19-1406; Rev 1; 1/99
MAX1729 Evaluation Kit
General Description
The MAX1729 evaluation kit (EV kit) is a low-power,
step-up DC-DC converter followed by a low-dropout lin-
ear regulator. It accepts a positive input voltage
between 2.7V to 5.5V and converts it to an output volt-
age ranging from 2.5V to 16V. The output voltage is
dynamically adjustable through an external 3kHz to
12kHz pulse-width-modulated (PWM) control signal. An
on-chip temperature sensor provides compensation for
display temperature characteristics. This makes the
MAX1729 ideally suited for electrically controlled bire-
fringence (ECB) and LCD bias-supply generation
Features
o
High-Accuracy Reference Voltage (鹵1%)
o
On-Chip Temperature-Sensor Output
o
2.7V to 5.5V Input Range
o
Dynamic Control of Output Voltage
o
0.4碌A(chǔ) Typical Shutdown Current
o
10-Pin 碌MAX Package
o
Surface-Mount Construction
o
Fully Assembled and Tested
Evaluates: MAX1729
Component List
DESIGNATION QTY
C1, C6
C2
C3
C4, C7
C5
JU1
L1
R1鈥揜5
U1
2
0
1
2
1
1
1
0
1
DESCRIPTION
0.1碌F ceramic capacitors
Not installed
0.068碌F ceramic capacitor
1碌F ceramic capacitors
Taiyo Yuden TMK316BJ105KL
1000pF ceramic capacitor
3-pin jumper
220碌H inductor
Murata LQH3C221K34
Not installed
MAX1729EUB
PART
MAX1729EVKIT
Ordering Information
TEMP. RANGE
0擄C to +70擄C
IC PACKAGE
10碌MAX
Quick Start
The MAX1729 EV kit is a fully assembled and tested
surface-mount board. Follow the steps below to verify
board operation.
Do not turn on the power supply
until all connections are completed.
1) Connect a 2.7V to 5.5V supply to the pads marked
VIN and GND.
2) Connect a voltmeter and load, if any, to the VOUT
pad.
3) Place the shunt on JU1 across pins 2 and 3.
4) Turn on the power and verify that the output voltage
is approximately 16.35V.
Component Suppliers
SUPPLIER
Murata
Taiyo Yuden
PHONE
814-237-1431
408-573-4150
FAX
814-238-0490
408-573-4159
5) For other output voltages, refer to the
Output
Voltage Control
section.
Detailed Description
Jumper Selection
Jumper JU1, in the 2-3 position, connects CTLIN to
VIN. This places the output voltage at maximum and is
equivalent to applying a PWM signal with a 100% duty
cycle.
In the 1-2 position, CTLIN is connected to GND. This
places the MAX1729 into shutdown mode and is equiv-
alent to applying a PWM signal with a 0% duty cycle.
When applying a PWM signal to the CTLIN pad, the
shunt must be removed from jumper JU1.
________________________________________________________________
Maxim Integrated Products
1
For free samples & the latest literature: http://www.maxim-ic.com, or phone 1-800-998-8800.
For small orders, phone 1-800-835-8769.
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