Overview
The IS32LT3174 is a linear programmable current
regulator consisting of one output channel capable of
up to 200mA. It features an ON/OFF input pin to toggle
the channel between the OFF condition and the source
condition.
A single external resistor programs the current level for
the channel, while a separate, single resistor programs
the fade in and fade out rate for channel.
The device integrates a 63 steps fade in and fade out
algorithm (Gamma correction) which causes the output
LED current to gradually ramp up to the full source
value after the channel’s control pin is pulsed. The
same controller causes the LED current to gradually
ramp down to zero if the channel’s input control pin is
pulsed while the output channel is on. The LED current
output can be controlled by a momentary contact
switch or logic level signal.
The IS32LT3174 is targeted at the automotive market
with end applications to include map and dome lighting
as well as exterior accent lighting. For 12V automotive
applications the low dropout driver can support 1 to 3
LEDs per channel. It is offered in a small thermally
enhanced SOP-8-EP package.