Claims
- 1. In a gate including a switching portion and an emitter follower, wherein the switching portion defines a collector mode, the voltage at which is representative of an input signal and is characterized by a delay time relative to the input signal having a particular temperature dependence, and wherein the emitter follower includes a load current source and an emitter follower transistor having its base coupled to the collector node and its emitter coupled to the load current source to define an output node, the improvement wherein the load current source comprises:
- a current source resistor having first and second ends, said resistor having a temperature-dependent behavior characterized by a first temperature coefficient;
- a current source transistor having its collector coupled to the output node and its emitter coupled to said first resistor end, the voltage drop across the junction defined by the base and emitter of said current source transistor having a temperature-dependent behavior characterized by a second temperature coefficient; and
- a reference voltage source having a first voltage output terminal coupled to the base of said current source transistor and a second voltage output terminal coupled to said second resistor end for providing a defined voltage increment therebetween, said voltage increment having a temperature-dependent behavior characterized by a third temperature coefficient;
- wherein said first, second, and third temperature coefficients define a fourth temperature coefficient that characterizes the temperature-dependence of the load current source, which fourth temperature coefficient imparts a temperature dependence to the delay time in the emitter follower that is related to the particular temperature dependence of the delay time in the switching portion so as to compensate therefor and provides a total delay in the gate that is substantially temperature-independent.
- 2. The invention of claim 1 wherein the particular temperature dependence of the delay time in the switching portion is characterized by a positive temperature coefficient, and wherein the current supplied by the load current source is characterized by a positive temperature coefficient.
- 3. The invention of claim 1 wherein the switching portion comprises a differential transistor pair having emitter-coupled first and second transistors and a collector network having a cross-coupled diode pair in series with at least one resistor to provide voltage swings at the output node having levels that exhibit substantial temperature independence.
- 4. A temperature-compensated gate structure comprising:
- a differential pair including first and second gate transistors having their respective emitters coupled to a common circuit point;
- a gate current source coupled to said common circuit point to provide current flow through said gate transistors, the relative flow through said gate transistors being determined by the relative voltage levels at the respective bases of said gate transistors;
- wherein an output signal representative of an input signal at the base of at least one of said gate transistors appears at the collector of said first gate transistor, and bears a temperature-dependent time relationship to the input signal, thus defining a partial gate delay and a temperature coefficient thereof;
- an emitter follower transistor having its base connected to the collector of said first gate transistor, and having its emitter coupled to an output node; and
- a load current source including
- a resistor having first and second ends, said resistor being characterized by a first temperature coefficient,
- a current source transistor having its collector coupled to said output node and its emitter coupled to said first resistor end, the voltage drop across the base-emitter junction of said current source transistor being characterized by a second temperature coefficient, and
- a reference voltage source having a first voltage output terminal coupled to the base of said current source transistor and a second voltage output terminal coupled to said second resistor end for providing a defined voltage increment therebetween, said voltage increment being characterized by a third temperature coefficient,
- wherein said first, second, and third temperature coefficients define a fourth temperature coefficient that characterizes said load current source;
- wherein said fourth temperature coefficient is of the same sign as the temperature coefficient of said partial gate delay so that a change in temperature that increases the partial gate delay through said differential pair also increases the load current to decrease the delay through said emitter follower, in a manner that provides a total delay in the gate that is substantially temperature-independent.
- 5. The invention of claim 4 wherein said reference voltage source is a band-gap regulator operable to supply a voltage V.sub.0 characterized by a temperature coefficient dV.sub.0 /dT, comprising:
- a regulating transistor having its base connected to an intermediate node and its emitter connected to said second voltage output terminal, the voltage across the base-emitter junction of said regulating transistor being denoted V.sub.1 and being characterized by a temperature coefficient dV.sub.1 /dT;
- a current source pair of transistors Q1 and Q2 in a current mirror configuration, transistor Q1 having its collector coupled to said intermediate node, transistor Q2 having its base and collector coupled to the base of transistor Q1 and its emitter coupled to said second voltage output terminal;
- means defining current paths to the base of transistor Q1, to the base and collector of transistor Q2, and to said first voltage output terminal;
- a first resistor having value R.sub.1 coupled between said first voltage output terminal and said intermediate node;
- a second resistor having value R.sub.2 coupled between the emitter of transistor Q1 and said second voltage output terminal, the voltage across said second resistor being denoted V.sub.2 and being characterized by a temperature coefficient dV.sub.2 /dT; and
- a third resistor having value R.sub.3 coupled between said intermediate node and said second voltage output terminal;
- wherein the relative values of R.sub.1, R.sub.2, and R.sub.3 are chosen in relation to the values V.sub.1, V.sub.2, dV.sub.1 /dT, and dV.sub.2 /dT so as to provide the desired values of V.sub.0 and dV.sub.0 /dT that provide said current source with the desired temperature coefficient.
- 6. In a band-gap regulator for providing an output voltage V.sub.0 between first and second output terminals, voltage V.sub.0 being characterized by a desired temperature coefficient dV.sub.0 /dT, the band-gap regulator including
- a regulating transistor having a its base connected to an intermediate node and its emitter connected to the second output terminal, the voltage across the base-emitter junction of the regulating transistor being denoted V.sub.1 and being characterized by a temperature coefficient dV.sub.1 /dT,
- a current source pair of transistors Q1 and Q2 in a current mirror configuration, transistor Q1 having its collector coupled to the intermediate node, transistor Q2 having its base and collector coupled to the base of transistor Q1 and its emitter coupled to said second output terminal,
- means defining current paths to the base of transistor Q1, to the base and collector of transistor Q2, and to the first voltage output terminal,
- a first resistor having value R.sub.1 coupled between the first output terminal and the intermediate node, whereupon the voltage between said first and second output terminals is equal to the sum of the voltage drop across the first resistor and the voltage V.sub.1 across the base-emitter junction of the regulating transistor, and
- a second resistor having value R.sub.2 coupled between the emitter of transistor Q1 and the second output terminal, the voltage across the second resistor being denoted V.sub.2 and being characterized by a temperature coefficient dV.sub.2 /dT,
- the improvement comprising:
- a third resistor having value R.sub.3 coupled between the intermediate node and the second output terminal, the relative values of R.sub.1, R.sub.2, and R.sub.3 being chosen in relation to the values of V.sub.1, V.sub.2, dV.sub.1 /dT, and dV.sub.2 /dT, to provide the desired values of V.sub.0 and dV.sub.0 /dT.
Parent Case Info
This application is a continuation-in-part of U.S. Ser. No. 518,499, filed Aug. 1, 1983, now abandoned.
US Referenced Citations (4)
Continuation in Parts (1)
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Number |
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518499 |
Aug 1983 |
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