Features and Benefits
- Charge pump with automatic gain selection of 1×, 1.5×, and 2× for maximum efficiency
- Up to two built-in comparator inputs with programmable modes for ambient light sensing
- Outdoor, office, and dark modes for maximum backlight power savings
- 7 independent and programmable LED drivers
6 drivers capable of 30 mA (maximum)
1 driver capable of 60 mA (maximum)
- Programmable maximum current limit (128 levels)
- Standby mode for <1μA current consumption
- 16 programmable fade in and fade out times 0.1 sec to 5.5 sec
Choose from linear, square, or cubic rates
- Fading override
- I2C-compatible interface for all programming
- Dedicated reset pin and built-in power on reset (POR)
- Short-circuit, overvoltage, and overtemperature protection
- Internal soft start to limit inrush currents
- Input-to-output isolation during faults or shutdown
- Operation down to VIN = 2.5 V with undervoltage lockout (UVLO) at VIN = 2.0 V /li>
- Small wafer level chip scale package (WLCSP) or lead frame chip scale package (LFCSP)
The ADP8860 combines a programmable backlight LED charge pump driver with automatic phototransistor control. This combination allows for significant power savings because it changes the current intensity in office and dark ambient light conditions. By performing this function automatically, it eliminates the need for a processor to monitor the phototransistor.
The light intensity thresholds are fully programmable via the I2C® interface. A second phototransistor input, with dedicated comparators, improves the ambient light detection levels for various user operating conditions.
The ADP8860 allows as many as six LEDs to be independently driven up to 30 mA (maximum). A seventh LED can be driven to 60 mA (maximum). All LEDs are programmable for minimum/ 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.
Driving this entire configuration is a two-capacitor charge pump with gains of 1×, 1.5×, and 2×. This setup is capable of driving a maximum IOUT of 240 mA from a supply of 2.5 V to 5.5 V. The device includes a variety of safety features including shortcircuit, overvoltage, and overtemperature protection. These features allow 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.
The ADP8860 is available in two package types, either a compact 2 mm × 2.4 mm × 0.6 mm WLCSP (wafer level chip scale package) or a small LFCSP (lead frame chip scale package).
Markets and Technologies
Product Lifecycle Production
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.
Evaluation Kits (1)
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 reinitia-lizes the ADP8860 at the default state and places the device in standby mode.
Software & Systems Requirements
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.
Sample & Buy
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.