ICS1735EB

General Description

Galaxy Power, Inc.'s ICS1735 Evaluation Board helps provide
a practical way of evaluating the ICS1735 conditioning/charge
method on lead acid batteries. The evaluation board provides
some circuit options for interfacing to an external regulating
current to voltage charging source or for building an adjustable
regulating source for charging 6V, 12V, and 24V lead acid
batteries.

The board provides a constant current discharge circuit, so R1,

R2, and R3 are jumpers. The added .51

, 1W resistor and

2N3903 NPN transistor provides constant amplitude 1.25A
discharge pulses for conditioning the battery through out the
charging process. The amplitude of the discharge current is
independent of battery voltage and may be increased or decreased

by changing the value of the .51

resistor. The amplitude of the

current is typically 0.64V/.XX

. Jumper provisions are provided

for selecting a charge time for performance improvement
evaluations. The board includes a bread- boarding area consisting
of a matrix of holes for user added components.

Before using the ICS1735 Evaluation Board, the user should
review the ICS1735 data sheet to become familiar with the
operation of the IC. The board can be purchased either as an
ICS1735EB or an ICS1735EB/CVR. The CVR version provides
a parts kit for the user to make an adjustable, regulating charging
source.

Setting-up for Your Application

Refer to the evaluation board schematic diagram. If the
ICS1735EB is to interface to an external regulating current to
voltage source, both the current and the voltage of the external
source must be set according to the battery manufacturer's
requirements. Two charge signal options are provided to control
an external charging source. There is a CHG output which uses a
logic high for switching on an external charging source and
another signal which uses a logic low for switching on an external
charging source. If the CVR kit is installed to provide an on-board
adjustable current to voltage regulator, a 1N52XXB type diode
must be installed by the user per Table 1. A regulated input supply
is required per Table 2 when using the on board charging source.

Table 1

Cells

Battery Type

* ZD (V)

1N5231B (5.1V)

12V

1N5242B (12V)

24V

1N5252B (24V)

*User provides ZD1 and associated components (SD103A schottky
diode is made by Diodes Inc.)

The ICS1735EB/CVR contains a parts kit for configuring an
LM317T as an adjustable current to voltage regulating charging
source on the board. The charging current is set by the value of
R15 and the forward voltage drop of D5 1N5822. The maximum
current the LM317T provides for this on-board application is
1.25A. In this application with R13 = 3K, U3 LM317 regulates a
voltage difference of about 1.35 volts between its OUT and ADJ
pins. With the 1N5822 D5 voltage drop equal to .4V at 1.25A,

(1.35V-.4V)/1.25A makes R15 a .75

, 2W resistor.

With all of the ICS1735EB/CVR kit and user provided
components installed, connect only a voltmeter between +BAT
terminal and a GND terminal of the board and apply regulated
input power per Table 2 below. About 3.5 minutes after the CHG

LED lights, adjust the 500

potentiometer until the pulsed voltage

on the +BAT terminal reads the required end of charge voltage per
the battery manufacturer.

Table 2

Cells

Battery Type

+V (Reg. Input)

12V

18V

24V

30V

Whenever input power is applied to the board, the ICS1735 starts a
charge sequence. A logic low applied to the RESET terminal of the
board holds the ICS1735 in reset and all of its outputs stay off.
When RESET is removed by a logic high or an open, or by
releasing the board's push button reset switch SW1, a new charge
sequence begins.

The amplitude of the discharge current may be increased or

decreased by changing the value of the .51

resistor. The

amplitude of the current is typically 0.64V/.XX

. Normally the

amplitude of the discharge pulse is set to the same amplitude as the
current setting of the charging source.

ICS1735 Evaluation Board

ICS1735 Evaluation Board

PC Board Design Considerations

When designing a current to voltage regulator battery charger,
there are several important considerations to address before
starting the design and the PC board layout. In general, linear
chargers are less complex and more cost effective, but less
efficient than switch mode chargers. Size or power dissipation
restraints may warrant a switch mode type.

For the input power supply, the charging source, and the pulse
discharge power circuit, keep the physical separation between
power and return (ground) to a minimum to minimize field
effects, particularly if switch mode type circuits are used for
the input supply and/or current source. Keep the ICS1735 and
all control circuits outside the power and return loops
described above. These precautions prevent fields and coupled
noise from disturbing normal operation.

Normal care must be exercised to minimize noise coupling and
ground bounce. Prevent wires and connector locations from
adding excessive resistance and inductance to both power and
control circuits. When designing a printed circuit board, make
sure power and control grounds and power traces are wide as
practical. Locate bypass and noise reduction capacitors right at
or very close to IC pins and their ground pin(s). Be sure to
connect power and control grounds together at or close to the
negative terminal that connects to the negative lead of the
battery.

Galaxy Power Incorporated wants to help create a successful
battery charging solution using the ICS1735. If you need
assistance from sales, technical help, or applications
information please contact at our headquarters:

Galaxy Power, Inc.
2500 Eisenhower Avenue
Valley Forge, PA 19482
USA
Phone: (610) 676-0188
Fax: (610) 676-0189

Visit:

www.galaxypower.com

for product info. and

e-mail contacts

REV 0 120800

Table 3: Charge Stages

Max. Fast

Charge

Jumper

Float Charge

Duty Cycle

Maint. Charge

Duty Cycle

40 min

1 & 2

1 pulse, 40 rests

1 pulse, 160 rests

145 min

2 & 3

1 pulse, 10 rests

1 pulse, 40 rests

400 min

None

1 pulse, 4 rests

1 pulse, 16 rests

The 35 minute charge time option is intended for charging a battery

that is already at least � full. Charging a lead acid battery from
empty to full in this short of a time involves considerations beyond
the scope of this document.

Table 4: Termination Select

Termination Method

Jumper DTSEL

*Voltage slope termination

None

Timer termination only

2 & 3

* Requires additional circuitry-contact Galaxy Power

Operation

Before running evaluations with the board, ensure that the board is
initialized as required.

�

Set S0 jumper for the desired fast charge time.

�

Set the DTSEL jumper per Table 4

�

If applicable, calculate another value for R15 using the
procedure described on page 1.

�

Set the amplitude of the discharge current to be the same
amplitude as the current setting of the charging source.

Ordering Option
blank = populated board
/CVR = populated board with regulator
parts kit for user installation

Ordering Information

ICS1735EB/CVR

Device type:
ICS1735 Evaluation Board

ICS1735EB

ICS1735EB AND ICS1735EB/CVR SCHEMATIC DIAGRAM

NOTES:

N1. CVR Kit,user installs in locations

provided

N2. User provides/installs.

(see Table 1 for Zener ZD type)

N3. Galaxy Power installed component.

N4. Reg. input per Table 2.

N5. 5V logic level FET

N6. LM340,AN7805 or equivalent

N7. U3 requires Heat Sink.

*Component not used in this application.

(jumper)

+5V

RESET

+5V

3 2 1

GND

TP1

+5V

+BAT

+CUR

___

CHG

+5V

1 2 3

+5V

2N3903

SD103A

R17

R12

500

35V

1uF

R16

ADJ

OUT

LM317

OUT

GND

.047uF

CTSEL

.047uF

4.7uF

AUX 1

AUX 0

DTSEL

(TENB)

100pF

2N7000

.1uF

1N5822

R14

1
2

6
7

ICS1735

CHG

DCHG

PFN

MCN

FCN

CLN

CTSEL

VSS

MRN

TENB

CLS

XREF2

XREF1

N/U

VDD

470

.51

510

R18

390

R10
24k

0.0

R13 3k

R15

.75

0.0 ohm

330k

30k

68k

Электронный компонент: ICS1735