Dear TI Experts,
I design a solar charger circuit with a 6V/1W solar panel for a ~2000 mAh Li-ion battery.
Based on Fig. 13 Typical Application Schematic (on page 20 of SLUSA76B), I want to:
- use LPCM, therefore connect TS to VTSB (no thermistor)
- use battery tracking mode, therefore leave VDPM floating
- enable auto charging, thus connect /PG to /EN
- but I don't need LED or any status indication for the MCU
Since /PG is open drain, I'll still need a pullup to VBAT (e2e.ti.com/.../1991028, but I don't want to waste energy here. So my questions:
1. what is the maximum allowed pullup resistor value, taking into account the combined leakage currents of /PG and /EN, and also not violating the voltage thresholds of /EN?
2. how will a high value pullup resistor affect the noise immunity of the circuit (a GSM module is also onboard)? How can I improve it, if necessary?
Thank you very much for your help!