Semiconductor device for electrical isolation using a photocoupler and isolator to convey a signal

• US 9,363,023 B2
• Filed: 04/11/2013
• Issued: 06/07/2016
• Est. Priority Date: 05/22/2012
• Status: Active Grant

• Current Assignee: Renesas Electronics Corporation
• Original Assignee: Renesas Electronics Corporation
• Inventors: Yamazaki, Hiroaki
• Primary Examiner(s): Epps, Georgia Y
• Assistant Examiner(s): Moore, Carolynn A
• Application Number:
  US13/861,287
• Publication Number:
  US 20130313446A1
• Time in Patent Office: 1,153 Days
• Field of Search: 250/551, 250/214.R, 327/514, 327/515
• US Class Current: 1/1
• CPC Class Codes: H01L 2224/05554 being square
• CPC Class Codes: H01L 2224/48091 Arched
• CPC Class Codes: H01L 2224/48137 the bodies being arranged next to each other, e.g. on a common substrate
• CPC Class Codes: H01L 2224/48247 connecting the wire to a bond pad of the item
• CPC Class Codes: H01L 2924/00012 Relevant to the scope of the group, the symbol of which is combined with the symbol of this group
• CPC Class Codes: H01L 2924/00014 the subject-matter covered by the group, the symbol of which is combined with the symbol of this group, being disclosed without further technical details
• CPC Class Codes: H01L 2924/181 Encapsulation
• CPC Class Codes: H01L 31/02016 Circuit arrangements of general character for the devices
• CPC Class Codes: H04B 10/802 for isolation, e.g. using optocouplers

Abstract

A semiconductor device including: a filter circuit to subdivide and output the received signal as a first signal with a relatively low frequency and a second signal with a relatively high frequency; a first channel containing a photocoupler to convey the first signal output from the filter circuit; a second channel containing an isolator to convey the second signal from the filter circuit; and a signal synthesis circuit to sum and output the first signal conveyed by way of a first channel and a second signal conveyed by way of a second channel.

Claims

1. A semiconductor device, comprising:

a filter circuit to sub-divide and output a received signal as a relatively low frequency first signal and a relatively high frequency second signal;

a first channel containing a photocoupler to convey the first signal output from the filter circuit;

a second channel containing an isolator, the isolator conveying the second signal output from the filter circuit independent of the output of the photocoupler; and

a signal synthesis circuit to sum and output the first signal conveyed by way of the first channel and the second signal conveyed by way of the second channel.

2. The semiconductor device according to claim 1, wherein the isolator mounted in the second channel comprises a capacitive coupling type isolator.

3. The semiconductor device according to claim 2, wherein the photocoupler mounted in the first channel contains a light emitting diode to emit light according to the first signal, and a photodiode to receive light from the light emitting diode, and

wherein the isolator mounted in the second channel contains a capacitor.

4. The semiconductor device according to claim 3, further comprising:

a first semiconductor chip including the filter circuit;

a second semiconductor chip including the light emitting diode; and

a third semiconductor chip including the photodiode, the capacitor, and the signal synthesis circuit.

5. The semiconductor device according to claim 4, wherein the photodiode and the capacitor are formed over a single substrate in the third semiconductor chip.

6. The semiconductor device according to claim 5, wherein the photodiode, the capacitor, and the signal synthesis circuit are formed over a single substrate in the third semiconductor chip.

7. The semiconductor device according to claim 1, wherein the isolator mounted in the second channel comprises an inductive coupling type isolator.

8. The semiconductor device according to claim 1, wherein the first channel comprises a DC channel, and the second channel comprises an AC channel, and

wherein the semiconductor device further comprises:

an amplifier that amplifies a current signal output from the photocoupler and outputs the amplified current signal to the signal synthesis circuit.

9. The semiconductor device according to claim 8, wherein, in the first channel, only the amplified current signal is provided to the signal synthesis circuit.

10. The semiconductor device according to claim 1, wherein the photocoupler comprises an LED and a photo diode in the first channel that transmits the first signal to convert an optical signal to a photo current by a photo detector.

11. The semiconductor device according to claim 1, wherein the photocoupler comprises a photo diode in the first channel, and

wherein, in the semiconductor device, only an electrical shield film installed over the photo diode protects against noise.

12. A semiconductor device, comprising:

a first filter circuit to sub-divide and output a signal received from a first input terminal into a relatively low frequency first signal and a relatively high frequency second signal;

a second filter circuit to sub-divide and output a signal received from a second input terminal into a relatively low frequency third signal and a relatively high frequency fourth signal;

a first channel including a first photocoupler to convey the first signal output from the first filter circuit;

a second channel including a first isolator, the isolator conveying the second signal output from the first filter circuit independent of the output of the first photocoupler;

a third channel including a second photocoupler to convey the third signal output from the second filter circuit;

a fourth channel including a second isolator to convey the fourth signal output from the second filter circuit;

a first signal synthesis circuit to sum and output the first signal conveyed by way of the first channel and the second signal conveyed by way of the second channel; and

a second signal synthesis circuit to sum and output the third signal conveyed by way of the third channel and the fourth signal conveyed by way of the fourth channel.

13. The semiconductor device according to claim 12, wherein the first photocoupler mounted in the first channel includes a first light emitting diode to emit light according to the first signal, and a first photodiode to receive the light from the first light emitting diode,

wherein the first isolator mounted in the second channel includes a first capacitor,

wherein the second photocoupler mounted in the third channel includes a second light emitting diode to emit light according to the third signal, and a second photodiode to receive the light of the second light emitting diode, and

wherein the second isolator mounted in the fourth channel includes a second capacitor.

14. The semiconductor device according to claim 13, further comprising:

a first semiconductor chip including the first filter circuit, the second signal synthesis circuit, the second photodiode, and the second capacitor;

a second semiconductor chip including the first light emitting diode;

a third semiconductor chip including the second filter circuit, the first signal synthesis circuit, the first photodiode, and the first capacitor; and

a fourth semiconductor chip including the second light emitting diode.

15. The semiconductor device according to claim 14, wherein the second photodiode and the second capacitor are formed over a single substrate in the first semiconductor chip, and

wherein the first photodiode and the first capacitor are formed over a single substrate in the third semiconductor chip.

16. The semiconductor device according to claim 15, wherein the first filter circuit, the second signal synthesis circuit, the second photodiode, and the second capacitor are formed over a single substrate in the first semiconductor chip, and

wherein the second filter circuit, the first signal synthesis circuit, the first photodiode, and the first capacitor are formed over a single substrate in the third semiconductor chip.

17. The semiconductor device according to claim 12, wherein the first isolator mounted in the second channel, and the second isolator mounted in the fourth channel, include a capacitive coupling type isolator or an inductive coupling type isolator.

18. The semiconductor device according to claim 12, wherein the second isolator, independent of the output of the second photocoupler, conveys the fourth signal output from the second filter circuit.

19. The semiconductor device according to claim 12, wherein the first channel comprises a DC channel, and the second channel comprises an AC channel, and

wherein the semiconductor device further comprises:

an amplifier that amplifies a current signal output from the first photocoupler and outputs the amplified current signal to the first signal synthesis circuit.

20. The semiconductor device according to claim 19, wherein, in the first channel, only the amplified current signal is provided to the first signal synthesis circuit. transmits the first signal to convert an optical signal to a photo current by a photo detector.