IS32LT3175N-GRLA3-TR ISSI

IS32LT3175N/P SINGLE CHANNEL LINEAR LED DRIVER WITH FADE IN/OUT AND PWM DIMMING July 2016 GENERAL DESCRIPTION FEATURES The IS32LT3175 is a single channel linear Operating voltage 5V to 42V programmable current regulator capable of up to Single channel current source 150mA. It integrates a debounce and latch circuit on - Programmable current via a single external the channel enable pin (EN) to facilitate the use of a resistor low cost momentary contact switch. The PWM pin can - Configurable from 20mA to 150mA be interfaced to a logic level courtesy light signal to Momentary contact button EN input directly drive the LED channel. The IS32LT3175P - Input is debounced and latched accepts a positive polarity PWM signal while the - Higher priority than PWM input IS32LT3175N accepts a negative polarity PWM signal. - Gamma corrected Fade In/Out algorithm The device operates as a stand-alone LED driver - Pull down resistors set independent fade IN and configurable with external resistors no microcontroller OUT ramp time is required. A single external resistor programs the PWM input pin driven by external PWM source current level, while two separate resistors - PWM directly drives the current source independently program the fade in and fade out ramp - IS32LT3175P Positive polarity rate for the channel. - IS32LT3175N Negative polarity The device integrates a 63 steps fade in and fade out Fault Protection: algorithm (Gamma correction) which causes the output - OUT pin shorted to GND LED current to gradually ramp up to the full source - ISET pin shorted to GND value after the EN pin is pulsed. The same controller - Over temperature causes the LED current to gradually ramp down to zero if the EN pin is pulsed while the output channel is SOP-8-EP package ON. The fade ramp can be interrupted mid-cycle Automotive Grade: before completion of the ramp cycle. The EN pin will - IS32LT3175P AEC-Q100 accept either a momentary contact switch or logic level - IS32LT3175N AEC-Q100 signal pulsed low. Operating temperature range from -40C ~ +125C The IS32LT3175 is targeted at the automotive market APPLICATIONS with end applications to include map and dome lighting as well as exterior accent lighting. For 12V automotive Automotive Interior: applications the low dropout driver can support 1 to 3 - Map/Dome light LEDs (V = 3.2V) per channel. It is offered in a small F - Puddle lamp in doors thermally enhanced SOP-8-EP package. - Glove box - Vanity mirror TYPICAL APPLICATION CIRCUIT Figure 1 Typical Application Circuit Note: The resistor R is a fixed value. Please dont change it. C is optional. Add it for robust electromagnetic susceptibility. PWM PWM Lumissil Microsystems www.lumissil.com 1 Rev.A, 07/19/2016 IS32LT3175N/P PIN CONFIGURATION Package Pin Configuration (Top view) SOP-8-EP PIN DESCRIPTION No. Pin Description Internally debounced input pin for control of LED current. A negative going pulse on this pin will toggle the state of the OUT 1 EN current. The pin condition is constantly monitored after the debounce time period. Output current setting for channel. Connect a resistor between 2 ISET this pin and GND to set the maximum output current. Timing control for the Fade In feature. Connect a resistor 3 TSET UP between this pin and GND to set the Fade In time. Connect this pin directly to ground to disable the fade function for instant ON. Timing control for the Fade Out feature. Connect a resistor between this pin and GND to set the Fade Out time. Connect 4 TSET DN this pin directly to ground to disable the fade function for instant OFF. 5 GND Ground pin for the device. 6 OUT Output current source channel. Power supply input pin. A capacitor on this pin will help maintain 7 VCC EN latch status during low voltage conditions. PWM (or BCM) signal via a 10k to drive OUT pin. Pin condition is ignored if EN pin has latched and activated OUT 8 PWM pin. IS32LT3175P positive polarity, IS32LT3175N negative polarity. Thermal Pad Connect to GND. Lumissil Microsystems www.lumissil.com 2 Rev.A, 07/19/2016