Datasheet

TPS65950
SWCS032E–OCTOBER 2008–REVISED JANUARY 2011 www.ti.com
8 Battery Interface
8.1 General Description
8.1.1 Battery Charger Interface Overview
The TPS65950 has a BCI for complete battery management. The main function of the BCI is to control the
charging of either 1-cell Li-ion or Li-ion polymer batteries, or 1-cell Li-ion batteries with
cobalt-nickel-manganese anodes. It supports regulated ac chargers of 7-V absolute maximum and can
charge with USB host devices, MCPC devices, USB chargers, or carkits of 7-V absolute maximum. The
BCI can perform software-controlled linear charging with the sources mentioned, software-controlled
pulsed charging with current-limited ac chargers, and automatic linear charging with ac chargers, USB
chargers, and carkits.
The battery is monitored using the 10-bit ADC from the MADC to measure battery voltage, battery
temperature, battery type, battery charge current, USB device input voltage, and ac charger input voltage.
The magnitude of the charging current and the charging voltage is set by 10 bits of a programming
register converted by a 10-bit DAC, whose output sets the reference input of the charging current and
charging voltage control loop.
The BCI also performs monitoring functions:
• ac charger detection
• VBUS detection
• Battery detection
• ac charger overvoltage detection
• VBUS overvoltage detection
• Battery overvoltage detection
• Battery voltage level detection
• Battery charge current level detection
• Battery temperature out-of-range detection
• Battery end-of-charge detection
• Battery overcurrent detection
• Watchdog
8.1.2 Battery Backup Overview
The TPS65950 implements a backup mode, in which the backup battery keeps the RTC running. A
rechargeable backup battery can be recharged from the main battery.
When the main battery is below 2.7 V or is removed, the backup battery powers the backup if the backup
battery voltage is greater than 1.8 V. The backup domain powers up the following:
• Internal 32.768-kHz oscillator
• RTC
• Hash table (20 registers of 8 bits each)
• Eight GP storage registers
8.2 Typical Application Schematics
8.2.1 Functional Configurations
The BCI can be used in different configurations (see Figure 8-1). Each configuration requires a dedicated
typical application schematic:
• ac charge supported (see Figure 8-1A, Figure 8-1B, and Figure 8-1D)
• USB charge supported (see Figure 8-1A and Figure 8-1C)
114 Battery Interface Copyright © 2008–2011, Texas Instruments Incorporated
Submit Documentation Feedback
Product Folder Link(s): TPS65950