ZHCS549K January 2010 – April 2019 LMZ10505
PRODUCTION DATA.
Alternatively, the tracking feature can be used to have similar output voltage ramp rates. This is referred to as simultaneous start-up. In this case, the tracking resistors can be determined based on Equation 5:
and to ensure proper overdrive of the SS pin:
For the example case of VOUT1 = 5 V and VOUT2 = 2.5 V, with Rtrkt set to 33 kΩ as before, Rtrkb is calculated from the above equation to be 15.5 kΩ. Figure 20 shows an example of tracking using the equal slew rates.