MC75i Hardware Interface Description
5.5 Pin Assignment and Signal Description
101
MC75i_HD_v01.100a
Page 84 of 122
2009-08-13
Confidential / Released
Please note that the reference voltages listed in
are the values measured directly on
the MC75i module. They do not apply to the accessories connected.
Table 30:
Signal description
Function
Signal name
IO
Signal form and level
Comment
Power
supply
BATT+
I
V
I
max = 4.5V
V
I
typ = 3.8V
V
I
min = 3.2V during Tx burst on
board
I
2A, during Tx burst
n Tx = n x 577µs peak current
every 4.616ms
Five lines of BATT+ and GND
must be connected in parallel
for supply purposes because
higher peak currents may
occur.
Minimum voltage must not fall
below 3.2V including drop, rip-
ple, spikes.
Power
supply
GND
Ground
Application Ground
Charge
Interface
VCHARGE
I
V
I
min = 3.1V
V
I
max = 7.00V
This line signalizes to the pro-
cessor that the charger is con-
nected.
If unused keep line open.
BATT_TEMP
I
Connect NTC with R
NTC
10k
@
for B value of NTC.
Battery temperature measure-
ment via NTC resistance.
NTC should be installed inside
or near battery pack to enable
proper charging and deliver
temperature values.
If unused keep line open.
ISENSE
I
V
I
max = 4.65V
V
I
max to V
BATT+
= +0.3V at nor-
mal condition
ISENSE is required for measur-
ing the charge current. For this
purpose, a shunt resistor for
current measurement needs to
be connected between ISENSE
and VSENSE.
If unused connect line to
VSENSE.
VSENSE
I
V
I
max = 4.5V
VSENSE must be directly con-
nected to BATT+ at battery con-
nector or external power
supply.
CHARGE-
GATE
O
V
O
max = 7.0V
I
O
typ = 5.2mA (for fast charging @
CHARGEGATE = 1V)
Control line to the gate of
charge FET or bipolar transis-
tor.
If unused keep line open.
