MichaelZ writes: While poking around SparkFun’s website I found USB Host Shield which is only marginally interesting unless you are an Arduino fan. But the USB host controller chip is interesting. The MAX3421E is a USB Peripheral/Host Controller with SPI Interface. This is an alternate to the FTDI VNC USB host controllers. It has only […]
Category Archives: app notes
High temperature floating point digital signal controller
McZ writes: I have used the SM320F28335-HT microcontroller in several projects including military applications. With the floating point it is blinding fast. The standard temperature comes in a QFP and the high temp version comes in a Ceramic Pin Grid Array which is more friendly than the BGA’s. The TI compiler/IDE is cheap by high […]
App note: smart card communication using PIC MCUs
Microchip has released a new application note explaining smart card communication using PIC MCUs. This is a good read for beginners, taking you from the basics of what a smart card is, to how data I/O occurs and how to build a PC-to-smart card interface using the PIC18F14K50.
App note: Monitor negative power supplies
Precision circuit monitors negative-supply threshold: Using an IC (MAX971) that includes an open-drain comparator and a precision 1% voltage reference, this circuit monitors the magnitude of a negative supply voltage and provides a digital warning of fault conditions. To monitor multiple negative voltages, use the MAX974, which includes four comparators. Thanks for the tip rsdio!
App note: MAX16834 high-power LED driver
rsdio writes: Why regulate the voltage from your supply when you really need a controlled current to drive an LED? Any regulator is less than 100% efficient, and the losses increase as more current is drawn. It looks like the circuit in this application note would allow you to skip the voltage regulator and thus […]
App note: Long twisted pair reads digital temperature sensor
This digital temperature sensor design uses a twisted cable pair to read the sensor over long distances: This circuit is a simple and economical interface for remote IC thermal sensors. The temperature sensor (MAX6576), an absolute temperature-to-period converter that integrates the sensor with the necessary signal electronics, connects to the receiver (a MAX9140 comparator) using […]
The basics of USB battery charging: a survival guide
An introduction to USB battery charging: a survival guide Arguably the most useful part of USB’s power capabilities is the ability to charge batteries in portable devices, but there is more to battery charging than picking a power source, USB or otherwise. This is particularly true for Li+ batteries, where improper charging can not only […]
Low-Power, 8-Channel, 24-Bit Analog front-end for biopotential measurements
The TI ADS1298R could be perfect for that EKG project you dreamed of. It has a 8 analog to digital converters with programmable gain amplifiers, an internal reference, and a clock source. The ADS1294/6/8/4R/6R/8R incorporate all of the features that are commonly required in medical electrocardiogram (ECG) and electroencephalogram (EEG) applications. FEATURES Eight Low-Noise PGAs […]
App note: Intro to digital communications systems
Digital modulation techniques are seeing increasing use worldwide. In the US, the FCC is actually mandating narrowband digital mobile radio (DMR) for certain Land Mobile Radio (LMR) users as explained in this Digital Mobile Radio Association white paper. Datasheets for various chips increasingly made reference to acronyms like GMSK, FSK and others. Agilent has published […]
App notes: RGB LED driver reference design
An introduction to RGB LED driver reference design for a low-power projector. This application note is an RGB LED driver reference design for a low-power projector. The design features a single MAX16821 HB LED driver to drive the RGB LEDs one at a time. This approach reduces the components needed, resulting in an efficient, small, […]
Notes on the SMBus
The System Management Bus (SMBus) was defined by Intel® Corporation in 1995. It was originally used in personal computers and servers for low-speed system management communications. It is more or less a derivative of the I2C bus. The current SMBus specification document is Version 2. Today the SMBus is being used in a small but […]
App note: High-quality white noise generator
A white noise circuit could be interesting part of a modular synthesizer. This design has no 1/f component, meaning no annoying repeating sounds in the white noise. In this noise-generator circuit, the amplifier (MAX4238) has no 1/f component in its input voltage noise. It amplifies its own input-voltage noise with a feedback network made with […]
App note: Hot-surface warning light with no external power
This design harvests heat energy to make electricity, and uses it to flash a warning light. Flashing LED hot-surface detector: Using a thermoelectric generator (TEG) to sense the temperature of a surface and a step-up switching regulator to boost the TEG output to a useful level, this warning circuit flashes a high-brightness LED when the […]
FTDI FT232H single channel USB 2.0 chip
MichaelZ writes: Well FTDI is at it again. FT232H is a Single Channel Hi-Speed USB to Multipurpose UART/FIFO IC. It appears to be 1/2 of a FT2232H which requires the crystal and EEPROM. It’s a single MPSSE (JTAG, serial module) version of the FT2232H used in the Bus Blaster, and it comes in a friendly […]
Xilinx XC9500 CPLD docs
Here’s a quick link to the Xilinx library of support documentation for the XC9500 series of CPLDs. Datasheets, user guide, app notes and more!
App note: Locked-sync sine generator
rsdio sends an app note: Locked-sync sine generator This circuit synchronizes a sinewave output through three decades of frequency (20Hz to 20kHz) while maintaining low THD and constant amplitude. Thanks for the tip!
App note: Bridge from USB to I²C
rsdio tipped us to an app note on interface circuits: hmm… breakout board candidate? This circuit provides a direct I²C interface to your PC’s USB port. A USB to 1-Wire® dongle supplies the PC with a 1-Wire master, which controls a 1-Wire I/O extender. This I/O extender has two bidirectional open drain ports, which the […]
App note: One-wire control of SPI peripherals
rsdio presents: 1-Wire network via an SPI-compatible display controller. To produce the 3-wire SPI™ interface required by a MAX7221 display controller (active-low CS, DIN, and CLK), this 1-Wire network serially addresses three 1-Wire switches (DS2413). The first switch creates Chip Select directly (active-low CS), the second creates the serial-data line directly (DIN), and the third […]
MAX8934G dual-input linear Li-Poly battery charger
rsdio serves us another heaping helping of interesting parts today. Check out the MAX8934G dual-input Li+/Li-Poly linear battery charger: Monitors temperature to ensure safe charging and JEITA battery charging specification compliance Charges safely by lowering the termination voltage and charge rate in hot or cold temperature Includes all integrated MOSFETs Delivers smart power path control […]
64-channel, current-input analog-to-digital converter
MichaelZ tipped us to a 64-channel, current-input analog-to-digital converter The DDC264 is a 20-bit, 64-channel, current-input analog-to-digital (A/D) converter. It combines both current-to-voltage and A/D conversion so that 64 separate low-level current output devices, such as photodiodes, can be directly connected to its inputs and digitized. For each of the 64 inputs, the DDC264 uses […]