Lighting Technology Solutions

The ADD5203 is a white LED driver for backlight applications based on high efficiency, current-mode, step-up converter technology. It is designed with a 0.15 Ω, 2.9 A internal switch and a pin-adjustable operating frequency between 350 kHz and 1 MHz. The ADD5203 contains eight regulated current sources for uniform brightness intensity. Each current source can be driven up to 30 mA, and the LED driving current is pin adjustable by an external resistor. The ADD5203 drives up to eight parallel strings of multiple series connected LEDs with a ±1.5% current matching between strings.

The ADD5203 provides various dimming modes. Each dimming mode is selectable with an external dimming mode selection pin. The LED dimming control interface can be achieved through PWM input and/or SMBus. The device provides adjustable output dimming frequency range from 200 Hz to 10 kHz by an external resistor and capacitor. The ADD5203 operates over an input voltage range of 6 V to 21 V, but the device can function with a voltage as low as 5.6 V. The ADD5203 also has multiple safety protection features to prevent damage during fault conditions. If any LED is open or short, the device automatically disables the faulty current source. The internal soft start prevents inrush current during startup. Thermal shutdown protection prevents thermal damage.

The ADD5203 is available in a low profile, thermally enhanced, 4 mm × 4 mm × 0.75 mm, 28-lead, RoHS-compliant lead frame chip scale package (LFCSP_WQ) and is specified over the industrial temperature range of −25°C to +85°C.

APPLICATIONS

• Notebook PCs, UMPCs, and monitor displays

The ADD5211 is a four-string, white LED driver for backlight applications based on high efficiency, current mode, step-up converter technology. The boost controller drives an external MOSFET switch for step-up regulation from an input voltage of 4.5 V to 40 V and a pin adjustable operating frequency from 200 kHz to 1.2 MHz. An adjustable UVLO function is implemented to reduce input current during power-off.

The ADD5211 provides four regulated current sinks for uniform brightness intensity. Each current sink can be driven from 40 mA to 200 mA; the LED driving current is pin adjustable using an external resistor. With an input PWM interface, the ADD5211 drives up to four parallel strings of multiple series connected LEDs.

Additional features include LED short protection, LED open protection, boost output short protection, overvoltage protection, cycle-by-cycle current limit, and thermal shutdown for both the IC and the LED array. An open-drain fault output is also included. A programmable soft start is implemented to reduce inrush current during startup.

• LCD monitor and TV LED backlights
• Industrial lighting

The ADPD105/ADPD106/ADPD107 are highly efficient, photometric front ends, each with an integrated 14-bit analog-to-digital converter (ADC) and a 20-bit burst accumulator that works with flexible light emitting diode (LED) drivers. The accumulator is designed to stimulate an LED and measure the corresponding optical return signal. The data output and functional configuration occur over a 1.8 V I²C interface on the ADPD105 or SPI on the ADPD106 and ADPD107. The control circuitry includes flexible LED signaling and synchronous detection.

The analog front end (AFE) features best-in-class rejection of signal offset and corruption due to modulated interference commonly caused by ambient light.

Couple the ADPD105/ADPD106/ADPD107 with a low capacitance photodiode of <100 pF for optimal performance. The ADPD105/ADPD106/ADPD107 can be used with any LED. The ADPD105 is available in a 2.46 mm × 1.4 mm WLCSP and a 4 mm × 4 mm LFCSP. The SPI only versions, ADPD106 and ADPD107, are available in a 2.46 mm × 1.4 mm WLCSP.

Applications

• Wearable health and fitness monitors
• Clinical measurements, for example, SpO₂
• Industrial monitoring
• Background light measurements

The ADXL372 is an ultralow power, 3-axis, ±200 g MEMS accelerometer that consumes 22 μA at a 3200 Hz output data rate (ODR). The ADXL372 does not power cycle its front end to achieve its low power operation and therefore does not run the risk of aliasing the output of the sensor.

In addition to its ultralow power consumption, the ADXL372 has many features to enable impact detection while providing system level power reduction. The device includes a deep multimode output first in, first out (FIFO), several activity detection modes, and a method for capturing only the peak acceleration of over threshold events.

Two additional lower power modes with interrupt driven, wake-up features are available for monitoring motion during periods of inactivity. In wake-up mode, acceleration data can be averaged to obtain a low enough output noise to trigger on low g thresholds. In instant on mode, the ADXL372 consumes 1.4 μA while continuously monitoring the environment for impacts. When an impact event that exceeds the internally set threshold is detected, the device switches to normal operating mode fast enough to record the event.

High g applications tend to experience acceleration content over a wide range of frequencies. The ADXL372 includes a 4-pole low-pass antialiasing filter to attenuate out of band signals that are common in high g applications. The ADXL372 also incorporates a high-pass filter to eliminate initial and slow changing errors, such as ambient temperature drift.

The ADXL372 provides 12-bit output data at 100 mg/LSB scale factor. The user can access configuration and data registers via the serial peripheral interface (SPI) or limited I²C protocol. The ADXL372 operates over a wide supply voltage range and is available in a 3 mm × 3.25 mm × 1.06 mm package.

Multifunction pin names may be referenced by their relevant function only.

APPLICATIONS

• Impact and shock detection
• Asset health assessment
• Portable Internet of Things (IoT) edge nodes
• Concussion and head trauma detection

The ADXL375 is a small, thin, 3-axis MEMS accelerometer that provides low power consumption and high resolution measurement up to ±200 g. The digital output data is formatted as 16-bit, twos complement data and is accessible through a SPI (3- or 4-wire) or I²C digital interface.

An integrated memory management system with a 32-level first in, first out (FIFO) buffer can be used to store data to minimize host processor activity and lower overall system power consumption.

Low power modes enable intelligent motion-based power management with threshold sensing and active acceleration measurement at extremely low power dissipation.

The ADXL375 is supplied in a small, thin, 3 mm × 5 mm × 1 mm, 14-lead LGA.

APPLICATIONS

• Concussion and head trauma detection
• High force event detection

The circuit shown in Figure 1 uses three photodiodes that are sensitive to different wavelengths (red, green, and blue), to measure light intensity levels over the light spectrum where plants are photosynthetically active. The measured results can be used to optimize the light source to match the requirements of the specific plants, enhance the growth rate, and minimize energy losses.

This circuit uses three precision current to voltage conversion stages that drive a single-supply, low power, low noise, 16-bit, Σ-Δ analog-to-digital converter (ADC) with three differential inputs.

The circuit deviates from the traditional approach by eliminating all mechanical and optical components, and uses only electrical components to achieve the same goal.

The circuit consumes less than 10 mW typical, making it ideal for battery operated portable field applications.

The printed circuit board (PCB) is designed in an Arduino-compatible shield form factor and interfaces to the EVAL-ADICUP360 Arduino-compatible platform board for rapid prototyping.