Single supply level converter
AssigneeInternational Business Machines Corporation
InventorsAnthony Correale, Jr., Rajiv V. Joshi, David S. Kung, Zhigang Pan, Ruchir Puri
Life of this patent
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Abstract
A level converter for interfacing two circuits supplied by different supply voltages, and integrated circuit including the level converter interfacing circuit in two different voltage islands. A first buffer is supplied by a virtual supply and receives an input signal from a lower voltage circuit. The first buffer drives a second buffer, which is supplied by a higher supply voltage. An output from the second buffer switches a supply select to selectively pass the higher supply voltage or a reduced supply voltage to the first buffer.
Claims12
An integrated circuit (IC) comprising:
- a plurality of circuit rows;
- at least one low voltage island in at least one of said plurality of circuit rows, circuit elements in each said at least one low voltage island being powered by a low voltage (Vddl) supply;
- and
- at least one high voltage island in said at least one of said plurality of circuit rows, circuit elements in each said at least one high voltage island being powered by a high voltage (Vddh) supply) Vddh being a higher voltage than Vddl;
- and,
- at least one level converter comprising:
- a first buffer receiving an input signal from said at least one low voltage island, said first buffer being connected between a virtual supply and a supply return;
- a second buffer receiving an output of said first buffer and connected between Vddh and said supply return;
- and
- a supply select between Vddh and said virtual supply, said supply select receiving an output from said second buffer and selectively passing Vddh or a reduced supply voltage to said virtual supply responsive to said output from said second buffer.
Dependencies are inferred from the claim text.