User Guide

PAMS Technical Documentation System Module & UI
NHM-8NX
Issue 1 05/02 ãNokia Corporation Page 39
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:
Figure 13: DC-OUT Interface
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).
Inside
phone
Cover
connection
Cover Type
Indicator
(resistor)
SLOWAD(6)
Q
pass
R
sense
V
batt
Q
lim
R
base
Enable
V
out
VFLASH1
100K
UIDRV(6)
"KLIGHT"
MIDI out
Cover
electronics
PWM out