ZHCSKY4B November 2018 – December 2020 TPS55288
PRODUCTION DATA
An internal LDO to supply the TPS55288 outputs regulated 5.2-V voltage at the VCC pin with 60-mA output current capability. When VIN is less than VOUT, the internal LDO selects the power supply source by comparing VIN to a rising threshold of 6.2 V with 0.3-V hysteresis. When VIN is higher than 6.2 V, the supply for LDO is VIN. When VIN is lower than 5.9 V, the supply for LDO is VOUT. When VOUT is less than VIN, the internal LDO selects the power supply source by comparing VOUT to a rising threshold of 6.2 V with 0.3-V hysteresis. When VOUT is higher than 6.2 V, the supply for LDO is VOUT. When VOUT is lower than 5.9 V, the supply for LDO is VIN. Table 7-1 shows the supply source selection for the internal LDO.
| VIN | VOUT | INPUT for VCC LDO |
|---|---|---|
| VIN > 6.2 V | VOUT>VIN | VIN |
| VIN < 5.9 V | VOUT>VIN | VOUT |
| VIN > VOUT | VOUT> 6.2 V | VOUT |
| VIN > VOUT | VOUT< 5.9 V | VIN |
To minimize the power dissipation of the internal LDO when both input voltage and output voltage are high, an external 5-V power source can be applied at the VCC pin to supply the TPS55288. The external 5-V power supply must have at least 100-mA output current capability and must be within the 4.75-V to 5.5-V regulation range. To use an external power supply for VCC, a resistor with proper resistance must be connected to the MODE pin.