19-4278; Rev 0; 9/08
MAX8819A Evaluation Kit
General Description
The MAX8819A evaluation kit (EV kit) is a fully assem-
bled and tested PCB for evaluating the MAX8819A
power-management IC (PMIC). The MAX8819A PMIC is
ideal for use in MP3 players and other handheld appli-
cations. In addition to the three step-down converters
and WLED driver, the MAX8819A integrates a 1-cell
lithium ion (Li+) or lithium polymer (Li-poly) charger and
Smart Power Selector™ with a power input that accepts
a USB or AC-to-DC adapter.
The MAX8819A EV kit can also be used to evaluate the
MAX8819B, MAX8819C, or MAX8819D. Request a pin-
compatible sample when ordering this EV kit.
Features
o
USB/AC Adapter 1-Cell Li+ Charger
o
Jumper Options Offer Four Input Current Limits
o
Jumper Options Allow for Easy Evaluation of Five
Charge-Current Settings
o
Three 2MHz Step-Down Converters
o
External Resistors Allow for Output-Voltage
Adjustment
o
Resistor Option Allows for Reducing Quiescent
Current by Disabling Regulator 2
o
6-Series WLEDs Showcase WLED Driver
o
Jumper Option Allows for WLED Overvoltage
Protection Evaluation
o
On-Board Pulse Generator Allows for Pushbutton
Evaluation of the WLED Dimming Feature
o
Lead-Free and RoHS Compliant
o
Fully Assembled and Tested
Evaluates: MAX8819A–MAX8819D
Ordering Information
PART
MAX8819AEVKIT+
TYPE
EV Kit
+Denotes
lead-free and RoHS compliant.
Component List
DESIGNATION
QTY
DESCRIPTION
4.7µF ±10%, 10V X5R ceramic
capacitor (0805)
Murata GRM21BR61A475K
TDK C2012X5R1A475K
Taiyo Yuden LMK212BJ475MG
Not installed, capacitor (0603)
0.1µF ±10%, 50V X7R ceramic
capacitor (0603)
TDK C1608X7R1H104K
0.022µF ±10%, 10V X5R ceramic
capacitors (0402)
Murata GRM155R61A223K or
TDK C1005X5R1E223K
10µF ±10%, 6.3V X5R ceramic
capacitors (0805)
Murata GRM21BR61A106K
TDK C2012X5R0J106M
4.7µF ±10%, 6.3V X5R ceramic
capacitors (0603)
Murata GRM188R61A475K
TDK C1608X5R0J475M
C1
1
C2
C3
0
1
Figure 1. MAX8819A EV Kit Photo
C4, C14
2
C5, C8,
C10, C11
4
Smart Power Selector is a trademark of Maxim Integrated
Products, Inc.
C6, C7
2
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
MAX8819A Evaluation Kit
Evaluates: MAX8819A–MAX8819D
Component List (continued)
DESIGNATION
C9
QTY
1
DESCRIPTION
2.2µF ±10%, 6.3V X5R ceramic
capacitor
TDK C1608X5R0J225K
0.1µF ±10%, 10V X5R ceramic
capacitors (0402)
TDK C1005X5R1A104K or equivalent
Murata GRM155R61A104K
1µF ±10%, 10V X5R ceramic
capacitors (0603)
Murata GRM188R61C105K
TDK C1608X5R1C105K
Taiyo Yuden EMK107BJ105KA
White LEDs
Nichia NSCW215T
500mA, 30V Schottky diode
(SOD-523)
NXP PMEG3005EB
10-pin header, 1.25mm pitch, right-
angle, surface-mount, lead-free
Molex 53261-1071
3-pin headers, 0.1in
Sullins PEC36SAAN or equivalent
(36-pin strip, cut to size as needed)
2-pin headers, 0.1in
Sullins PEC36SAAN or equivalent
(36-pin strip, cut to size as needed)
4.7µH, 0.88A, 130mΩ inductors
(3.2mm x 3mm x 1.2mm)
TOKO 1098AS-4R7M (DE2812C series)
10µH, 0.77A, 290mΩ inductor
(3.2mm x 3mm x 1.2mm)
TOKO 1098AS-4R7M (DE2812C series)
DESIGNATION
R1
R2, R3, R5
R4
R6, R10
R7, R11
R8
R9, R13,
R15, R17
R12
R14
R18, R19
R20
R21, R22
S1
QTY
1
3
1
2
0
1
4
1
1
2
1
2
1
DESCRIPTION
20Ω ±1% resistor (0402)
15kΩ ±1% resistors (0402)
7.5kΩ ±1% resistor (0402)
470kΩ ±1% resistors (0402)
Not installed, resistors (0402)
200kΩ ±1% resistor (0402)
100kΩ ±1% resistors (0402)
80.6kΩ ±1% resistor (0402)
20kΩ ±1% resistor (0402)
10kΩ ±1% resistors (0402)
221kΩ ±1% resistor (0402)
1MΩ ±5% resistors (0402)
Momentary pushbutton switch
Panasonic EVQ-Q2K03W
Power-management IC
(28 TQFN-EP*)
Maxim MAX8819AETI+
74HC series monostable
multivibrator
Texas Instruments CD74HC123PW
or equivalent
LDO linear regulator (5 SOT23)
Maxim MAX8875EUK25+
PCB: MAX8819A Evaluation Kit+
C12, C13, C15
3
C16, C17
2
D1–D6
6
D7
1
J1
1
U1
1
JU1, JU2, JU10
3
U2
1
JU3–JU9
7
U3
—
1
1
L1, L2, L3
3
*EP
= Exposed pad.
L4
1
Component Suppliers
SUPPLIER
Molex
Murata Electronics North America, Inc.
Nichia Corp.
NXP Semiconductors
Panasonic Corp.
Sullins Electronics Corp.
Taiyo Yuden
TDK Corp.
Texas Instruments Inc.
TOKO America, Inc.
PHONE
800-768-6539
770-436-1300
248-352-6575
408-474-8142
800-344-2112
760-744-0125
800-348-2496
847-803-6100
972-644-5580
847-297-0070
WEBSITE
www.molex.com
www.murata-northamerica.com
www.nichia.com
www.nxp.com
www.panasonic.com
www.sullinselectronics.com
www.t-yuden.com
www.component.tdk.com
www.ti.com
www.tokoam.com
Note:
Indicate that you are using the MAX8819A, MAX8819B, MAX8819C, or MAX8819D when contacting these component suppliers.
2
_______________________________________________________________________________________
MAX8819A Evaluation Kit
Quick Start
Recommended Equipment
Before beginning, the following equipment is needed:
• Battery
1-cell Li+ or Li-poly battery (Figure 2A)
Preloaded power supply (Figure 2B)
•
•
•
Voltmeter
Loads
5V > 1A power source
Procedure
The MAX8819A EV kit is fully assembled and tested.
Follow the steps below to verify board operation:
1) Verify that all jumpers are in default position, as
shown in Table 1.
2) Connect loads from the desired step-down outputs
(V1, V2, and V3) to the nearest GND pad. The maxi-
mum load current for each output is shown in Table 2.
3) Connect a Li+ or Li-poly battery from the BAT termi-
nal to GND, or plug battery into connector J1.
Evaluates: MAX8819A–MAX8819D
Table 1. Jumper Functions
JUMPER
NODE OR
FUNCTION
SHUNT
POSITION
1-2
JU1
DLIM2
2-3*
1-2
JU2
DLIM1
2-3*
JU3
JU4
CEN
EN123
Open*
Short
Open
Short*
Open
Short*
JU6
JU7
JU8
JU9
JU10
CISET
CISET
CISET
EN4
IN supply for
U3 (MAX8875)
Short*
Short*
Short*
Open
Short*
1-2*
2-3
Low
—
—
—
—
—
—
—
—
—
—
—
High
Low
Disconnects the pulse circuit from EN4
Connects the pulse circuit to EN4
Enable the series pulse circuit
Disable the series pulse circuit
For evaluating other charge currents, see the
Evaluating Other Charge
Currents
section and Table 3.
If DLIM2 = high, then 475mA DC current limit
If DLIM2 = low, then 1000mA DC current limit
Battery charge disabled
Battery charge enabled
V1, V2, V3, and IC off, if VDC is invalid; otherwise V1, V2, V3, and IC are on.
V1, V2, V3, and IC on
LED string disconnected from REG4. If REG4 is enabled, it enters its
overvoltage protection mode and latches off.
LED string connected to REG4 output
Low
High
If DLIM1 = high, then 95mA DC current limit
If DLIM1 = low, then 1000mA DC current limit
If DLIM2 = high, then suspend
If DLIM2 = low, then 95mA DC current limit
LOGIC
LEVEL
High
FUNCTION
If DLIM1 = high, then suspend
If DLIM1 = low, then 475mA DC current limit
JU5
OVP4 (OUT4)
*Default
position.
Table 2. Default Output Voltages and Maximum Load Currents
MAX8819A/MAX8819B
OUTPUT
V1
V2
V3
DEFAULT VOLTAGE
(V)
3
1.8
1.2
MAXIMUM LOAD CURRENT
(mA)
400
300
300
MAX8819C/MAX8819D
DEFAULT VOLTAGE
(V)
3
1.8
1.2
MAXIMUM LOAD CURRENT
(mA)
550
500
500
_______________________________________________________________________________________
3
MAX8819A Evaluation Kit
Evaluates: MAX8819A–MAX8819D
4) Optionally, connect an AC-to-DC adapter to the DC
pad and nearest GND pad.
5) Using a voltmeter, verify that the output voltages
match the values shown in Table 2.
6) Verify that the WLEDs are brightly lit.
7) Dim the WLEDs by repeatedly pressing pushbutton
S1. Verify that the WLEDs are dimming with each
pulse and then return to full brightness on the 32nd
button press.
8) Verify that the WLEDs turn off by removing the
shunt on jumper JU9 or by moving the shunt from
pins 1-2 of jumper JU10 to pins 2-3.
Battery Charger
To enable the battery charger, short jumper JU3 (CEN).
To disable the battery charger, open jumper JU3 (CEN).
The battery regulation voltage is factory set to 4.2V (typ).
The resistor/jumper network allows for easy evaluation of
many charge-current settings (Table 3). The maximum
charge time is factory set and detailed in the
MAX8819A–MAX8819D IC data sheet.
Input Power Connections
Either a USB or AC-to-DC adapter can be connected to
DC. The AC-to-DC adapter must output between 4.1V
and 6V DC and be capable of providing 1A. One suit-
able AC-to-DC adapter is the CUI EPS050260UHH-
P5P-SZ.
The Li+ or Li-poly battery connects from the BAT pad to
the GND pad on the EV kit. Alternatively, a battery con-
nector (J1) is provided. J1 is a 10-circuit, 1.25mm
(0.049in) pitch surface-mount header, Molex part num-
ber 53261-1071. The recommended mating connector
is Molex 51021-1000 with crimp terminals 50058-8100.
To crimp the terminals, use Molex crimper 63811-0200.
Detailed Description of Hardware
The MAX8819A has four outputs: three step-down DC-
DC regulators (V1, V2, and V3) and one LED driver. All
three step-down regulator output voltages are
adjustable and set by external resistors on the EV kit.
See the
Setting the Output Voltages
section for informa-
tion on calculating these resistor values. The default
voltage and maximum current for each output is listed
in Table 2.
All regulators are powered from the system supply
(SYS) by default.
CHG
and
RST1
Output indicators are provided on the MAX8819A EV kit
for charger status (CHG) and REG1 converter reset
output (RST1). These pads connect to open-drain out-
puts with a pullup resistor to V1.
CHG
pulls low to indi-
cate that the battery is charging.
RST1
pulls low to indi-
cate that V
FB1
is below its regulation threshold.
RST1
goes high 200ms after V
FB1
reaches its regulation
threshold. Refer to the MAX8819A–MAX8819D IC data
sheet for more details.
Setting the Output Voltages
The step-down output voltages are adjustable from 1V
to V
SYS
. The voltage is adjusted by changing two resis-
tors on the EV kit board. First, select the lower feed-
back resistor (R
FBL
) connected from FB_ to GND. R
FBL
is typically 100kΩ for the step-down regulator. Next,
find the value of R
FBH
(connected between FB_ and
OUT_) from the following equation:
⎛
V
⎞
R
FBH
=
R
FBL
× ⎜
OUT
−
1
⎟
⎝
V
FB
⎠
where V
FB
is 1V.
LED Serial-Pulse Dimming
Pushbutton S1 and associated circuitry (Figure 4) allow
for easy evaluation of the WLED dimming feature. To
enable the pushbutton interface, install a shunt from
pins 1-2 on jumper JU10. Install a shunt on jumper JU9
to connect the pushbutton circuit to the MAX8819A IC
EN4 terminal.
When power is first applied to the REG4 (WLED driver)
converter and serial-pulse dimming circuit, the WLEDs
are set to maximum brightness (25mA per R1 on the EV
kit). To dim the WLEDs, repeatedly press S1. Each
pulse reduces the WLED current by 1/32 of maximum
WLED current. On the 32nd button press, the WLEDs
return to full brightness. To turn the WLEDs off, remove
the shunt from jumper JU9 to pull EN4 to ground. If
dimming control is not required, EN4 works as a simple
on/off control. Drive EN4 high to enable the WLEDs, or
drive EN4 low for shutdown.
Smart Power Selector
The MAX8819A Smart Power Selector seamlessly dis-
tributes power between the current-limited external
input (DC), the battery (BAT), and the system load
(SYS). For detailed information on the MAX8819A oper-
ation, refer to the MAX8819A–MAX8819D IC data sheet.
The DC input is current limited to 95mA, 475mA, 0mA
(suspend), or 1000mA, depending upon the pins
selected on jumper JU2 and JU1 (DILIM1 and DILIM2,
respectively). See Table 1 for jumper settings.
4
_______________________________________________________________________________________
MAX8819A Evaluation Kit
The serial-pulse dimming-control signal can also be
supplied by an external pulse generator. To configure
the EV kit for external serial-pulse control, remove the
shunt on jumper JU9, connect pins 2-3 on jumper
JU10, and apply the external serial-pulse control signal
to the EN4 pad. Refer to the MAX8819A–MAX8819D IC
data sheet for timing information.
Evaluating Other Charge Currents
The maximum fast-charge current is selected with
jumpers JU6, JU7, and JU8 (Table 3).
Evaluates: MAX8819A–MAX8819D
Programming the WLED Current
The MAX8819A uses sense resistor R1 to program the
maximum WLED current. The MAX8819A regulates
V
FB4
to 0.5V (typ) for full-scale output current.
Calculate R1 using the following equation:
R1
=
V
FB4
I
LED(MAX)
Disabling Regulator 2
If regulator 2 is not needed, disable it to reduce the qui-
escent current. To disable regulator 2, remove R11 and
replace C9 with a 0Ω resistor. Although components
L2, C10, R12, and R13 are not needed, they do not
have to be removed for EV kit evaluation. For produc-
tion circuits that do not need regulator 2, connect PV2,
PG2, LX2, and FB2 to ground.
MAX8819A EV Kit Temperature Range
The PCB and components of the MAX8819A EV kit
allow for operation with ambient temperatures from
-20°C to +70°C. Remove S1 to increase the ambient
temperature operating range from -30°C to +85°C.
where I
LED(MAX)
is the maximum WLED current.
Maximum WLED current is programmed to 25mA using
a 20Ω resistor.
Evaluating the
MAX8819B/MAX8819C/MAX8819D
Order a sample of the pin-compatible MAX8819B,
MAX8819C, or MAX8819D along with the MAX8819A
EV kit. Replace the MAX8819A (U1) with the sampled
IC. When evaluating the MAX8819C/MAX8819D, it is
recommended for optimal performance to replace
capacitors C8, C10, and C11 with a 22µF ceramic
capacitor. The 22µF ±20%, 6.3V X5R (0805) Taiyo
Yuden JMK212BJ226MD is recommended.
Table 3. Maximum Fast-Charge
Current Settings
JU6
Short
Short
Short
Open
Open
Open
Open
Short
JU7
Short
Short
Open
Open
Open
Short
Short
Open
JU8
Short
Open
Open
Open
Short
Open
Short
Short
MAXIMUM FAST-CHARGE
CURRENT (mA)
1000
800
400
200
400
600
800
600
ALTERNATE SETTINGS
A: 1-CELL Li+/Li-POLY BATTERY
B: PRELOADED POWER SUPPLY
BAT
BAT
MAX8819EVKIT
GND
0 TO 4.2V
≥
2.5A
2Ω
≥10W
GND
MAX8819EVKIT
Figure 2. Battery Options for Evaluating the MAX8819 Charger
_______________________________________________________________________________________
5
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