User's Manual

MC55/56 Hardware Interface Description
Confidential / Preliminary
s
MC55/56_hd_v03.00 Page 75 of 104 16.08.2005
Table 26: Electrical description of application interface
Function Signal name IO Signal form and level Comments
BATT+ I V
I
= 3.3V to 4.8V
V
I
norm = 4.2V
Inorm  1.6A during Tx burst
Power
supply
GND
1 Tx, peak current 577µs every 4.616ms
2 Tx, peak current 1154µs every 4.616ms
Power supply input.
5 BATT+ pins to be
connected in parallel.
5 GND pins to be
connected in parallel.
The power supply must be
able to meet the
requirements of current
consumption in a Tx burst
(up to 2A).
Sending with two timeslots
doubles the duration of
current pulses to 1154µs
(every 4.616ms)!
POWER I
V
I
min = 3.0V
V
I
max = 15V
This line signalises to the
processor that the charger
is connected.
If unused keep pin open.
BATT_TEMP I
Connect NTC with R
NTC
 10kΩ @ 25°C to
ground.
Input to measure the
battery temperature over
NTC resistor.
NTC should be installed
inside or near battery pack
to enable the charging
algorithm and deliver
temperature values.
If unused keep pin open.
Charge
interface
CHARGE O
I
CHARGE
= -300µA ... -600µA
@ 3V < V
CHARGE
< V
LOAD
This line is a current source
for the charge FET with a
10kΩ resistance between
gate and source.
If unused keep pin open.
External
supply
voltage
VDD O
VDDmin = 2.84V, VDDmax = 2.96V
Imax = -10mA
C
L
max = 1µF
Supply voltage, e.g. for an
external LED or level
shifter. The external digital
logic must not cause any
spikes or glitches on
voltage VDD.
Not available in POWER
DOWN mode.
VDD signalises the “ON”
state of the module.
If unused VDD keep pin
open.
VDD Low
Power
VDDLP I/O
R
I
=1kΩ
V
O
max  4.0V (output)
V
I
min = 2.2V, V
I
max = 5.5V (input)
I
I
typ = 10µA at BATT+ = 0V
Mobile in POWER DOWN mode:
V
I
min = 1.2V
Supplies the RTC with
power via an external
capacitor or buffer battery if
no V
BATT+
is applied.
If unused keep pin open.