ALLEGRO Manuals

The A8500 is a multi-output WLED driver for medium display backlighting. It integrates a boost converter and eight current-sinks to provide a flexible WLED/RGB backlight driver. The boost converter can provide output voltage up to 47 V. The flexible channel selection control and high voltage capability allow a wide range of LED backlight applications. The A8500 can support any application requiring 4 to 96 WLEDs. The boost converter is a constant frequency current-mode converter. Each LED channel can sink 25 mA, and channels can be paralleled for higher currents. Flexible dimming allows output channels to either run at an adjustable DC value or with externally controlled PWM duty cycles.

Advantages: Suitable for interfacing between low-level logic circuitry and multiple peripheral power loads. Disadvantages: None.

The A6285 is designed for LED display applications. It includes an On/Off shift register, a Dot Correction shift register, data latches, and 16 MOS constant-current sink drivers. It supports direct interfacing with microprocessor-based systems and has a high serial data input rate. The LED drive current can be set by an external resistor. It supports cascading of multiple devices, individual LED light intensity adjustment, and open LED detection. It also has fault output and delay control features.

A6821 DABiC-5 8-Bit Serial Input Latched Sink Drivers

This data sheet provides detailed information on the DABiC-IV, 10-BIT SERIAL-INPUT, LATCHED SOURCE DRIVER A6810xA, including absolute maximum ratings, pin descriptions, package, logic supply voltage, driver supply voltage, continuous output current range, input voltage range, package power dissipation, operating temperature range, storage temperature range, cautions, design features, application circuit diagrams, and application examples.

Designed to reduce logic supply current, chip size, and system cost, the A6833 integrated circuits offer high-speed operation for thermal print- ers.

This document describes the A1185 and A1186, two ultrasensitive two-wire unipolar Hall effect switches. These switches have an operable point that can be field-programmed after final packaging and placement in the application, allowing for optimized sensor switching performance.

The ACS755SCB-200 is an economical and precise current sensor from Allegro that provides solutions for current sensing in industrial, automotive, commercial and other applications. It features a single +5 V supply, 3 kVRMS isolation voltage, 35 kHz bandwidth, end-of-line factory-trimmed gain and offset, ultra-low power loss and extremely stable output offset voltage.

These Hall-effect switches are designed for magnetic actuation using a bipolar magnetic field, i.e., a north-south alternating field. They combine extreme magnetic sensitivity with excellent stability over varying temperature and supply voltage. The high sensitivity permits their use with multi-pole ring magnets over relatively large distances. Each device includes a voltage regulator, quadratic Hall voltage generator, temperature stability circuit, signal amplifier, Schmitt trigger, and open-collector output on a single silicon chip. The on-board regulator permits operation with supply voltages of 4.5 to 24 V. The switch output can sink up to 25 mA. With suitable output pull up, they can be used directly with bipolar or MOS logic circuits. The three package styles available provide a magnetically optimized package for most applications. Suffix ‘LT’ is a miniature SOT-89/TO-243AA transistor package for surface-mount applications; suffixes ‘U’, and ‘UA’ feature wire leads for through-hole mounting. Prefix ‘UGN’ devices are rated for continuous operation over the temperature range of -20°C to +85°C, prefix ‘UGS’ devices over an extended range of -40°C to +125°C, and prefix ‘UGL’ devices over the range of -40°C to +150°C.

A1205 is the upgraded version of A3134, used for applications that require pulsing VCC to conserve power.

The A8434 is a high-efficiency charge pump IC that offers a simple, low-cost white LED driver solution for driving up to six WLEDs in various application configurations. It can be used to backlight a single display with all six LEDs or to backlight multiple displays, such as using four LEDs for the main display and the other two for a sub display or flash/torch. The A8434 utilizes a proprietary control scheme (1×, 1.5×, and 2×) to deliver well-matched WLED current while maintaining high efficiency and low EMI. The WLED current is regulated over the entire range of Li+ battery voltage to provide uniform intensity. The brightness and on/off of the WLEDs for the main display and sub display/torch can be controlled through 2 single-wire serial interface pins. The A8434 is available in a space-conserving QFN/MLP-16 ES package with a 3×3 mm footprint. Applications include white LED backlights for cellular phones, PDAs, digital cameras, camcorders, portable audio devices, and MP3 players.

The SEPM series of LEDs provides a range of high-powered ALGaInP red (λD = 616 nm), and InGaN green (523 nm) and blue (461 nm) LEDs that can be used in general lighting applications, amusement and gaming equipment, and for backlighting TFT displays. Each module combines 8 LED chips in 4 separate channels. Modular design allows the SEPM devices to be easily assembled into string arrays by simply connecting the modules in series. The devices also provide superior color balance throughout the display because of the high density of LEDs that can be achieved. This also minimizes the distance that power and control lines must run between LEDs and from the LEDs to the control electronics. The white thermoplastic case is an innovative Sanken original design with exceptional heat dissipation properties. The white resin compound is especially formulated for superior reflectance and transmittance of the generated light. Enhanced thermal dissipation is achieved through the incorporated heatsink on the bottom of the package. The heatsink can be mated directly to an external radiator through the PCB for superior heat conduction allowing dense placement of modules. The leadframe is plated with silver, providing a highly-reflective surface for the bottom and sides of the emitting area. The terminals and heatsink are also silver-plated.

The UDN2981A is an 8-channel source driver that is useful for interfacing between low-level logic and high-current loads. This device is recommended for high-side switching applications that benefit from separate logic and load grounds, with load supply voltages to 50 V and output currents to -500 mA.

The A6277x is specifically designed for LED display applications. Each BiCMOS device includes an 8-bit CMOS shift register, accompanying data latches, and eight npn constant-current sink drivers. Two package styles and two operating temperature ranges are available. The CMOS shift register and latches allow direct interfacing with microprocessor-based systems. With a 5 V logic supply, typical serial data-input rates are up to 20 MHz. The LED drive current is deter- mined by the user’s selection of a single resistor. A CMOS serial data output permits cascade connections in applications requiring additional drive lines. For inter-digit blanking, all output drivers can be disabled with an ENABLE input high. In addition, a HIGH/LOW function enables full selected current with the application of a logic low, or 50% selected current with the application of a logic high. The first character of the part number suffix determines the device operating temperature range. Suffix ‘E–’ is for -40°C to +85°C, and suffix ‘S–’ is -20°C to +85°C. Two package styles are provided for through-hole DIP (suffix ‘–A’) or surface-mount SOIC (suffix ‘–LW’) applications. The copper lead frame and low logic-power dissipation allow the dual in-line package to sink 122 mA through all outputs continuously over the operating temperature range (1.0 V drop, +85°C). Note that the A6277EA (DIP) and the A6277ELW (SOIC) are electrically identical.