User's Manual

SC14CVMDECT SF Cordless Voice Module
© 2012 Dialog Semiconductor B.V. 21 July 1, 2014 v1.6
SC14CVMDECT SF crystal.
When the SC14CVMDECT SF is configured as a PP,
the clock has the same accuracy as the FP clock.
When the PP synchronises with a FP, the PP crystal is
synchronized with the FP crystal and the PP clock will
change accordingly.
The accuracy is expected to be within 1 minute for up
to 6 weeks without being locked to a FP.
4.9 BATTERY MANAGEMENT
Figure 18 shows a handset application with NiMH.
SOC (State Of Charge) is used to measure the amount
of charge in the rechargeable batteries.
Figure 19 shows an FP application. The FP uses an
external LDO, so the SOC pins are not used and can
be connected to GND.
The PP API supports battery management to calculate
the battery capacity and to indicate charge status.
Refer to API document [2].
The SOC circuit is used to very accurately determine
the amount of charge in rechargeable batteries as well
as the discharge state of Alkaline batteries. This infor-
mation is essential for the battery charging algorithm
and necessary for battery status indication to the user.
Battery status information is supported by the API.
Detailed information can be found in AN-D-174 (Bat-
tery Management).
Pin CHARGE_CTRL is driven high when either the
“sensed voltage on the VBAT pin” is lower than the
voltage setting or “sensed current via SOCp” is lower
than the current setting. Pin CHARGE_CTRL can drive
up to 500 A as source current (see Table 20).
Detailed setting information can be found in document
[4] under “Battery settings”.
4.10 PROTOCOL STACK
The protocol stack handles the RF interface, the MAC-,
DLC-, NWK-layer and encryption according to the
DECT standard EN300 175 1-9.
4.10.1 DECT TBR22
The SC14CVMDECT SF supports the DECT GAP
standard according to EN300 444. For TBR22 type
approval (optional) switching off the authentication and
encryption is required, which can be done with the VES
parameter Tbr_22.
Figure 17 Clock synchronization
Figure 18 Handset (PP) application with 2x NiMH
100
CHARGE_CTRL
1k
1k
0.1
SOC
CHARGE
SOCp SOCn
Vsupply
VBAT IN
Figure 19 Base station (FP) application
CHARGE_CTRL
1k
SOC
CHARGE
SOCp
SOCn
Vsupply
VBAT IN
LDO