Datasheet

VBAT (Battery sense voltage )
VSYS (System voltage )
001
010
2R
1R
VICH (Voltage proportional to charge current )
VTS (Thermistor voltage )
MUX_OUT
001/ 010
100
011
000
MUX[2:0]
HiZ
+
-
MUX_IN
101
TPS65217A, TPS65217B, TPS65217C, TPS65217D
www.ti.com SLVSB64F –NOVEMBER 2011–REVISED APRIL 2013
ANALOG MULTIPLEXER
The TPS65217 provides an analog multiplexer that allow access to critical system voltages such as:
• battery voltage (VBAT)
• system voltage (VSYS)
• temperature sense voltage (VTS), and
• VICHARGE, a voltage proportional to the charging current.
In addition one external input is available to monitor an additional system voltage. VBAT and VSYS are divided
down by a factor of 1:3 to be compatible with input voltage range of the ADC that resides on the system host
side. The output of the MUX is buffered and can drive a maximum of 1-mA load current.
Figure 7. Analog Multiplexer
BATTERY CHARGER AND POWER PATH
TPS65217 provides a linear charger for Li+ batteries and a triple system-power path targeted at space-limited
portable applications. The power path allows simultaneous and independent charging of the battery and
powering of the system. This feature enables the system to run with a defective or absent battery pack and
allows instant system turn-on even with a totally discharged battery. The input power source for charging the
battery and running the system can be either an AC adapter or a USB port. The power path prioritizes the AC
input over the USB and both over battery input to reduce the number of charge and discharge cycles on the
battery. Charging current is automatically reduced when system load increases and if the system load exceeds
the maximum current of the USB or AC adapter supply, the battery will supplement, meaning that the battery will
be discharged to supply the remaining current. A block diagram of the power path is shown in Figure 8 and an
example of the power path management function is shown in Figure 9.
Copyright © 2011–2013, Texas Instruments Incorporated Submit Documentation Feedback 23
Product Folder Links: TPS65217A TPS65217B TPS65217C TPS65217D