Toshiba - Integrated constant current drivers provide responsive LED brightness

A new family of integrated constant-current LED drivers has been introduced by Toshiba Electronics Europe (TEE). They provide very high levels of ESD protection while significantly reducing component count and board space in applications built around multiple LEDs.

Ideal for panel displays, devices in the TB62747 LED driver family feature 16 driver outputs with the ability to deliver constant currents of between 1.5mA to 45mA. ESD protection in accordance with Man Machine (MM) and Human Body (HB) models is ±500V and ±4000V respectively.

The drivers 'guarantee' a maximum current accuracy between outputs and between different devices of ±1.5%. This ensures constant brightness in designs built around large number of LEDs. The high number of integrated outputs, coupled with the ability to adjust the current through the use of a single, external resistor, significantly reduces the number of components needed to drive LED array applications.

All TB62747 drivers operate with a supply voltage of between 3.3V and 5V and deliver output voltages up to 26V. Internally the devices are based around 16 channels of shift registers, latches, AND gates and the constant current outputs. Control data format is serial-in, parallel-out. The devices are fully BiCMOS-compatible and can accommodate 3.3V and 5V input signals. A power-on-reset (POR) facility is also available.

The TB62747 drivers deliver fast output current response (tWOE(L) = 100ns min) and, when cascaded, support serial data transfer rates of 25MHz. Package options are 1mm pitch SSOP-24 (TB62747AFG), 0.65mm pitch SSOP-24 (TB62747AFNG) and 0.64mm pitch QSOP24 (TB62747AFNAG and TB62747BFNAG). All of the drivers will operate between -40C and 85C, says the company.