Jun 1 2016
A single chip solution for automotive interior lighting has been launched by Integrated Silicon Solution (ISSI), a key provider of sophisticated memory and analog IC solutions.
Full Function LED Driver IC For Automotive Interior Lighting
The new chip solution, named IS32LT3175, is an AEC-Q100 (Automotive Electronics Council) certified linear LED driver. It allows reduced BOM count for compact and cost- effective designs, and features a built-in programmable fade-in/fade-out lighting control, a single channel LED driver equipped with a programmable 150mA current source, a courtesy signal input, and a push-button control. The IS32LT3175 device has been specifically developed for automotive lighting applications, such as in dome lights, LED-based map lights, and door lights.
Incorporating all functions, the IS32LT3175 chip eliminates the requirement for a microcontroller and a number of separate components. Only individual resistors are needed to tune the fade up/down ramp speed and the LED current from 10 to 150mA. Individual software programming is also not required, and a courtesy signal input or a momentary contact switch is all that is required to control the LED driver. The switch input is conditioned using a latch circuit and a built-in debounce. As a result, a single press of the mechanical switch does not look like many presses.
The Key features and benefits of IS32LT3175 are as follows:
- Linear LED Driver: Low-EMI, low-noise, linear current source that can be adjusted from 10 to ~150mA into a single or more LEDs.
- AEC-Q100: Fulfills stress testing specifications, and hence is perfect for using in adverse automotive environment with ensured operation from –40°C to +125°C.
- Reduced BOM: Theatrical dimming LED driver in a compact 8 pin SOP package leads to 65% less components needing less printed circuit board area.
- Local or Remote: Can be controlled locally with a momentary contact switch or remotely with the automobile's microcontroller. With priority over the remote microcontroller, the local switch allows users to directly control the LED lamp.
- Switch Input: Integration of switch debounce and latching logic allows use of cost-effective momentary contact switch. The On/Off state of the switch is held during start-stop operation when voltage dips below 6V for a short time.
- No Microcontroller: Using simple resistors, sophisticated LED performance can be tuned, thereby preventing the necessity for a microcontroller.
According to market reports, the Automotive Lighting market is pegged to grow at a CAGR of 7.22% between 2016 and 2021 and will reach USD 29.53 billion by the year 2021. Features like energy efficiency, compactness, and lightweight of the LED make it the fastest growing technology in the automotive lighting market. These features contribute to the rapid growth and increased usage of LEDs by the automotive lighting market globally.
IS32LT3175 is a feature rich LED Driver which is robust and easy to design with. This unique product is precisely what premier auto makers are looking for in their Map lights, Dome lights and other interior LED lighting designs to replace bulky incandescent bulbs for improved light efficiency and sleek designs.
Ven Shan, VP of Analog Products at ISSI.
Protection features like open and short LED fault detection, thermal shut down, and thermal rollback are integrated in the IS32LT3175 device to boost its reliability and longevity. Until the junction die temperature of the IC remains less than 145°C (typical), the LED current will continue to remain at the configured level. In case the die temperature goes beyond the threshold, the output current will decrease at a speed of 3%/°C. If the die temperature surpasses 175°C, the device will enter into the thermal shutdown phase.
Tools and support
An evaluation board (EVB) can be used by engineers to easily and quickly assess the performance of the IS32LT3175 device. Further, ISSI can be contacted to obtain more details on tools and support.
Packaging and Pricing
Based on the polarity of the incoming courtesy signal, the IS32LT3175 device comes
in two options. One is the IS32LT3175P, which is used for applications that require "positive going" courtesy signal, and the other is the IS32LT3175N which is meant for interfacing with "negative going" courtesy signals.
Both of these versions are available in a RoHS-compliant thermally enhanced SOP-8EP package. Evaluation boards and IC samples can be ordered via global distribution partners and the ISSI's global sales team.