Scheme-it

An inverting op amp is an operational amplifier circuit with an output voltage that changes in the opposite direction as the input voltage.

A non-inverting op amp is an operational amplifier circuit with an output voltage that is in phase with the input voltage.

LEDs, both low cost and available in many configurations, continue to dramatically transform signage and lighting. The MAX7219 has long been the developer’s best friend in LED driving, offering both simplicity and flexibility. Most systems, however, drive 8x8 arrays, limiting the amount of communication, specifically character size, and not utilizing the daisy chain feature of the MAX7219. 16x16 displays, in contrast, provide the capability to display most international alpha-numeric characters.

Enter the MAXREFDES99#, which drives a 16x16 display, making it a powerful tool for prototyping and developing applications.

The MAXREFDES99# is mbed and Arduino compatible, allowing fast development for both platforms. The shield contains four daisy-chained MAX7219s that drive four 8x8 red LED dot-matrix displays installed on the top arranged to make a 16x16-matrix display.

Maxim’s MAXREFDES82# features a next generation industrial, smart force sensor. Mounted on a quadrant of load cells channeled into a multi-channel, 24-bit analog-todigital converter (ADC), MAXREFDES82# senses weight and center of mass for objects placed on the platform. The scale provides full-scale responses up to 780g. The user interface provides an active display of center of mass on the platform, as well as total measured weight. In addition to serving as a smart force sensor, the design works very well as a ruggedized touch interface with force sensing. The system consumes less than 50mA during normal operation and features a USB interface for quick evaluation and integration.

MAXREFDES131# is a sensing solution featuring the Panasonic AMG8833 Grid-EYE® and the Maxim 1-Wire® bus, enabled by the DS28E17. The system enables presence sensing, people counting, and gestures while tethered up to 100m along the 1-Wire bus. The board features RJ-11 connectors and convenient mounting holes for quick evaluation and implementation.

To meet the increasing demands for non-isolated Power over Ethernet (PoE) power solutions, Maxim has developed innovative, non-isolated PoE powered device (PD) power solutions. These non-isolated PoE power solutions efficiently convert high voltage PoE power into 5V and 12V outputs, respectively. Each design was tested for load and line regulation, as well as efficiency and transient performance. As with all Maxim reference designs, the BOM, schematics, layout files, and Gerber files are all available and may be downloaded from the Design Resources tab. In addition, boards are available for purchase. These boards feature a module architecture, with throughhole pins for immediate board placement and accelerated prototyping.

The ADG904 and ADG904-R are wideband analog 4:1 multiplexers that use a CMOS process to provide high isolation and low insertion loss to 1 GHz. The ADG904 is an absorptive/matched mux with 50 Ω terminated shunt legs; the ADG904-R is a reflective mux. These devices are designed such that the isolation is high over the dc to 1 GHz frequency range.

The MAXREFDES117# reference design is a low power, optical heart-rate module complete with integrated red and IR LEDs, and a power supply. This tiny board, perfect for wearable projects, may be placed on a finger or earlobe to accurately detect heart rate. This versatile module works with both Arduino and mbed platforms for quick testing, development and system integration. A basic, open-source heart-rate and SpO2 algorithm is included in the example firmware.

The MAXREFDES67# reference design is a complete universal analog input for industrial applications. This unique 24-bit front-end accepts bipolar voltage and current, resistance temperature detector (RTD) and thermocouple (TC) inputs. Built in Maxim Integrated’s ultra-small Micro PLC form factor, the MAXREFDES67# performs with a effective resolution up to 22.3 bits with temperature error as low as ±0.1% across a range of -40°C to 150°C.