19-2683; Rev 1; 2/03
MAX1997 Evaluation Kit
General Description
The MAX1997 evaluation kit (EV kit) is a fully assembled
and tested surface-mount circuit board that provides
voltages and features required for active-matrix thin-film
transistor (TFT) liquid-crystal displays. The EV kit con-
tains a step-up switching regulator, a positive three-
stage charge pump and linear regulator for the TFT
gate-on supply, a negative three-stage charge pump
and linear regulator for the TFT gate-off supply, a
gamma reference, a low-voltage logic supply, and a
high-current backplane buffer. The gate-on supply,
gate-off supply, and gamma reference supply can be
sequenced in any power-up order.
The EV kit operates from a DC supply voltage of +2.7V
to +5.5V. The step-up switching regulator is configured
for a +9V output providing up to 250mA. The positive
charge pump and regulator are configured for a +20V
output using two charge-pump stages providing up to
10mA. The negative charge pump and regulator are
configured for a -7V output using a single charge-pump
stage providing up to 10mA. The gamma reference is
configured for +8.6V providing up to 10mA. The low-
voltage logic linear-regulator is configured for +2.5V,
providing up to 200mA. The backplane buffer is config-
ured for +4.3V and can source or sink current peaks
more than 300mA.
The MAX1997 EV kit demonstrates low-quiescent cur-
rent and high efficiency (85%) for maximum battery life.
The EV kit features overload protection for the input and
all outputs. Operation at 1.5MHz allows the use of tiny
surface-mount components. The MAX1997 QFN pack-
age (0.8mm max) with low-profile external components
allows this circuit to be less than 1.25mm high.
o
+2.7V to +5.5V Input Range
o
Output Voltages
+9V Output at 250mA
Step-Up Switching Regulator)
+20V Output at 10mA (Positive Charge Pump
and Linear Regulator)
-7V Output at 10mA (Negative Charge Pump
and Linear Regulator)
+8.6V Output at 30mA (Gamma Reference
Regulator)
+2.5V Output at 200mA from 2.7V to 3.6V Input
(Low-Voltage Logic Supply)
+4.3V Output (鹵300mA Peak Backplane Buffer
Output)
o
Up to Three Positive and Three Negative Charge-
Pump Stages
o
More than -20V Linear-Regulated Output (Resistor
Adjustable)
o
More than +30V Linear-Regulated Output (with
Additional Circuitry)
o
Greater than 85% Efficiency (Step-Up Switching
Regulator)
o
375kHz/750kHz/1.5MHz Selectable Step-Up
Switching Frequency (Configured for 1.5MHz)
o
Programmable Power-Up Sequencing and Soft-
Start for All Outputs
o
Multilevel Protection
Output Undervoltage Protection
Input Overcurrent Protection
Input Switch Disconnects Step-Up Output from
Input Source
Selectable Fault-Delay Period
o
Low-Profile Surface-Mount Components
o
Fully Assembled and Tested
Features
Evaluates: MAX1997
Ordering Information
PART
MAX1997EVKIT
TEMP RANGE
0擄C to +70擄C
IC PACKAGE
32 QFN 5mm
脳
5mm
________________________________________________________________
Maxim Integrated Products
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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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