19-2881; Rev 0; 6/03
MAX1543 Evaluation Kit
General Description
The MAX1543 evaluation kit (EV kit) is a fully assembled
and tested surface-mount circuit board that provides
the voltages and features required for active-matrix,
thin-film transistor (TFT) liquid-crystal displays (LCDs).
The EV kit contains a step-up switching regulator, a
positive two-stage charge pump for the TFT gate-on
supply, and a negative single-stage charge pump for
the TFT gate-off supply. Also included are two opera-
tional amplifiers that can be used to drive the LCD
backplane (VCOM) or the gamma-correction divider
string, and a logic-controlled, high-voltage switch with
adjustable delay. The EV kit also evaluates the
MAX1542 after IC replacement.
The EV kit operates from a DC supply voltage of +2.6V
to +5.5V. The step-up switching regulator is configured
for a +8V output providing at least 250mA. The positive
charge pump is configured for a +22V output providing
at least 20mA. The negative charge pump is configured
for a -7V output providing at least 20mA. The two oper-
ational amplifiers are both configured for +4V, each
capable of providing up to ±150mA peak. The high-
voltage switch can be used to delay the startup of the
positive charge pump’s output. The delay time is set
with an external capacitor.
The MAX1543 EV kit demonstrates low quiescent cur-
rent and high efficiency (85%) for maximum battery life.
Operation at 1.2MHz allows the use of tiny surface-
mount components. The MAX1543 QFN package
(0.8mm maximum height) with low-profile external com-
ponents allows this circuit to be less than 1.25mm high.
Features
o
+2.6V to +5.5V Input Range
o
Output Voltages
+8V Output at 300mA (3V Input Step-Up
Switching Regulator)
+22V Output at 20mA (Positive Charge Pump)
-7V Output at 20mA (Negative Charge Pump)
+4V Output at ±150mA (Operational Amplifiers
VOUT1 and VOUT2)
o
Resistor-Adjustable Switching Regulator and
Op-Amp Output Voltages
o
Logic-Controlled, High-Voltage Switch with
Adjustable Delay
o
Greater than 85% Efficiency (Step-Up Switching
Regulator)
o
Selectable 600kHz/1.2MHz Step-Up Switching
Frequency
o
Low-Profile Surface-Mount Components
o
Also Evaluates the MAX1542 (IC Replacement
Required)
o
Fully Assembled and Tested
Evaluates: MAX1542/MAX1543
Ordering Information
PART
MAX1543EVKIT
TEMP RANGE
0°C to +70°C
IC PACKAGE
20 TQFN
(5mm x 5mm x 0.8mm)
Quick Start
Component List
DESIGNATION
C2, C7, C8, C9
C3
QTY
0
1
DESCRIPTION
Capacitors (0603), not installed
10µF ±10%, 6.3V X5R ceramic
capacitor (1206)
TDK C3216X5R0J106K-0.85
4.7µF ±10%, 10V X5R ceramic
capacitors (1210)
TDK C3225X5R1A475K-1.15
220pF ±10%, 50V X7R ceramic
capacitor (0603)
TDK C1608X7R1H221K
0.033µF ±10%, 25V X7R ceramic
capacitor (0603)
TDK C1608X7R1E333K
The MAX1543 EV kit is fully assembled and tested.
Follow these steps to verify board operation.
Do not
turn on the power supply until all connections are
completed.
Recommended Equipment
• +2.6V to +5.5V, 2A DC power supply
• Voltmeter
C4, C5
2
Procedure
1) Verify there is no shunt across jumper JU1.
2) Verify there is a shunt installed across jumper JU2.
3) Connect the positive terminal of the power supply to
the VIN pad. Connect the negative terminal of the
power supply to the GND pad.
4) Turn on the power supply and verify the step-up
switching regulator output (VMAIN) is +8V.
C6
1
C10
1
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
MAX1543 Evaluation Kit
Evaluates: MAX1542/MAX1543
Component List (continued)
DESIGNATION
C11–C16,
C18, C19
QTY
8
DESCRIPTION
0.1µF ±10%, 50V X7R ceramic
capacitors (0603)
TDK C1608X7R1H104K
100µF ±20%, 16V aluminum
electrolytic capacitor (6.3mm x 5mm)
Sanyo 16MV100UAX
1A, 30V Schottky diode (S-flat)
Toshiba CRS02
200mA, 100V dual ultra-fast diodes
(SOT23)
Fairchild MMBD4148SE
DESIGNATION
L1
R1
R2
R3–R6
R7, R9, R18
R13–R17, R19
U1
JU1, JU2
None
None
QTY
1
1
1
4
3
0
1
2
2
1
DESCRIPTION
4.7µH, 1.1A inductor
Sumida CLS5D11HP-4R7
169kΩ ±1% resistor (0805)
30.9kΩ ±1% resistor (0805)
100kΩ ±1% resistors (0805)
100kΩ ±5% resistors (0805)
Resistors (0805), not installed
MAX1543ETP (20-pin TQFN)
2-pin headers
Shunts (JU1, JU2)
MAX1543 PC board
C17
1
D1
1
D2, D3, D4
3
Component Suppliers
SUPPLIER
Fairchild
Sanyo
Sumida
TDK
Toshiba
PHONE
888-522-5372
619-661-6322
847-545-6700
847-803-6100
949-455-2000
FAX
N/A
619-661-1055
847-545-6720
847-390-4405
949-859-3963
WEBSITE
www.fairchildsemi.com
www.sanyovideo.com
www.sumida.com
www.component.tdk.com
www.toshiba.com/taec
Note:
Please indicate that you are using the MAX1543 when contacting these component suppliers.
5) Verify the gate-on supply (GON) is approximately
+22V.
6) Verify the gate-off supply (GOFF) is approximately
-7V.
7) Verify the operational amplifier output 1 (VOUT1) is
+4V.
8) Verify the operational amplifier output 2 (VOUT2) is
+4V.
9) Verify the high-voltage switch output (COM) is
+22V.
For instructions on selecting the step-up switching regula-
tor feedback and op-amp divider resistors for other out-
put voltages, see the
Output Voltage Selection
section.
Detailed Description
The MAX1543 EV kit contains a step-up switching regu-
lator, a positive two-stage charge pump, a negative sin-
gle-stage charge pump, two operational amplifiers, and
a high-voltage switch matrix. The EV kit operates from a
DC power supply between +2.6V and +5.5V that can
provide at least 2A. The switching frequency is jumper
2
selectable between 600kHz and 1.2MHz. The EV kit
also evaluates the MAX1542 after replacing IC U1.
As configured, the step-up switching regulator (VMAIN)
generates a +8V output and can provide at least
250mA from a +2.6V input. It also provides at least
300mA from a +3.0V input and 500mA from a +5V
input. The step-up switching-regulator output voltage
can be adjusted up to +13V with other feedback resis-
tors (see the
Output-Voltage Selection
section).
The GON supply consists of two positive charge-pump
stages to generate approximately +22V and can pro-
vide greater than 20mA. The GOFF supply consists of a
single negative charge-pump stage to generate
approximately -7V and can provide greater than 20mA.
The operational amplifier outputs, VOUT1 and VOUT2,
are set to +4V and can source or sink approximately
150mA. These two outputs can be reconfigured to
other voltages by changing the voltage-divider resistors
(see the
Output-Voltage Selection
section).
The high-voltage switch between the SRC and COM pins
can be used to delay the GON output startup. The GON
voltage is connected to the source of the switch (SRC),
_______________________________________________________________________________________
MAX1543 Evaluation Kit
and the drain of the switch (COM) is used as an output.
The startup delay time is set with an external capacitor at
the DEL pin. Refer to the
Delay Control Circuit
section in
the MAX1543 data sheet for information on setting the
delay time.
The switch between the SRC and COM pins and the
switch between the COM and DRN pins can be con-
trolled by jumper JU2 or by external logic connected to
the CTL pad. See Table 2 for switch states and refer to
the
Delay Control Circuit
section in the MAX1543 data
sheet for further information about the high-voltage
switches connected to the COM pin.
The MAX1543 EV kit also evaluates the MAX1542. To
evaluate the MAX1542, replace U1 with a MAX1542 IC
(refer to the MAX1542/MAX1543 data sheet for specifi-
cations of the MAX1542).
Inductor Selection
section in the MAX1542/MAX1543
data sheet).
Evaluates: MAX1542/MAX1543
High-Voltage Switch Control (CTL)
The MAX1543 EV kit features an option to control the
high-voltage switches between SRC, COM, and DRN
on the MAX1543 or the high-voltage switch between
SRC and COM on the MAX1542. Table 2 lists the selec-
table JU2 jumper options.
Output-Voltage Selection
Step-Up Switching-Regulator Output
Voltage (VMAIN)
The MAX1543 EV kit’s step-up switching-regulator out-
put (VMAIN) is set to +8V by feedback resistors R1 and
R2. To generate output voltages other than +8V (up to
+13V), select different external voltage-divider resis-
tors, R1 and R2. Note that changing the VMAIN voltage
setting also changes the GON and GOFF charge-pump
output voltages. Output capacitors C4 and C5 are
rated for +10V. To set the output voltage greater than
+10V, use higher voltage-rated capacitors. Refer to the
Main Step-Up Converter
and
Output Voltage
sections in
the MAX1542/MAX1543 data sheet for instructions on
selecting resistors R1 and R2.
Jumper Selection
Switching-Frequency Selection (FREQ)
The MAX1543 EV kit features an option to choose the
step-up regulator switching frequency. Jumper JU1
selects the switching frequency. Table 1 lists the selec-
table jumper options. The EV kit is configured for
1.2MHz operation. Optimum performance at lower fre-
quencies requires a larger inductor value (refer to the
Table 1. Jumper JU1 Functions
SHUNT
LOCATION
None
(default)
Installed
FREQ PIN
Connected to VIN
through R7
Connected to GND
MAX1543 EV KIT
FREQUENCY
1.2MHz
600kHz
Operational-Amplifier Output Voltages
(VOUT1 and VOUT2)
The MAX1543’s operational amplifiers are configured
as unity-gain buffers by the PC board traces shorting
R14 between NEG1 and OUT1 and R16 between NEG2
and OUT2. The voltages at the noninverting inputs
POS1 and POS2 are set to half of VMAIN by voltage-
divider resistors (R3, R4) and (R5, R6), respectively. To
set VOUT1 and VOUT2 to other voltages (up to
VMAIN), select different divider resistors.
Table 2. Jumper JU2 Functions
SHUNT LOCATION
Installed (default)
None
CTL PIN
Connected to VIN
Connected to PGND
through R18
Connected to
external logic
MAX1543 COM
COM connected to SRC (GON, +22V)
COM connected to DRN
Logic low, COM connected to DRN;
logic high, COM connected to SRC
(GON, +22V)
MAX1542 COM
COM connected to SRC (GON, +22V)
COM disconnected from SRC (GON, +22V)
Logic low, COM disconnected from SRC
(GON, +22V); logic high, COM connected
to SRC (GON, +22V)
None
_______________________________________________________________________________________
3
MAX1543 Evaluation Kit
Evaluates: MAX1542/MAX1543
GON
GOFF
-7V
C12
0.1µF
3
1
D2
C11
0.1µF
2
1
D3
3
C13
0.1µF
2
C14
0.1µF
VMID
3
1
D4
2
C15
0.1µF
GON
+22V
GND
GND
VIN
+2.5V TO +5.5V
C17
100µF
16V
C3
10µF
6.3V
L1
4.7µH
R7
100kΩ
14
JU1
15
FREQ
IN
D1
R1
169kΩ
1%
FB
16
R2
30.9kΩ
1%
SUP
12
C2
OPEN
C8
OPEN
R13
OPEN
NEG1
7
R14
SHORT
(PC TRACE)
VOUT1
+4V
TP1
R3
100kΩ
1%
R5
100kΩ
1%
C4
4.7µF
10V
C5
4.7µF
10V
VMAIN
+8V
GND
GND
13
LX
17
R9
100kΩ
C6
220pF
C7
OPEN
3
4
5
R19
SHORT
(PC TRACE)
COMP
U1
I.C.
PGND
AGND
MAX1543
GND
GON
C16
0.1µF
COM
2
SRC
OUT1
POS1
8
6
C18
0.1µF
1
COM
R15
OPEN
20
DRN
NEG2
10
R16
SHORT
(PC TRACE)
C9
OPEN
TP2
R4
100kΩ
1%
R6
100kΩ
1%
DRN
GND
VIN
CTL
19
R17
SHORT
(PC TRACE)
OUT2
POS2
DEL
18
9
11
VOUT2
+4V
CTL
JU2
C19
0.1µF
GND
R18
100kΩ
C10
0.033µF
Figure 1. MAX1543 EV Kit Schematic
4
_______________________________________________________________________________________
MAX1543 Evaluation Kit
Evaluates: MAX1542/MAX1543
Figure 2. MAX1543 EV Kit Component Placement Guide—
Component Side
Figure 3. MAX1543 EV Kit PC Board Layout—Component Side
Figure 4. MAX1543 EV Kit PC Board Layout—GND Layer 2
Figure 5. MAX1543 EV Kit PC Board Layout—VCC Layer 3
_______________________________________________________________________________________
5
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