Datasheet

Output Voltage Holdup
2-4
2.4.2 Mode 2 Automatic Switching (TPS2110/1/2/3 Only)
In Mode 2 automatic switching, OUT connects to IN1 if the voltage at IN1 is
sufficiently high, otherwise OUT connects to the higher of IN1 and IN2. The
threshold at which IN1 is selected corresponds to approximately 0.8 V at test
point TP3. The corresponding value of the IN1 voltage depends upon the
setting of potentiometer R2. Adjusting R2 clockwise increases the IN1
selection threshold voltage.
Refer to Table 2-2 to configure the EVM for Mode 2 automatic switching.
Table 2-2.EVM Shorting Jumper Placement for Mode 2 Automatic Switching
Header
EVM Device
J1 J2 J3 J4
SLVP227-001 TPS2110 X X
SLVP227-002 TPS2111 X X
SLVP227-003 TPS2112 X X
SLVP227-004 TPS2113 X X
A manufacturer can provide a secondary battery pack option to extend the
product run time with Mode 2 automatic switching. The TPS2110–TPS2113
drains the primary battery at IN1 and automatically switches to the secondary
battery at IN2.
2.5 Output Voltage Holdup
Headers J5–J8 select the output holdup capacitance.
The output voltage drops out for 60 µs (max) whenever the TPS211x switches
between the IN1 and IN2 supplies. Some capacitance at the TPS211x output
is necessary to prevent the output voltage from dropping too much during the
supply switchover. Excessive voltage drop can cause a system to reset or lose
data.
2.6 Switch Status (TPS2112/3/4/5 Only)
The switch status output can be monitored at the positive terminal of header
J1. A switch status output equal to logic 1 corresponds to an IN2 switch that
is on.