPC Bus pins and the following
pins:
nPCI_RESET
PCI_CLK
SER_IRQ
nIO_PME
5.2
5.3
VCC Power
The LPC47M182 is a 3.3 Volt part. The VCC supply is 3.3 Volts (nominal). See section 12.2 Operational
DC Characteristics and section 12.1 Maximum Guaranteed Ratings.
VTR Power
The LPC47M182 requires a trickle supply (VTR) to provide sleep current for the programmable wake-up
events in the PME interface and other suspend state logic when VCC is removed. The VTR supply is 3.3
Volts (nominal). See the Operational Description Section. The maximum VTR current that is required
depends on the functions that are used in the part. See Trickle Power Functionality subsection and
Maximum Current Values subsection. If the LPC47M182 is not intended to provide wake-up and/or
suspend power capabilities on standby current, VTR can be connected to VCC. The VTR pin generates a
VTR Power-on-Reset signal to initialize these components.
Note:
If VTR is to be used for programmable wake-up events when VCC is removed, VTR must be at its full
minimum potential at least 10 µs before VCC begins a power-on cycle. When VTR and VCC are fully
powered, the potential difference between the two supplies must not exceed 500mV.
Revision 1.8 SMSC/Non-SMSC Register Sets (02-24-05)
30
SMSC LPC47M182
DATASHEET
SMSC [ SMSC CORPORATION ]
