Level shift circuit

• US 9,900,009 B2
• Filed: 08/25/2015
• Issued: 02/20/2018
• Est. Priority Date: 10/01/2014
• 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: Akahane, Masashi
• Primary Examiner(s): JAGER, RYAN C
• Application Number:
  US15/301,219
• Publication Number:
  US 20170019106A1
• Time in Patent Office: 910 Days
• Field of Search: 327333, 326 80, 326 81
• CPC Class Codes: H03K 17/162 without feedback from the output circuit to the control circuit
• CPC Class Codes: H03K 17/687 the devices being field-effect transistors
• CPC Class Codes: H03K 19/00361 in field effect transistor circuits
• CPC Class Codes: H03K 19/00369 Modifications for compensating variations of temperature, supply voltage or other physical parameters
• CPC Class Codes: H03K 19/018507 Interface arrangements
• 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

The present invention provides a level-shift circuit that can suppress the malfunction caused by the noise due to the ON/OFF of a level-shift transistor and the dV/dt noise due to external noise. The present invention provides a level-shift circuit for transmitting a signal from a primary potential side to a secondary potential side, comprising: a first serial circuit a first resistance including serially-connected to a first switching element; a second serial circuit including a second resistance serially-connected to a second switching element; a latch malfunction protection circuit for which the respective output terminals of the first and second serial circuits are connected to an input terminal; a latch circuit for receiving a signal outputted from the latch malfunction protection circuit; and a capacitor connected between drain terminals of the first resistance and the first switching element and between drain terminals of the second resistance and the second switching element.

Claims

1. A level-shift circuit for IC for transmitting a signal from a primary potential side to a secondary potential side different from the primary potential side, comprising:

a first serial circuit including a first resistance serially-connected to a first switching element, wherein the input of the first switching element is a first input signal for turning ON or OFF the first switching element, and a connecting point of the first resistance and the first switching element acts as an output terminal;

a second serial circuit including a second resistance serially-connected to a second switching element, wherein the input of the second switching element is a second input signal for controlling the ON/OFF of the second switching element, a connecting point of the second resistance and the second switching element acts as an output terminal, and the first input signal and the second input signal are not simultaneously turned ON;

a latch circuit for changing a status depending on the output of the output terminal of the first serial circuit and the output of the output terminal of the second serial circuit;

a first capacitor connected between the output terminal of the first serial circuit and the output terminal of the second serial circuit; and

one or more additional capacitors parallelly connected to the first capacitor,

wherein the first capacitor and the one or more additional capacitors have a different frequency characteristic, respectively.

2. The level-shift circuit according to claim 1, wherein:

both the first switching element and the second switching element are an N channel-type semiconductor switching element or a P channel-type semiconductor switching element.

3. The level-shift circuit according to claim 1, wherein:

both the first switching element and the second switching element are an N channel-type semiconductor switching element or a P channel-type semiconductor switching element.