Power Management Solutions: Battery Chargers


Maurizio @ dev.emcelettronica.com writes:

Out of all portable devices, the most numerous are the mobile phones (Figure 1). Most of them feature Li-ion or Li-polymer accumulators and Freescale has a broad range of charger ICs dedicated to supporting all the phases of a complete recharge cycle. Generally speaking the charging of a mobile phone is performed by taking energy from:

a) from a wall outlet
b) from the USB port of a computer
c) from the 12V output of a vehicle

Power Management Solutions: Battery Chargers – [Link]

1A from the sugar cube sized module


With continuous improvement TRACO unveils the SMD version of enormously successful 1A DC/DC converter, the TSR1SM.

The TSR1SM series models of step-down switching regulators (non isolating – POL) have a high efficiency up to 96 % which allows full load operation up to +65°C ambient temperature without the need of any heat transmission layer. Excellent output voltage accuracy (±2%) and low standby current (~1 μA) are features that distinguish these switching regulators from linear regulators.To make a SMD version of such a DC/DC converter is not a simple task, the package should withstand temperatures up to 245°C, used in a lead free soldering ovens. TRACO solved successfully this problem and the TSR1SM is qualified for lead free soldering processes as per J-STD-020D.01 (to find at: www.jedec.org – free registration required) with max. peak body temperature 245°C. Also low MSL level 1 allows PCB washing after soldering with baking at 100°C for 30min.

For applications which require lower supply currents up to 0,5Amps, there is a TSR0,5(SM)series of DC/DC converters with better price level available.

1A from the sugar cube sized module – [Link]

8T49NS010 Clock Synthesizer and Fanout Buffer/Divider

This reference design features the 8T49NS010 integrated circuit that functions as a clock synthesizer with a built-in fanout buffer and divider. By using an external clock source or a crystal, the 8T49NS010 can generate high performance timing geared towards the communications and datacom markets, especially for applications demanding extremely low phase noise jitter, such as 10, 40 and 100GE. Depending on the input used, the 8T49NS010’s low phase noise integer-N PLL can multiply the reference to 2400MHz or 2500MHz.

The device offers ten clock outputs (QCLK[9:0]/nQCLK[9:0]). Each output can be disabled individually through registers. With ÷2, ÷4, ÷8 and ÷16 values one can get output frequencies of 156.25MHz, 312.5MHz, 625MHz and 1250MHz when driven from a 25MHz input, for example. The input select pin REF_SEL will choose either XTAL input or CLK_IN input will be used and this pin also set the pre-divider PRE to either x2 or ÷1. The feedback divider FB_SEL pin will set the feedback divider to either ÷50, ÷25. The feedback divider should be properly set to assure the PLL lock for VCO=2.5GHz. The N1 and N0 are pins for output frequency divider setting. Aside from the divider values that can be set using pins N1 and N0, additional divider values are available through registers that can be programmed with I2C interface. This reference design recommends the FT2232 USB to UART converter to program the device divider value via I2C pins. The 8T49NS010 operates over the industrial temperature range of -40°C to +85°C with a 3.3V supply voltage.

The 8T49NS010 provides versatile frequency configurations and output format that is optimized to deliver excellent phase noise performance. The device delivers an optimum combination of high clock frequency and low phase noise performance, combined with high power supply noise rejection.

8T49NS010 Clock Synthesizer and Fanout Buffer/Divider – [Link]

Smart Garden


by FABLAB Dhahran @ instructables.com:

In this project we will design and program a smart garden watering system. This system will use Arduino UNO and a moisture sensor to measure the volumetric water content in soil. It will also have a light (photocell) sensor to detect when the plant should get sunlight. So, when the soil is dry a red LED will light up, when it’s wet a blue LED will light up, and when the plant needs a light a white LED will blink. You will need basic 2D-designing skills and CNC machine to design and build our own planter box. Alternatively, you can just use a normal jar. Also, you can make your planter box using acrylic and cut it by a laser cutting machine.

Smart Garden – [Link]

Industruino – Arduino compatible industrial controller


Industruino is a fully featured Arduino Leonardo compatible board housed in a DIN-rail mountable case + prototyping area + onboard LCD + membrane panel. With this product you will be able to permanently install your Arduino application in no-time.

Whether you use it for automation projects, data loggers or an interactive art installation, Industruino offers you ruggedness, plenty of features and low cost.

Industruino – Arduino compatible industrial controller – [Link]


AC energy metering board using an Atmel 90E24 energy metering chip


Steve Rodgers writes:

Here’s my latest project. Its an AC energy metering board using an Atmel 90E24 energy metering chip. The board can either take an ESP8266-12 and run a native C application, or the ESP8266-12 can be omitted, and an external microcontroller can be used to talk to the Atmel 90E24 energy metering chip. I have firmware to support both the AVR and the ESP8266. I built a really nice energy monitoring box using the AVR and a 12864 display.

AC energy metering board using an Atmel 90E24 energy metering chip – [Link]

Surface-mount device prototyping in education


In this article Vassilis K. Papanikolaou explains how SMD prototyping practice can be used in learning environments using simple and wide available tools and equipment:

A feasibility study is herein attempted, towards the adaptation of modern surface-mount device (SMD) prototyping practice to learning environments. This necessity emerges not only from the profound advantages of the above technology (e.g. component size, availability, low cost etc.) but also from the fact that contemporary designs often require special board layout considerations, which may be incompatible with through-hole components. In addition, the long process between prototyping and product finalization can be greatly shortened. Nevertheless, the employment of surface-mount techniques in education may be discouraged by both the unappealing part sizes (i.e. handling difficulty) and the excessive cost of commercial supporting equipment. The main objective of this study is to suggest practical and low-cost solutions for all different SMD prototyping/manufacturing stages, which can demystify and render this procedure welcome and easily applicable in laboratory classes.

Surface-mount device prototyping in education – [Link]

MC34VR500V1ES Multi-Output DC/DC Regulator

The circuit in this reference design features the capability of MC34VR500V1ES to supply multiple DC voltage outputs. This device is designed to support the LS1/T1 family of communication processors, which require efficient and precise level of voltage supplies. With its four switching and five linear regulators, the MC34VR500V1ES can supply power to the whole system, e.g., the processor, memory, system peripherals.

The MC34VR500V1ES device runs with a supply voltage ranging from 2.8V to 4.5V. It can provide nine outputs. Four of these outputs (SW1-4) are buck regulators while the rest (LDO1-5) are general purpose LDOs. Each one of the buck regulator is capable of operating in Pulse Frequency Modulation (PFM), Auto Pulse Skip (APS), and Pulse Width Modulation (PWM) switching modes. These buck regulators also have a current limit feature that generates a fault interrupt whenever there is an overcurrent condition. The SW1 output is capable of providing 0.625-1.875V/4.5A supply while SW2 and SW3 can provide 0.625-1.975V/2A and 0.625-1.975V/2.5A, respectively. The SW1, SW2 and SW3 voltages can be varied with a step size of 25mV. The SW4 output is half of the voltage output of SW3. The general output LDOs can output voltages ranging from 1.8-3.3V with a step size of 100mV except for LDO1 which can only give 0.8-1.55V output with 50mV step size. The LDO1 output can provide current up to 250mA, while LDO2 and LDO4 can output up to 100mA only. The LDO5 output can provide 200mA of current while LDO3 can output up to 350mA. Aside from these nine outputs, the MC34VR500V1ES also have a REFOUT output dedicated for DDR memory reference voltage. The voltage of this REFOUT output is usually half of the SW3 output and can only provide up to 10mA of current. The MC34VR500V1ES outputs can be changed by programming it via the I2C interface.

The operation of the MC34VR500V1ES can be reduced to four states, or modes: ON, OFF, Sleep, and Standby. For the device to turn ON, the input voltage must surpass a voltage threshold of 3.1V, the EN pin must be high, and PORB is de-asserted. The 34VR500 enters the OFF mode when the EN pin is low or there is a thermal shutdown event that forces the device into the OFF mode. Standby mode is usually entered when the STBY pin is asserted for low-power mode of operation. The device only goes into sleep mode if the EN pin is de-asserted. To exit sleep mode, assert the EN pin.

MC34VR500V1ES Multi-Output DC/DC Regulator – [Link]

DIY Miniature and Wearable Electronics


MiniWear – DIY Miniature And Wearable Modules That Can Be Worn Anywhere On The Body. James Cannan writes:

We love electronics, especially Wearables, and that is why we have made super cool modules that include heart rate detection, movement, non contact temperature sensing, and ultraviolet (UV), infra-red (IR), and light sensing technology. We are also one of the first in the world to have combined our modules with a variety of open source 3d printed cases, which will take your projects to a whole new level!

DIY Miniature and Wearable Electronics – [Link]

NE555 timer sparks low-cost voltage-to-frequency converter


by Gyula Dioszegi @ edn.com:

In 1971, Signetics—later Philips—introduced the NE555 timer, and manufacturers are still producing more than 1 billion of them a year. By adding a few components to the NE555, you can build a simple voltage-to-frequency converter for less than 50 cents. The circuit contains a Miller integrator based on a TL071 along with an NE555 timer (Figure 1). The input voltage in this application ranges from 0 to –10V, yielding an output-frequency range of 0 to 1000 Hz. The current of C1 is the function of input voltage: IC=–VIN/(P1+R1).

NE555 timer sparks low-cost voltage-to-frequency converter – [Link]