Semiconductor Components Industries, LLC, 2011
September, 2011
−
Rev. 1
1
Publication Order Number:
EVBUM2022/D
CAT4101AGEVB
CAT4101 LED Driver
Evaluation Board
User's Manual
Introduction
This document describes the CAT4101AGEVB
evaluation board for the ON Semiconductor CAT4101 low
dropout current sink. The functionality and major
parameters of the CAT4101 can be evaluated with the
CAT4101AGEVB board.
The CAT4101 is a low dropout current sink capable of
driving strings of high-brightness LEDs up to 1 A. The
current sink is programmed by a single resistor from the
RSET pin to GND. Enable and dimming control is available
via the EN/PWM pin. Additional details and electrical
characteristics can be found in the CAT4101 data sheet.
Figure 1. CAT4101AGEVB Board
Board Hardware
The evaluation board contains one CAT4101 in a typical
application circuit. A six pin header receptacle is available
to connect strings of LED modules. If LED modules are not
available, a separate LED string can be used by connecting
the cathode end to the LED test point.
The VIN test point is connected to the VIN supply of the
CAT4101. The voltage between test points VIN and GND
should not exceed 6.0 V.
The EN/PWM test point is the enable and PWM input for
the CAT4101. The control signal should be connected
between test points EN/PWM and GND.
Trimmer potentiometer R2 can be adjusted to change the
LED current. The RSET pin of the CAT4101 is a fixed 1.2 V
reference and the LED current is set by changing the current
through the RSET resistor (R1 + R2).
The CAT4101 has a typical dropout voltage of 500 mV for
1 A LED current. To measure the dropout there are kelvin
connections at test points KL and KG. These connections
allow for accurate measurement of the LED pin voltage. At
high current, there could be a significant voltage drop across
board traces. These test points should be used for
measurement purposes only as they are not meant to carry
any current.
http://onsemi.com
EVAL BOARD USER’S MANUAL
www.BDTIC.com/ON/
