ZHCSI58C October 2009 – May 2018 TPS65720 , TPS65721
PRODUCTION DATA.
For TPS65720 and TPS657201, the default output voltage is 1.85 V while the default output voltage is 2.85 V for TPS657202, defined by register LDO_CTRL. The programmable voltage range is 0.8 V to 3.3 V. A voltage change to a higher voltage needs to be accomplished in steps of 8% maximum otherwise the power-good comparator will detect a too low voltage, will trigger and generate a reset. There is no limitation in programming output voltages to lower values.
For the TPS65721, the output voltage for LDO1 is externally adjustable using a resistor-divider at pin FB_LDO1. The feedback voltage is 0.8 V and the total resistance of the voltage divider should be kept in the 100-kΩ to
1-MΩ range. A feed-forward capacitor in parallel to the resistor from Vout to FB_LDO1 is required. It´s value should be based on transient performance and will be in the range from 4.7 pF to 22 pF.
The output voltage with an internal reference voltage VFB-LDO1 = 0.8 V is calculated by Equation 4:
OUTPUT VOLTAGE | R3 | R4 | NOMINAL VOLTAGE |
---|---|---|---|
3.3 V | 470 kΩ | 150 kΩ | 3.31 V |
1.85 V | 200 kΩ | 150 kΩ | 1.86 V |
1.8 V | 300 kΩ | 240 kΩ | 1.80 V |