DRIVER CIRCUIT FOR A DEVICE CIRCUIT

• US 20190326900A1
• Filed: 04/24/2018
• Published: 10/24/2019
• Est. Priority Date: 04/24/2018
• Status: Active Application

• Current Assignee: Infineon Technologies AG
• Original Assignee: Infineon Technologies AG
• Inventors: Calabro, Rocco, Vitrenko, Oleg
• Application Number:
  US15/960,807
• Publication Number:
  US 20190326900A1
• Time in Patent Office: Days
• CPC Class Codes: H03K 17/06 Modifications for ensuring a fully conducting state
• CPC Class Codes: H03K 17/107 in composite switches
• CPC Class Codes: H03K 19/0185 using field effect transistors only

Abstract

A driver circuit for driving a device circuit, including: a diode-connected transistor having a bulk input coupled to a driver supply voltage, coupled between the driver supply voltage and a positive control node, wherein the driver supply voltage is less than a threshold voltage of the device circuit; a capacitor coupled between the positive control node and a signal input, wherein when an input signal received at the signal input is high, a positive control voltage at the positive control node configured to control an input transistor of the device circuit is higher than the threshold voltage of the device circuit.

Claims

1. A driver circuit for driving a device circuit, comprising:

a diode-connected transistor having its bulk input coupled to its drain, and coupled between a driver supply voltage and a positive control node, wherein the driver supply voltage is less than a threshold voltage of the device circuit; and

a capacitor coupled between the positive control node and a signal input,

wherein when an input signal received at the signal input is high, a positive control voltage at the positive control node configured to control an input transistor of the device circuit is higher than the threshold voltage of the device circuit.

2. The driver circuit of claim 1, wherein when the input signal received at the signal input is high, the control voltage at the positive control node is approximately double the driver supply voltage minus a threshold voltage of the diode-connected transistor.

3. The driver circuit of claim 1, wherein the diode-connected transistor is configured to charge the capacitor when a voltage at the positive control node is less than the driver supply voltage minus a threshold voltage of the diode-connected transistor.

4. The driver circuit of claim 1, wherein when the input signal received at the signal input is low, the control voltage at the positive control node is approximately equal to the driver supply voltage minus a threshold voltage of the diode-connected transistor.

5. The driver circuit of claim 1, further comprising:

an inverter circuit coupled between the signal input and a negative control node of the input transistor of the device circuit, and configured to invert the input signal.

6. The driver circuit of claim 1, wherein when the input signal received at the signal input is high, a negative control voltage at a negative control node of the input transistor is approximately equal to a driver ground voltage.

7. The driver circuit of claim 1, wherein when the input signal received at the signal input is low, a negative control voltage at a negative control node of the input transistor is approximately equal to the driver supply voltage.

8. A semiconductor circuit, comprising:

a device circuit, comprising;

an input transistor; and

a load circuit coupled between a device supply voltage and the input transistor; and

a driver circuit, comprising;

a diode-connected transistor having a bulk input coupled to a driver supply voltage, and coupled between the driver supply voltage and a positive control node, wherein the driver supply voltage is less than a threshold voltage of the device circuit; and

a capacitor coupled between the positive control node and a signal input,

wherein when an input signal received at the signal input is high, a differential control voltage between the positive and a negative control nodes configured to control the input transistor of the device circuit is higher than the threshold voltage of the device circuit.

10. The semiconductor circuit of claim 8, wherein the driver circuit and the device circuit are arranged on a same semiconductor die.

11. The semiconductor circuit of claim 8, wherein the load circuit is a resistor or a controlled current source.

12. The semiconductor circuit of claim 8, wherein the semiconductor circuit is a differential signal circuit.

13. The semiconductor circuit of claim 12, wherein the load circuit is a cross-coupled transistor circuit.

9. The semiconductor circuit of claim 9, wherein the driver circuit further comprises:

an inverter circuit coupled between the signal input and the negative control node of the input transistor, and configured to invert the input signal,

wherein when the input signal received at the signal input is high, a negative control voltage of the negative control node of the input transistor is approximately equal to a driver ground voltage.

14. A semiconductor circuit, comprising:

a device circuit, comprising;

a first input transistor;

a second input transistor; and

a load circuit comprising cross-coupled transistors coupled between a device supply and the first and second input transistors, wherein the cross-coupled transistors have a polarity opposite that of the first and second input transistors; and

a driver circuit configured to drive the device circuit, comprising;

a first diode-connected transistor having its bulk input coupled to its drain, and coupled between a driver supply voltage and a first positive control node, wherein the driver supply voltage is less than a threshold voltage of the device circuit;

a second diode-connected transistor having a bulk input coupled to the driver supply voltage, and coupled between the driver supply voltage and a second positive control node;

a first capacitor coupled between the first positive control node and a first differential signal input; and

a second capacitor coupled between the second positive control node and a second differential signal input,

wherein when a first of a pair of differential input signals received at the first differential signal input is high and a second of the pair of differential input signals received at the second differential signal input is low, a first positive control voltage at the first positive control node configured to control the first input transistor of the device circuit is higher than the threshold voltage of the device circuit, a second positive control voltage at the second positive control node to control the second input transistor is approximately equal to the driver supply voltage minus a threshold voltage of the first diode-connected transistor, a first negative control voltage at a first negative control node configured to control the first input transistor of the device circuit is approximately equal to a driver ground voltage, and a second negative control voltage at a second negative control node configured to control the second input transistor of the device circuit is approximately equal to the driver supply voltage.

15. The semiconductor circuit of claim 14, wherein when the first of the pair of differential input signals received at the first differential signal input is low and the second of the pair of differential input signals received at the second differential signal input is high, the first positive control voltage at the first positive control node is approximately equal to the driver supply voltage minus the threshold voltage of the first diode-connected transistor, the second positive control voltage at the second positive control node is higher than the threshold voltage of the device circuit, the first negative control voltage at the first negative control node is approximately equal to the driver supply voltage, and the second negative control voltage at the second negative control node is approximately equal to the driver ground voltage.

16. A method of a driver circuit driving a device circuit, comprising:

controlling, when an input signal received at a signal input is high, a positive control voltage at a positive control node of an input transistor of the device circuit to be higher than a threshold voltage of the device circuit,

wherein the driver circuit comprises;

the diode-connected transistor having its bulk input coupled to its drain, and coupled between a driver supply voltage and the positive control node, wherein the driver supply voltage is less than the threshold voltage of the device circuit; and

a capacitor coupled between the positive control node and the signal input.

17. The method of claim 16, further comprising:

controlling, when the input signal received at the signal input is low, the positive control voltage to be approximately equal to a driver supply voltage minus a threshold voltage of a diode-connected transistor.