MAX8900A Evaluation Kit
Evaluates: MAX8900A/MAX8900B
General Description
The MAX8900A evaluation kit (EV kit) is a fully assembled
and tested circuit for evaluating the MAX8900A switch-
mode Li+/Li-Poly charger with ±22V input rating and
JEITA* battery temperature monitoring. The MAX8900A
charges a 1-cell lithium-ion (Li+) or lithium-polymer
(Li-Poly) battery. The MAX8900A delivers up to 1.2A of
current to the battery from a 3.4V to 6.3V supply. External
resistors and potentiometers adjust the fast-charge
current and the prequalification and done current thresh-
olds. A JEITA battery temperature monitor adjusts
charge current and termination voltage.
The MAX8900A EV kit comes with the MAX8900A
installed, but can also be used to evaluate the MAX8900B
with IC replacement of U1. Request a free sample of the
MAX8900B when you order the MAX8900A EV kit.
Features
S
3.25MHz Switching Li+/Li-Poly Battery Charger
S
JEITA Battery Temperature Monitor Adjusts
S
S
Ordering Information
PART
MAX8900AEVKIT+
TYPE
EV KIT
+Denotes
lead(Pb)-free and RoHS compliant.
S
S
S
Charge Current and Termination Voltage
On-Board 3380K NTC Thermistor
On-Board Potentiometer Allows Easy
Evaluation
Battery Fast-Charge Current-Limit Adjustment
Range of 50mA to 1200mA
Dynamic Charge Current Programming Using
MOSFET and Resistor Array on the EV Kit
Potentiometer Adjustment Available
Prequalification and Done Threshold Adjustment
Range of 10mA to 200mA
Dynamic Charge Current Programming Using
MOSFET and Resistor Array on the EV Kit
Potentiometer Adjustment Available
Selectable Charge Source Connector
2.1mm Barrel or Micro-USB
Three Status LED Indicators
Fully Assembled and Tested
Figure 1. MAX8900 EV Kit Photo
*JEITA
(Japan Electronics and Information Technology Industries Association) standard, “A Guide to the Safe Use of Secondary
Lithium Ion Batteries in Notebook-type Personal Computers” April 20, 2007.
For pricing, delivery, and ordering information, please contact Maxim Direct
at 1-888-629-4642, or visit Maxim’s website at www.maximintegrated.com.
19-5244; Rev 0; 4/10
MAX8900A Evaluation Kit
Evaluates: MAX8900A/MAX8900B
Component List
DESIGNATION QTY
C1, C6
2
DESCRIPTION
0.47FF
Q20%,
25V X5R ceramic
capacitors (0603)
TDK C1608X5R1E474M
0.1FF
Q20%,
10V X5R ceramic
capacitors (0402)
TDK C1005X5R1A104K
2.2FF
Q20%,
6.3V X5R ceramic
capacitors (0603)
TDK C1608X5R0J225M
0.47FF
Q20%,
10V X5R ceramic
capacitor (0402)
TDK C1005X5R1A474M
Not installed, capacitor (0603)
1FF
Q20%,
6.3V X5R ceramic capaci-
tor (0402)
TDK C1005X5R0J105M
Green LEDs
Avago Technologies HSMG-C190
Male 2.1mm power connector
CUI Inc. PJ-002A-SMT
Not installed, 1.25mm (0.049in) pitch
header (surface-mount,
right-angle, lead-free, 10 circuits)
Micro-USB connector
Hirose Electric ZX62-AB-5PA
3-pin headers, 0.1in centers
Sullins PEC36SAAN
2-pin headers, 0.1in centers
Sullins PEC36SAAN
2 x 4-pin header, 0.1in centers
Sullins PEC36SAAN
3 x 3-pin header, 0.1in centers
Sullins PEC36SAAN
2 x 3-pin header, 0.1in centers
Sullins PEC36SAAN
1FH, 0.055I, 1.6A chip inductor
(2.5mm x 2mm x 0.9mm)
Murata LQM2HPN1R0MGO
20V, 238mA n-channel MOSFETs
(SC-75)
ON Semi NTA4001NT1G
U1
1
DESIGNATION QTY
R1, R2, R3
R4, R5, R6
R7, R26
R8, R16
R9, R17, R22
R10, R18
R11
R12
R13, R14, R15
R19
R20
R21
R23, R24
R25
R27
R28
3
3
2
0
3
2
1
1
3
1
1
0
2
1
1
1
DESCRIPTION
422I
Q1%
resistors (0402), lead-free
560kI
Q1%
resistors (0402),
lead-free
10kI
Q1%
resistors (0402), lead-free
Not installed, resistors (0402)
0I
Q1%
resistors (0402), lead-free
35.7kI
Q1%
resistors (0402),
lead-free
9.09kI
Q1%
resistor (0402),
lead-free
4.75kI
Q1%
resistor (0402),
lead-free
100kI
Q1%
resistors (0402),
lead-free
7.68kI
Q1%
resistor (0402),
lead-free
3.83kI
Q1%
resistor (0402),
lead-free
Not installed, resistor (0603)
50kI, 25-turn potentiometers
Bourns 3296Y-1-503LF
200kI, 25-turn potentiometer
Bourns 3296Y-1-204LF
1.21kI
Q1%
resistor (0402),
lead-free
2.26kI
Q1%
resistor (0402),
lead-free
10kI NTC thermistor (0402)
Murata NCP15XH103F03
(A = 3380K)
High-frequency, switch-mode
charger (30 WLP)
Maxim MAX8900AEWV+
Shunts (see Table 1 for jumper
settings)
USB A-to-Micro-USB B, 2.0m cable
Molex 68784-0003
Digi-Key WM17147-ND
Adjustment tool
Bourns H-90
Digi-Key H90-ND
PCB: MAX8900A EVALUATION KIT+
Maxim Integrated
C2, C5
2
C3, C8
2
C4
C7
C9
1
0
1
D1, D2, D3
J1
3
1
J2
0
J3
JU1, JU2
JU3, JU6, JU7,
JU9, JU10
JU4
JU5
JU11
1
2
5
1
1
1
THRM
1
—
12
L1
1
—
1
M1, M2, M3
3
—
—
1
1
2
MAX8900A Evaluation Kit
Evaluates: MAX8900A/MAX8900B
Component Suppliers
SUPPLIER
Avago Technologies
Bourns, Inc.
CUI Inc.
Digi-Key Corp.
Hirose Electric Co., Ltd.
Murata Manufacturing Co., Ltd.
ON Semiconductor
Sullins Electronics Corp.
TDK Corp.
www.avagotech.com
www.bourns.com
www.cui.com
www.digikey.com
www.hirose.com
www.murata.com
www.onsemi.com
www.sullinselectronics.com
www.component.tdk.com
WEBSITE
Note:
Indicate that you are using the MAX8900A when contacting these component suppliers.
Quick Start
•
•
Adjustable DC power supply capable of at least
1.2A at 6V
Battery or simulated battery
1-cell Li+ or Li-Poly battery (Figure 2A)
Simulated battery, preloaded power supply
(Figure 2B)
•
•
Digital multimeter (DMM)
Two 3A ammeters
3)
Recommended Equipment
Connect the EV kit to the power supply, battery, or
preloaded power supply and meters, as shown in
Figure 3. Adjust the ammeters to their largest current
range to minimize their series impedance. Do not
allow the ammeters to operate in their “autorange”
mode. If current readings are not desired, short
across the ammeters.
Turn on the power supply.
If 3V ≤ V
BAT
≤ 4.1V, then verify that the current from
BAT into the battery is approximately 95mA. If V
BAT
is not in this specified range, refer to Figure 6 in the
MAX8900A/MAX8900B IC data sheet for more infor-
mation.
B. SIMULATED BATTERY
(PRELOADED POWER SUPPLY)
BAT
MAX8900A EV KIT
4)
5)
The MAX8900A EV kit is fully assembled and tested.
Follow the steps below to verify board operation. Use
twisted wires of appropriate gauge (20AWG) that are
as short as possible to connect the battery and power
sources.
1)
2)
Procedure
A. Li+/Li-POLY BATTERY
BAT
0 TO 4.2V
R
2.5A
2I
R
10W
Ensure that the EV kit has the jumper settings as
shown in Figure 3 and Table 1.
Preset the DC power supply to 5V. Turn off the
power supply. Do not turn on the power supply until
all connections are completed.
MAX8900A EV KIT
GND
GND
Figure 2. Battery Options for Evaluating the MAX8900A EV Kit
Maxim Integrated
3
MAX8900A Evaluation Kit
Evaluates: MAX8900A/MAX8900B
A*
BATTERY OR
SIMULATED
BATTERY
(FIGURE 2)
BAT
3
2
1 IN
JU1
GND
MAX8900A
BAT
VOLTMETER
GND
EV KIT
A*
POWER
SUPPLY
*ADJUST THE AMMETERS TO THEIR
LARGEST CURRENT RANGE TO
MINIMIZE THEIR SERIES IMPEDANCE.
DO NOT ALLOW THE AMMETERS TO
OPERATE IN THEIR “AUTORANGE” MODE.
IF CURRENT READINGS ARE NOT
DESIRED, SHORT ACROSS THE AMMETERS.
THERMISTOR
JU11
ADJ
ROOM
NTC
123
CEN
JU2
FAST-CHARGE RATE
JU5 0 1
FC0
FC1
FC2
ADJ
JU10
JU4
100mA
50mA
10mA
ADJ
DONE/PREQUAL
THRESHOLD
Figure 3. Connection Diagram and Default Jumper Connections
Table 1. Jumper Functions
JUMPER
JU1
NODE OR FUNCTION
IN input selector
POSITION
Open
1-2
2-3*
JU2
JU3
CEN
STAT1 output
1-2
2-3*
1-2*
Open
1-2
JU4
DONE/PREQUAL
THRESHOLD adjustment
3-4
5-6*
7-8
1-2*
2-3
JU5
FAST-CHARGE RATE
adjustment
4-5
5-6*
7-8
8-9*
*Default
position.
4
FUNCTION
Only the “IN” pad is connected to the MAX8900A’s power input (IN).
Both the “IN” pad and J3 are connected to IN.
Both the “IN” pad and J1 are connected to IN.
Charger is disabled (logic-high).
Charger is enabled (logic-low).
D1 LED indicator is connected to STAT1.
D1 LED indicator is not connected to STAT1.
Adjustable setting. R23 (50kI potentiometer) and R27 are
connected to DNI.
10mA setting. R18 (35.7kI) is connected to DNI.
50mA setting. R19 (7.68kI) is connected to DNI.
100mA setting. R20 (3.83kI) is connected to DNI.
Gate of M1 driven high. R10 (35.7kI) is connected to SETI, which
increases the fast-charge current setting by 95mA.
Gate of M1 driven low. R10 is disconnected from SETI.
Gate of M2 driven high. R11 (9.09kI) is connected to SETI, which
increases the fast-charge current setting by 375mA.
Gate of M2 driven low. R11 is disconnected from SETI.
Gate of M3 driven high. R12 (4.75kI) is connected to SETI, which
increases the fast-charge current setting by 717mA.
Gate of M3 driven low. R12 is disconnected from SETI.
Maxim Integrated
JU9
JU3
JU6
JU7
MAX8900A Evaluation Kit
Evaluates: MAX8900A/MAX8900B
Table 1. Jumper Functions (continued)
JUMPER
JU6
JU7
NODE OR FUNCTION
STAT2 output
STAT3 output
POSITION
1-2*
Open
1-2*
Open
1-2*
JU9
LOGIC
Open
FAST-CHARGE RATE R24
(potentiometer) connection
1-2
Open*
1-2
JU11
*Default
position.
Thermistor adjustment
3-4*
5-6
FUNCTION
D2 LED indicator is connected to STAT2.
D2 LED indicator is not connected to STAT2.
D3 LED indicator is connected to STAT3.
D3 LED indicator is not connected to STAT3.
Connects VBAT to LOGIC. LOGIC serves as the pullup node for the
STAT_ indicator LED. Pin 1 of JU2 connects to LOGIC.
LOGIC must be supplied by an independent power supply that is
less than 5V.
Adjustable setting R24 (50kI potentiometer) and R28 are
connected to SETI.
R24 and R28 are not connected to SETI.
NTC is connected to THM.
R26 is connected to THM.
R25 (200kI potentiometer) is connected to THM.
JU10
Detailed Hardware Description
Input Power Connection
Two input power connectors are provided on the EV kit.
J1 is a 2.1mm power connector and J3 is a Micro-USB
connector. Shunting pins 1-2 of jumper JU1 connects
J1 to IN on the MAX8900A. Shunting pins 2-3 of JU1
connects J3 to IN on the MAX8900A. The IN pad next to
JU1 is always connected and can be used to measure
the voltage on JU1 or JU3, or used as an input only.
CEN
is a digital input. Driving
CEN
(JU2) high (pins 1-2)
disables the battery charger. Driving
CEN
(JU2) low
(pins 2-3) enables the MAX8900A. Leaving
CEN
(JU2)
unconnected (pins open) also enables the charger.
Charger Input Enable (CEN)
As shown in Figure 3, several different resistor values can
be connected from DNI to ground by using jumper JU4.
The resistance from DNI to ground sets the prequalifica-
tion current (I
PQ
) and done current (I
DN
). The MAX8900A
supports I
DN
and I
PQ
currents from 10mA to 200mA.
Table 3 shows the I
DN
and I
PQ
values that are easily
attained with the EV kit. The relationship between R
DNI
,
I
DN
, and I
PQ
is as follows:
I
DN
= 384V/R
DNI
I
PQ
= 415V/R
DNI
The MAX8900A adjusts the charge current and termi-
nation voltage, as described in the JEITA specification
for safe use of secondary lithium-ion batteries (A
Guide
to the Safe Use of Secondary Lithium Ion Batteries in
Notebook-type Personal Computers,
April 20, 2007).
The temperature thresholds are explained in detail in the
MAX8900A/MAX8900B IC data sheet.
The EV kit includes four options for thermistor evaluation:
1)
Disable thermistor (JU11 = Pins 3-4): Biases THM
at AVL/2, which the MAX8900A interprets as the
battery temperature at +25°C.
Setting the Prequalification Current
and Done Threshold (DNI)
Thermistor (THM)
As shown in Figure 3, MOSFET and resistor combina-
tions adjust the total resistance from SETI to ground.
The MAX8900_ supports values of fast-charge current
(I
FC
) from 50mA to 1200mA. Table 2 shows the I
FC
values that are easily obtainable by adjusting jumpers JU5
and JU10. The relationship between R
SETI
and I
FC
is as
follows:
I
FC
= 3405V/R
SETI
Setting the Fast-Charge
Current Limit (SETI)
Maxim Integrated
5
stm32/stm8
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