Microchip Technology SOT23-5, Руководство пользователя

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SOT23-5 Voltage Regulator Evaluation Board User’s Guide
DS51811A-page 10
©
2009 Microchip Technology Inc.
2.3 GETTING STARTED
The SOT23-5 Voltage Regulator Evaluation Board is fully assembled and tested. All
that is required for operating is a user supplied voltage regulator and a supply voltage
source. Some of the tests that may be completed using the SOT23-5 Voltage Regulator
Evaluation Board shall now be described.
2.3.1 Ground Current and Quiescent Current
When measuring ground current, jumper JP3 should be removed, otherwise leave
jumper JP3 on. To measure ground current, perform the following steps:
1. Add desired load resistor to R5.
2. Remove jumpers JP3 and JP4.
3. Connect an ammeter across testpoints TP6(+) and TP7(-). Select the
appropriate meter scale for the evaluated device.
4. Connect a voltmeter across testpoints TP9(+) and TP10(-).
5. Add jumper JP1.
6. Add jumper JP2 to pins 1 and 2.
7. Apply source voltage to testpoints TP1(+) and TP2(-).
8. Verify the voltage across testpoints TP9 and TP10 is within the expected range
of the device being tested.
9. Read the Ground Current directly from the ammeter connected to testpoints TP6
and TP7.
10. Vary the input voltage to obtain data for ground current versus input voltage.
With no load attached to the output of the voltage regulator, the measured ground
current is also called the quiescent current of the regulator.
11. Add the load selection jumper, JP4.
12. Read the Ground Current directly from the ampere meter connected to testpoints
TP6 and TP7.
13. The data collected will be the ground current versus load current.
2.3.2 Adjustable Output Voltage (ADJ)
The output voltage of some adjustable voltage regulators may be adjusted by selecting
appropriate resistor divider values connected to the Adjust (ADJ) pin. R2 and R3 pads
are available to be used as the voltage divider.
2.3.3 Shutdown input selection (SHDN)
The Shutdown (SHDN) input selection may be set to V
IN
, GND, or a user supplied
voltage using testpoint TP5. To select V
IN
as the SHDN voltage, place a jumper across
pins JP2-1 and JP2-2. To select GND as the SHDN voltage, place a jumper across pins
JP-2 and JP-3. To select a user specified input such as a function generator, remove
the jumper from JP2 and connect the external voltage source positive lead (+) to
testpoint TP5 and the negative lead (-) to testpoint TP4.