Systems and methods for reuse of battery pack-side current and voltage sensing

Abstract

Systems and methods for reuse of battery pack-side current and voltage sensing are disclosed. By reusing elements within a battery pack, a battery field effect transistor (FET) within a power management integrated circuit (PMIC) may be eliminated or at least bypassed. In a first aspect, a current mirror is coupled to a charge protection circuit in the battery pack to capture a sensed current. Likewise, a voltage sensor captures a voltage level for a charging path. Current and voltage are output to the PMIC for use in regulating a buck charger. In a second aspect, current data and voltage data are collected and digitized before being sent to the PMIC for use in regulating the buck charger.

What is claimed is: 
     
         1 . A power management integrated circuit (PMIC) comprising:
 a power source input;   a buck charger circuit coupled to the power source input and having a buck output;   a power output coupled to the buck output; and   a feedback input configured to receive information from a battery pack, wherein the information includes data from a voltage sense circuit in the battery pack and information about current flowing to a battery cell in the battery pack.   
     
     
         2 . The PMIC of  claim 1 , further comprising a charge controller configured to receive the data and the information about the current flowing to the battery cell and control the buck charger circuit based on the data and the information about the current flowing to the battery cell. 
     
     
         3 . The PMIC of  claim 2 , further comprising a battery field effect transistor (FET) switchably positioned between the buck charger circuit and the power output and configured to provide voltage information and current information to the charge controller. 
     
     
         4 . The PMIC of  claim 2 , further comprising a current analog to digital converter (ADC) configured to convert the information about the current flowing to the battery cell to digital information for the charge controller. 
     
     
         5 . The PMIC of  claim 2 , further comprising a voltage analog to digital converter (ADC) configured to convert the data to digital data for the charge controller. 
     
     
         6 . The PMIC of  claim 2 , wherein the buck charger circuit is directly coupled to the power output without using a battery field effect transistor (FET). 
     
     
         7 . The PMIC of  claim 1  integrated into a device selected from the group consisting of: a set top box; an entertainment unit; a navigation device; a communications device; a fixed location data unit; a mobile location data unit; a global positioning system (GPS) device; a mobile phone; a cellular phone; a smart phone; a session initiation protocol (SIP) phone; a tablet; a phablet; a server; a computer; a portable computer; a mobile computing device; a wearable computing device; a desktop computer; a personal digital assistant (PDA); a monitor; a computer monitor; a television; a tuner; a radio; a satellite radio; a music player; a digital music player; a portable music player; a digital video player; a video player; a digital video disc (DVD) player; a portable digital video player;
 an automobile; a vehicle component; avionics systems; a drone; and a multicopter. 
 
     
     
         8 . A method for controlling charging of a battery at a power management integrated circuit (PMIC), comprising:
 receiving, from a battery pack, information relating to current and voltage passing to a battery cell within the battery pack; and   controlling a buck charger circuit based on the information.   
     
     
         9 . The method of  claim 8 , wherein receiving the information comprises receiving multiplexed digital information. 
     
     
         10 . The method of  claim 8 , wherein receiving the information comprises receiving the information across two separate data paths. 
     
     
         11 . The method of  claim 8 , further comprising receiving temperature data from the battery pack. 
     
     
         12 . The method of  claim 8 , further comprising switching out a battery field effect transistor (FET) within the PMIC.