LTC4124
Recommended for New Designs
The LTC4124 is a simple high performance wireless Li-Ion charger with low battery disconnect. The pin-selectable charge current (up to 100mA) and charge...
Datasheet
LTC4124 on Analog.com
Hi,
I would like to place the LTC4124 in Ship Mode after charging, as I only use the wireless charging capabilities of the IC. I would like to eliminate the 28uA consumed in Ideal Diode Mode, as my circuit is powered (and protected) in a different way.
The datasheet mentions:
Ship mode activates when a 1.5V (± 100mV) DC voltage
is simultaneously applied to both the DCIN and the ACIN
pins while the LTC4124 is in ideal diode mode (the bat -
tery is supporting the VCC voltage at or above the battery
disconnect voltage VBAT_LBDIS).
In this answer, the following is mentioned: "For the part to enter ship mode, ACIN and DCIN has to be above 1.5V simultaneously. Simply put a diode between VCC and DCIN, with the anode side connecting to DCIN".
I simulated the circuit in LTspice, but I cannot get the part to go in Ship Mode with the diode connected, or both ACIN and DCIN (far) above 1.5V. It seems only to work with aproximately 1.5V on those pins. Could you please elaborate a bit on how to tackle this issue?
Thank you,
Samot
Hi Samot,
It should be the LTspice model issue. The actual IC should be able to enter ship mode when >1.5V is applied to both DCIN and ACIN.
"For the part to enter ship mode, ACIN and DCIN has to be above 1.5V simultaneously. Simply put a diode between VCC and DCIN, with the anode side connecting to DCIN".
I tested this method on bench and it should also work on your setup.
Thanks,
Wenwei.
Hi Wenwei,
Thank you for your very fast response. In this configuration, I guess the diode is in parallel to the diode D2 of the functional block diagram of the datasheet. What is then the added functionality of the external diode? Or should it be connected the other way round?
Kind regards,
Samot
Hi Samot,
Sorry it should be the other way around. Cathode on DCIN side. It is just to bias DCIN to be over 1.5V.
Thanks,
Wenwei.
Hi Wenwei,
Thanks! I guess any (Schottky) diode will do then?
Kind regards,
Samot
Yes. As long as it can pull DCIN to be higher than 1.5V, it should be okay.
Thanks,
Wenwei.
All right, thanks!