S1K50000 Epson Electronics America, Inc., S1K50000 Datasheet - Page 105

• Manufacturer Part Number: S1K50000
• Description: Design Guide S1k50000 Series
• Manufacturer: Epson Electronics America, Inc.

Chapter 9: Precautions on the Use of Dual Power Supplies
Chapter 9 Precautions on the Use of Dual Power
9.1 Power-Supply Accommodation
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The S1K50000 series supports a dual-power-supply system (5.0 V and 3.3 V, or 3.3 V and 2.0
V), allowing input/output buffers to be individually interfaced with a signal of 5.0 V, 3.3 V, or 2.0
V. The internal cell area operates with a single power supply of 3.3 V or 2.0 V.
The S1K50000 series allows signals operating at voltages that differ from the internal
operating voltage to be interfaced. The following two methods can be used to interface with
different power-supply systems:
• For a single power supply
• For dual power supplies
For a single power supply, signals with voltages higher than the power-supply voltage can be
fed into the chip through the use of N-channel open-drain buffers or Fail-Safe cells.
However, signals with higher voltages than the power-supply voltage cannot be output from
the chip. In such a case, the N-channel open-drain buffers and external pull-up resistors can
be used in combination.
Signals with higher voltages than the power-supply voltage can be fed into the chip through
the use of dedicated dual-power-supply input buffers. Similarly, signals with higher voltages
than the power-supply voltage cannot be output from the chip through the use of dedicated
dual-power-supply output buffers.
Supplies
EPSON
STANDARD CELL S1K50000 SERIES
DESIGN GUIDE