19-4396; Rev 0; 12/08
MAX17075 Evaluation Kit
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.
DESIGNATION
QTY
DESCRIPTION
10µF ±20%, 6.3V X5R ceramic
capacitors (0603)
Murata GRM188R60J106M
TDK C1608X5R0J106M
10µF ±20%, 25V X5R ceramic
capacitors (1206)
Murata GRM31CR61E106M
TDK C3216X5R1E106M
1µF ±10%, 6.3V X5R ceramic
capacitor (0402)
Murata GRM155R60J105K
TDK C1005X5R0J105K
1µF ±10%, 25V X5R ceramic
capacitor (0603)
Murata GRM188R61E105K
TDK C1608X5R1E105K
1000pF ±10%, 50V X7R ceramic
capacitor (0805)
Murata GRM216R71H102K
TDK C2012X7R1H102K
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
Ordering Information
PART
MAX17075EVKIT+
TYPE
EV Kit
+Denotes
lead(Pb)-free RoHS compliant.
Component List
DESIGNATION
QTY
DESCRIPTION
0.033µF ±10%, 16V X7R ceramic
capacitor (0603)
Murata GRM188R71C333K
TDK C1608X7R1E333K
0.22µF ±10%, 6.3V X5R ceramic
capacitor (0402)
Murata GRM155R60J224K
TDK C1005X5R0J224K
1µF ±10%, 50V X7R ceramic
capacitors (1206)
Murata GRM31MR71H105KA
TDK C3216X7R1H105K
0.1µF ±10%, 50V X7R ceramic
capacitors (0603)
Murata GRM188R71H104K
TDK C1608X7R1H104K
220pF ±10%, 50V X7R ceramic
capacitor (0402)
Murata GRM155R71H221K
TDK C1005X7R1H221K
C1, C2
2
C8
1
C3, C4
2
C9
1
C5
1
C10, C14
2
C6
1
C11, C15, C16,
C17
4
C7
1
C12
1
________________________________________________________________
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.
MAX17075 Evaluation Kit
Evaluates: MAX17075
Component List (continued)
DESIGNATION
QTY
DESCRIPTION
0.01µF ±10%, 10V X5R ceramic
capacitor (0402)
Murata GRM155R61A103K
TDK C1005X5R1A103K
1500pF ±10%, 50V X7R ceramic
capacitor (0603)
Murata GRM188R71H152K
TDK C1608X7R1H152K
Not installed, capacitor (1206)
Not installed, capacitor (0402)
0.22µF ±10%, 25V X7R ceramic
capacitor (0603)
Murata GRM188R71E224K
TDK C1608X7R1E224K
3A, 30V Schottky diode (M-Flat)
Toshiba CMS02
(Top Mark: S2)
220mA, 100V dual diodes (SOT23)
Fairchild MMBD4148SE
(Top Mark: D4)
3-pin header
2-pin headers
3µH, 3A
DC
inductor
Sumida CDRH6D28-3R0
Not installed, transistor (SOT223)
Recommended: 20V, 1A npn
transistor (SOT223)
Fairchild BCP68
DESIGNATION
QTY
DESCRIPTION
Not installed, transistor (SOT223)
Recommended: -20V, -1.5A pnp
transistor (SOT223)
Fairchild BCP69
10Ω ±5% resistor (0603)
Not installed, 100Ω ±5% resistor
(0603) recommended
100kΩ ±1% resistors (0603)
13.7kΩ ±1% resistor (0603)
187kΩ ±1% resistor (0603)
20kΩ ±1% resistors (0603)
82kΩ ±5% resistor (0603)
8.45kΩ ±1% resistor (0603)
10kΩ ±1% resistor (0603)
10kΩ ±5% resistor (0603)
1kΩ ±5% resistor (0603)
464kΩ ±1% resistor (0603)
10kΩ SMT cermet trimmer, 9 to 15
turns
Boost regulator (24 TQFN)
Maxim MAX17075ETG+
Shunts
PCB: MAX17075 Evaluation Kit+
C13
1
Q2
0
R1
R2
R3, R4, R5, R7
R6
R8
R9, R16
R10
R11
R12
R13
R14
R15
R17
U1
—
—
1
0
4
1
1
2
1
1
1
1
1
1
1
1
3
1
C18
1
C19
C20
0
0
C21
1
D1
1
D2, D3, D4
JU1
JU2, JU3
L1
3
1
2
1
Q1
0
Component Suppliers
SUPPLIER
Fairchild Semiconductor
Murata Electronics North America, Inc.
Sumida Corp.
TDK Corp.
Toshiba America Electronic Components, Inc.
PHONE
888-522-5372
770-436-1300
847-545-6700
847-803-6100
949-623-2900
WEBSITE
www.fairchildsemi.com
www.murata-northamerica.com
www.sumida.com
www.component.tdk.com
www.toshiba.com/taec
Note:
Indicate that you are using the MAX17075 when contacting these component suppliers.
Quick Start
Required Equipment
Before beginning, the following equipment is needed:
• +4.5V to +5.5V, 5A DC power supply
• One voltmeter
2
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).
_______________________________________________________________________________________
MAX17075 Evaluation Kit
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.
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.
Evaluates: MAX17075
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).
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
1-2*
2-3**
None
VCOM
Buffered
Unbuffered
Not connected
*Install
appropriate transistors Q1, Q2, and resistor R2 to buffer
the VCOM output. See the
Component List.
**Default
position.
_______________________________________________________________________________________
3
MAX17075 Evaluation Kit
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.
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.
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,
Table 2. JU2 Jumper Selection (CTL)
SHUNT POSITION
Installed
Not installed*
CTL PIN CONNECTED TO
VIN
GND through resistor R5
External logic controller
through the CTL pad
HIGH-VOLTAGE SWITCH CONFIGURATION
COM pin connected to SRC pin
COM pin disconnected from DRN pin
COM pin connected to DRN pin
COM pin disconnected from SRC pin
CTL driven by external logic controller
CTL high: COM pin connected to SRC pin
CTL low: COM pin connected to DRN pin
None
*Default
position.
Table 3. JU3 Jumper Selection (C18)
SHUNT POSITION
Installed
Not installed*
VGON
Connected to C18
Not connected to C18
Dummy load testing
Normal operation, no load
OPERATION
*Default
position.
4
_______________________________________________________________________________________
MAX17075 Evaluation Kit
Evaluates: MAX17075
Figure 1. MAX17075 EV Kit Schematic
_______________________________________________________________________________________
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