ICS1712M GALAXY [Galaxy Power, Inc.], ICS1712M Datasheet - Page 15

• Manufacturer Part Number: ICS1712M
• Description: Charge Controller for Nickel-Cadmium and Nickel-Metal Hydride Batteries
• Manufacturer: GALAXY [Galaxy Power, Inc.]

If a temperature sensor is not used, the THERM pin must be
grounded.
Termination Selection: DTSEL Pin
The ICS1712 has the capability of either temperature slope
termination,
simultaneously. The DTSEL pin has an internal 75k
resistor that enables voltage slope termination as the primary
method and is the default condition. Tying the pin high enables
both temperature slope and voltage slope termination methods.
Temperature slope termination as the primary method is enabled by
tying the DTSEL pin to the CMN output (pin 4). CMN must have
an external 15k
activation of temperature slope termination. The ICS1702 must be
reset if a new termination method is desired. Table 6 summarizes
the DTSEL pin settings. NOTE: Maximum temperature and fast
charge timer termination methods are always enabled when using
temperature slope termination. Refer to the sections on Fast
Charge
Termination for more information.
Voltage Input: VIN Pin
The battery voltage must be normalized by an external resistor
divider network to one cell. The electrochemical potential of one
cell is about 1.2V. For example, if the battery consists of six cells
in series, the voltage at the VIN pin must be equal to the total
battery voltage divided by six. This can be accomplished with two
resistors, as shown in Figure 13. To determine the correct resistor
values, count the number of cells to be charged in series. Then
choose either R1 or R2 and solve for the other resistor using:
Using no temperature sensor:
(No Connect)
R1 = R2 * (# of cells -1) or R2 =
Tie DTSEL
Pin to ...
CMN
High
Low
Timer
Table 6: Termination Select List
voltage
or lower value pull-up resistor to V
Termination
slope
Voltage slope termination only
Voltage slope and temperature slope
termination
Temperature slope termination only
(CMN with external pull-up to V
termination
and
Maximum
Result
(# of cells -1)
R1
or
both
Temperature
DD
for proper
pull-down
DD
methods
)
15
Power: VDD Pin
The power supply for the device must be connected to the VDD
pin. The voltage should be +5 VDC and should be supplied to the
part through a regulator that has good noise rejection and an
adequate current rating. The controller requires up to a maximum
of 11mA with V
Grounding: VSS, AVSS Pins
There are two ground pins. Both pins must be connected together
at the device. This point must have a direct connection to a solid
ground plane.
# of cells
Figure 13: Resistor divider network
DD
=5.00V.
at the VIN pin
R1
ICS1712
VIN pin
R2