POWER SUPPLIES
Issue 1
Section 9
MCUK001001G8
Revision 0
– 40 –
Technical Guide
DV28VB: Power Supply for Hercules ASIC I/O
Provides power for the ASIC I/Os in Hercules.
D18V: Power Supply for Hercules LMM block
Provides power for the HERCULES Lead Mega Module block
D20V: Digital Power Supply for Omega
Provides power for the OMEGA internal analogue circuits.
VBB: Voltage for Hercules Core Block backup
Power provided by the backup battery to maintain HERCULES internal memory.
9.5.6.
Battery Charging and Monitoring
The status of the LCD battery icon is determined by the value of ‘BAT_VOLT’ returned from OMEGA as shown in the following
table:
Battery charging is controlled by the CPU. If rechargeable cells and external power are detected and the temperature is within
specified limits, the rapid charge algorithm is started.
Charging is determined by constant voltage and constant current control with time, temperature and voltage safeguards. A
current limit no greater than the maximum charge current for any battery option must be provided by the external power source.
Deeply discharged batteries may not have enough power to initiate charging. In this case, the charging circuit must
automatically start trickle charging until there is enough power to switch on the telephone.
Voltage:
2.9 V ±0.2 V
Current:
120 mA max.
Dropout:
150 mV max (max. load)
Voltage:
1.8 V ±0.15 V
Current:
120 mA max.
Dropout:
250 mV max (load max)
Voltage:
2.0 V ±0.2 V
Current:
50 mA max.
Dropout:
500 mV max (load max)
Voltage:
1.6 V ±5 %
Current:
120 mA max.
Dropout:
150 mV max (load max)
Icon Status
Battery Pack
3 bar
3.77 V
2 bar
3.68 V <
< 3.77 V
1 bar
3.46 V <
< 3.68 V
Low Voltage Alarm
< 3.46 V
Summary of Contents for EB-GD93
Page 46: ...Printed in UK UK001001500PJ...
