Datasheet

TPS65217
VIN_DCDC2
VIN_DCDC3
VIN_DCDC1
VIN_LDO
USB
AC
SYS
4.7u
BAT
BAT_SENSE
10k
TS
5V power supply
(2.7..5.5V)
18u
L4
10u
BAT
SYS
10u 10u 10u
TPS65217
VIN_DCDC2
VIN_DCDC3
VIN_DCDC1
VIN_LDO
USB
AC
SYS
22u
BAT
BAT_SENSE
TS
5V power supply
(4.3..5.8V)
18u
L4
10u
BAT
SYS
10u 10u 10u
BAT , BAT _SENSE ,
and TS pins are
floating
22u
TPS65217A, TPS65217B, TPS65217C, TPS65217D
SLVSB64F –NOVEMBER 2011–REVISED APRIL 2013 www.ti.com
BATTERY-LESS/5-V OPERATION
TPS65217 provides a linear charger for Li+ batteries but the IC can operate without a battery attached. There are
three basic use-cases for battery-less operation:
1. The system is designed for battery operation, but the battery is not inserted. The system can be powered by
connecting an AC adaptor or USB supply.
2. A non-portable system running off a (regulated) 5-V supply, but the PMIC must provide protection against
input over-voltage up to 20 V. Electrically this is the same as the previous case where the IC is powered off
an AC adaptor. The battery pins (BAT, BATSENSE, TS) are floating and power is provided through the AC
pin. DCDC converters, WLED driver, and LDOs connect to the over-voltage protected SYS pins. Load
switches (or LDO3 and LDO4, depending on configuration) typically connect to one of the lower system rails
but may also be connected to the SYS pin.
3. A non-portable system running of a regulated 5-V supply that does not require input-over-voltage protection.
In this case the 5-V power supply is connected through the BAT pins and the DCDC converter inputs, WLED
driver, LDO1, and LDO2 are connected directly to the 5-V supply. A 10-kΩ resistor is connected from TS to
ground to simulate the NTC of the battery. Load switches (or LDO3 and LDO4, depending on configuration)
typically connect to one of the lower system rails, but may also be connected to the 5-V input supply directly.
The main advantage of connecting the supply to the BAT pins is higher power-efficiency because the internal
power-path is by-passed and power-loss across the internal switches is avoided.
Figure 18 shows the connection of the input power supply to the IC for 5-V only operation with and without 20-V
input over-voltage protection and Table 5 lists the functional differences between both setups.
Figure 18. Left: Power-connection for battery-less/5-V only operation. The SYS node and DCDC
converters are protected against input over-voltage up to 20 V. Right: Power-connection for 5-V only
operation. The DCDC converters are not protected against input over-voltage, but power-efficiency is
higher because the internal power-path switches are bypassed.
Table 5. Functional Differences Between Battery-Less/5-V Only Operation With and Without 20-V Input
Over-Voltage Protection
POWER SUPPLIED THROUGH AC PIN POWER SUPPLIED THROUGH BAT PIN
(CASE (1) AND (2)) (CASE (3))
Max operating input voltage is 5.8 V, but IC is
Input protection Max operating input voltage is 5.5 V.
protected against input over-voltage up to 20 V.
DCDC input current passes through AC-SYS Internal power-path is bypassed to minimize IxR
Power efficiency
power-path switch (approximately 150 mΩ). losses.
BATTEMP bit (bit 0 in register 0x03h) always
BATTEMP bit (bit 0 in register 0x03h) always reads
BATTEMP bit reads 1, but has no effect on operation of the
0.
part.
LDO1 is automatically powered up when AC pin
LDO1 is OFF when BAT is connected to 5-V supply.
Output rail status upon initial is connected to 5-V supply and device enters
PB_IN must be pulled low to enter [WAIT PWR_EN]
power connection [WAIT PWR_EN] state. IF PWR_EN pin is not
state.
asserted within 5s, LDO1 turns OFF.
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Product Folder Links: TPS65217A TPS65217B TPS65217C TPS65217D