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4 Channel Analog Video Distribution Amplifier

The project presented here is a low-cost video distribution amplifier capable of driving up to four video lines. The amplifier is configured with a non-inverting gain of 2. The input video source is terminated in 75 Ohms and is applied to the high impedance non-inverting input. Each output line is connected to the op-amp’s output via 75 Ohms series back termination resistor for proper cable termination. The termination resistor at the other end of the lines divides the output signal by 2, which is compensated by the gain of 2 of the op-amp. The project is built using AD8010 op-amp which is optimized for this specific function of providing excellent video performance in driving multiple video loads in parallel. Significant power is saved and heat sinking is greatly simplified because of the ability of the AD8010 to obtain this performance when running on ±5 V supply. Circuit provides 46dB of output-to-output isolation at 5Mhz driving back terminated 75 Ohms cable. Ferrite beads and high-value ceramic capacitors are used on the power supply input to reduce the noise.

Features

Power Supply +/-5V DC (Dual 5V Symmetrical Power Supply) @ 20mA
RCA Connector for Video In
4 x RCA Connector for Video Output
Power LED
PCB Dimensions 69.06 x 29.69 mm

The AD8010 is a low-power, high current amplifier capable of delivering a minimum load drive of 175 mA. Signal performance such as 0.02% and 0.03° differential gain and phase error is maintained while driving eight 75 Ω back terminated video lines. The current feedback amplifier features gain flatness to 60 MHz and –3 dB (G = +1) signal bandwidth of 230 MHz and only requires a typical 15.5 mA supply current from ±5 V supplies. These features make the AD8010 an ideal component for Video Distribution Amplifiers.

Schematic

Parts List

NO.	QNTY.	REF.	DESC.	MANUFACTURER	SUPPLIER	SUPPLIER PART NO
1	1	CN1	3 PIN MALE HEADER 2.54MM PITCH	WURTH	DIGIKEY	732-5316-ND
2	3	C1,C3,C5	0.1uF/50V SMD SIZE 0805	YAGEO
3	2	C2,C4	100uF/10V SMD SIZE 1210	KEMET	DIGIKEY	399-11631-1-ND
4	1	D1	LED RED SMD SIZE 0805	OSRAM	DIGIKEY	475-1415-1-ND
5	1	J1	RCA FEMALE CONNECTOR	KYCON INC	DIGIKEY	2092-KLPX-0848A-2-R-ND
6	1	J2	RCA FEMALE CONNECTOR	KYCON INC	DIGIKEY	2092-KLPX-0848A-2-R-ND
7	1	J3	RCA FEMALE CONNECTOR	KYCON INC	DIGIKEY	2092-KLPX-0848A-2-R-ND
8	1	J4	RCA FEMALE CONNECTOR	KYCON INC	DIGIKEY	2092-KLPX-0848A-2-R-ND
9	1	J5	RCA FEMALE CONNECTOR	KYCON INC	DIGIKEY	2092-KLPX-0848A-2-R-ND
10	2	L1,L2	FERRITE BEAD SMD SIZE 0805	WURTH	DIGIKEY	732-1613-1-ND
11	3	R1,R7,R8	499E 1% SMD SIZE 0805	YAGEO
12	5	R2,R3,R5,R6,R9	75E 1% SMD SIZE 0805	YAGEO
13	1	R4	150E 1% SMD SIZE 0805	YAGEO
14	1	U1	AD8010 SO IC	ANALOG DEVICES	DIGIKEY	AD8010ARZ-ND

Connections

Gerber View

Photos

Video

AD8010 Datasheet

3 Channel Analog Video Splitter with Video Amplifier

If you need to drive multiple video gadgets or monitors from a single video signal source then this board is the right choice for you. This is a 3-channel video splitter with an amplifier and the circuit is built using discrete components. Q2 and Q1 act as a signal amplifier, Q3 act as output driver, trimmer potentiometer PR1 is provided to adjust the input signal swing, PR2 Trimmer is provided to set the gain of the amplifier, D1 is the power LED. The operating power supply is 12V DC and it draws 100mA current. RCA Connector J4 is the Video signal input, RCA Connector J1, J2, J3 provide the outputs. The default gain of the circuit is 4. The bandwidth is 5Mhz, input and outputs impendence are 75 Ohms. It is important to use all 3 channels at a time or change R11 to 150 Ohms if you will only use 1 x channel or 82 Ohms if 2 x channels are in use. Adjusting the board is very easy, just connect a voltmeter at the base of Q2 and adjust the PR1 so the voltage at the base of Q2 is 1V.

Features

Power Supply 12V V_dc
Current Consumption 100mA
RCA Connector for Video Input
3 x RCA Connectors for Video Output
Trimmer Potentiometer for Gain Adjust
Trimmer For input signal Swing Adjust
On-board Power LED
PCB Dimensions 48.74 x 43.66mm

Schematic

Parts List

No.	Qnty.	Ref	Desc.	Manufacturer	Supplier	Supplier Part No
1	1	CN1	4 PIN MALE HEADER 2.54MM PITCH		DIGIKEY	S1011EC-40-ND
2	3	C4,C5,C7	100uF/25V ELECTROLYTIC CAPACITOR	NICHICON	DIGIKEY	399-6650-1-ND
3	2	C2,C8	0.1uF/50V SMD SIZE 0805	YAGEO	YAGEO
4	2	C3,C6	10uF/50V ELECTROLYTIC	NICHICON	DIGIKEY	493-5915-1-ND
5	1	C1	100uF/16V SMD SIZE 1210	TAIYO YUDEN	DIGIKEY	587-5426-1-ND
6	1	D1	LED RED COLOR SMD SIZE 0805	OSRAM	DIGIKEY	475-1415-1-ND
7	1	D2	1N4148 SMD DIODE	MICROCHIP	DIGIKEY	1N4148UR-1-ND
8	1	J1	RCA JACK	KYCON INC	DIGIKEY	2092-KLPX-0848A-2-R-ND
9	1	J2	RCA JACK	KYCON INC	DIGIKEY	2092-KLPX-0848A-2-R-ND
10	1	J3	RCA JACK	KYCON INC	DIGIKEY	2092-KLPX-0848A-2-R-ND
11	1	J4	RCA JACK	KYCON INC	DIGIKEY	2092-KLPX-0848A-2-R-ND
12	2	PR1,PR2	2.2K TRIMMER POTENTIOMETER	BOURNS	DIGIKEY	3362P-1-222LF-ND
13	1	Q1	BC857 SMD SOT23-3	NEXPERIA	DIGIKEY	1727-2924-1-ND
14	1	Q2	BC847 SMD SOT23-3	NEXPERIA	DIGIKEY	BC857BLT3GOSCT-ND
15	1	Q3	BD139	ST	DIGIKEY	497-12137-ND
16	1	R1	8.2K 5% SMD SIZE 0805	YAGEO	MOUSER
17	2	R2,R3	1K 5% SMD 0805	YAGEO	MOUSER
18	1	R4	10K 5% SMD SIZE 0805	YAGEO	MOUSER
19	1	R5	3.3K 5% SMD SIZE 0805	YAGEO	MOUSER
20	4	R6,R7,R8,R12	75E 1% SMD SIZE 0805	YAGEO	MOUSER
21	2	R9,R13	180E 5% SMD SIZE 0805	YAGEO	MOUSER
22	1	R10	470E 5% SMD SIZE 0805	YAGEO	MOUSER
23	1	R11	56E 5% SMD SIZE 0805	YAGEO	MOUSER

Connections

Gerber View

Photos

Video

BD139 Datasheet

4 Tactile Switch Breakout Board

This breadboard-friendly board breaks out all 4 tactile switch signals and includes pullup resistors configured so that the outputs read low or high when configured common VCC or GND.

Schematic

Gerber View

Photos

Bosch BME688 AI Gas Sensor

Posted on 27 February, 202128 February, 2021 by mixos

Bosch BME688 AI Gas Sensor offers a 1.2V to 3.6V supply voltage range and 3mm x 3mm x 0.93mm³ package dimensions. This sensor features integrated high linearity and high-accuracy pressure, humidity, and temperature sensors. The BME688 gas sensor can detect Volatile Organic Compounds (VOC) and other gases such as hydrogen and carbon monoxide in the part per billion (ppb) range. Bosch BME688 AI Gas Sensor is ideal for mobile and connected applications where size and low power consumption are critical requirements.

Specifications

1.2V to 3.6V supply voltage
I²C and SPI interface
3mm x 3mm x 0.93mm³
8s response time
±3% relative humidity accuracy tolerance
≤1.5% relative humidity hysteresis
RoHS compliant, halogen-free, MSL1
Average Current Consumption
- 2.1µA at 1Hz humidity and temperature
- 3.1µA at 1Hz pressure and temperature
- 3.7µA at 1Hz humidity, pressure and temperature
- 90µA at ULP mode for p/h/T & air quality
- 0.9mA at LP mode for p/h/T & air quality

more information: https://www.bosch-sensortec.com/products/environmental-sensors/gas-sensors/bme688/

Bosch BMP384 Pressure Sensor

Posted on 27 February, 2021 by mixos

Bosch BMP384 Pressure Sensor offers a 1.2V to 3.6V supply voltage range and comes in a 2mm x 2mm x 1mm³ package. This sensor has a gel-filled cavity that allows higher robustness against liquids, water, and other chemicals. The BMP384 sensor is compatible for use with other Bosch Sensortec sensors, including the BMI088 for better performance. The small footprint of this sensor allows for outstanding design flexibility, and makes this a single package solution that can be easily integrated into existing and upcoming devices for smart homes, industrial products, and wearables.

In addition to the interrupt functionality that provides simple access to data and storage, the BMP384 sensor includes FIFO functionality that improves ease of use while reducing power consumption of the overall device system during full operation. Bosch BMP384 Pressure Sensor is ideal for applications of water-level detection and for precise differential barometric pressure measurement.

Specifications

Low noise, 24-bit
1.2V to 3.6V supply voltage
I²C and SPI interface
±50Pa absolute accuracy rating
200Hz maximum sampling rate
300… 1250hPa operation range
2mm x 2mm x 1mm³ package

more information: https://www.bosch-sensortec.com/products/environmental-sensors/pressure-sensors/bmp384/

Nexperia Silicon Germanium (SiGe) rectifiers offer Cutting-edge high efficiency

Posted on 27 February, 202127 February, 2021 by mixos

Nexperia’s SiGe rectifiers combine the high efficiency of Schottky rectifiers with the thermal stability of fast recovery diodes. Targeting automotive, server markets, and communications infrastructure, the AEC-Q101 compliant rectifiers are of particular benefit in high-temperature applications. These extremely low leakage devices allow an extended safe-operating area with no thermal runaway up to 175 °C. And, at the same time, offer significant room to optimize your design towards higher efficiency.

Nexperia has developed this new rectifier technology based on silicon-germanium (SiGe) for applications in the 100-200V range. Furthermore, they have been developing SiGe rectifier technology in recent years, and already have several patents for the process which address the apparently conflicting demands for high efficiency and high-temperature operation.

Key features

VR of 120 V, 150 V, 200 V
IR of 1, 2, 3 A
Low forward voltage and low Qrr
Extremely low leakage current of < 1nA
Thermal stability up to 175 °C Tj
Fast and smooth switching
Low parasitic capacitance
AEC-Q101 qualified
Space-saving, rugged CFP packaging

more information: https://www.nexperia.com/products/diodes/silicon-germanium-sige-rectifiers/

Diodes’ AL5810Q 60 V adjustable current up to 200 mA linear LED driver offers excellent stability

Posted on 27 February, 2021 by mixos

Diodes Incorporated introduces the AL5810Q, an automotive AEC-Q100 linear LED driver offering an excellent temperature and voltage-current stability with output-adjustable handling capability. The device simplifies the design of LED drivers by setting the LED current with an external resistor using standard value resistors. The AL5810Q has an open-drain output that can swing from 2.0 V up to 60 V supply voltage enabling it to drive long LED chains for high side or low side LED strings. Its low 0.5 V_RSET pin is outside of the LED current path and can maintain current accuracy while minimizing the required overheads to regulate the LED current reducing power dissipation. It makes it ideal for driving LEDs up to 200 mA. The AL5810Q is available in the wettable flank W-DFN2020-3/SWP (Type A) package (2 mm x 2 mm), power dissipation (PD) up to 2 W, and has been qualified to AEC-Q100 Grade-2 with automotive compliant supporting PPAPs available.

Features

AEC-Q100 Grade-2 qualified
Wide input voltage range: 2.0 V to 60 V
Low reference voltage: V_RSET equals 0.5 V
Overtemperature shutdown
Ambient temperature range: -40°C to +105°C
Adjustable sink or source LED current up to 200 mA
±5% LED current tolerance at room temperature
Parallel devices to increase regulated current
Lead-free and RoHS compliant
Halogen- and antimony-free
Available in a wettable W-DFN2020-3/SWP (Type A) (2 mm x 2 mm) PD up to 2 W

more information: https://www.diodes.com/part/view/AL5810Q

Understanding The Ways to Debug Your Raspberry Pi Pico Development Board

Posted on 27 February, 2021 by Abhishek Jadhav

If you want to debug any microcontroller, it can be tricky at times. But with the newly launched Raspberry Pi Pico, we have several options to debug the board. It is now possible to use one Raspberry Pi Pico to debug another Raspberry Pi Pico using the ‘Picoprobe’ application or the traditional way of using SWD protocol.

It is always difficult to figure out what is not working. However, Pico comes with three pins for debugging using the Serial Wire Debug (SWD) protocol. To debug a binary program, you need to build a debug version of the binary and get some additional tools.

The above reference image shows the wiring of Raspberry Pi 4 with Pico board. Connect the SWD port directly to the Raspberry Pi to maintain the signal strength. For more information on this method, refer to “Chapter 5” of the “Getting Started with Raspberry Pi Pico” guide.

What makes Pico debugging different is the additional approach of using one RPi Pico to debug another. Even if you use platforms like Windows, Mac, and Linux, you can still use the ‘Picoprobe’ application. This application allows a Raspberry Pi Pico to act as a USB to SWD and UART converter.

“This interface allows you to add up to four breakpoints and two watchpoints. This gives you more control over how your program runs as you develop software.”

If you plan to try the new approach, the UF2 binary file of ‘Picoprobe’ is available to download on the getting started page. To interface both the Raspberry Pi Pico, use the following reference image. Connect the VSYS pin of both the Raspberry Pi Picos to power them.

If you are using the Windows platform, note that you need to install the ‘Picoprobe’ driver for which details are provided in the “Getting Started with Raspberry Pi Pico” guide. This $4 board has provided everything you can ever expect from a microcontroller with PIOs and support for powerful addons.

Note: All the images are taken from the official Raspberry Pi guide.

nRF91 Based cellular-IoT Tracker For Your Blockchain-Based Applications

Posted on 27 February, 2021 by Tope Oluyemi

IoTeX has launched a campaign on crowdsupply for Pebble Tracker, which is a secure, battery-operated, cellular-IoT prototyping platform designed for blockchain-based applications. Pebble Tracker is based on Nordic Semiconductor’s latest low-power nRF9160 System-in-Package (SiP), and it is powered by open-source firmware. Pebble Tracker enables GPS support, a host of rich sensors, NB-IoT/LTE-M connectivity, and advanced security features which makes it suitable for sophisticated logistical applications where trust is necessary. The cellular IoT prototyping platform as well as the IoTeX blockchain enables developers to design and build innovative, decentralized IoT solutions that go well beyond conventional asset tracking.

Pebble Tracker utilizes open-source firmware and functions properly with developer-friendly tools, with the addition of ThingsBoard, which is an open-source IoT platform for device management, data processing, and data visualization. Pebble Tracker consists of an expansive array of sensors — internal/external GPS, climate (temperature, humidity, air pressure, air quality), motion (acceleration, angular velocity), and light intensity. They enable trustworthy insights into an asset’s environment and movement. Pebble Tracker is verifiable and tamper-proof right from the source. It is transmittable in real-time to the IoTex blockchain of MQTT endpoint of your choice. These are possible because data is cryptographically signed. Pebble Tracker also enables you to convert real-world phenomena into verifiable digital data. By this, you can focus on building innovative asset tracking, remote monitoring, and automation solutions.

Pebble Tracker Nordic Semiconductor’s nRF9160 enables advanced processing and security accessible for low-power, cellular-IoT use cases. The nRF9160 SiP uses an ARM Cortex-M33 dedicated application processor, a multimode LTE-M/NB-IoT modem, and power management abilities to provide high performance, energy efficiency, and unparalleled security.

The nRF9160’s powerful 64 MHz Arm Cortex-M33 processor enables 1 MB of on-chip flash and 256 KB of RAM to enable advanced cellular-IoT applications possible with a single-device solution. Available also is an integrated cellular-IoT modem for LTE-M & NB-IoT which enables Pebble Tracker to operate globally and to connect with mobile network operators via SIM card, therefore eliminating the need for regional variants. The nRF9160 SiP enables power-saving features like eDRX, PSM, IPv4, and IPv6 communication, including TCP transport and TLS security.

Pebble Tracker offers top-notch security with trusted execution abilities via Arm TrustZone, which helps to secure and identify the most critical processes and peripherals for your applications. Its Arm CryptoCell-310 helps improves the security of Pebble Tracker by enabling cryptographic and security resources to protect your applications from attacks. With the combined blockchain + IoT, Pebble Tracker guarantees both the authenticity of data and the verifiability of data processing without needing centralized intermediaries which can lead to errors.

Pebble Tracker enables two backend configurations: hosted and custom. The hosted backend configuration uses open-source software like hmq (MQTT broker), minIO (K8S storage), and ThingsBoard (data visualization) to enable ideation and development in a convenient plug-and-play environment. For custom configuration, you can configure Pebble to send data to any custom backend like AWS IoT Core (device management), AWS S3 (object storage), and ThingsBoard (data visualization). The configuration supports SSL/TLS client certificates, enabling maximum security and scalability.

Features & Specifications

MCU
- Core: Arm Cortex-M33 @ 64 MHz
- Operating supply voltage: 3 V to 5.5 V
- Flash size: 1 MB
- RAM size: 256 KB
- Arm Trust zone
- Arm Cryptocell 310
Modem
- LTE-M / NB-IoT (support in bands from 700 MHz to 2.2 GHz)
- GPS receiver (time-multiplexed with LTE modem)
- Power saving modes
- Secure socket (TLS/DTLS) API
Buzzer
- Frequency: 2700 Hz
- Sound pressure level (dB/min): 85 at 10 cm
Physical
- Weight: ~10 g
- Dimensions: 3.5 cm x 5.3 cm

On-board Sensors

TD1030 GPS
- Position accuracy: 3m
- Speed accuracy: 0.1 m/s
Bosch BME680 Environmental Sensor
- Humidity
- Pressure
- Temperature
- Air Quality (VOCs)
ICM-42605 Motion Sensor
- 3-axis gyroscope
- 3-axis accelerometers
AMS TSL2572 Ambient Light Sensor
- 45,000,000:1 dynamic range
- Up to 60,000 lux in sunlight
- Very high sensitivity
- Package UV rejection filter

Funding ends on Mar 25, 2021 at 04:59 PM PDT (11:59 PM UTC). For more information, visit the campaign page on Crowdsupply.

CP2102 USB to UART Breakout Board Features USB Type-C

Posted on 27 February, 202127 February, 2021 by Saumitra Jagdale

Most of the devices now come with a USB Type-C for interfacing and connectivity. Also, the USB to UART conversion is crucial for interfacing if the working device only supports a UART port. CP2102 features a USB Type-C plug for this conversion from USB to UART. We also saw a USB to UART module based on MCP220 through GPIOs, also compact USB to a UART converter using a CH330 chip with an interface speed of 2Mbps. However, there is no mention of USB Type-C for these devices.

CP2102 USB to UART is a breakout board supporting USB Type-C. The board features the CP2102 chip which belongs to Silicon Labs’ CP210x series dedicated for USB to UART Bridge through virtual COM port drivers that are needed for device functioning to facilitate host communication with CP210x based devices. These devices can also interface with a host using the direct access driver. These drivers make the USB device appear as an additional COM port available to the system.

Block Diagram of CP2102 Chip

Talking more about the CP2102 chip, it has an integrated USB transceiver with no additional need for external resistors. It comes with a 1KB programmable ROM along with the one-time programmable EPROM. The voltage regulator gives a 3.3 V output. The asynchronous serial data bus of the C02102 USB to UART supports 576 bytes receive buffer and a 640 bytes transmit buffer with hardware handshaking functionality.

The device is a fast USB 2.0 compatible that can work at data transfer rates up to 1 Mbaud. Additionally, the board supports not only the common break-out RX/TX/RTS/CTS pins, but it also breaks out almost all the other pins. For more details regarding the break-out pins, you can see them at the back of the board. “The signal pins are 5V tolerant – they should work with both 3.3V and 5V.” The CP2102 USB to UART board also comes with RX and TX LEDs for easing the debug issues by lighting up when data is transferring through an interface.

The motive of creating this device according to Tindie :

“We made this because certain laptops have only one USB A slot but have two USB Type-C slots. So, this board can have my USB-to-UART bridge connected and still have an empty USB A slot. This is even more useful with computers that have only USB Type-C slots.”

The CP2102 USB to UART board is available on Tindie at $5.50 USD. It comes with an assembled CP2102 breakout board with a USB Type-C Plug and a male pin header. For more information visit the product page. Images and technical specifications have also been taken from the product page.