I would like to use the LTC4124 for a prototype device where the battery(LIR1620) is fix installed. I was wondering if the VCC output power from the battery if no voltage is supplied on ACIN(Pin11) and DCIN(Pin 12). If not how would you recommend to use the LTC4124 as part of a device and not as "charger only"?
When there is no power at ACIN and DCIN, LTC4124 enters ideal diode path mode. In this mode of operation, power is delivered from BAT pin to Vcc pin via M2 (Page 8 block diagram). For detail operations of this ideal diode power path, please refer to IDEAL DIODE POWER PATH FROM BAT TO VCC on page 12.
We have tested LTC4124 IDEAL DIODE MODE using LTC4124 reference schematic. LTC4124 M3 Switch does not work on ideal diode mode when BAT is 3.7V.. Please support us.
Could you share the schematic you are using for this test? LTC4124 M3 switch is the low battery disconnect switch, and it will disconnect the power path once battery voltage is lower then 3.2V or 2.7V. I am not sure what do you mean that M3 does not work when BAT is 3.7V. If you do not see voltage on VCC pin in ideal diode mode when BAT is 3.7V, how do you know that M3 does not work?
We attached our schematic. We can know M3 switch because we can not find any output power on VCC pin
Have you checked whether this is in Ship mode? The first time the battery is inserted on the BAT pin, the part will be in ship mode, and M3 will be off.
One easy way to check is to power the receiver by a transmitter, or supply the receiver with around 0.5V above Vbatt on ACIN (please do not have 1V over Vbatt on ACIN as it might trigger the threshold to turn on SW1), and then remove the power, and check whether you can measure a voltage close to Vbat on VCC pin.