Emitter-coupled logic (ECL) with data heavy duty function
Technical field
(Emitter Couple Logic, ECL) circuit is particularly about utilizing the transistorized emitter-coupled logic (ECL) with data heavy duty function of bond oxide-semiconductor field effect (MOSFET) to the present invention relates to emitter coupled logic.
Background technology
Because the service speed of emitter coupled logic (hereinafter to be referred as ECL) circuit is fast, so the ECL circuit has been widely used in logic gates (logic gate circuit), for example D flip-flop (Flip-Flop).Figure 1 shows that the ECL circuit " ECL circuit for forcibly setting ahigh level output " of the 4th, 546, No. 272 patents of the U.S..This ECL circuit comprises emitter-coupled bipolar transistor TR1, the TR2 of a pair of reception differential wave and the resistance R that load resistance R1, R2, are connected in the emitter of bipolar transistor TR1, TR2
s, one be connected in resistance R
sCurrent source and a pair of bipolar transistor TR3, the TR4 that is used for receive being provided with (set) or (reset) signal that resets.
This traditional ECL circuit utilizes resistance R
sVoltage difference is provided, make the base stage and base stage and the emitter voltage poor (VBE1, VBE2) of emitter voltage poor (VBE3, VBE4) greater than the emitter-coupled bipolar transistor TR1, the TR2 that receive differential wave, the output signal of forcing setting to be output as setting or to reset of bipolar transistor TR3, TR4 that (set) or (reset) signal that resets receive to be set.
Though providing, this traditional ECL circuit is provided with and the function that resets, not the function of heavy duty (Reload).Because the ECL circuit is not that complementary metal oxide is partly led (CMOS) transistorized logic digital circuits, can't directly receive digital overloading data as signalization and reset signal.Therefore, during for needs numeral overloading data, must judge earlier that the overloading data of required loading is logic high (Logichigh) H, or logic low (Logic low) L.If H then is set at high-voltage level with signalization, and reset signal is set at low voltage level.If anti-L then is set at low voltage level with signalization, and reset signal is set at high-voltage level.So, with the complexity that causes in the design, and when carrying out overloading data conversion ECL voltage level, can cause the delay on the data heavy duty speed, and influence the data over-loading operation speed of this ECL circuit.
Summary of the invention
Because the problems referred to above the objective of the invention is to propose a kind of ECL circuit with data heavy duty function.
The objective of the invention is to propose the ECL circuit that a kind of digital overloading data can direct-coupledly have data heavy duty function.
For reaching above-mentioned purpose, the present invention has the ECL circuit of data heavy duty function, and comprise: a differential and double bipolar transistor is right, comprises first bipolar transistor and second bipolar transistor, the emitter of these two bipolar transistors is connected to each other, and base stage receives a differential wave; One load resistance is right, comprises first load resistance and second load resistance, is serially connected with the right collector electrode of differential and double bipolar transistor respectively; One resistance has first end and second end, and this first end is connected in the right emitter of differential and double bipolar transistor; One fixed current source is connected in second end of resistance; The first serial connection transistor, comprise the 3rd bipolar transistor and first field-effect transistor, the collector electrode of the 3rd bipolar transistor is connected in the collector electrode of first bipolar transistor, base stage receives an override signal, and emitter is connected in the drain electrode of this first field-effect transistor, and the source electrode of this first field-effect transistor is connected in second end of resistance, and grid receives an overloading data; One inverter is oppositely exported overloading data; And second the serial connection transistor, comprise the 4th bipolar transistor and second field-effect transistor, the collector electrode of the 4th bipolar transistor is connected in the collector electrode of second bipolar transistor, base stage receives override signal, and emitter is connected in the drain electrode of this second field-effect transistor, and the source electrode of this second field-effect transistor is connected in second end of resistance, and grid receives the dateout of inverter, wherein, the current collection of described the 4th bipolar transistor is first output very, and the current collection of described the 3rd bipolar transistor second output very.
Because the present invention utilizes field-effect transistor directly to receive the setting overloading data, therefore digital overloading data needn't be passed through preposition ECL voltage level conversion treatment.And overloading data can be set earlier and be sent to field-effect transistor, so field-effect transistor can be set conducting earlier or close before heavily loaded control signal action.Therefore, as long as one action of heavily loaded control signal can promote the data heavy duty responsiveness of ECL circuit according to the state of overloading data control output end.
Description of drawings
Fig. 1 is a traditional E CL circuit.
Fig. 2 has the ECL circuit of data heavy duty function for the present invention.
Embodiment
The ECL circuit that has the data heavy duty below with reference to graphic detailed description the present invention.
Fig. 2 has the ECL circuit of data heavy duty function for the present invention.As shown in the drawing, ECL circuit of the present invention comprises a differential emitter coupling bipolar transistor B1, B2, a load resistance is connected in bipolar transistor is connected in the current source Is of resistance R e, a pair of reception overloading data to the resistance R e, of the emitter of B1, B2 field effect transistor M 1, M2 and an inverter INV to R1, R2, a pair of heavy duty control bipolar transistor B3, B4.
The emitter-coupled bipolar transistor is connected in high working voltage VCC to the collector electrode (collector) of B1, B2 via resistance R 1, R2, and base stage (base) then receives differential wave DA, DB respectively.This emitter-coupled bipolar transistor is connected to low-work voltage VEE to the emitter (emitter) of B1, B2 via resistance R e and current source Is.The current collection of bipolar transistor B2 is the output OUTA of this ECL circuit very, and the current collection of the bipolar transistor B1 inverse output terminal OUTB of this ECL circuit very.
The collector electrode of heavy duty control bipolar transistor B3 is connected in the collector electrode of bipolar transistor B1, and base stage receives a heavily loaded control signal RL.And the drain electrode of field effect transistor M 1 (drain) is connected in the emitter of heavy duty control bipolar transistor B3, and grid (gate) receives an overloading data DATA, and source electrode (source) is connected in current source Is.The collector electrode of heavy duty control bipolar transistor B4 is connected in the collector electrode of bipolar transistor B2, and base stage receives heavily loaded control signal RL.And the drain electrode of field effect transistor M 2 is connected in the emitter of heavy duty control bipolar transistor B4, and grid receives via the reverse reverse overloading data of inverter, and source electrode is connected in current source Is.
Because the conducting resistance of field effect transistor M 1 and M2 is much smaller than resistance R e, therefore heavy duty control bipolar transistor B3 is identical with the bipolar transistor TR3 function of traditional E CL circuit (with reference to figure 1) with the combination of field effect transistor M 1, and the bipolar transistor TR4 function of the heavily loaded combination of controlling bipolar transistor B4 and field effect transistor M 2 and traditional E CL circuit (with reference to figure 1) is identical.So, when the equal conducting of heavy duty control bipolar transistor B3 and field effect transistor M 1, output OUTA can be set at H.And when the equal conducting of heavy duty control bipolar transistor B4 and field effect transistor M 2, output OUTA can be set at L.
But because the present invention utilizes field effect transistor M 1 and M2 directly to receive to set overloading data, therefore digital overloading data needn't be passed through preposition ECL voltage level conversion treatment.And overloading data can be set earlier and be sent to field effect transistor M 1 and M2, so field effect transistor M 1 can be set conducting earlier with M2 or close before heavily loaded control signal RL action.So, as long as heavily loaded control signal RL one action can promote data heavy duty responsiveness according to overloading data DATA control output end OUTA and OUTB state.
The below operation of explanation ECL circuit of the present invention.At first, when heavily loaded control signal RL is L, bipolar transistor B3, all not conductings of B4.Therefore, the output of this ECL circuit is controlled by differential wave DA, DB.The action of this part identical with conventional art (with reference to figure 1), no longer repeat specification.
When heavily loaded control signal RL is H, because the equal conducting of bipolar transistor B3, B4.At this moment, if overloading data DATA is H, then field effect transistor M 1 conducting, field effect transistor M 2 not conductings are L so the output OUTA of this ECL circuit is H, OUTB.And if overloading data DATA is L, then field effect transistor M 1 not conducting, field effect transistor M 2 conductings are H so the output OUTA of this ECL circuit is L, OUTB.The operation principle of this part identical with conventional art (with reference to figure 1), no longer repeat specification.
Though more than with embodiment the present invention is described, therefore do not limit scope of the present invention, only otherwise break away from main idea of the present invention, those skilled in the art can carry out various distortion or change.For example, the differential and double bipolar transistor among Fig. 2 to replaceable be different emitter coupled logic frameworks, as " with " (and collection (AND)), latch (breech lock (latch)) etc., be applicable to that still this has the function of data heavy duty.