Thursday, July 05, 2007

LF398 - Monolithic Sample and Hold Circuit

LF398 - Monolithic Sample and Hold Circuit
The LF198/LF298/LF398  are monolithic sample-and-hold circuits which utilize BI-FET technology to obtain ultra-high dc accuracy with fast acquisition of signal and low droop rate. Operating as a unity gain follower, dc gain accuracy is 0.002% typical and acquisition time is as low as 6 µs to 0.01%. A bipolar input stage is used to achieve low offset voltage and wide bandwidth. Input offset adjust is accomplished with a single pin, and does not degrade input offset drift. The wide bandwidth allows the LF198 to be included inside the feedback loop of 1 MHz op amps without having stability problems. Input impedance of 1010Ohm allows high source impedances to be used without degrading accuracy.
P-channel junction FET's are combined with bipolar devices in the output amplifier to give droop rates as low as 5 mV/min with a 1 µF hold capacitor. The JFET's have much lower noise than MOS devices used in previous designs and do not exhibit high temperature instabilities. The overall design guarantees no feed-through from input to output in the hold mode, even for input signals equal to the supply voltages.

Related Circuits and Projects

Wednesday, July 04, 2007

TDA5051AHome automation modem

TDA5051AHome automation modem

The TDA5051A PDF, is a modem IC, specifically dedicated to ASK transmission by means of the home power supply network, at 600 or 1200 baud data rate. It operates from a single 5 V supply.

  • Full digital carrier generation and shaping
  • Modulation/demodulation frequency set by clock adjustment, from microcontroller or on-chip oscillator
  • High clock rate of 6-bit A/D (Digital to Analog) converter for rejection of aliasing components
  • Fully integrated output power stage with overload protection
  • Automatic Gain Control (AGC) at receiver input
  • 8-bit A/D (Analog to Analog) converter and narrow digital filtering
  • Digital demodulation delivering baseband data
  • Easy compliance with EN50065-1 with simple coupling network
  • Few external components for low cost applications
  • SO16 plastic package.

75015979;USB evaluation kits and USB evaluation kits and reference tools (01-Mar-07)

Tuesday, July 03, 2007

LM3914 - Dot Bar Display Driver

The LM3914 is a monolithic integrated circuit that senses analog voltage levels and drives 10 LEDs, providing a linear analog display. A single pin changes the display from a moving dot to a bar graph. Current drive to the LEDs is regulated and programmable, eliminating the need for resistors. This feature is one that allows operation of the whole system from less than 3V.

LM3914 - Versatile and Easy use Display
  • Drives LEDs, LCDs or vacuum fluorescents
  • Bar or dot display mode externally selectable by user
  • Expandable to displays of 100 steps
  • Internal voltage reference from 1.2V to 12V
  • Operates with single supply of less than 3V
  • LED driver outputs are current regulated, open-collectors
The circuit contains its own adjustable reference and accurate 10-step voltage divider. The low-bias-current input buffer accepts signals down to ground, or V-, yet needs no protection against inputs of 35V above or below ground. The buffer drives 10 individual comparators referenced to the precision divider. Indication non-linearity can thus be held typically to ½%, even over a wide temperature range.

My LM3914 Circuits

Millivolt Meter using a LM3914 LED Dot Display
Millivolt Meter using a LM3914 LED Dot Display

Monday, July 02, 2007

Spread Spectrum and RF Resources

Spread Spectrum and RF Resources

A collection of exceptional resources that will prove useful in your spread spectrum and other wireless projects, ranging from spread spectrum & CDMA tutorials, theory, and circuit diagrams, to development tools, OEM products, and consultants.

RF Resources -

A comprehensive collection of RF & microwave resources for wireless communication engineers. Includes tutorials, theory, design aids, circuit diagrams, products, and more.