Nokia RH-9 Series Ccs Technical Documentation page 41

CCS Technical Documentation
state.
DC-OUT Interface
A special type of electrically A-cover called "DC-Out cover" is supported by the phone via
an electrical/mechanical interface connection. The kind of circuit, that has to be pow-
ered, can be anything from simple LED's to a "smarter" type of circuit.
The implementation is designed to fulfil the below mentioned features:
• No idle power consumption.
• Phone must not be damaged by misuse (of cover connection) or ESD
• Detection of "DC-out" cover type (for UI-SW and Energy Management SW pur-
pose)
• PWM control of cover
• Frequency control of cover (via ringing/game tones)
Implementation
The implemented concept, which is using three pads/connections between the phone
and the accessory cover, is shown in the figure below:
V
batt
Q
lim
R
base
UIDRV(6)
Enable
"KLIGHT"
VFLASH1
MIDI out
SLOWAD(6)
PWM out
Detection of cover is done via a "CTI" (Cover Type Indicator), which basically serves the
same purpose as the BSI resistors in the battery packs. Detection is done in the same way
as currently used for the BSI. By using the "CTI" it gives the possibility to categorise the
covers in different groups (i.e. Current consumption or the like).
Issue 1 11/02
Figure 13: DC-OUT Interface
Inside
phone
R
sense
Q
pass
V
out
100K
ãNokia Corporation
RH-9
System Module & UI
Cover
connection
Cover
electronics
Cover Type
Indicator
(resistor)
Page 41