MAX8903AEVKIt+ ,Evaluation Kit for the MAX8903A, MAX8903B, MAX8903C, MAX8903D, and MAX8903YFeaturesThe MAX8903A evaluation kit (EV kit) is a fully assem-♦ DC-DC Converter Output Current-Limi ..
MAX8903BETI+ ,2A 1-Cell Li+ DC-DC Charger for USB and Adapter Powerfeatures optimized smart power controlto make the best use of limited USB or adapter power.Ordering ..
MAX8903BETI+T ,2A 1-Cell Li+ DC-DC Charger for USB and Adapter Powerfeatures optimized smart power controlto make the best use of limited USB or adapter power.Ordering ..
MAX8903CETI+ ,2A 1-Cell Li+ DC-DC Charger for USB and Adapter PowerELECTRICAL CHARACTERISTICS(V = V = 5V, V = 4V, circuit of Figure 2, T = -40°C to +85°C, unless othe ..
MAX8903CETI+T ,2A 1-Cell Li+ DC-DC Charger for USB and Adapter PowerELECTRICAL CHARACTERISTICS(V = V = 5V, V = 4V, circuit of Figure 2, T = -40°C to +85°C, unless othe ..
MAX8903HETI+T ,2A 1-Cell Li+ DC-DC Charger for USB and Adapter PowerFeatures♦ Efficient DC-DC Converter Eliminates HeatThe MAX8903A–MAX8903E/MAX8903G/MAX8903H/MAX8903J ..
MB88101A ,A/D Converter (With 4-channel Input at 12-bit Resolution)FEATURES• 4-channel analog input• One analog input channel selectable for conversion by external co ..
MB88101A ,A/D Converter (With 4-channel Input at 12-bit Resolution)FUJITSU SEMICONDUCTORDS04-13105-2EDATA SHEETLinear IC ConverterCMOSA/D Converter(With 4-channel I ..
MB88101APF ,A/D Converter (With 4-channel Input at 12-bit Resolution)FEATURES• 4-channel analog input• One analog input channel selectable for conversion by external co ..
MB88141 ,D/A Converter for Digital Tuning (With Built-in OP Amp and I/O Expander)FUJITSU SEMICONDUCTORDS04-13211-3EDATA SHEETGeneral Purpose Linear IC’s General Purpose ConvertersC ..
MB88141A ,D/A Converter for Digital Tuning (Compatible with I 2 C Bus)FUJITSU SEMICONDUCTORDS04-13213-1EDATA SHEETLinear IC ConverterCMOSD/A Converter for Digital Tuning ..
MB88141APF ,D/A Converter for Digital Tuning (Compatible with I2C Bus)FUJITSU SEMICONDUCTORDS04-13213-1EDATA SHEETLinear IC ConverterCMOSD/A Converter for Digital Tuning ..
MAX8903AEVKIt+
Evaluation Kit for the MAX8903A, MAX8903B, MAX8903C, MAX8903D, and MAX8903Y
General DescriptionThe MAX8903A evaluation kit (EV kit) is a fully assem-
bled and tested circuit board for evaluating the 2A, 1-cell
Li+DC-DC battery charger. The EV kit charges a sin-
gle-cell lithium-ion (Li+) battery from a DC input (AC
adaptor) or a USB 100mA/500mA source and provides
system power from the DC input, USB input, or battery.
Battery charge current and SYS current limit are inde-
pendently set. Charge current and DC converter output
current limit can be set up to 2A, respectively. The USB
input current can be set to 100mA or 500mA and USB
suspend mode is also supported. Power not used by
the system is available to charge the battery.
The EV kit comes standard with the MAX8903A
installed. However, the EV kit can also be used to evalu-
ate the MAX8903B–MAX8903E and MAX8903Y by
replacing the MAX8903A (U1) with the preferred IC.
FeaturesDC-DC Converter Output Current-Limit
Adjustment Range of 0.5A to 2A (EV Kit Standard
Configuration: 2A)Battery Charger Current-Limit Adjustment Range
of 0.5A to 2A (EV Kit Standard Configuration: 1A)USB Current Limit of 100mA or 500mAEfficient 4MHz Switching DC-DC Converter
Powers System Load and ChargerInstant On—Works with No Battery or Low
Battery28-Pin, 4mm x 4mm Thin QFN Package with
Exposed PadFully Assembled and Tested
Evaluates: MAX8903A–MAX8903E/MAX8903Y
MAX8903A Evaluation Kit19-4413; Rev 2; 10/10
Component List
Ordering Information
DESIGNATIONQTYDESCRIPTION1
2.2μF ±10%, 16V X5R ceramic
capacitor (0805)
TDK C2012X7R1C225K or
equivalent1
4.7μF ±10%, 25V X5R ceramic
capacitor (0805)
Murata GRM21BR61E475KA12L or
equivalent
C3A, C42
10μF ±10%, 10V X5R ceramic
capacitors (0805)
Taiyo Yuden LMK212BJ106KG or
equivalent
C5, C72
0.1μF ±10%, 10V X7R ceramic
capacitors (0402)
TDK C1005X5R1A104K or
equivalent1
2.2μF ±10%, 6.3V X5R ceramic
capacitor (0603)
Taiyo Yuden LMK107BJ225MA or
equivalent
PARTTYPE MAX8903AEVKIT+ EV Kit
+Denotes lead(Pb)-free and RoHS compliant
Figure 1. MAX8903A EV Kit Photo
Evaluates: MAX8903A–MAX8903E/MAX8903Y
MAX8903A Evaluation Kit
Component List (continued)
DESIGNATIONQTYDESCRIPTIONC8, C9, C110Not installed, capacitors (0402)
C101
4.7μF ±10%, 16V X5R ceramic
capacitor (0805)
Taiyo Yuden EMK212BJ475K or
equivalent
D1, D3, D43Small green LEDs
Panasonic LNJ308G8PRA1Small red LED
Panasonic LNJ208R8ARA
J1, J22USB type-AB right-angle mini jacks
Molex 56579-057612.1mm male power connector
CUI Inc. PJ-002A-SMT1
1.25mm (0.049in) surface-mount,
right-angle pitch header, lead-free,
10 circuits
Molex 53261-1071
JU1, JU2, JU3,
JU8, JU95
3-pin headers
Sullins PEC36SAAN
Digi-Key S1012E-36-ND
JU4–JU7,
JU10, JU116
2-pin headers
Sullins PEC36SAAN
Digi-Key S1012E-36-ND
DESIGNATIONQTYDESCRIPTION1
1μH, 2.8A, 54mΩ inductor
(4.1mm x 4.1mm x 1.2mm)
TOKO A1101AS-1R0 (DEA4012CK
series)
NTC0100kΩ NTC thermistor (0402)
Murata NCP15WF104J03RC
R1–R442.2kΩ ±5% resistors (0402)1100kΩ ±1% resistor (0402)
R6, R10, R14,
R17, R180Not installed, resistors (0402)
R7, R823.01kΩ ±1% resistors (0402)16.04kΩ ±1% resistor (0402)
R11, R122604Ω ±1% resistors (0402)
R1311.21kΩ ±1% resistor (0402)
R1510.56Ω ±1% resistor (0603)
Panasonic ERJ-3RQJR56V11-cell Li+ charger (28 TQFN-EP*)
Maxim MAX8903AETI+
—10Shunts (see Table 1)
Digi-Key S900-ND or equivalentP C B: M AX 8903A E V ALU ATION KIT+
*EP = Exposed pad.
Component Suppliers
SUPPLIERPHONEWEBSITE CUI Inc. 503-612-2300 www.cui.com
Digi-Key Corp. 800-344-4539 www.digikey.com
Molex 800-768-6539 www.molex.com
Murata Electronics North America, Inc. 770-436-1300 www.murata-northamerica.com
Panasonic Corp. 800-344-2112 www.panasonic.com
Sullins Electronics Corp. 760-744-0125 www.sullinselectronics.com
Taiyo Yuden 800-348-2496 www.t-yuden.com
TDK Corp. 847-803-6100 www.component.tdk.com
TOKO America, Inc. 847-297-0070 www.tokoam.com
Note:Indicate that you are using the MAX8903 when contacting these component suppliers.
Evaluates: MAX8903A–MAX8903E/MAX8903Y
MAX8903A Evaluation KitA. Li+\Li-POLY BATTERYB. SIMULATED BATTERY (PRELOADED POWER SUPPLY)
MAX8903A EV KIT
BAT
GND
MAX8903A EV KIT
BAT
GND
≥ 10W
0 TO 4.2V
≥ 2.5A
Figure 2. Battery Options for Evaluating the MAX8903A EV Kit
Quick Start
Recommended EquipmentMAX8903A EV kitAdjustable DC power supply capable of greater than
6V at 3ABattery or simulated battery
1-cell Li+ or Li-poly battery (Figure 2A)
Simulated battery—preloaded power supply
(Figure 2B)Two digital multimeters (DMM)Up to 3A adjustable loadThree 10A ammeters
ProcedureThe EV kit is fully assembled and tested. Follow the
steps below to verify board operation. Use twisted
wires of appropriate gauge that are as short as possi-
ble to connect the battery and power sources.Preset the DC power supply to 6V. Turn off the
power supply. Caution: Do not turn on the power
supply until all connections are completed.Preset the adjustable load to 0A.Connect the EV kit to the power supply, battery or
preloaded power supply, adjustable load, and
meters, as shown in Figure 3.Ensure that the EV kit has the jumper settings
shown in Figure 3 and Table 1.Turn on the power supply.Verify that the voltage at SYS is approximately 4.4V
and that the current from BATT into the battery is 0A.Remove the shunt from pins 1-2 of jumper JU8 and
place the shunt on pins 2-3 of jumper JU8.If 3V ≤VBAT≤4.1V for MAX8903A/MAX8903B/
MAX8903C, or 3V ≤VBAT≤4.0V for MAX8903D/
MAX8903E/MAX8903Y, verify that the current
from BATT into the battery is approximately 1A.Increase the load current on SYS to 1A.
10)Verify that the voltage on SYS remains approximate-
ly equal to VBATT.
11)Verify that the charge current into the battery
remains near 1A.
12)Increase the load current on SYS to 1.5A.
13)Verify that the voltage on SYS remains approximate-
ly equal to VBATT.
14)Verify that the charge current into the battery
decreased to approximately 0.5A.
15)Increase the load current on SYS to 2.5A.
16)Verify that current out of the battery (from the bat-
tery to SYS) is near 0.5A.
Detailed Description of Hardware
Adjusting the EV Kit for In-Circuit
EvaluationVerify that the AC adapter source current limit is higher
than the SYS and BAT current requirements. Note that if
SYS current demand exceeds the DC-DC converter
output current limit, then the battery will help supply the
extra current. The DC-DC converter output current limit
can also be adjusted on the MAX8903A EV kit by
replacing R7 or adjusting JU4 and JU5. Verify that the
USB source supplies at least 500mA. Verify the maxi-
mum charge current rating or desired charge current
Evaluates: MAX8903A–MAX8903E/MAX8903Y
MAX8903A Evaluation KitMAX8903A
EVALUATION KIT
GND
SYS
GNDPOWER
SUPPLY
*ALL AMMETERS NEED TO BE SET FOR 10A READINGS. THIS MINIMIZES THE SERIES IMPEDANCE OF THE AMMETER.
SYS
VOLTMETER
ADJUSTABLE
LOAD
JU12
JU5JU4JU6JU7JU10/THM
JU3/IUSB
JU2/DCM
JU11
BATA
GND
BAT
VOLTMETER
BATTERY OR
SIMULATED BATTERY
JU9/USUS
JU8/CEN
Figure 3. Connection Diagram and Default Jumper Connections
DESCRIPTIONJUMPERLABELDEFAULT
POSITIONPINS 1-2PINS 2-3JU1—Pins 2-3 shuntedUse the DC pad or J2 as the DC inputUse the DC pad or J3 as the DC input
JU2DCMPins 1-2 shuntedConfigures DC input as adapter source
(see Table 2)
Configures DC input for USB power
(see Table 2)
JU3IUSBPins 1-2 shuntedWith DCM pins 1-2 shunted, IUSB sets
500mA USB charge current
With DCM pins 2-3 shunted, IUSB sets
100mA USB charge current
JU4—ShuntedShorts out R8 (see Table 3)
JU5—ShuntedShorts out R9 (see Table 3)
JU6—OpenShunting JU6 shorts out R12 (see Table 4)
JU7—ShuntedShorts out R13 (see Table 4)
JU8CENPins 1-2 shuntedDisables the battery charger
(when the charger is off, SYS remains on)
Enables the battery charger
(when the charger is on, SYS remains on)
JU9USUSPins 2-3USB suspend modeUSB not suspended
JU10THMShuntedConnects THM to GND to bypass thermistor function
JU11—ShuntedIndicator LED anodes connected to SYS
Table 1. Jumper Settings (JU1–JU11)
rating of the battery. Ensure that the charge current set-
ting of the EV kit does not exceed the battery rating, or
replace resistor R11 (or adjust JU6 and JU7) as
required. See the Adjusting the DC-DCConverter
Output Current Limit and BAT Fast-Charge Current
Limitsection for more details.
Adjusting the DC-DC Converter Output
Current Limit and BAT Fast-Charge
Current LimitInput and charger current limits are set, as shown in
Table 2. It is often preferable to change the input cur-
rent limit as the input power source is changed. The
MAX8903A facilitates this by allowing different input
current limits for the DC and USB inputs.
The SYS voltage regulates to three different regulation
points depending on the state of the MAX8903:If CENis high to disable the charger, or charging is
done, the SYS voltage regulates to 4.4V.When charging the battery with VBAT< VSYSMIN, the
SYS voltage regulates to VSYSMIN+ 0.2V and stays
above VSYSMINduring transient loads.When charging the battery with VBAT> VSYSMIN,
the SYS voltage is regulated at the battery voltage
for lowest power dissipation.
When the input current limit is reached, the first action
taken by the MAX8903 is to reduce battery charge cur-
rent. This allows the charging current to be pro-
grammed for the fastest charge time, without dropping
the SYS load at load currents that would cause the
input supply regulation current to be exceeded.
If, after the charge current is reduced to 0mA, the load
at SYS still exceeds the input current limit, the battery
helps supply power to support the system load.
The MAX8903 features flexible input connections (at the
DC and USB inputs) and current-limit settings (set by
DCM and IUSB) to accommodate nearly any input power
configuration. However, it is expected that most systems
use one of two external power schemes: separate con-
nections for USB and an AC adapter, or a single connec-
tor that accepts either USB or the AC adapter output.
Input and charger current limits are shown in Table 2.
Evaluates: MAX8903A–MAX8903E/MAX8903Y
MAX8903A Evaluation Kit
Table 2. Input Limiter Control Logic***Charge current cannot exceed the input current limit. Charge may be less than the maximum charge current if the total SYS load
exceeds the input current limit.
POWER SOURCEDOKUOK
DCMIUSBUSUS
DC STEP-DOWN
OUTPUT
CURRENT LIMIT
USB INPUT
CURRENT LIMIT
MAXIMUM
CHARGE
CURRENT***AC Adapter at DC Input L X H X X 6000/RIDC
Lesser of
1200/RISET and
6000/RIDCX L L L 100mA
Lesser of
1200/RISET and
100mA
L X L H L 500mA
Lesser of
1200/RISET and
500mA
USB Power at DC Input
L X L X H USB suspend
USB input off. DC
input has priority. L X L L 100mA
Lesser of
1200/RISET and
100mA
H L X H L 500mA
Lesser of
1200/RISET and
500mA
USB Power at USB Input,
DC Unconnected
H L X X H USB suspend 0
DC and USB Unconnected H H X X X
No DC input
No USB input 0
EV Kit On-Board Current-Limit AdjustmentThe MAX8903’s DC-DC converter output current limit
can be adjusted on the EV kit by shunting JU4, JU5, or
both. See Table3 for jumper and resistor combinations
and corresponding current limits. The BAT fast-charge
current limit can be adjusted by shunting JU6, JU7, or
both. See Table 4 for jumper and resistor combinations
and corresponding fast-charge current limits.
Thermistor (THM)The EV kit comes with a thermistor preinstalled on the
NTC footprint. To evaluate the MAX8903A with a bat-
tery-pack thermistor, remove the thermistor and connect
to the EV kit using the THM pad. Details of thermistors
are covered in the MAX8903 IC data sheet. To disable
the thermistor function, shunt jumper JU10.
Charge TimersA fault timer prevents the battery from charging indefi-
nitely. The fault prequalification and fast-charge timers
are controlled by the capacitance at CT (C5).
(tPREQUALis when VBATT< 3V).
While in fast-charge mode, a large system load or device
self-heating could cause the MAX8903 to reduce charge
current. Under these circumstances, the fast-charge
timer is slowed by 2x if the charge current drops below
50% of the programmed fast-charge level, and suspend-
ed if the charge current drops below 20% of the pro-
grammed level. The fast-charge timer is not affected at
any current if the charger is regulating the BAT voltage at
4.2V (i.e., the charger is in voltage mode).
Indicator LEDsIndicator LEDs are provided for CHG, FLT, DOK, and
UOK. The CHGLED (D3) is on when the battery charg-
er is in its prequalification and fast-charge states. The
FLTLED (D2) is on when the battery charger has
entered a fault state after the charge timer expires. The
DOKLED (D1) is on when 4.15V < VDC< 16V. The
UOKLED (D4) is on when the source at USB is 4.1V <
VUSB< 6.6V. Refer to the MAX8903 IC data sheet for
more details regarding CHG, FLT, DOK, and UOK.
Charge Enable (CEN)When CENis low, the charger is on. When CENis high,
the charger turns off. CENdoes not affect the SYS out-
put, which remains on. In many systems, there is no
need for the system controller (typically a microproces-
sor) to disable the charger, because the MAX8903
Smart Power Selector™ circuitry independently man-
ages charging and adapter/battery power hand-off. In
these situations, CENmay be connected to ground.tsMAXACDY
TOPOFF
TOPOFF8903
132//)
min××.(/)CMAXBECT
0158903CFSTCHG-=×6605
015min.CPREQUAL=×335
015min.
Evaluates: MAX8903A–MAX8903E/MAX8903Y
MAX8903A Evaluation Kit
Table 3. DC-DC Converter Output Current Limit (JU4, JU5)
JUMPER
JU4JU5
RESISTORS FROM IDC TO
GND
RESISTANCE FROM IDC TO
GND ()SYS CURRENT LIMIT (A) Open Open R7 + R8 + R9 12k 0.5
Open Shunt R7 + R8 6k 1
Shunt Open R7 + R9 9k 0.66
Shunt Shunt R7 3k 2
Table 4. BAT Fast-Charge Current Limit (JU6, JU7)
JUMPER
JU6JU7
RESISTORS FROM IDC TO
GND
RESISTANCE FROM IDC TO
GND ()
BAT FAST-CHARGE CURRENT
LIMIT (A) Open Open R11 + R12 + R13 2.4k 0.5
Open Shunt R11 + R12 1.2k 1
Shunt Open R11 + R13 1.8k 0.66
Shunt Shunt R11 604 2
Evaluates: MAX8903A–MAX8903E/MAX8903YDC4DCVLIDC12GNDDOKPGLXCHGUSBTHMLXCS25
2.2μF
2.2μFPG
C10
4.7μF
4.7μF
TP1
LEDBST
0.1μFCT
0.1μF
R15
0.56Ω1JU1
TP3J3DCMJU2CENJU8USUSJU9IUSBJU3
GND
DOKJ2
2.2kΩ
3.01kΩ
3.01kΩ
6.04kΩ
JU4JU5
R17
OPEN
OPEN
R10
OPENISET
TP2
R11
604Ω
R12
604Ω
R13
1.21kΩ
JU6JU7
R18
OPEN
OPENR14
OPEN
MAX8903A
1μH
JU11SYS
SYS23C4
10μF
LED
LED
SYS
GND
CHG
2.2kΩUOK
LED
UOK
2.2kΩ
THM
USB
GNDFLT
LED
FLT
2.2kΩBAT
BAT20
THM
C3A
10μFGND
BATT
J4-10
J4-9
J4-8
J4-7
J4-6
J4-5
J4-4
J4-3
J4-2
J4-1J1
NTCJU10R6
OPEN
100kΩ
C11
OPEN
THM
MAX8903A Evaluation Kit
