JPS595665A - Semiconductor integrated circuit - Google Patents

Abstract

PURPOSE:To obtain an accurate output signal based on an input signal, by grounding an emitter, which is closest to each collector of each multiemitter transistor that is provided in the same direction, and supplying the input signal to the other emitter. CONSTITUTION:Four transistors Q11, Q12, Q13, and Q14 are formed. A Schottky barrier diode is formed between an N type epitaxial layer 3 and an aluminum layer 6. The bases of the transistors Q11, Q12, Q13, and Q14 are connected through internal resistances rb1, rb2, rb3, and rb4. A collector terminal C and each collector of the transistor Q11-Q14 are connected through internal resistances rc1, rc2, rc3, rc4, and rc5, and also connected to the cathode of the Schottky barrier diode through internal resistnaces r1 and r2. The collector terminal C is connected a load circuit. An emitter E14 of the transistor Q14 which is closest to the collector C, is grounded. An input signal is supplied to emitters E13, E12, and E11.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a TTL (Tranetstor-T
The present invention relates to a semiconductor integrated circuit suitable for use in a ranele-tor LIogLc) circuit.

At the input end of the TTL+ circuit, a Schottky barrier diode kW multi-emitter transistor (hereinafter referred to as a transistor) Ql as shown in FIG. 1 is often used. The transistor q1 has, for example, four transistors having a common space and a common collector on the same semiconductor substrate.
It is made up of m transistors. Then, only the emitter ε ivy is provided separately for g+''
! lj3 % W4 may be given an input invitation h6.

In the case of the above-mentioned method of using VO, according to the studies of the present inventors, the input signals supplied to the workpieces E, to E4 are simultaneously
When going from level to L level, the output dragon flow technique. I have become accustomed to the appearance of so-called sink marks on L. This phenomenon appears as an instantaneous large current at the rising position It and slightly falling position of the human input signal. As a result, if, for example, a latch circuit is connected to the output end of the TTLl path (not shown), the above-mentioned whisker, that is, an instantaneous large 1! The latch circuit malfunctions due to the L current. Note that the latch circuit includes a counter circuit, a shift register circuit, and the like.

SUMMARY OF THE INVENTION Accordingly, it is an object of the present invention to provide a cattle conductor collector circuit which can produce accurate output signals based on human input signals.

Hereinafter, one embodiment of the present invention will be described with reference to FIGS. 2 to 61r.

Is Maki 2 a Schottky barrier diode? 1 is a cross-sectional view of a main part of a semiconductor integrated circuit showing a circuit of a multi-emitter transistor Q+ and its structure.

1 is a P type substrate, 2 is an N+ buried layer 1-13 is an N type epitaxial layer, 4 is a P type base diffusion layer, 5a, 5b
, 5C15d is an N+ emine p diffusion layer, 6 is an aluminum layer, and 7 is a silicon dioxide layer. In the semiconductor integrated circuit of the above-mentioned vO structure (referred to as 0 in the cut),
+71j shown @ 4 transistors Q, 11% Q
txx QCs are formed, and a Schottky barrier diode is formed between the Hg epitaxial layer 3 and the aluminum layer 6. I configured this process
When C is illustrated as a circuit symbol, it becomes a transistor QI as shown in FIG.

The bases of each transistor Qz, Qth transistor, Q+++, and 4 transistors have internal resistances rbll bl, r b , ,
r b , and the collector terminal C and each collector of each transistor Q to GL14 have an internal resistance r
o+, . 3. 1. 4, ro is connected to the cand of the Schott 1,000-via diode through the internal resistance rI% rl.

Note that the anode of the Schottky barrier diode is connected to the +voo source via a resistor (not shown), and is also connected to the base of the transistor Ql. F,
The collector terminal C is connected to a negative loop circuit (not shown) by 71 threads.

In this embodiment, the transistor 7 closest to the collector C
Ground the four emitters Bj I4, and
! 'l! 1% 'L l! , gt+.

According to Honbenmei Nagisa's experiment, when the human power 4g changes from H level to B level, or from L level to H level, a large current momentarily flows through the collector current. There wasn't.

The above νIJ@favorable experimental results can be explained as follows.

However, the base of the transistor Q14 is 111.
The pace tonryuko is provided bI with S 8 resistance r ~ r
b4 Dark blue color. For this reason, the internal resistance rbi~rb4 has a base current υiuL of the amount of light that saturates the transistor Qt4, and the clamping effect by the Schottky barrier diode is reduced if d44 become. Then, when the input signal changes from the H level to the L level, the pace current of the transistor GL14 necessary to drive the output circuit OL is obtained. Therefore, the Q-th transistor does not deviate from the saturation region, and a large current does not momentarily flow through the output flow circuit OL.

By the way, when emitter E is grounded and an input signal is supplied to emitter E to the paper slot, and this input signal is changed from H level to L level, a large current momentarily appears in the output current oh. In this case, at the base of transistor Q,
Pace III flows through the internal resistance rbI.

From the pace current, if the current flowing through the Schottky barrier diode is 8, and the output current is OL, ■b:! :Eng s + Inr, /l'1rpQ mouth. In other words, only the base current for saturating the Qth transistor flows through the base of the Qth transistor. In this state, when the voltage is changed from the 5H level to the L level, the base tVi, bW flowing through the transistor Q511 decreases, and its collector current also decreases.

-force 1 Transistor Q11% Ql1% By the flow of the 6-N torque, each transistor qt
Collector current flows between z and Q points! However, there is a delay time from when the pace current reaches g to when the collector current starts to flow at 2L. If the collector current of the 9 transistors is 1-, then when the relationship ①<②oL is established, the transistor Q deviates from the saturated D region and the collector voltage increases. Then, after a predetermined delay time, transistor Q1. ~ Q14 operates and collector current flows in each, and the Qth transistor also writes and enters the saturation region. Therefore,
As the transistor Qll moves out of the saturation region and returns to the saturation region, a fluctuation appears in the output current OL.

However, if the emitter fit4 of VL transistor Q shown in this embodiment is grounded and human power 1 is supplied to emitters 11 to 8, transistor 9 will be removed from the saturated state. Therefore, the output current OL does not fluctuate.

When experimental data was obtained for the above-mentioned two types of circuit operations, characteristics as shown in FIGS. 4 and 5 were obtained. That is, as described in this embodiment, when emitter E is grounded and human signals are supplied to emitters E1 to E13, the operating points of transistors Q and I are lowered as shown in FIG. However, emitter E eye yk is grounded and emitter gt
If all human input signals are supplied from t to E, transistor Q,
The operating point of t becomes high as shown in FIG. 5, and the above-mentioned defects appear.

For the reasons stated above, if the emitter of the transistor Q closest to the collector C is connected to the ground, stable operation can be obtained even if any of the other emitters E to Is are grounded. That is clear.

Furthermore, when the above-mentioned transistor Q+ kIC is fabricated, a large number of transistors are formed simultaneously on the same semiconductor substrate. Since stable operation can be obtained by grounding the emitter fF2z'e, the transistor Q+ffi shown in FIG.
<By arranging them side by side on the same plane, the grounding circuit patterns P can be linearly provided as shown in the figure. If the collector and base are arranged in opposite directions, the grounding circuit pattern P must be provided in the form of a broken line. In this case, the number of intersections with other wiring patterns increases. However, by arranging the transistors Q1 side by side in the same space, the grounding circuit pattern Pi can be formed linearly, and the number of intersections with other circuit patterns can be reduced.

As described above, if the semiconductor stalk circuit to which the present invention is applied is used, there will be no fluctuation in the output flow when the human input signal is switched from the H level to the L level.Furthermore, the wiring pattern can be simplified. I can do it.

[Brief explanation of the drawing]

FIG. 1 is a circuit diagram of a conventionally known multi-emitter transistor having a Schottky barrier diode, and FIG. 2 is an equivalent circuit diagram of a multi-emitter transistor showing an embodiment of the present invention. Figure P Figure 4 Pika conductor and Figure 5 Gog voltage

Claims (1)

[Claims] 1, 1? 'i] - A multi-emitter transistor is provided on a half-quad board at one time, and the emitter closest to each collector of each of the above-mentioned multi-emitter transistors is grounded, and the input No. 16 r is supplied to the other terminals. 'It is a semiconductor integrated circuit with bamboo characteristics.