Lumissil Microsystems, a division of Integrated Silicon Solution, Inc. (ISSI), introduced a new family of advance matrix LED drivers targeted for large LED arrays in gaming keyboards, appliance interfaces, smart speakers, messaging and control panels. The new IS31FL374x family of matrix drivers build on the success of similar matrix drivers; IS31FL3741 (351 LEDs) and IS31FL3742 (180 LEDs).
Lumissil’s latest additions to the LED matrix product line are designed with the knowledge gained from being a long-term supplier of LED drivers to a large and diverse customer base. The family consists of three devices: IS31FL3743A/B, IS31FL3745, IS31FL3746A/B. The IS31FL374x line of matrix drivers provide designers with unprecedented control and flexibility in managing large LED arrays.
“It’s relatively simple to individually drive a few LEDs. However, once the LED count increases, the amount of resources needed to operate the LEDs grows to an unmanageable level.” Said Ven Shan, Vice President of Marketing. “Our new matrix drivers enable the control and management of large LED arrays while providing advanced monitoring and EMI noise reduction capabilities. One device is flexible enough to drive a number of matrices with its 1xn architecture, where n is configurable.”
The IS31FL374x family of matrix LED drivers integrates many advanced features such as configurable matrix size, individual LED open/short detection, individual LED current adjust and PWM registers, all accessible via a fast 1MHz I2C or 12MHz SPI bus interface. A configurable matrix size helps lower costs since the same matrix driver can be reused in different projects to support various LED array sizes without a major rewrite of the software.
The IS31FL374x devices enable each LED in the array with its own corresponding control and fault status register to provide individual LED color and dimming effects, de-ghosting and fault reporting for enhanced overall system performance health and reliability. LED matrix architectures typically experience a “ghosting effect” where an LED remains dimly ON due to a residual charge in the LED array matrix.
The IS31FL374x family eliminates this residual charge and therefore eliminates the LED ghosting effect. In addition, LEDs can fail to turn ON due to an LED open or short condition without the knowledge of the system. The IS31FL374x family can monitor the LED array to detect a failed LED within the array and make this information available for the system to access.
The IS31FL374x matrix driver family with its advanced feature set simplifies the management of a large number of LEDs, whether RGB color, single color or a mix of both. The package options range from a low profile UQFN for the IS31FL3743 to a chip scale packaged IS31FL3745 ideal for applications such as notebooks which have low height requirements. The IS32FL3746B is the automotive version of the IS31FL3746B and it comes in the automotive approved wettable flank QFN (WFQFN) package. The table below highlights the key differences and options available within the family.
| Part Number | Market | Matrix Size | LED Array Size | Bus Type | Package | Operating Temperature | Key Features |
| IS31FL3743A | Consumer Industrial | 18xn (n=1~11) | 198 | I2C (1MHz) | UQFN-40 | -40°C to +125°C | 8-bit (Dot Correction, PWM, Global Current), Spread Spectrum,LED Open/Short Detect, de-Ghost, Configurable Matrix Size |
| IS31FL3743B | 18xn (n=1~11) | 198 | SPI (12MHz) | UQFN-40 | |||
| IS31FL3745 | 18xn (n=1~8) | 144 | I2C (1MHz) | WLCSP-36 | |||
| IS31FL3746A | 18xn (n=1~4) | 72 | I2C (1MHz) | QFN-32 | |||
| IS31FL3746B | 18xn (n=1~4) | 72 | SPI (12MHz) | QFN-32 | |||
| IS32FL3746B | Automotive | 18xn (n=1~4) | 72 | SPI (12MHz) | WFQFN-32 | ||
Hordon Kim, International Editor, hordon@powerelectronics.co.kr
