MP2639B No NTC resistor connected

Battery Management
1

Hi,
We plan to use MP2639B in a new design : USB/5V input for charging, 9-16V/100-300mA output when used.
After we read the datasheet our questions are

  1. what are the RH/RL resistor value connected to NTC/VNTC if the battery has no NTC resistor ?
    And does MP2639B work whithout resistor ?
  2. If a NTC resistor is absolutely necessary, what reference can be used per example ? and what are the typical value for RH/RL ?
    Thank you in advance for your help,
    Best regards,
    Gilles
2

Hi,
if your application / system does not have NTC, we can have a psuedo-ntc implemented where we trick the IC.

Its usually best to calculate the resistor divider ratio for NTC. However, I have seen ratios of 10-15k as commonly used.

Best,
Nouman

3

Hi Nouman,
Thank you for your quick reply.
You mean RH= 10k and RL=15k ?
By the way we can add a NTC very close to the battery.
Best regards,
Gilles

4

Hi,
Yes, 10k for Rtop and 15k for Rbottom for the NTC pins.

You may utilize the EVB schematic to help guide throughout the system development and layout / component sizing, adding link for reference.

EV2639B-R-00A | Single-Cell Charger EV Board with 5A Charge Current, Wide Input & OTG | MPS (monolithicpower.com)

Best,
Nouman

5

Excellent !
Thank you for your great support.