Selective coupling of voltage feeds for body bias voltage in an integrated circuit device
View Patent ↗An integrated circuit device having a body bias voltage mechanism. The integrated circuit comprises a resistive structure disposed therein for selectively coupling either an external body bias voltage or a power supply voltage to biasing wells. A first pad for coupling with a first externally disposed pin can optionally be provided. The first pad is for receiving an externally applied body bias voltage. Circuitry for producing a body bias voltage can be coupled to the first pad for coupling a body bias voltage to a plurality of biasing wells disposed on the integrated circuit device. If an externally applied body bias voltage is not provided, the resistive structure automatically couples a power supply voltage to the biasing wells. The power supply voltage may be obtained internally to the integrated circuit.
1. An integrated circuit comprising:
a body bias distribution circuit;
a pad coupled to said body bias distribution circuit, said pad for receiving an externally applied voltage;
an internal voltage bus; and
a circuit component coupled to said internal voltage bus and coupled to said body bias distribution circuit, wherein said internal voltage bus supplies a body bias voltage to said distribution circuit absent a voltage applied to said pad.
2. An integrated circuit as described in claim 1 wherein said externally applied voltage is substantially applied to said distribution circuit when said externally applied voltage is applied to said pad.
3. An integrated circuit as described in claim 2 wherein said circuit component is a resistor element.
4. An integrated circuit as described in claim 2 further comprising an external pin coupled to said pad, said external pin for coupling with said externally supplied voltage.
5. An integrated circuit as described in claim 2 wherein said internal voltage bus is coupled to a power supply voltage of said integrated circuit.
6. An integrated circuit as described in claim 1 further comprising a plurality of metal oxide semiconductor transistors coupled to said body bias distribution circuit.
7. An integrated circuit as described in claim 6 wherein said plurality of metal oxide semiconductor transistors are coupled to said distribution circuit via respective body terminals.
8. A method of providing a body bias voltage in a semiconductor device comprising:
responsive to a coupling of an external body bias voltage to said semiconductor device, coupling said body bias voltage to body biasing wells of said semiconductor device; and
responsive to an absence of said external body bias voltage, automatically supplying said body biasing wells of said semiconductor device with an internal voltage of said semiconductor device through a resistance.
9. The method of claim 8 wherein said internal voltage is a power supply voltage for said semiconductor device.
10. The method of claim 8 wherein said internal voltage is a ground reference for said semiconductor device.
11. The method of claim 8 wherein said resistive structure comprises an n well region.
12. The method of claim 8 wherein said resistive structure forms a desired resistance between said internal voltage and said n well channels.
13. The method of claim 12 wherein said desired resistance is about 1 kilo ohm.
14. The method of claim 8 wherein said resistance is at least about one hundred times as large as a resistance of said coupling of said body bias voltage to said body biasing wells of said semiconductor device.