LMZ34002EVM-001 Datasheet, PDF (1/13 Pages) Texas Instruments – Negative Output Voltage Simple Switcher® Power Module Evaluation Module

SNVU297 – JULY 2013
Using the LMZ34002: Negative Output Voltage
Simple Switcher® Power Module Evaluation Module
1 Introduction
The LMZ34002EVM-001 Evaluation Module is designed as an easy-to-use platform that facilitates an
extensive evaluation of the features and performance of the Simple Switcher® power module. This guide
provides information on the correct usage of the EVM and an explanation of the numerous test points on
the board.
2 Description
The EVM features a LMZ34002 device configured for operation from a 4.5 V to 40 V input supply. The
LMZ34002 is a non-synchronous, buck-boost (negative output) converter optimized for output voltages
between -3 V and -17 V. The LMZ34002 operates at a fixed frequency of typically 800 kHz. The output
voltage can be set to one of four popular values by using a simple configuration jumper. The EVM can
supply up to 2 A of output current depending on the input and output voltage (See Figure 1). A minimal
amount of input and output capacitance is used on the board. Component pads are provided for additional
input and output capacitors if desired. Test points are provided that allow measurement of efficiency,
power dissipation, input ripple, output ripple, line and load regulation, soft-start behavior, transient
response, and UVLO behavior. The EVM uses a recommended PCB layout that maximizes thermal
performance and minimizes output ripple and noise.
3 Getting Started
The host power supply is connected to the EVM at terminal block TB1. The VIN and GND terminals are
clearly marked. The terminal block can accept up to number 16 AWG wire. For a complete evaluation, the
host supply should be adjustable up to 40 V and be capable of delivering at least 3 A of current. The
output of the EVM is presented to terminal block TB2. An electronic or resistive load can be connected to
the block.
Input and output voltage test points are provided near the terminal blocks. These test points are intended
to be used as voltage monitoring points where voltmeters can be connected to measure V_IN and V_OUT. Do
not use these test points as the input supply or output load connection points. The PCB traces connecting
to the test points are not designed to support high currents.
Before applying power, make certain that the V_OUT SELECT (J3) jumper is present and properly positioned
for the intended output voltage. Always remove power before changing the jumper settings.
Once the jumper setting has been confirmed, set the host input supply to a voltage level between 4.5 V to
40 V, making sure that the sum of V_IN + |V_OUT| does not exceed 50 V. See Table 1 for the maximum input
voltages for the four preset V_OUT settings. Turn the host supply ON and then confirm that the selected
output voltage is obtained.
Table 1. Output Voltage Settings and Maximum V_IN
V_OUT SELECT , J3 (V)
-3.3
-5
-12
-15
MAXIMUM V_IN (V)
40
40
38
35
SNVU297 – JULY 2013
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Using the LMZ34002: Negative Output Voltage Simple Switcher® Power
1
Module Evaluation Module
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