Texas Instruments Simple LED Driver for MR16 and AR111 Applications Evaluation Module TPS92560MR16BSTEVM TPS92560MR16BSTEVM Datenbogen
Produktcode
TPS92560MR16BSTEVM
I
LED
I
IN
V
IN
P
OUT
Efficiency
P
IN
=
x 100%
V
OUT
x I
OUT
P
OUT
=
V
IN
x I
IN
P
IN
=
Test Requirements and Setup
•
Connect an LED string of 6 six serial LEDs to the terminals LED+ and LED– of the EVM. An external
ammeter (Ammeter 2) can be used in series to the LED string as shown in
ammeter (Ammeter 2) can be used in series to the LED string as shown in
to measure the
RMS LED current.
•
Connect the power source (a 12-V
DC
power source, 12-V
AC
power source or electronic transformer) to
the terminals AC1 and AC2 of the EVM. An external ammeter (Ammeter 1) can be used in series to
the power source as shown in
the power source as shown in
to measure the RMS input current. Do not make the connection
when the power source is turned on.
•
A voltmeter (Voltmeter 2) can be connected across the LED+ and LED– terminals of the EVM to
measure the RMS forward voltage of the LED string.
measure the RMS forward voltage of the LED string.
•
A voltmeter (Voltmeter 1) can be connected across the AC1 and AC2 terminals of the EVM to measure
the RMS input voltage of the EVM.
the RMS input voltage of the EVM.
•
Using the measured RMS input current, input voltage, output current and output voltage, the input
power, output power and efficiency are calculated using the following equations:
power, output power and efficiency are calculated using the following equations:
(1)
(2)
(3)
6.3
Typical Waveforms
6 serial LEDs, T
A
= 25°C
I
LED
: 200 mA/DIV, I
IN
: 1 A/DIV, V
IN
: 20 V/DIV
Figure 5. Waveforms of Powering the TPS92560MR16BSTEVM with an Electronic Transformer
7
SLVU822 – December 2012
User's Guide for TPS92560MR16BSTEVM
Copyright © 2012, Texas Instruments Incorporated