Power protection apparatus and terminal using the apparatus

Patent metadata

Field	Value
Publication number	US-11527883-B2
Application number	US-202016825061-A
Country	US
Kind code	B2
Filing date	Mar 20, 2020
Priority date	Sep 23, 2017
Publication date	Dec 13, 2022
Grant date	Dec 13, 2022

Abstract

A battery protection apparatus power protection apparatus is configured to protect an electrochemical cell connected to a load, and includes a protection IC, a switching transistor group, and a sampling resistor. The protection IC includes two power input terminals respectively connected to positive and negative electrodes of the electrochemical cell, and an operational amplifier, where the operational amplifier includes a positive input pin, a negative input pin, and an output pin. The switching transistor group is connected between the negative electrode of the electrochemical cell and the load, and is configured to control turn-on and turn-off of a charge and discharge circuit of the electrochemical cell. The sampling detection resistor Rs is serially connected between the sampling circuit detection terminal and the output pin, where the main circuit detection terminal is connected to the positive input pin, and the sampling circuit detection terminal is connected to the negative input pin.

First claim

What is claimed is:

1. A power protection apparatus configured to protect an electrochemical cell connected to a load, comprising:
a protection integrated circuit (IC), comprising two power input terminals respectively connected to positive and negative electrodes of the electrochemical cell, at least one charge and discharge protection terminal, and an operational amplifier, wherein the operational amplifier comprises a positive input pin, a negative input pin, and an output pin;
a switching transistor group, connected between the negative electrode of the electrochemical cell and the load, and configured to turn on or turn off a charge and discharge of the electrochemical cell, wherein the switching transistor group comprises a main circuit part and a sampling part, a first connection terminal connected to the negative electrode of the electrochemical cell, a second connection terminal connected to the load, and at least one control terminal, wherein the first connection terminal and the second connection terminal are respectively connected to an input terminal and an output terminal of the main circuit part, and the control terminal is connected to the at least one charge and discharge protection terminal of the protection IC, and is configured to receive a control signal of the protection IC to control turn-off of the switching transistor group to implement protection against an abnormality of the electrochemical cell; and
a sampling detection resistor Rs, serially connected between the sampling part of the switching transistor group and the output pin, and configured to detect a current of the sampling part of the switching transistor group, wherein
the input terminal or the output terminal of the main circuit part of the switching transistor group is connected to the positive input pin, and a connection terminal of the sampling part of the switching transistor group is connected to the negative input pin, wherein the switching transistor group comprises (X+KX) switching transistor units that are connected in parallel; X switching transistor units are connected in parallel to form the sampling part of the switching transistor group; KX switching transistor units are connected in parallel to form the main circuit part, wherein X is an integer greater than 1, K is greater than 1, and KX is an integer.

2. The power protection apparatus according to claim 1 , wherein the operational amplifier is configured to enable the negative input pin and the positive input pin to have a same potential, so that a current passing through the sampling part of the switching transistor group is equally proportional to a current passing through the main circuit part of the switching transistor group.

3. The power protection apparatus according to claim 1 , wherein a ratio of the current passing through the sampling part to the current passing through the main circuit part is equal to a ratio of a quantity of switching transistor units of the sampling part to a quantity of switching transistor units of the main circuit part, that is, is equal to 1:K.

4. The power protection apparatus according to claim 3 , wherein the switching transistor group comprises a sampling output terminal SS 1 connected to the connection terminal of the sampling part, and a main circuit detection output terminal S 1k connected to the input terminal of the main circuit part of the switching transistor group, the S 1k is connected to the positive input pin of the operational amplifier, the SS 1 is connected to both the negative input pin and the output pin of the operational amplifier, and the sampling detection resistor Rs is serially connected between the SS 1 and the output pin of the operational amplifier.

5. The power protection apparatus according to claim 4 , wherein the switching transistor group further comprises a sampling output terminal SS 2 connected to the connection terminal of the sampling part, and a main circuit detection output terminal S 2k connected to the output terminal of the main circuit part, the protection IC further comprises a secondary operational amplifier, the S 2k is connected to a positive input pin of the secondary operational amplifier, the SS 2 is connected to both a negative input pin and an output pin of the secondary operational amplifier, and the power protection apparatus further comprises a sampling detection resistor R 2 that is serially connected between the SS 2 and the output pin of the secondary operational amplifier.

6. The power protection apparatus according to claim 3 , wherein the switching transistor group comprises a sampling output terminal SS 1 and a sampling detection output terminal SS 1k that are connected to the connection terminal of the sampling part, and a main circuit detection output terminal S 1k connected to the input terminal of the main circuit part, the S 1k is connected to the positive input pin of the operational amplifier, the SS 1 is connected to the output pin of the operational amplifier, the SS 1k is connected to the negative input pin of the operational amplifier, and the sampling detection resistor Rs is serially connected between the SS 1 and the output pin of the operational amplifier.

7. The power protection apparatus according to claim 6 , wherein the switching transistor group further comprises a sampling output terminal SS 2 and a sampling detection output terminal SS 2k that are connected to the connection terminal of the sampling part, and a main circuit detection output terminal S 2k connected to the output terminal of the main circuit part of the switching transistor group, the protection IC further comprises a secondary operational amplifier, the S 2k is connected to a positive input pin of the secondary operational amplifier, the SS 2 is connected to an output pin of the secondary operational amplifier, the SS 2k is connected to a negative input pin of the secondary operational amplifier, and the power protection apparatus further comprises a sampling detection resistor R 2 that is serially connected between the SS 2 and the output pin of the secondary operational amplifier.

8. The power protection apparatus according to claim 6 , wherein each switching transistor unit comprises a first switching transistor Sa and a second switching transistor Sb that is serially connected to the Sa reversely, each of the Sa and Sb is connected to a diode D 1 in parallel, one of the Sa and the Sb is a charge switching transistor and the other is a discharge switching transistor, the X switching transistor units are connected in parallel to form the sampling part of the switching transistor group, and the KX switching transistor units are connected in parallel to form the main circuit part of the switching transistor group.

9. The power protection apparatus according to claim 8 , wherein the at least one control terminal comprises a discharge control terminal G 1 and a charge control terminal G 2 , D electrodes of all Sa's and Sb's of the (X+KX) switching transistor units are connected together, G electrodes of all Sa's of the (X+KX) switching transistor units are connected together to form the G 1 , G electrodes of all Sb's of the (X+KX) switching transistor units are connected together to form the G 2 , S electrodes of all Sa's of the X switching transistor units constituting the sampling part of the switching transistor group are connected to a same pin to form the sampling output terminal SS 1 , S electrodes of all Sb's of the X switching transistor units are connected to a same pin to form a sampling output terminal SS 2 , S electrodes of all Sa's of the KX switching transistor units constituting the main circuit part of the switching transistor group are connected to a same pin to form the first con

Assignees

• Huawei Tech Co Ltd

Inventors

• Liu Xinyu
• Liu Yanding
• Liu Ce
• Wang Pinghua
• Cao Yong

Classifications

• H02J7/663

  using battery or load disconnect circuits (H02J9/002 takes precedence) · CPC title

• H02J7/62

  against overcurrent · CPC title

• H02H7/18 Primary

  for batteries; for accumulators · CPC title

• H02H3/087 Primary

  for DC applications · CPC title

• G01R19/16519

  using FET's · CPC title