
XT65/XT75 Hardware Interface Overview
6.5 Pin Assignment and Signal Description
s
XT65_XT75_HO_v00.130
Page 34 of 67
2006-10-12
Confidential / Preliminary
Please note that the reference voltages listed in
Table 17
are the values measured directly on the XT65/XT75
module. They do not apply to the accessories connected.
Table 17:
Signal description
Function
Signal name
IO
Signal form and level
Comment
Power
supply
BATT+
I
V
I
= 3.3V to 4.5V
V
I
typ = 3.8V
I
≈
2A, during Tx burst
n Tx = n x 577µs peak current every
4.616ms
Five pins of BATT+ and GND must
be connected in parallel for supply
purposes because higher peak
currents may occur.
Power
supply
GND
Ground
Application Ground
Charge
Interface
VCHARGE
I
V
I
min = 3.1 V
V
I
max = 5.25V
This line signalizes to the proces-
sor that the charger is connected.
If unused keep pin open.
BATT_TEMP
I
Connect NTC with R
NTC
≈
10k
Ω
@
25°C to ground.
Battery temperature measurement
via NTC resistance.
NTC should be installed inside or
near battery pack to enable proper
charging and deliver temperature
values.
If unused keep pin open.
ISENSE
I
V
I
max = 4.65V
Δ
V
I
max to V
BATT+
= +0.3V at normal
condition
Connect ISENSE directly at the
shunt for current measurement.
If unused connect pin 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.
CHARGEGATE
O
V
I
max = 5.5V
I
I
max = 0.6mA (for fast charging)
Control line to the gate of charge
FET
If unused keep pin open.
External
supply
voltage
VEXT
O
Normal mode:
V
O
min = 2.75V
V
O
typ = 2.93V
V
O
max = 3.05V
I
O
max = -50mA
C
load,max,extern
= 1µF
VEXT may be used for application
circuits, for example to supply
power for an I
2
C.
If unused keep pin open.
Not available in Power-down
mode. The external digital logic
must not cause any spikes or
glitches on voltage VEXT.