Texas Instruments LM3402HV Evaluation Board LM3402HVEVAL/NOPB LM3402HVEVAL/NOPB 用户手册
产品代码
LM3402HVEVAL/NOPB
C535676
Connector
P6
P1
Anode of
First LED
Cathode of
Last LED
User's Guide
SNVA175C – September 2006 – Revised April 2013
AN-1500 LM3402/02HV Demo Board
1
Introduction
The LM3402/LM3402HV is a buck regulator derived controlled current source designed to drive a series
string of high power, high brightness LEDs (HBLEDs) such as the Luxeon™ I Emitter at forward currents
of up to 500 mA. The board can accept an input voltage ranging from 6V to 42V when using the LM3402.
When using the pin-for-pin compatible LM3402HV the upper bound of input voltage is 75V. The converter
output voltage adjusts as needed to maintain a constant current through the LED array. The
LM3402/02HV is a true step-down regulator with an output voltage range extending from a V
string of high power, high brightness LEDs (HBLEDs) such as the Luxeon™ I Emitter at forward currents
of up to 500 mA. The board can accept an input voltage ranging from 6V to 42V when using the LM3402.
When using the pin-for-pin compatible LM3402HV the upper bound of input voltage is 75V. The converter
output voltage adjusts as needed to maintain a constant current through the LED array. The
LM3402/02HV is a true step-down regulator with an output voltage range extending from a V
O(MIN)
of 200
mV (the reference voltage) to a V
O(MAX)
determined by the minimum off time (typically 300 ns). It can
maintain regulated current through any number of LEDs as long as the combined forward voltage of the
array does not exceed V
array does not exceed V
O(MAX).
.
2
Circuit Performance LM3402
The LM3402 circuit and BOM have been designed to provide a constant forward current of 350 mA to a
single LED with a forward voltage of approximately 3.5V. (Typical of white, blue, and green LEDs using
InGaN technology.) When powered from a 24V ±5% input the demo board will maintain the average LED
current, I
single LED with a forward voltage of approximately 3.5V. (Typical of white, blue, and green LEDs using
InGaN technology.) When powered from a 24V ±5% input the demo board will maintain the average LED
current, I
F
, to within 10% of 350 mA. The ripple current,
Δ
i
F
, will not exceed 70 mA peak-to-peak.
Switching frequency for the demo board is 600 kHz ± 10% over the input voltage range of 6V to 42V.
3
Circuit Performance LM3402HV
The LM3402HV circuit and BOM have been designed to provide a constant forward current of 350 mA to
a single LED with a forward voltage of approximately 3.5V. When powered from a 48V ± 5% input the
demo board will maintain I
a single LED with a forward voltage of approximately 3.5V. When powered from a 48V ± 5% input the
demo board will maintain I
F
to within ±5% of 350 mA. Ripple current will not exceed 70 mA peak-to-peak.
Switching frequency for the demo board is 250 kHz ±10% over the input voltage range of 6V to 75V.
4
Connecting to LED Array
The LM3402/02HV demo board includes a female 6-pin SIP, J1, connector as well as two standard 94mil
turret connectors for the cathode and anode connections of the LED array.
turret connectors for the cathode and anode connections of the LED array.
shows the pinout of
J1. Solid, 18 or 20 gauge wire with about 1 cm of insulation stripped away makes a convenient, solderless
connection to J1.
connection to J1.
Figure 1. Connecting to LED Array
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1
SNVA175C – September 2006 – Revised April 2013
AN-1500 LM3402/02HV Demo Board
Copyright © 2006–2013, Texas Instruments Incorporated