19-6061; Rev 0; 10/11
MAX16928 Evaluation Kit
Evaluates: MAX16928
General Description
The MAX16928 evaluation kit (EV kit) is a fully assembled
and tested surface-mount PCB that provides the voltages
and features required for automotive thin-film transistor
(TFT), liquid-crystal display (LCD) applications. The EV
kit includes a boost converter, a 3.3V regulator controller
with external npn transistor, two gate voltage regulators,
a single-stage positive charge pump, and a single-stage
negative charge pump.
The EV kit can operate from 4.5V to 5.5V input voltages
and is optimized for automotive TFT-LCD applications.
The boost converter is configured for a 12V output that
provides at least 400mA. The regulator controller output
is 3.3V and provides at least 500mA. The positive-gate
voltage regulator provides 18V output and the negative-
gate voltage regulator provides -5.9V.
S
4.5V to 5.5V Input Range
S
Output Voltages
12V Output at 400mA (Boost Converter)
3.3V Output at 500mA (Regulator Controller)
18V Output (Positive-Gate Voltage Regulator)
-5.9V Output (Negative-Gate Voltage Regulator)
S
High-Frequency Operation
2.2MHz (Boost Converter)
S
Single-Stage Positive and Negative Charge Pumps
S
Proven PCB Layout
S
Fully Assembled and Tested
Ordering Information
appears at end of data sheet.
Features
Component List
DESIGNATION
C1, C4, C22,
C24
QTY
DESCRIPTION
10FF
Q20%,
25V X7R ceramic
capacitors (1210)
Murata GRM32DR71E106M
TDK C3225X7R1E106M
0.1FF
Q10%,
50V X7R ceramic
capacitors (0603)
Murata GRM188R71H104K
TDK C1608X7R1H104K
2.2FF
Q10%,
10V X7R ceramic
capacitor (0805)
Murata GRM21BR71A225K
220pF
Q10%,
50V X7R ceramic
capacitor (0603)
Murata GRM188R71H221K
22pF
Q5%,
50V C0G ceramic
capacitor (0603)
Murata GRM1885C1H220J
150pF
Q5%,
50V C0G ceramic
capacitor (0603)
Murata GRM1885C1H151J
1FF
Q10%,
25V X7R ceramic
capacitors (0805)
Murata GRM21BR71E105K
Not installed, ceramic capacitors
(1210)
DESIGNATION
C26
QTY
1
DESCRIPTION
4.7FF
Q20%,
25V X7R ceramic
capacitor (1206)
Murata GRM31CR71E475M
200mA, 100V dual-series diodes
(SOT23)
Fairchild MMBD4148SE
3A, 30V Schottky diode (M Flat)
Toshiba CMS02(TE12L,Q)
2A, 50V fast-recovery diode
(SMB)
Fairchild ES2A
3-pin headers
3.3FH, 9A power inductor
Würth 744314330
-20V, -2.4A p-channel MOSFET
(3 SuperSOT)
Fairchild FDN304P
npn bipolar transistor (SOT23)
Fairchild MMBT3904
npn high-gain transistor (SOT89)
Zetex ZXTN25012EZ
30kI
Q1%
resistor (0603)
6.8kI
Q5%
resistors (0603)
180kI
Q5%
resistor (0603)
4
D1, D6
2
C2, C3, C5,
C14, C25, C27
6
D2
1
C6
1
D4
JU1, JU2
L1
1
2
1
C7
1
C8
1
P1
1
C9
1
Q1
Q2
R1
R2, R13
R5
1
1
1
2
1
C12, C13, C21
C23, C37, C38,
C39
3
0
_________________________________________________________________
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.
MAX16928 Evaluation Kit
Evaluates: MAX16928
Component List (continued)
DESIGNATION
R6
R7
R9, R16, R17
R10
R11
R12
R14
QTY
1
1
3
1
1
1
1
DESCRIPTION
169kI
Q1%
resistor (0603)
10kI
Q1%
resistor (0603)
10kI
Q5%
resistors (0603)
100kI
Q5%
resistor (0603)
133kI
Q1%
resistor (0603)
12.1kI
Q1%
resistor (0603)
316kI
Q1%
resistor (0603)
—
—
2
1
U1
1
DESIGNATION
R15
R18
QTY
1
1
DESCRIPTION
51.1kI
Q1%
resistor (0603)
33I
Q5%
resistor (0603)
TFT-LCD power supply
(20 TSSOP-EP )
Maxim MAX16928AGUP/V+
Shunts
PCB: MAX16928 EVALUATION
KIT
Component Suppliers
SUPPLIER
Fairchild Semiconductor
Murata Electronics North America, Inc.
TDK Corp.
Toshiba America Electronic Components, Inc.
Würth Electronik GmbH & Co. KG
Zetex Semiconductors (Division of Diodes Incorporated)
PHONE
888-522-5372
770-436-1300
847-803-6100
949-623-2900
201-785-8800
805-446-4800
WEBSITE
www.fairchildsemi.com
www.murata-northamerica.com
www.component.tdk.com
www.toshiba.com/taec
www.we-online.com
www.diodes.com
Note:
Indicate that you are using the MAX16928 when contacting these component suppliers.
Quick Start
• MAX16928 EV kit
• Voltmeter
The EV kit is fully assembled and tested. Follow the steps
below to verify board operation.
Caution: Do not turn on
the power supply until all connections are completed.
1) Verify that a shunt is installed on pins 1-2 on jumper
JU1.
2) Verify that a shunt is installed on pins 2-3 on jumper
JU2.
3) Connect the positive terminal of the power supply to
the INA PCB pad. Connect the negative terminal of the
power supply to the PGNDP PCB pad closest to INA.
4) Set the power-supply INA to 5V.
5) Turn on the power supply.
6) Verify that the step-up switching regulator (VSH)
is 12V.
7) Verify that the 3.3V regulator is 3.3V.
8) Verify that the positive-gate voltage regulator (GH) is
approximately 18V.
9) Verify that the negative-gate voltage regulator (VGL)
is approximately -5.9V.
Recommended Equipment
• 4.5V to 5.5V, 2A DC power supply
Detailed Description of Hardware
Procedure
Several jumper settings in the following tables illustrate
features of the EV kit.
Jumper Settings
The device’s ENP pin enables the boost circuitry and the
3.3V regulator controller.
For
normal operation, drive ENP
high by installing a shunt on pins 1-2 on jumper JU1. For
shutdown mode, drive ENP low by installing a shunt on
pins 2-3 on JU1. See Table 1 for JU1 configuration.
Boost Circuitry and 3.3V Regulator
Controller Enable Input (JU1)
Table 1. Jumper Functions (JU1)
SHUNT
POSITION
1-2*
2-3
*Default
position.
ENP PIN
Connected to INA
Connected to GND
VSH AND 3.3V
OUTPUTS
Enabled
Disabled
_________________________________________________________________
Maxim Integrated Products
2
MAX16928 Evaluation Kit
Evaluates: MAX16928
Table 2. Jumper Functions (JU2)
SHUNT
POSITION
1-2
2-3*
*Default
position.
SEQ PIN
Connected to INA
Connected to GND
SUPPLY
SEQUENCING
ORDER
VSH, VGL, VGH
VSH, VGH, VGL
Negative-Gate Voltage Regulator
The EV kit’s negative-gate voltage regulator output (VGL)
is set to -5.9V by feedback resistors R14 and R15. To
generate output voltages other than -5.9V, select R15
to be greater than 20kI to avoid loading down the
reference output. Select R14 according to the following
equation:
V
−
V
GL
R14
=
R15
×
FBGL
V
REF
−
V
FBGL
where V
GL
is the desired negative-gate regulator output
voltage, V
REF
= 1.25V, and V
FBGL
is the negative-gate
feedback set point (0.25V typ). Note that the negative-
gate voltage regulator is not short-circuit protected and
can be damaged by overcurrent.
Charge Pumps
The EV kit provides a single-stage positive charge pump
(VCP) and single-stage negative charge pump (VCN).
The output voltages generated on the storage capacitors
are given by:
V
VCP
=
2
×
V
VSH
+
V
SCHOTTKY
−
2
×
V
D
V
VCN
= −
(
V
VSH
+
V
SCHOTTKY
−
2
×
V
D
)
The device’s SEQ pin controls the order in which the
VGH and VGL supplies are sequenced. When a shunt
is installed on pins 1-2 on jumper JU2, VGL is turned on
first followed by VGH. When a shunt is installed on pins
2-3, VGH is turned on first followed by VGL. See Table 2
for JU2 configuration.
Supply Sequencing (JU2)
Output-Voltage Selection
Boost Converter
The EV kit’s boost-converter output (VSH) is set to
12V by feedback resistors R11 and R12. To generate
output voltages other than 12V, select R12 in the 10kI
to 50kI range and select R11 according to the following
equation:
V
R11
=
R12
×
VSH
−
1
V
FBP
where V
VSH
is the desired boost output voltage and
V
FBP
is the boost converter’s feedback set point
(1V typ). When increasing the boost output voltage, be
careful not to exceed the absolute maximum rating of
the CP pin (31V with INA = 5V and 29V with INA = 3.3V).
Positive-Gate Voltage Regulator
The EV kit’s positive-gate voltage regulator output (GH)
is set to 18V by feedback resistors R6 and R7. To gener-
ate output voltages other than 18V, select R7 in the 10kI
to 50kI range and select R6 according to the following
equation:
V
R6
=
R7
×
GH
−
1
V
FBGH
where V
GH
is the desired positive-gate regulator output
voltage and V
FBGH
is the positive-gate feedback set
point (1V typ). With the installed charge-pump doubler,
GH voltages greater than approximately 2 x VSH cannot
be produced.
where V
SCHOTTKY
is the forward-voltage drop of the
Schottky diode and V
D
is the forward-voltage drop of the
charge-pump diode.
The EV kit comes standard with the MAX16928AGUP/
V+ IC installed, but can also evaluate several versions
of the MAX16928. The IC provides a variety of power
options to meet the most common automotive TFT-LCD
display-power requirements, as outlined in the
Ordering
Information
table in the MAX16928 IC data sheet. Note
some components, such as the inductor value and
compensation component values, may need to change
when evaluating other versions of the IC. Refer to the
Design Procedure
section of the MAX16928 IC data
sheet for further details.
Evaluating Other Versions of MAX16928
_________________________________________________________________
Maxim Integrated Products
3
MAX16928 Evaluation Kit
Evaluates: MAX16928
Figure 1. MAX16928 EV Kit Schematic
_________________________________________________________________
Maxim Integrated Products
4
MAX16928 Evaluation Kit
Evaluates: MAX16928
1.0”
1.0”
Figure 2. MAX16928 EV Kit Component Placement Guide—
Component Side
Figure 3. MAX16928 EV Kit PCB Layout—Component Side
1.0”
Figure 4. MAX16928 EV Kit PCB Layout—Solder Side
_________________________________________________________________
Maxim Integrated Products
5
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