Bias current generator
AssigneeAnalog Devices, Inc.
InventorStefan Marinca
Life of this patent
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Abstract
A bias current generator for generating bias current is described. The generator comprises an amplifier having an inverting input, a non-inverting input and an output. A first bipolar transistor is associated with one of the inverting and non-inverting inputs of the amplifier. A load MOS device is associated with the other one of the inverting and non-inverting inputs of the amplifier. The load MOS device is driven by the amplifier to operate in the triode region with a corresponding drain-source resistance ron. The first bipolar transistor and the load MOS device are arranged such that a voltage derived from the first bipolar transistor is developed across the drain-source resistance ron of the load MOS device thereby generating a bias current.
Claims23
A bias current generator comprising:
- a first amplifier having an inverting input, a non-inverting input and an output,
- a first bipolar transistor associated with one of the inverting and non-inverting inputs of the first amplifier,
- a load MOS device associated with the other one of the inverting and non-inverting inputs of the first amplifier,
- the load MOS device being driven by the first amplifier to operate in the triode region with a corresponding drain-source resistance ron, the first bipolar transistor and the load MOS device being arranged such that a voltage derived from the first bipolar transistor is developed across the drain-source resistance ron of the load MOS device thereby generating a bias current.
A bias current generator comprising:
- an amplifier having an inverting input, a non-inverting input and an output,
- a bipolar transistor associated with one of the inverting and non-inverting inputs of the amplifier,
- a load MOS device associated with the other one of the inverting and non-inverting inputs of the amplifier,
- the load MOS device being driven by the amplifier to operate in the triode region with a corresponding drain-source resistance ron, the bipolar transistor and the load MOS device being arranged such that the voltage developed across the drain-source resistance ron of the load MOS device corresponds to the base-emitter voltage Vbe of the bipolar transistor thereby generating a CTAT bias current.
A bias current generator comprising:
- an amplifier having an inverting input, a non-inverting input and an output,
- a first bipolar transistor associated with one of the inverting and non-inverting inputs of the amplifier,
- a load MOS device associated with the other one of the inverting and non-inverting inputs of the amplifier, and
- a second bipolar transistor operating at a lower collector current density than that of the first bipolar transistor and being associated with the load MOS device such that a base-emitter voltage difference ΔVbe between the first bipolar transistor and the second bipolar transistor is developed across the drain-source resistance ron of the load MOS thereby generating a PTAT bias current.
Dependencies are inferred from the claim text.