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 鹵150mA peak. The high-
voltage switch can be used to delay the startup of the
positive charge pump鈥檚 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.
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 鹵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
Features
Evaluates: MAX1542/MAX1543
Ordering Information
PART
MAX1543EVKIT
TEMP RANGE
0擄C to +70擄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
10碌F 鹵10%, 6.3V X5R ceramic
capacitor (1206)
TDK C3216X5R0J106K-0.85
4.7碌F 鹵10%, 10V X5R ceramic
capacitors (1210)
TDK C3225X5R1A475K-1.15
220pF 鹵10%, 50V X7R ceramic
capacitor (0603)
TDK C1608X7R1H221K
0.033碌F 鹵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
鈥?+2.6V to +5.5V, 2A DC power supply
鈥?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鈥檚 website at www.maxim-ic.com.
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