SEMICONDUCTOR DEVICE

• US 20130063123A1
• Filed: 04/26/2012
• Published: 03/14/2013
• Est. Priority Date: 09/14/2011
• Status: Active Grant

• Current Assignee: Mitsubishi Electric Corporation
• Original Assignee: Mitsubishi Electric Corporation
• Inventors: LIANG, Xiaoguang
• Granted Patent: US 8,536,847 B2
• Time in Patent Office: Days
• US Class Current: 323/313
• CPC Class Codes: H03K 17/687 the devices being field-effect transistors
• CPC Class Codes: H03K 2217/0063 High side switches, i.e. the higher potential [DC] or life wire [AC] being directly connected to the switch and not via the load
• CPC Class Codes: H03K 2217/0072 Low side switches, i.e. the lower potential [DC] or neutral wire [AC] being directly connected to the switch and not via the load
• CPC Class Codes: H03K 2217/0081 Power supply means, e.g. to the switch driver

Abstract

A semiconductor device includes high-side and low-side switching elements totem-pole-connected between high-voltage-side and low-voltage-side potentials; a high-side drive circuit, having high-voltage and low-voltage terminals which are connected to a floating power supply, which supplies either a voltage at the high-voltage terminal or a voltage at the low-voltage terminal for driving the high-side switching element; and a low-side drive circuit driving the low-side switching element and a reference voltage circuit generating a reference voltage between the voltages at high-voltage and low-voltage terminals of the high-side drive circuit. The reference voltage circuit supplies the reference voltage to a connection point between the high-side and low-side switching elements. The semiconductor device includes a charging switching element having a control terminal, a first terminal connected to the low-voltage terminal of the high-side drive circuit, and a grounded second terminal.

Claims

1. A semiconductor device comprising:

a high-side switching element and a low-side switching element totem-pole-connected in this order from a high-voltage side between a high-voltage-side potential and a low-voltage-side potential;

a high-side drive circuit including a high-voltage terminal and a low-voltage terminal which are connected to a floating power supply, the high-side drive circuit supplying one of a voltage at the high-voltage terminal and a voltage at the low-voltage terminal to the high-side switching element to drive the high-side switching element;

a low-side drive circuit driving the low-side switching element;

a reference voltage circuit generating a reference voltage between the voltage at the high-voltage terminal and the voltage at the low-voltage terminal of the high-side drive circuit and supplying the reference voltage to a connection point between the high-side switching element and the low-side switching element; and

a charging switching element having a control terminal, a first terminal connected to the low-voltage terminal of the high-side drive circuit, and a second terminal grounded.

2. The semiconductor device according to claim 1, wherein the control terminal of the charging switching element is connected to an output terminal of the low-side drive circuit.

3. The semiconductor device according to claim 2, further comprising a delay circuit connected between the control terminal of the charging switching element and the output terminal of the low-side drive circuit.

4. The semiconductor device according to claim 1, further comprising a reverse current prevention diode connected between the low-voltage terminal of the high-side drive circuit and the charging switching element.