概觀
The IS32LT3125/3125A is a linear programmable
current regulator consisting of a single output channel
capable of 250mA. It features an EN pin to enable and
disable the output channel’s current source. It supports
PWM dimming via EN pin or power supply modulation
(PSM). The UV pin can be used to set external VCC
undervoltage lockout threshold via a resistor divider.
An external resistor programs the current level for the
channel current source. In addition,
IS32LT3125/3125A integrates fault protection for LED
open/short, ISET pin open/short and over temperature
condition for robust operation. Detection of these
failures is reported by the FAULTB pin. When a fault is
detected the device will disable itself and output an
open drain low signal. Multiple devices can have their
FAULTB pins connected to create a “one-fail-all-fail”
condition. Under a fault condition, the IS32LT3125 will
sink 30mA ICC current, while the IS32LT3125A will sink
a lower 2mA (Max.) ICC.
The IS32LT3125/3125A is targeted at the automotive
market with end applications to include interior and
exterior lighting. For 12V automotive applications the
low dropout driver can support one to several LEDs on
the output channel.
Both devices are offered in a small thermally enhanced
SOP-8-EP package.