JPS6241471Y2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to circuit blocks such as monolithic or hybrid integrated circuits, and particularly to an integrated circuit that controls a power supply line depending on whether one integrated circuit among a plurality of circuit blocks is used or not.

In a radio receiver that is generally constructed by combining multiple integrated circuits (hereinafter referred to as IC), for example,
PLL if equipped with FM and AM bands
When combining an IC that adopts the (Phase Locked Loop) method with another block's IC, a prescaler IC is especially necessary as a component when receiving FM, but it is not necessary when receiving AM. If the V _CC line of the power source is left connected, power consumption occurs, and in the case of battery drive, not only is there a loss and the battery is consumed, but it is also a cause of unnecessary radiation. Therefore, in order to reduce power consumption during AM reception, the present invention connects a switching element 8 between the semiconductor substrate 7 and the ground terminal 16, and sends a control signal to a control terminal 17 that controls the switching element during AM reception. Applying voltage to the semiconductor substrate 7
and the ground terminal 16. On the other hand, FM
During reception, in order to operate the prescaler IC, the transistor 8, which is a switching element, is applied with a voltage higher than the rising voltage via the control terminal 17 to be turned on, and the semiconductor substrate 7 becomes approximately at ground potential.

However, the semiconductor substrate 7 shifts by the collector-emitter voltage V _CE of the transistor 8, and when an AC signal is input to the input terminals 13 and 14, the output signal swings between V _CE and V _CC .
There was a problem in that level matching between the prescaler IC and the PLL circuit 11 could not be performed.

The present invention therefore provides a novel integrated circuit which eliminates the above-mentioned drawbacks. Referring to the drawings, 1 includes buffer amplifiers 2, 3, frequency dividers 4, 5, 6, semiconductor substrate 7, switching transistor 8, and bias resistors 9, 1.
0 for prescaler IC, 11 for PLL
IC 21 represents a capacitor for grounding the semiconductor substrate 7 in an alternating current manner.

The IC1 has a power supply V _CC terminal 12 and an input terminal 1.
3, 14, a substrate terminal 15, a ground terminal 16, a control terminal 17, and an output terminal 18.

Next, when the prescaler IC 1 is used, that is, during FM reception, the control signal _Vc is output from the PLL IC 11 through the terminal 19. This control signal is equal to or higher than the rising voltage of the switching transistor 8, and the switching transistor 8 is on, that is, the substrate is at the ground potential.
The input signal Vi is divided by 25 by the power supply voltage V _CC , and the output voltage V ₀ is derived from the output terminal 18 .
The buffer amplifiers 2, 3 and the frequency dividers 4, 5, 6
In this case, the grounding capacitor 2 operates normally.
Here, the grounding capacitor 21 serves as an AC ground for the semiconductor substrate 7, as described above, so that when an AC signal is applied to the input of the prescaler IC, the semiconductor substrate 7 is
The AC signal flowing from the transistor 8 is bypassed by the capacitor 21. Therefore, the voltage V
Since _CE is AC pulled down to ground, the output voltage will swing fully between OV and V _CC .

Therefore, since the high frequency output waveform has a full swing, the level matching between the output terminal 18 and the external connection circuit (for example, the PLL circuit 11) which is a high frequency IC becomes good.

On the other hand, when the prescaler IC 1 is not used, that is, during AM reception, the control signal V _C from the terminal 19 of the PLL IC 11 is zero, so the switching transistor 8 is turned off and the buffer amplifiers 2, 3 and Since no energizing current flows through the frequency dividers 4, 5, and 6, they become inoperative, and in the illustrated example,
By simply applying the power supply voltage V _CC to the terminal 20 of the PLL IC 11 , predetermined signals are derived from various terminals (not shown) according to the input signals to perform the AM reception operation.

As described above, according to the present invention, when one integrated circuit among a plurality of circuit blocks is switched into an active state or a non-active state according to the purpose, the substrate potential of the integrated circuit is controlled. It is possible to cut off the power current, reduce current consumption in battery-powered electronic equipment, and furthermore, it is possible to completely eliminate disturbances such as unnecessary radiation that conventionally occur when the integrated circuit is not in operation. Furthermore, in order to connect the capacitor 21 between the board terminal 15 and the ground to ground the semiconductor board 7 in an alternating current manner, the high frequency output waveform changes from OV to V _CC
The level matching between the output terminal 18 and the external connection circuit 11 is improved.

[Brief explanation of the drawing]

The drawing shows an embodiment of the integrated circuit of the present invention. Explanation of main drawing numbers, 1... prescaler IC,
7...Semiconductor substrate, 11 ...IC for PLL, 15...
... Board terminal, 16 ... Ground terminal, 17 ... Control terminal.

Claims (1)

[Scope of utility model registration request] In an integrated circuit including a plurality of components, a semiconductor substrate is commonly connected to one power supply terminal of the components, and a capacitor is connected to the semiconductor substrate and has one end connected to an external ground potential. a substrate terminal for connecting the ends, a ground terminal for connecting to the external ground potential, and a switching element connected between the ground terminal and the semiconductor substrate;
An integrated circuit comprising: a control terminal for controlling the switching element.