SEMICONDUCTOR DEVICE

• US 20170264184A1
• Filed: 05/30/2017
• Published: 09/14/2017
• Est. Priority Date: 06/16/2015
• Status: Active Grant

• Current Assignee: Fuji Electric Company Limited (Fuji Electric Systems Company Limited)
• Original Assignee: Fuji Electric Company Limited (Fuji Electric Systems Company Limited)
• Inventors: TEZUKA, Shinichi, OHASHI, Hidetomo
• Granted Patent: US 9,979,272 B2
• Time in Patent Office: Days
• CPC Class Codes: G11C 11/4091 Sense or sense/refresh amplifiers, or associated sense circuitry, e.g. for coupled bit-line precharging, equalising or isolating
• CPC Class Codes: G11C 2211/4013 Memory devices with multiple cells per bit, e.g. twin-cells
• CPC Class Codes: H01L 29/0603 characterised by particular constructional design considerations, e.g. for preventing surface leakage, for controlling electric field concentration or for internal isolations regions isolation regions between components H01L21/76; design considerations for integrated circuits H01L27/00; geometrical design considerations for devices H01L29/0657
• CPC Class Codes: H01L 29/772 Field effect transistors
• CPC Class Codes: H01L 29/7802 Vertical DMOS transistors, i.e. VDMOS transistors
• CPC Class Codes: H02M 1/084 using a control circuit common to several phases of a multi-phase system
• CPC Class Codes: H02M 1/32 Means for protecting converters other than automatic disconnection
• CPC Class Codes: H02M 7/48 using discharge tubes with control electrode or semiconductor devices with control electrode
• CPC Class Codes: H02M 7/5387 in a bridge configuration
• CPC Class Codes: H03K 17/08122 in field-effect transistor switches
• CPC Class Codes: H03K 17/0822 in field-effect transistor switches
• 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

Abstract

In a semiconductor device, a high-side potential determination circuit outputs an event signal when a high-side reference potential detected by a high-side potential detection circuit rises. If at that time an input logic signal for controlling a high side is at a low (L) level, a pulse generation circuit regenerates a reset signal for a high-side drive circuit. When the input logic signal for controlling the high side is at the L level and the event signal is inputted, an overcurrent detection determination circuit makes an overcurrent detection signal from an overcurrent detection circuit invalid. When the event signal is not inputted, the overcurrent detection determination circuit makes the overcurrent detection signal valid.

Claims

1. A semiconductor device for driving a power device including a high-side power device and a low-side power device that are connected in series, comprising:

a high-side drive circuit, configured to drive the high-side power device on the basis of a high-side logic signal, for controlling the high-side power device;

a high-side potential detection circuit configured to detect a high-side potential to be supplied to the high-side drive circuit;

a high-side potential determination circuit configured to output an event signal on the basis of a change in the high-side potential detected by the high-side potential detection circuit;

a low-side drive circuit, configured to drive the low-side power device on the basis of a low-side logic signal, for controlling the low-side power device;

an overcurrent detection circuit configured to output, to the low-side drive circuit upon detecting an overcurrent by inputting a current signal indicative of a current value of a principal current of the low-side power device, an overcurrent detection signal for turning off the low-side power device; and

an overcurrent detection determination circuit configured to disable the overcurrent detection signal while both the event signal and the low-side logic signal for turning on the low-side power device are output.

2. The semiconductor device according to claim 1, wherein the overcurrent detection determination circuit includes:

a first inverter configured to receive the high-side logic signal;

a first AND circuit having one input connected to an output of the first inverter and another input for receiving the event signal;

a second inverter having an input connected to an output of the first AND circuit; and

a second AND circuit having one input connected to an output of the second inverter, another input for receiving the overcurrent detection signal from the overcurrent detection circuit, and an output connected to the low-side drive circuit.

3. The semiconductor device according to claim 2, wherein the overcurrent detection determination circuit further includes a first RS flip-flop between the first AND circuit and the second inverter, the RS flip-flop having a set input terminal connected to the output of the first AND circuit, a reset input terminal connected so as to receive an inversion of the low-side logic signal, and an output connected to the input of the second inverter.

4. The semiconductor device according to claim 2, wherein the overcurrent detection circuit includes:

a comparator configured to compare the current signal with an overcurrent detection threshold;

a second RS flip-flop configured to

hold an overcurrent detection state signal, and

output the overcurrent detection signal, the comparator outputting the overcurrent detection state signal at the time of the current signal exceeding the overcurrent detection threshold;

a delay circuit configured to delay the overcurrent detection signal for a determined time;

a third inverter having an input connected to an output of the comparator; and

a third AND circuit having one input connected to an output of the delay circuit, another input connected to an output of the third inverter, and an output connected to a reset input terminal of the second RS flip-flop.

5. The semiconductor device according to claim 1, wherein the high-side potential detection circuit detects one of a high-side reference potential and a high-side power supply potential as the high-side potential.

6. The semiconductor device according to claim 1, wherein the high-side potential determination circuit includes a rising edge trigger circuit configured to output an output signal as the event signal upon detecting the high-side potential rising.