Half-Half-Bridge Pulse Width Modulation Low Power Magnetic Secure Transmission Systems

Patent metadata

Field	Value
Publication number	US-2020220384-A1
Application number	US-201916368791-A
Country	US
Kind code	A1
Filing date	Mar 28, 2019
Priority date	Jan 3, 2019
Publication date	Jul 9, 2020
Grant date	—

Abstract

According to some embodiments, a magnetic secured transmission (MST) driver is provided. The MST driver includes a full-bridge switching circuit that includes a first half-bridge coupled to a first node and a second half-bridge coupled to a second node; and a control circuit coupled to drive the first half-bridge according to MST input data and to drive the second half bridge according to a high-frequency pulse width modulation (PWM) signal.

First claim

What is claimed is:

1 . A magnetic secure transmission (MST) driver circuit, comprising:
a first half-bridge component; a second half-bridge component coupled to the first half-bridge component to form a full-bridge component; a control circuit coupled to drive the first half-bridge component according to a MST input signal and drive the second half-bridge component according to a pulse width modulation (PWM) signal.

2 . The MST driver circuit of claim 1 , wherein the first half-bridge component includes a first transistor switch and a second transistor switch coupled to the first transistor switch via a first connection node, and
wherein the control circuit is configured to apply the MST input signal to a first gate of the first transistor switch, and an inversed version of the MST input signal to a second gate of the second transistor switch.

3 . The MST driver circuit of claim 2 , wherein the second half-bridge component includes a third transistor switch and a fourth transistor coupled to the third transistor switch via a second connection node, and
wherein the control circuit is configured to apply the PWM signal to a third gate of the third transistor switch, and an inversed version of the PWM signal to a fourth gate of the fourth transistor switch.

4 . The MST driver circuit of claim 3 , further comprising:
a high-frequency oscillator coupled to the control circuit, configured to provide the PWM signal having a frequency higher than the MST input signal.

5 . The MST driver circuit of claim 3 , wherein the first connection node is coupled to the second connection node via a coil.

6 . The MST driver circuit of claim 5 , wherein the coil is operated as a MST coil or a wireless power transfer coil.

7 . The MST driver circuit of claim 6 , wherein the full-bridge component is configured to operate as a wireless power transceiver using the coil as the wireless power transfer coil.

8 . The MST driver circuit of claim 5 , wherein the coil has a first current flowing from the first connection node to the second connection node when the MST input signal is high, and a second current flowing from the second connection node to the first connection node when the MST input signal is low.

9 . The MST driver circuit of claim 8 , wherein the second half-bridge component is configured to control an amplitude, a slew rate of transition, or a power saving slope of the first current or the second current flowing through the coil according to the PWM signal.

10 . The MST driver circuit of claim 9 , wherein the controlled amplitude, the controlled slew rate of transition, or the controlled power saving slope is reconfigurable through the control circuit.

11 . A method for operating a magnetic secure transmission (MST) driver circuit, comprising:
driving, via a control circuit, a first half-bridge component according to a MST input signal; and driving, via the control circuit, a second half-bridge component coupled to the first half-bridge component that form a full-bridge component, according to a pulse width modulation (PWM) signal.

12 . The method of claim 11 , wherein the first half-bridge component includes a first transistor switch and a second transistor switch coupled to the first transistor switch via a first connection node, and the method comprises:
applying the MST input signal to a first gate of the first transistor switch, and an inversed version of the MST input signal to a second gate of the second transistor switch.

13 . The method of claim 12 , wherein the second half-bridge component includes a third transistor switch and a fourth transistor coupled to the third transistor switch via a second connection node, and the method comprises:
applying the PWM signal to a third gate of the third transistor switch, and an inversed version of the PWM signal to a fourth gate of the fourth transistor switch.

14 . The method of claim 13 , further comprising:
providing, via a high-frequency oscillator coupled to the control circuit, the PWM signal having a frequency higher than the MST input signal.

15 . The method of claim 13 , further comprising:
passing a current between the first connection node and the second connection node via a coil.

16 . The method of claim 15 , further comprising:
operating the coil as a MST coil or a wireless power transfer coil.

17 . The method of claim 16 , further comprising:
operating the full-bridge component as a wireless power transceiver using the coil as the wireless power transfer coil.

18 . The method of claim 15 , further comprising:
passing, via the coil, a first current flowing from the first connection node to the second connection node when the MST input signal is high; and passing, via the coil, a second current flowing from the second connection node to the first connection node when the MST input signal is low.

19 . The method of claim 18 , further comprising:
controlling, via the second half-bridge component, an amplitude, a slew rate of transition, or a power saving slope of the first current or the second current flowing through the coil according to the PWM signal.

20 . The method of claim 19 , further comprising:
reconfiguring, through the control circuit, the controlled amplitude, the controlled slew rate of transition, or the controlled power saving slope.

Assignees

• Integrated Device Tech

Inventors

• Qi Tao
• Mehas Gustavo
• Liu Rui

Classifications

• H02J50/10 Primary

  using inductive coupling · CPC title

• G06K7/10316 Primary

  using at least one antenna particularly designed for interrogating the wireless record carriers (antennas in general H01Q1/22) · CPC title

• H02J50/20

  using microwaves or radio frequency waves · CPC title

• G06K19/07779

  the inductive antenna being a coil · CPC title

• G06K19/06187

  with magnetically detectable marking · CPC title