US 6,184,723 B2 · Direct voltage to PTAT current converter for multiple gain control slope for wide dynamic range VGA

Abstract

A system and method for converting an analog control voltage to a PTAT current. A plurality of differential transistor pairs is provided, each differential pair including a reference transistor and a non-reference transistor, each transistor having a current path and a control electrode. A first output is coupled to a first end of the current path of each of said non-reference transistors and output means is coupled to a first end of the current path of each of the reference transistors. A plurality of current sources is provided, one current source for each differential pair, each current source having a current path coupled to an opposing end of the current path of a different one of the transistor pairs and a control electrode. A PTAT current generator is coupled to the control electrode of each of the current sources. Each differential pair is provided with a pair of electron emitting electrodes coupled together, the current source being coupled to the electron emitting electrodes. The current sources can provide the same or different current outputs. A pair of such circuits can be provided, each with a different slope, with a control determining which circuit output will be provided to the system.

Claims16

Dependent claims

A system for converting a control voltage to a PTAT current which comprises:

(a) a plurality of differential transistor pairs, each differential transistor pair including a reference transistor and a non-reference transistor, each said transistor having a current path and a control electrode for controlling current in said current path, the control electrodes of said reference transistors each being coupled to a different reference voltage source;
(b) a first output path coupled to a first end of the current path of each of said non-reference transistors;
(c) a second output path coupled to a first end of the current path of each of said reference transistors;
(d) a plurality of current sources, one current source for each differential pair, each said current source having a current path coupled to an opposing end of the current path of a different one of said transistor pairs and each current sources also having a control electrode;
and
(e) a PTAT current generator coupled to the control electrode of each of said current sources to control said current sources.

3 more elements

A system for converting a control voltage to a PTAT current which comprises:

(a) a first circuit which comprises:
(i) a plurality of differential transistor pairs, each differential pair including a reference transistor and a non-reference transistor, each transistor having a current path and a control electrode;
(ii) a first output coupled to a first end of the current path of each of said non-reference transistors;
(iii) output means coupled to a first end of the current path of each of said reference transistors;
(iv) a plurality of current sources, one current source for each differential pair, each said current source having a current path coupled to an opposing end of the current path of a different one of said transistor pairs and a control electrode;
and
(v) a PTAT current generator coupled to the control electrode of each of said current sources;
(b) a second circuit which comprises;
(i) a plurality of differential transistor pairs, each differential pair including a reference transistor and a non-reference transistor, each transistor having a current path and a control electrode;
(ii) a first output coupled to a first end of the current path of each of said non-reference transistors;
(iii) output means coupled to a first end of the current path of each of said reference transistors;
(iv) a plurality of current sources, one current source for each differential pair, each said current source having a current path coupled to an opposing end of the current path of a different one of said transistor pairs and a control electrode;
and
(v) a PTAT current generator coupled to the control electrode of each of said current sources;
and
(c) means to enable the output means of one of said first and second circuits and disable the output means of the other of said first and second circuits.

13 more elements

A method for converting a control voltage to a PTAT current which comprises:

(a) providing a first circuit which comprises:
(i) a plurality of differential transistor pairs, each differential pair including a reference transistor and a non-reference transistor, each transistor having a current path and a control electrode;
(ii) a first output coupled to a first end of the current path of each of said non-reference transistors;
(iii) output means coupled to a first end of the current path of each of said reference transistors;
(iv) a plurality of current sources, one current source for each differential pair, each said current source having a current path coupled to an opposing end of the current path of a different one of said transistor pairs and a control electrode;
and
(v) a PTAT current generator coupled to the control electrode of each of said current sources;
(b) providing a second circuit which comprises;
(i) a plurality of differential transistor pairs, each differential pair including a reference transistor and a non-reference transistor, each transistor having a current path and a control electrode;
(ii) a first output coupled to a first end of the current path of each of said non-reference transistors;
(iii) output means coupled to a first end of the current path of each of said reference transistors;
(iv) a plurality of current sources, one current source for each differential pair, each said current source having a current path coupled to an opposing end of the current path of a different one of said transistor pairs and a control electrode;
and
(v) a PTAT current generator coupled to the control electrode of each of said current sources;
and
(c) enabling the output means of one of said first and second circuits and disabling the output means of the other of said first and second circuits.

13 more elements

Dependencies are inferred from the claim text.

Direct voltage to PTAT current converter for multiple gain control slope for wide dynamic range VGA

Life of this patent

Direct voltage to PTAT current converter for multiple gain control slope for wide dynamic range VGA

Life of this patent

Abstract

Claims16