Charger Detection - Nokia 7088 Troubleshooting Manual

7088 (Flower)
Base band Description and Troubleshooting

Charger Detection

Connecting a charger creates a voltage on the VCHG ("VEXT_DC" net in schematic)
input of the PM6610. Charging starts when the PM6610 detects the VCHG input
voltage level above 3.3V (Min. working voltage of VCHG pin).
The VCHG signal of PM is generated to indicate the presence of the charger for the
software. The power management (PM) software controls the charger identification/
acceptance. The charger recognition is initiated when the EM software receives
a "charger connected" interrupt. The algorithm basically consists of the following
three steps:
1. Check that the system current (the collector current of PNP transistor) is within
safety limits.
2. Check the power consumption of PNP transistor is within safety limits.
3. Check that the charger is within the charger window (voltage and current). If the
charger is accepted and identified, the appropriate charging algorithm will be
initiated.
Figure 13: Mobile terminal DC Jack power input circuit.
Page 18 © 2006 Nokia Corporation
Figure 14: PNP Charging Control Circuit.
Company Confidential Issue 1 12/2006