Browse Prior Art Database

Low Voltage Receiver with No Leakage Current

IP.com Disclosure Number: IPCOM000105121D
Original Publication Date: 1993-Jun-01
Included in the Prior Art Database: 2005-Mar-19
Document File: 2 page(s) / 41K

Publishing Venue

IBM

Related People

Nishihara, M: AUTHOR

Abstract

Disclosed is a new low voltage receiver circuit which receives a lower signal voltage than a supply voltage to the circuit, and yet preventscurrent flowing thrugh P-channel FET.

This text was extracted from an ASCII text file.
This is the abbreviated version, containing approximately 79% of the total text.

Low Voltage Receiver with No Leakage Current

      Disclosed is a new low voltage receiver circuit which receives
a lower signal voltage than a supply voltage to the circuit, and yet
preventscurrent flowing thrugh P-channel FET.

      When chips with more than two supply voltage levels are used in
the same planar circuit, a receiver circuit with higher supply
voltage will see lower high-level signal than its supply voltage.  It
will induce leakage current through P-channel FET which turns on
weakly.  For usual application it will not be a significant problem
since the leakage current will be quite small compared to total
current.  But for battery operation it is required to reduce stand-by
current as much as possible since it will impact to battery life at
suspended mode.  Proposed new receiver  circuit will receive lower
voltage but prevent DC leakage cuttent through P-channel FET.

      The Figure shows the proposed receiver circuit.  Input signal
will be applied to the terminal IN and its swing will be 0 to 3.3V or
less while the receiver circuit supply voltage is 5V.  To prevent the
DC current path PFET 1 is inserted between Vdd andreceiver PFET 2.
Due to stored charge in capacitor C1, node N1 will be brought up to
Vdd level and shut off DC current path from Vdd to ground.  Node N1
will be kept high through PFET 4 which is driven by input signal.
Then the circuit has to respond when the input signal goes down.
Since PFET 1 is turned off there will...