EV2104DJ-00A Datasheet, PDF (4/4 Pages) Monolithic Power Systems – 600mA Synchronous Buck Step-Down Converter

EV2104DJ-00A – 600mA SYNCHRONOUS BUCK STEP-DOWN CONVERTER
INITIAL RELEASE
QUICK START GUIDE (ADJUSTABLE OUTPUT)
The default output voltage of this board is set to 1.8V.
The board layout accommodates most commonly used inductors and output capacitors.
1. Attach the positive and negative ends of the load to the VOUT and GND pins, respectively.
2. Attach the Input Voltage (2.5V ≤ V_IN ≤ 6V) and Input Ground to the VIN and GND pins,
respectively.
3. To enable the MP2104 apply a voltage, 1.5V ≤ V_EN ≤ 6V, to the EN pin. To disable the MP2104
apply a voltage, V_EN < 0.3V, to the EN pin. The default setting for the jumper J1 on the board
connects V_IN to the EN pin. In this configuration, the part will operate without applying any
external voltage to the EN pin.
4. The Output Voltage V_OUT can be changed by varying R2. Calculate the new value by formula:
R2 = ^R1
⎜⎜⎝⎛
V_OUT
V_FB
⎟⎟⎠⎞
−1
Where V_FB = 0.6V and R1 = 300kΩ.
Example:
For V_OUT = 2.5V:
R2 = ^300kΩ = 150kΩ
⎜⎛ ^2.5V ⎟⎞ − 1
⎝ ^0.6V ⎠
Therefore, use a 150kΩ standard 1% value.
QUICK START GUIDE (MODIFICATION FOR FIXED OUTPUT)
For modifying the EV2104DJ-00A to accommodate a fixed output voltage version of the MP2104:
1. Verify that a fixed output version of the MP2104 chip is on the evaluation board. Refer to
MP2104 datasheet for fixed voltage package codes.
2. Remove both R1 and R2.
3. Short R1 while leaving R2 open.
4. Attach the positive and negative ends of the load to the VOUT and GND pins, respectively.
5. Attach the Input Voltage (2.5V ≤ V_IN ≤ 6V) and Input Ground to the VIN and GND pins,
respectively.
6. To enable the MP2104 apply a voltage, 1.5V ≤ V_EN ≤ 6V, to the EN pin. To disable the MP2104
apply a voltage, V_EN < 0.3V, to the EN pin. The default setting for the jumper J1 on the board
connects V_IN to the EN pin. In this configuration, the part will operate without applying any
external voltage to the EN pin.
NOTICE: The information in this document is subject to change without notice. Please contact MPS for current specifications.
Users should warrant and guarantee that third party Intellectual Property rights are not infringed upon when integrating MPS
products into any application. MPS will not assume any legal responsibility for any said applications.
Ev2104DJ-00A Rev. 1.1
www.MonolithicPower.com
4
8/24/2005
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