I have a few questions stemming BQ24650 specification review and eval board observation.
1. Per the spec, Iwake is 125mA nominal when a 10mOhm sense resistor is used.
I presume if a 100mOhm sense resistor is used then Iwake decreases to 12.5mA.
Please confirm that Iwake servos such that (SRP-SRN) = 1.25mV.
The block diagram does not appear to include Iwake control elements.
Please confirm and detail.
2. As related to item 1 above, when is the Low Charge Current Comparator applicable?
How does this comparator influence the device operation?
Is this comparator only used for battery detection and to invoke non-sync operation?
3. Can you elaborate on how Ifault is used?
The block diagram implies that SRN is used to source 2mA referenced to ground.
Is the 2mA current only activated if battery precharge fails the 30min condition?
What is the intent of activating the 2mA current source?
4. Is the battery detection routine (reference spec sheet flow diagram) activated after each charge termination?
When executing the battery detection flow chart and VFB > Vrechg, will the charger remain enabled (at 125mA) for 500mS?
When battery is disconnected from the eval board, the charger appears to execute the battery detection routine at 500mS intervals.
In this case, the charger is enabled most of the 500mS duration.
5. The spec sheet indicates that the charger will operate in non-sync mode if (SRP-SRN) < 5mV and will also operate in this mode if average (SRP-SRN) voltage is < 1.25mV.
Is averaging used for 1.25mV case and not for 5mV?
1.Yes. It is 12.5mA with 100mohm sense resistor. Please verify it on an EVM.
2. I doesn't understand what concern do you have? The battery detection current is 125mA @ 10mohm sense resistor.
3. I think you are right. The 2mA current is activated if battery precharge fails the 30min condition
4. When VFB > Vrechg, the 125mA is disabled. And then, the charger apply 8mA discharge current to check battery present or not.
When VFB < Vrechg for 0.5s, the battery is present or not.
5. 5mV is for non-sync mode (the low side FET early terminated). 1.5mV is for discontinue mode (low side FET off until a refresh pulse).
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