Linear Technology LT3473EDD Quick Start Manual

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QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 883
DESCRIPTION
LI-ION TO 25V STEP-UP DC-DC CONVERTER
LT3473EDD
Demonstration circuit DC883 features the LT®3473 micropower step-up DC/DC converters with inte­grated Schottky diode and output disconnect cir­cuitry. The output on DC883 is 25V at up to 80mA from a 3~4.2V input, while automatic Burst Mode op­eration maintains efficiency at light load. The lithium ion battery input voltage range, high output voltage, internal NPN power switch, minimal external compo­nents and simple design make the LT3473 an excel­lent solution for OLED and CCD Bias.
The DC883 has a jumper for enabling the output (JP2). Placing the jumper to “OFF”, disables the DC-
Table 1. Performance Summary ( TA = 25
PARAMETER CONDITION VALUE
Minimum Input Voltage 3V
Maximum Input Voltage 4.2V
Maximum Output Current Vin = 3 − 4.2V 80mA
Typical Switching Frequency 1.2MHz
°°°°
C )
DC converter and jumper to “ON”, enables the DC-DC converter. There is a jumper (JP1) and a control pin (CTRL) for varying the output voltage. Placing the jumper to “VIN” provides 25V output. Placing the jumper to “CTRL” and changing the voltage at CTRL pin can change the output voltage. The voltage of the PGOOD pin is approximately 0V as the output voltage reaches 90% of final value.
Design files for this circuit board are available. Call the LTC factory.
LT is a registered trademark of Linear Technology Corporation
QUICK START PROCEDURE
Demonstration circuit 883 is easy to set up to evalu­ate the performance of the LT3473. Refer to Figure 1. for proper measurement equipment setup and follow the procedure below:
1. Set the input supply between 3V to 4.2V.
With power off, connect the input power sup­ply to VIN and GND. Make sure JP2 is set to “ON” and JP1 is set to “VIN”.
2. Turn on the power at the input.
3. The output voltage should measure about 25V
across the “VOUT” terminal to “GND” terminal and the voltage across the PGOOD pin and “GND” terminal should measure about 0V.
4. Test the shutdown function by placing JP2 to
“OFF”. Observe the output voltage is about
0.7V lower than the input voltage.
5. The output voltage can be controlled by DC
voltage at the CTRL terminal. With JP2 placed at “ON” and JP1 placed at “CTRL”, observe the output voltage change with DC voltage applied to the CTRL terminal. The DC voltage range recommended is 200mV ~ 1.5V. The maximum DC voltage is 10V. Refer to the datasheet for further details.
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QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 883
LI-ION TO 25V STEP-UP DC-DC CONVERTER
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Figure 1. Proper Measurement Equipment Setup
Figure 2. Scope Probe Placement for Measuring Input or Output Ripple
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QUICK START GUIDE FOR DEMONSTRATION CIRCUIT 883
LI-ION TO 25V STEP-UP DC-DC CONVERTER
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Mouser Electronics
Authorized Distributor
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Analog Devices Inc.: DC883A
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