General Description
The MAX17075 evaluation kit (EV kit) is a fully assem-
bled and tested surface-mount circuit board that pro-
vides the voltages and features required for active-
matrix thin-film transistor (TFT), liquid-crystal display
(LCD) panels in LCD monitors and LCD TVs. The EV kit
contains a step-up switching regulator, a two-stage pos-
itive charge pump for the TFT gate-on supply, a single-
stage negative charge pump for the TFT gate-off sup-
ply, and a high-current op amp. Also included is a logic-
controlled high-voltage switch array, with capacitor con-
trol delay, for the positive gate-driver supply. A capaci-
tive dummy load is provided at the high-voltage switch
output for ease of testing without an attached panel.
The MAX17075 EV kit is designed to operate from a DC
supply voltage of +2.5V to +5.5V. At +5V (±10%) nomi-
nal input voltage, the step-up switching regulator pro-
vides a +13V output and up to 500mA. The positive
charge pump provides a +30V output and up to 30mA.
The negative charge pump provides a -7V output and
up to 60mA. The high-current op amp provides a +6.5V
output that can source or sink 500mA peak current. The
high-voltage switch array is controlled by external logic.
The MAX17075 switches at 1.2MHz, allowing the use of
tiny surface-mount components. The MAX17075 thin
QFN package (0.8mm maximum height) with low-profile
external components allows this circuit to be less than
3mm high.
Features
♦+2.5V to +5.5V Input-Voltage Range
♦Output Voltages (+4.5V to +5.5V Input Voltage)
+13V Output at 500mA (Step-Up Switching
Regulator)
+30V Output at 30mA (Positive Charge Pump)
-7V Output at 60mA (Negative Charge Pump)
High-Current Op Amp (±500mA Peak Current)
♦1.2MHz Switching Frequency
♦All Output Voltages are Resistor Adjustable
♦Logic-Controlled High-Voltage Switches with
Capacitor Control Delay
♦Low-Profile Surface-Mount Components
♦Lead(Pb)-Free and RoHS Compliant
♦Fully Assembled and Tested
Evaluates: MAX17075
MAX17075 Evaluation Kit
________________________________________________________________
Maxim Integrated Products
1
19-4396; Rev 0; 12/08
Component List
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.
DESIGNATION QTY DESCRIPTION
C1, C2 2
10µF ±20%, 6.3V X5R ceramic
capacitors (0603)
Murata GRM188R60J106M
TDK C1608X5R0J106M
C3, C4 2
10µF ±20%, 25V X5R ceramic
capacitors (1206)
Murata GRM31CR61E106M
TDK C3216X5R1E106M
C5 1
1µF ±10%, 6.3V X5R ceramic
capacitor (0402)
Murata GRM155R60J105K
TDK C1005X5R0J105K
C6 1
1µF ±10%, 25V X5R ceramic
capacitor (0603)
Murata GRM188R61E105K
TDK C1608X5R1E105K
C7 1
1000pF ±10%, 50V X7R ceramic
capacitor (0805)
Murata GRM216R71H102K
TDK C2012X7R1H102K
DESIGNATION QTY DESCRIPTION
C8 1
0.033µF ±10%, 16V X7R ceramic
capacitor (0603)
Murata GRM188R71C333K
TDK C1608X7R1E333K
C9 1
0.22µF ±10%, 6.3V X5R ceramic
capacitor (0402)
Murata GRM155R60J224K
TDK C1005X5R0J224K
C10, C14 2
1µF ±10%, 50V X7R ceramic
capacitors (1206)
Murata GRM31MR71H105KA
TDK C3216X7R1H105K
C11, C15, C16,
C17 4
0.1µF ±10%, 50V X7R ceramic
capacitors (0603)
Murata GRM188R71H104K
TDK C1608X7R1H104K
C12 1
220pF ±10%, 50V X7R ceramic
capacitor (0402)
Murata GRM155R71H221K
TDK C1005X7R1H221K
Ordering Information
PART TYPE
MAX17075EVKIT+ EV Kit
+
Denotes lead(Pb)-free RoHS compliant.
Evaluates: MAX17075
MAX17075 Evaluation Kit
2 _______________________________________________________________________________________
Component Suppliers
SUPPLIER PHONE WEBSITE
Fairchild Semiconductor 888-522-5372 www.fairchildsemi.com
Murata Electronics North America, Inc. 770-436-1300 www.murata-northamerica.com
Sumida Corp. 847-545-6700 www.sumida.com
TDK Corp. 847-803-6100 www.component.tdk.com
Toshiba America Electronic Components, Inc. 949-623-2900 www.toshiba.com/taec
Component List (continued)
DESIGNATION QTY DESCRIPTION
C13 1
0.01µF ±10%, 10V X5R ceramic
capacitor (0402)
Murata GRM155R61A103K
TDK C1005X5R1A103K
C18 1
1500pF ±10%, 50V X7R ceramic
capacitor (0603)
Murata GRM188R71H152K
TDK C1608X7R1H152K
C19 0 Not installed, capacitor (1206)
C20 0 Not installed, capacitor (0402)
C21 1
0.22µF ±10%, 25V X7R ceramic
capacitor (0603)
Murata GRM188R71E224K
TDK C1608X7R1E224K
D1 1
3A, 30V Schottky diode (M-Flat)
Toshiba CMS02
(Top Mark: S2)
D2, D3, D4 3
220mA, 100V dual diodes (SOT23)
Fairchild MMBD4148SE
(Top Mark: D4)
JU1 1 3-pin header
JU2, JU3 2 2-pin headers
L1 1 3µH, 3A
DC
inductor
Sumida CDRH6D28-3R0
Q1 0
Not installed, transistor (SOT223)
Recommended: 20V, 1A npn
transistor (SOT223)
Fairchild BCP68
DESIGNATION QTY DESCRIPTION
Q2 0
Not installed, transistor (SOT223)
Recommended: -20V, -1.5A pnp
transistor (SOT223)
Fairchild BCP69
R1 1 10Ω ±5% resistor (0603)
R2 0 Not installed, 100Ω ±5% resistor
(0603) recommended
R3, R4, R5, R7 4 100kΩ ±1% resistors (0603)
R6 1 13.7kΩ ±1% resistor (0603)
R8 1 187kΩ ±1% resistor (0603)
R9, R16 2 20kΩ ±1% resistors (0603)
R10 1 82kΩ ±5% resistor (0603)
R11 1 8.45kΩ ±1% resistor (0603)
R12 1 10kΩ ±1% resistor (0603)
R13 1 10kΩ ±5% resistor (0603)
R14 1 1kΩ ±5% resistor (0603)
R15 1 464kΩ ±1% resistor (0603)
R17 1 10kΩ SMT cermet trimmer, 9 to 15
turns
U1 1 Boost regulator (24 TQFN)
Maxim MAX17075ETG+
— 3 Shunts
— 1 PCB: MAX17075 Evaluation Kit+
Quick Start
Required Equipment
Before beginning, the following equipment is needed:
• +4.5V to +5.5V, 5A DC power supply
• One voltmeter
Procedure
The MAX17075 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 across pins 2-3 of
jumper JU1 (VCOM unbuffered).
Note: Indicate that you are using the MAX17075 when contacting these component suppliers.
Evaluates: MAX17075
MAX17075 Evaluation Kit
_______________________________________________________________________________________ 3
2) Verify that a shunt is installed across jumper JU2
(VGON internally connected to SRC).
3) Verify that no shunt is installed across jumper JU3
(VGON is not connected to capacitive dummy load
C18).
4) Connect the positive terminal of the power supply
to the VIN pad on the EV kit. Connect the negative
terminal of the power supply to the PGND pad next
to the VIN pad.
5) Turn on the power supply and set the supply to
+4.5V.
6) Verify that the step-up switching regulator output
(AVDD) is +13V.
7) Verify that the gate-on supply (VGON) is +30V.
8) Verify that the gate-off supply (VGOFF) is -7V.
9) Verify that the op-amp output (VCOM) is +6.5V.
Detailed Description of Hardware
The MAX17075 EV kit contains a step-up switching reg-
ulator, a positive charge pump, a negative charge
pump, a high-current op amp, and a high-voltage
switch array. The EV kit is configured to operate from a
DC power supply between +2.5V and +5.5V that pro-
vides at least 5A. The MAX17075 switching frequency
is 1.2MHz.
With +5V input voltage, the step-up switching regulator
(AVDD) generates a +13V output and provides at least
500mA. The step-up switching regulator output voltage
can be adjusted up to +18V by replacing feedback
resistors R8 and R9 (refer to the
Design Procedure,
Step-Up Regulator, Output-Voltage Selection
section in
the MAX17075 IC data sheet). Operation at significantly
higher output voltages could reduce the available out-
put current and require changes in component values
or component voltage rating.
The gate-on (VGON) supply consists of a two-stage
positive charge pump that generates +30V and pro-
vides greater than 30mA. This output can be adjusted
up to approximately +3xAVDD by replacing feedback
resistors R15 and R16 (refer to the
Design Procedure,
Charge-Pump Regulators, Output-Voltage Selection
section in the MAX17075 IC data sheet).
The VGOFF supply consists of a negative charge pump
that generates -7V and provides > 60mA. This output can
be adjusted from approximately 0 to -AVDD by replacing
feedback resistors R6 and R7 (refer to the
Design
Procedure, Charge-Pump Regulators, Output-Voltage
Selection
section in the MAX17075 IC data sheet).
The MAX17075 provides a high-current op amp that
sources or sinks 500mA peak current. The op amp out-
put is configured for +6.5V (AVDD/2).
The MAX17075 contains two high-voltage switches that
operate in a complementary fashion. One of the switch-
es provides a connection between the COM (VGON
PCB pad) and SRC pins. The other switch provides a
connection between the COM and DRN pins. The
switches are controlled by an external TTL logic signal
connected to the CTL pad.
When CTL is high, VGON is connected to SRC, charg-
ing VGON to the voltage of the positive charge pump at
the SRC pin. When CTL is low, VGON is connected to
DRN, allowing VGON to discharge toward AVDD
(through resistor R14). The MAX17075 EV kit also fea-
tures a capacitive dummy load of 1500pF (C18) at the
VGON output pad that can be connected through
jumper JU3 to simulate a TFT panel load for testing the
switch array.
The high-voltage switch delay time can be configured
by replacing capacitor C8. Refer to the
Power-Up
Sequence and Soft-Start
section in the MAX17075 IC
data sheet for additional details.
Jumper Selection
Op-Amp Output (VCOM)
Jumper JU1 configures the op-amp output (VCOM) on
the MAX17075 EV kit. The op-amp output (VCOM) of
the MAX17075 EV kit can be buffered with a push-pull
output stage, or unbuffered. See Table 1 for JU1 shunt
positions.
Table 1. JU1 Jumper Selection (VCOM)
SHUNT POSITION VCOM
1-2* Buffered
2-3** Unbuffered
None Not connected
*
Install appropriate transistors Q1, Q2, and resistor R2 to buffer
the VCOM output. See the
Component List
.
**
Default position.
Evaluates: MAX17075
High-Voltage Switch Control (CTL)
Jumper JU2 configures the positions of the high-
voltage switch control pin (CTL) of the MAX17075 IC.
The CTL pin can be controlled by an external logic con-
troller connected to the EV kit’s CTL pad. Remove the
shunt from jumper JU2 before connecting an
external controller to the CTL pad. See Table 2 for JU2
shunt positions.
High-Voltage Switch Output (VGON)
Dummy Load
The MAX17075 EV kit features a capacitive dummy
load of 1500pF (C18) at the VGON output pad to simu-
late a TFT panel load to test the switch array. When
testing with an actual LCD panel, disconnect the
dummy load. Jumper JU3 connects and disconnects
the dummy load. Table 3 lists the selectable JU3
jumper options.
Output-Voltage Selection
Step-Up Switching Regulator Output Voltage
(AVDD)
The MAX17075 EV kit’s step-up switching-regulator out-
put (AVDD) is set to +13V by feedback resistors R8 and
R9. To generate output voltages other than +13V (up to
+18V), select different voltage-divider resistors.
Operation at significantly higher output voltages could
reduce the available output current, and require
changes in component values or voltage rating for
capacitors C3 and C4. Refer to the
Design Procedure,
Step-Up Regulator, Output-Voltage Selection
section in
the MAX17075 IC data sheet for instructions on select-
ing resistors R8 and R9.
Positive Charge-Pump Output (SRC)
The positive charge-pump output (SRC) is set to +30V
by voltage-divider resistors R15 and R16. To set SRC to
other voltages (up to approximately 3xAVDD, limited to
+36V), select different voltage-divider resistors. Refer to
the
Design Procedure, Charge-Pump Regulators,
Output-Voltage Selection
section in the MAX17075 IC
data sheet for instructions on selecting resistors R15
and R16.
Negative Charge-Pump Output (VGOFF)
The negative charge-pump output (VGOFF) is set to
-7V by voltage-divider resistors R6 and R7. To set
VGOFF to other voltages (from 0 to -AVDD approxi-
mately), select different voltage-divider resistors. Refer
to the
Design Procedure, Charge-Pump Regulators,
Output-Voltage Selection
section in the MAX17075 IC
data sheet for instructions on selecting resistors R6 and
R7.
Op-Amp Output (OUT)
The op-amp output (OUT) is set to +6.5V by voltage-
divider resistors R3 and R4. To set the outputs to other
voltages (from 0 to AVDD), select different voltage-
divider resistors.
MAX17075 Evaluation Kit
4 _______________________________________________________________________________________
Table 2. JU2 Jumper Selection (CTL)
SHUNT POSITION CTL PIN CONNECTED TO HIGH-VOLTAGE SWITCH CONFIGURATION
Installed VIN COM pin connected to SRC pin
COM pin disconnected from DRN pin
Not installed* GND through resistor R5 COM pin connected to DRN pin
COM pin disconnected from SRC pin
None External logic controller
through the CTL pad
CTL driven by external logic controller
CTL high: COM pin connected to SRC pin
CTL low: COM pin connected to DRN pin
*
Default position.
Table 3. JU3 Jumper Selection (C18)
SHUNT POSITION VGON OPERATION
Installed Connected to C18 Dummy load testing
Not installed* Not connected to C18 Normal operation, no load
*
Default position.
Evaluates: MAX17075
MAX17075 Evaluation Kit
_______________________________________________________________________________________ 5
Figure 1. MAX17075 EV Kit Schematic
Figure 2. MAX17075 EV Kit Component Placement Guide—
Component Side
Figure 3. MAX17075 EV Kit PCB Layout—Component Side
Evaluates: MAX17075
MAX17075 Evaluation Kit
6 _______________________________________________________________________________________
Maxim cannot assume responsibility for use of any circuitry other than circuitry entirely embodied in a Maxim product. No circuit patent licenses are
implied. Maxim reserves the right to change the circuitry and specifications without notice at any time.
Maxim Integrated Products, 120 San Gabriel Drive, Sunnyvale, CA 94086 408-737-7600 _____________________
7
© 2008 Maxim Integrated Products is a registered trademark of Maxim Integrated Products, Inc.
Evaluates: MAX17075
MAX17075 Evaluation Kit
Figure 4. MAX17075 EV Kit PCB Layout—Solder Side
