IS32LT3175N-GRLA3-TR

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 programmable current regulator capable of up to 150mA. It integrates a debounce and latch circuit on the channel enable pin (EN) to facilitate the use of a low cost momentary contact switch. The PWM pin can be interfaced to a logic level “courtesy light” signal to directly drive the LED channel. The IS32LT3175P accepts a positive polarity PWM signal while the IS32LT3175N accepts a negative polarity PWM signal.   The device operates as a stand-alone LED driver configurable with external resistors; no microcontroller is required. A single external resistor programs the current level, while two separate resistors independently program the fade in and fade out ramp rate for the 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 EN pin is pulsed. The same controller causes the LED current to gradually ramp down to zero if the EN pin is pulsed while the output channel is ON. The fade ramp can be interrupted mid-cycle before completion of the ramp cycle. The EN pin will accept either a momentary contact switch or logic level signal pulsed low. The IS32LT3175 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 (VF = 3.2V) per channel. It is offered in a small thermally enhanced SOP-8-EP package.       Operating voltage 5V to 42V Single channel current source - Programmable current via a single external resistor - Configurable from 20mA to 150mA Momentary contact button EN input - Input is debounced and latched - Higher priority than PWM input - Gamma corrected Fade In/Out algorithm - Pull down resistors set independent fade IN and OUT ramp time PWM input pin driven by external PWM source - PWM directly drives the current source - IS32LT3175P – Positive polarity - IS32LT3175N – Negative polarity Fault Protection: - OUT pin shorted to GND - ISET pin shorted to GND - Over temperature SOP-8-EP package Automotive Grade: - IS32LT3175P – AEC-Q100 - IS32LT3175N – AEC-Q100 Operating temperature range from -40°C ~ +125°C APPLICATIONS  Automotive Interior: - Map/Dome light - Puddle lamp in doors - Glove box - Vanity mirror TYPICAL APPLICATION CIRCUIT Figure 1 Typical Application Circuit Note: The resistor RPWM is a fixed value. Please don’t change it. CPWM is optional. Add it for robust electromagnetic susceptibility. Lumissil Microsystems – www.lumissil.com Rev.A, 07/19/2016 1 IS32LT3175N/P PIN CONFIGURATION Package Pin Configuration (Top view) SOP-8-EP PIN DESCRIPTION No. Pin Description 1 EN Internally debounced input pin for control of LED current. A negative going pulse on this pin will toggle the state of the OUT current. The pin condition is constantly monitored after the debounce time period. 2 ISET Output current setting for channel. Connect a resistor between this pin and GND to set the maximum output current. 3 TSET_UP Timing control for the Fade In feature. Connect a resistor 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. 4 TSET_DN Timing control for the Fade Out feature. Connect a resistor between this pin and GND to set the Fade Out time. Connect 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. 7 VCC Power supply input pin. A capacitor on this pin will help maintain EN latch status during low voltage conditions. PWM PWM (or BCM) signal via a 10kΩ to drive OUT pin. Pin condition is ignored if EN pin has latched and activated OUT pin. IS32LT3175P positive polarity, IS32LT3175N negative polarity. Thermal Pad Connect to GND. 8 Lumissil Microsystems – www.lumissil.com Rev.A, 07/19/2016 2 IS32LT3175N/P ORDERING INFORMATION Automotive Range: -40°C to +125°C Order Part No. Package QTY/Reel IS32LT3175P-GRLA3-TR IS32LT3175N-GRLA3-TR SOP-8-EP, Lead-free 2500 Copyright  ©  2016  Lumissil  Microsystems.  All  rights  reserved.  Lumissil Microsystems reserves  the  right  to  make  changes  to  this  specification  and  its  products  at  any  time  without  notice.  Lumissil  Microsystems  assumes  no  liability  arising  out  of  the  application  or  use  of  any  information,  products  or  services described herein. Customers are advised to obtain the latest version of this device specification before relying on any published information and  before placing orders for products.  Lumissil Microsystems does not recommend the use of any of its products in life support applications where the failure or malfunction of the product can  reasonably be expected to cause failure of the life support system or to significantly affect its safety or effectiveness. Products are not authorized for use in  such applications unless Lumissil Microsystems receives written assurance to its satisfaction, that:  a.) the risk of injury or damage has been minimized;  b.) the user assume all such risks; and  c.) potential liability of Lumissil Microsystems is adequately protected under the circumstances Lumissil Microsystems – www.lumissil.com Rev.A, 07/19/2016 3 IS32LT3175N/P ABSOLUTE MAXIMUM RATINGS VCC, OUT, PWM EN, ISET, TSET_UP, TSET_DN Ambient operating temperature, TA=TJ Maximum continuous junction temperature, TJ(MAX) Storage temperature range, TSTG Maximum power dissipation, PDMAX ESD (HBM) ESD (CDM) -0.3V ~ +45V -0.3V ~ +7.0V -40°C ~ +125°C 150°C -55°C ~ +150°C 1.96W ±2kV ±750V Note: Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only and functional operation of the device at these or any other condition beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. THERMAL CHARACTERISTICS Characteristic Test Conditions Value Package Thermal Resistance (Junction to Ambient), θJA On 4-layer PCB based on JEDEC standard at 1W, TA=25°C 50.98°C/W Package Thermal Resistance (Junction to Pad), θJP 2.24°C/W ELECTRICAL CHARACTERISTICS TJ = -40°C ~ +125°C, VCC=12V, refer to each condition description. Typical values are at TJ = 25°C. Symbol Parameter VCC Supply voltage range VDO Minimum dropout voltage Condition tON Quiescent supply current Startup time IOUT_LIM Output limit current IOUT EOUT Output current (Note 3) Absolute current accuracy (Note 3) Typ. 5 Max. Unit 42 V VCC –VOUT, IOUT= -150mA (Note 1) 900 mV VCC –VOUT, IOUT= -100mA (Note 2) 700 mV 1 mA PWM pin floating. EN disables the output. ICC Min. 0.1 RISET=15kΩ, EN enable the output, PWM floating, OUT floating 2.3 3.8 mA VCC=4.2V, EN enable the output. VPWM=4V for IS32LT3175P and VPWM=GND for IS32LT3175N. 0.25 0.6 mA 400 μs VCC> 6V to IOUT