TPS65288 is a power management integrated circuit (IC) with three buck converters. High-side and low-side metal-oxide-semiconductor field effect transistors (MOSFET) are integrated to provide fully synchronous conversion with higher efficiency. This converter is designed to simplify its application while enabling designers to optimize their usage according to the target application. This converter can run in 5V, 9V, 12V or 15V systems. This output voltage can be set externally by a resistor divider to any voltage value between 0.8V and the input voltage minus the resistive voltage drop on the converter path. Each converter has an enable pin, which allows a delayed start for sequencing purposes, a soft start pin with adjustable soft start time by selecting a soft start capacitor, and a current limit (RLIM) pin, which enables designers to adjust the current limit by selecting an external resistor and optimize the selection of inductors. All converters operate in "intermittent mode": once an overcurrent condition lasting more than 10ms is sensed in any converter, they will be turned off for 10ms, and then the startup sequence will be retried. If the overload has been removed, the converter will ramp up and operate normally. If this is not the case, the converter will sense another overcurrent event, turn off again, and repeat this cycle (intermittently) before the fault is eliminated. If the overload condition lasts less than 10ms, only the affected related converters will be shut down and restarted, and there will be no global intermittent mode. The switching frequency of these converters is set by an external resistor connected to the ROSC pin. The switching regulator is designed to operate in the frequency range of 300kHz to 2.2MHz. Therefore, these converters operate with a phase difference of 180 degrees, which greatly reduces the input filtering requirements. All converters have peak current mode control, which can simplify external frequency compensation. This device has a built-in slope compensation slope. Slope compensation can prevent subharmonic oscillation in peak current mode control. A traditional type II compensation network can stabilize the system and realize fast transient response. In addition, an optional capacitor connected in parallel with the upper resistor of the feedback divider provides an extra zero value and makes the crossover frequency exceed 100kHz. All converters have an automatic low power pulse skip mode (PSM), which improves the efficiency during light load and standby operation, while ensuring an extremely low output ripple, thus achieving a value of less than 2% at a low output voltage. This device is equipped with an overvoltage transient protection circuit to greatly reduce voltage overshoot. The over-voltage protection (OVP) feature greatly reduces the output overshoot by implementing a circuit that compares the FB pin voltage with the OVP threshold (106% of the internal voltage reference). If the FB pin voltage is greater than the OVTP threshold, the high-side MOSFET is disabled, thus preventing the current from flowing into the output and greatly reducing the output overshoot. When the FB voltage drops below the lower threshold of OVP (104% of the internal voltage reference), the high-side MOSFET can turn on the next clock cycle. TPS65288 has a monitoring circuit, which monitors the output of each buck converter, and the PGOOD pin is set when the sequencing is completed. The PGOOD pin is an open-drain output. This PGOOD pin is pulled low when any buck converter is pulled down below 85% of the nominal output voltage value. When the output of all converters is more than 90% of their nominal output voltage, PGOOD is pulled up. The default reset time is 100ms. The polarity of PGOOD is active at high level. Two USB switches provide up to 1.2A current required by downstream USB devices. When the output load exceeds the current limit threshold or a short circuit occurs, the power management unit (PMU) limits the output current to a safe level by switching to the constant current mode and pulling down the over-current logic output to a low level. When the continuous heavy load and short circuit increase the power dissipation in the switch and cause the junction temperature to rise, an overheat alarm protection circuit closes the USB switch and keeps these buck converters running. This device performs an internal thermal shutdown to protect itself from damage when the junction temperature exceeds 160 C. When the junction temperature exceeds the thermal jump threshold, this thermal shutdown forces the device to stop running. Once the die temperature drops below 140°C, the device restarts the power-up sequence. Thermal shutdown hysteresis value is 20 C
Attribute parameter value Catalogue DC-DC power supply chip Functional type buck type The working voltage is 4.5V~18V Output voltage 800 mv ~ 18 v Output current 3A；; 2A； 2A Switching frequency 300 khz ~ 2.2 MHz Working temperature-40℃ ~+125℃ @ (TJ) Attribute parameter value Synchronous rectification is Number of output channels 3 Topological step-down type Static current (Iq) 700uA Switch tube (built-in/external) built-in Adjustable output type Functional characteristics light load and high efficiency mode; External compensation; Wave by wave current limiting; Adjustable soft start; Overcurrent protection; Working status indication; Adjustable current limiting; Hiccup limiting flow
