Sizing mp5048 question 2 to 5

[mohamed]

2. If I apply a voltage of 10V, for example, at the input, can I expect to have the same output voltage of 10V? I ask this because the datasheet states: "ABSOLUTE MAXIMUM RATINGS: VIN(DC) = -0.3V to +65V and VOUT = -0.3V to +65V."3.
3. The datasheet mentions “Current-sense output. CS requires an external resistor. The CS voltage (VCS) is compared to CLREF to determine the current limit.” However, what is the value of VCLREF_NORM? The datasheet states “VOUT ≥ 90% of VIN.” In this case, if VOUT = VIN, is VCLREF_NORM 2V?
4. How should I size RCLREF? Since the current limit value depends on VCS and VCLREF, is it a fixed value of 53.6kΩ?
5. Can you provide the equations for ICLREF and RCLREF?

[Edgar.FAE]

Hello Mohamed,

I will follow up with your questions regarding the MP5048.

2. As mentioned in my answer to your previous post question, the MP5048 Operating Conditions Range is 24V to 60V. As stated in the datasheet the device is not guaranteed to function outside of its operating conditions. Therefore, applying 10V to the input voltage does not assures an output voltage of 10V.
3. VCLREF_NOM is stated to be the CLREF pin voltage during “Normal Operation,” which is the voltage after soft start.
   For instance, you could use a controller like the MP5920 that can regulate the current limit by regulating the voltage fed to the CLREF pin on the MP5048. If not using a controller, then the MP5048 can generate a voltage on the CLREF pin using the Internal Current Source (ICLREF) of 26uA stated on page 6 of the datasheet and a shunt resistor (RCLREF).
4. For sizing the RCLREF resistor you need to choose a voltage value for the CLREF pin. For instance, let’s assume you want a VCLREF value of 1.5V, then you can find RCLREF using the following equation: RCLREF = VCLREF / ICLREF.
   So RCLREF is equal to 1.5V / 26uA ~ 57.7kOhm.
5. On page 6 of the device’s datasheet it is stated that ICLREF is 26uA. For RCLREF you can use the equation: RCLREF = VCLREF / ICLREF.

Regards,
Edgar