The datasheet for the MPM3515 states that only four components are necessary to operate the MPM3515. However, later in the datasheet, circuits are presented with seven components. While the addition of a 0.1 uf capacitor is logical (but not necessary), 100k pull-ups are indicated on the Enable and Power Good lines. Are these pullups necessary? Neither will be used and the normal situation is to tie the enable line to the Vin line. Or is that something that shouldn’t be done. The board space is extremely limited and my aim is to use a MPM3515 to replace an unavailable TI module. The caps exist and I’ll just be able to squeeze in the voltage divider (I’d really prefer a fixed output version). More than that is a non-starter.
Hi Steve,
The 100k pull up is recommended for proper operation of the device.
For the EN/SYNC pin, connecting it to the input with a pull up resistor limits the SYNC input current to below 100uA. As stated per the datasheet, you can read further in the Enable/SYNC section on page 13.
For PG pin, since it is an open drain output. It helps with OTP, UVLO, or Over Current protection events. PG pin is also typically connected with a 100kohm resistor to VCC.
Can you please confirm what is the size consideration? we have other solutions that are smaller.
Regards,
Nouman
Thanks for the reply. However, if those two pull-ups are pretty much required, then I’d change your datasheet to reflect that. Anyways, for my application, I was attempting to use a TI module, TPSM265R1V3SILR. The typical input voltage is 20 to 28V, although up to 32V input may be possible (depending on application), so the maximum can be 36 Volts, or because of the application, as high as possible. Output needs to be 3.3V at a minimum of 100 mA. The footprint of the TI part was 2.9 x 3.8 mm. Input and output caps are already on the board. Board space is limited and we need to be efficient as we will be operating from battery power. Thanks for the help.
Hi Steve,
I have looked into our power module family of parts available. With the voltage specs you provided, we are limited to 3x5mm pkg size with 1.6mm in height.
Couple alternative solutions I would suggest looking into for comparison are MPM3506A, MPM3509, MPM35010A.
The MPM3515 part you have picked will work as well without the pull up resistors. I wanted to clarify, I may have misunderstood your inquiry earlier. The typical application circuits are for reference purposes. Most datasheets from any vendor will have such a section as I am sure you have come across.
Additionally, you can tie the EN/SYNC to source input VIN pin. Just note the following:
Regards,
Nouman