ZHCSFF5G July 2016 – December 2019 TPS2660
PRODUCTION DATA.
Figure 64 shows a typical redundant power supply configuration of the system. Schottky ORing diodes have been popular for connecting parallel power supplies, such as parallel operation of wall adapter with a battery or a hold-up storage capacitor. The disadvantage of using ORing diodes is high voltage drop and associated power loss. The TPS2660x with integrated, N-channel back to back FETs provide a simple and efficient solution.
A fast reverse comparator controls the internal FET and it is turned ON or OFF with hysteresis as shown in Figure 65. The internal FET is turned off within 1.5 μs (typical) as soon as V(IN) – V(OUT) falls below –110 mV. It turns on within 40 µs (typical) once the differential forward voltage V(IN) – V(OUT) exceeds 100 mV. Figure 66 and Figure 67 show typical switch-over waveforms of Active ORing implementation using the TPS26600.
VIN1 = 22 V | Cout = 47 μF | Rload = 24 Ω |
VIN2: Plugged In at 24 V | C(dVdT) = 22 nF |
VIN1 = 22 V | Cout = 47 μF | Rload = 24 Ω |
VIN2: Plugged Out | C(dVdT) = 22 nF |
NOTE
All control pins of the un-powered TPS2660x device in the Active ORing configuration will measure approximately 0.7 V drop with respect to GND. The system micro-controller should ignore IMON and FLT pin voltage measurements of this device when these signals are being monitored.