Software Description
2016 Microchip Technology Inc.
DS50002510A-page 33
4.3.1.4
CURRENT MONITORING AND CHARGE RATIONING
To view current monitoring and current rationing, perform the following on the
Main
tab:
1. Set a ration limit. The ration limit is expressed in mAh (electric charge).
2. Set rationing behavior. The ration completion behavior defaults to “Report & Dis-
connect”. Once the ration limit is reached, portable device charging will cease,
the ALERT# pin will assert, and the Ration Complete bit will be set. If you do not
want the system to behave in this fashion, select one of the other three options
from the “Ration Completion Behavior” drop-down list: Report, Report & Sleep or
Take No Action.
3. Connect V
S
to the evaluation board (see
Section 2.4 “Jumpers on the
Evaluation Board”
). The VS_LOW indicator on the bottom of the Main Tab must
be dark. If the VS_LOW indicator is red, the voltage is not high enough to charge
a portable device.
4. Connect a portable device to the evaluation board. Use the OEM USB charging
cable that comes with the portable device.
5. Enable rationing by checking the Ration Enable check box on the Main Tab.
6. Watch the GUI as the device starts charging.
Figure 4-10
shows the interface
after the ration limit was reached (for “Report & Disconnect” behavior setting).
FIGURE 4-10:
Main Tab - Ration Limit Reached.
Note:
As shown in
Figure 4-10
, the green trace is the instantaneous current, while
the red diagonal line is the charge being delivered in mAh. Both are also
presented in numeric format inside the bottom left boxes. Trace color and
characteristics can be changed by clicking on the waveform boxes to the
left of these numerical values.
Ration
Enable
Ration Limit
setting
Rationing
Behavior
Power state indicator
changed
Rationing
Complete
indicator
ALERT#
pin is
asserted
Measured
current status
Instantaneous
current (mA)
Delivered charge
current (mAh)
VS_LOW
indicator
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
Downloaded from
