Charge Pump, 7-Channel Smart LED Driver with I2C Interface
The ADP8861 provides a powerful charge pump driver with independent control of up to seven LEDs. These seven LEDs can be independently driven up to 30 mA (typical). The seventh LED can also be driven to 60 mA (typical). All LEDs are pro-grammable for maximum current and fade in/out times via the I2C interface. These LEDs can also be combined into groups to reduce the processor instructions during fade in/out.
This entire configuration is driven by a two-capacitor charge pump with gains of 1×, 1.5×, and 2×. The charge pump is capable of driving a maximum IOUT of 240 mA from a supply of 2.5 V to 5.5 V. A full suite of safety features, including short-circuit, overvoltage, and overtemperature protection, allows easy implementation of a safe and robust design. Additionally, input inrush currents are limited via an integrated soft start combined with controlled input-to-output isolation.
- Mobile display backlighting
- Mobile phone keypad backlighting
- Dual RGB backlighting
- LED indication
- General backlighting of small format displays
At least one model within this product family is in production and available for purchase. The product is appropriate for new designs but newer alternatives may exist.
This describes the functionality of the Analog Devices, Inc., ADP8860 and provides software development guidelines. The ADP8860 communicates with an external processor using an I2C interface and an interrupt line (nINT). The processor sends initialization and activation commands to the ADP8860, which acts as a slave device.
The interrupt line, from the ADP8860 to the processor, is used to indicate a failure condition, such as a thermal shutdown or an overvoltage and LED/output short circuit, or to indicate a light level threshold has been crossed. All interrupt sources are maskable. Refer to Figure 1 for a typical application diagram. Figure 2 shows a schematic with keypad light control.
The interrupt line is active low; each interrupt source has an individual masking bit. The processor can reset the ADP8860 anytime by pulling the nRST line low; this operation reinitializes the ADP8860 at the default state and places the device in standby mode.
ADI has always placed the highest emphasis on delivering products that meet the maximum levels of quality and reliability. We achieve this by incorporating quality and reliability checks in every scope of product and process design, and in the manufacturing process as well. "Zero defects" for shipped products is always our goal.
The USA list pricing shown is for BUDGETARY USE ONLY, shown in United States dollars (FOB USA per unit for the stated volume), and is subject to change. International prices may differ due to local duties, taxes, fees and exchange rates. For volume-specific price or delivery quotes, please contact your local Analog Devices, Inc. sales office or authorized distributor. Pricing displayed for Evaluation Boards and Kits is based on 1-piece pricing.