CD4093 Quad NAND Schmitt Trigger

The CD4093B consists of four Schmitt-trigger circuits. Each circuit functions as a 2-input NAND gate with Schmitt-trigger action on both inputs. The gate switches at different points for positive and negative-going signals.

CD4093 – Quad 2-Input NAND Schmitt Trigger

The difference be-tween the positive (VTa) and the negative voltage (VTb)isdefined as hysteresis voltage (VH). All outputs have equal source and sink currents and con-form to standard B-series output drive.

CD4093 Quad NAND Schmitt Trigger

CD4093 is a very useful chip, as it has a Schmitt-trigger and it is a nand, cmos, low power.  It can be even made to function like an amp in some configurations. It was used in debouncing circuits, oscillator circuits and input signal conditioning of digital circuits.

DMM range and AC-DC mode Logic

If you had a train of square pulses from a magnetic sensor or proximity sensor. You could use this as a monostable or singleshot to reject noise and get a clean square wave from a messy input.


These devices consist of four independent voltage comparators that are designed to operate from a single power supply over a wide range of voltages. Operation from dual supplies also is possible, as long as the difference between the two supplies is 2 V to 36 V, and VCC is at least 1.5 V more positive than the input common-mode voltage.

Quad General Purpose Differential Comparator – LM339

An application from an old TI datasheet showing the versatility of this comparator. For me it was a workhorse and like LM324 was used in many products.

Quad General Purpose Differential Comparator - LM339
Current drain is independent of the supply voltage. The outputs can be connected to other open-collector outputs to achieve wired-AND relationships.

Differential to TTL convertor using LM339

  • Single Supply or Dual Supplies
  • Wide Range of Supply Voltage:
  • Low Supply-Current Drain Independent of Supply Voltage… 0.8 mA Typ
  • Low Input Bias Current …25 nA Typ
  • Low Input Offset Voltage . . . 2 mV Typ
  • Common-Mode Input Voltage Range Includes Ground
  • Differential Input Voltage Range Equal to Maximum-Rated Supply Voltage . . . ±36 V
  • Low Output Saturation Voltage
  • Output Compatible With TTL, MOS, and CMOS

RF Microwave and Wireless Data Communication

The days of Voice Communication are coming to an end. In fact it has been happening in the background all along. It is Digital Replacing Analog Everywhere. Voice is now data. In the future Voice Communication is just an App you need to buy as an option.

Whatever the struggle between technologies, The future communications will be just Broadband Wireless Devices with Voice, Data and Web all in one. The intermediate technologies we see today, the Transitional Technologies are part of a Large Learning Curve. The future may be more of Optics, WiMax and more like Any Device can do Anything. Not Convergence but more an Intermeshed Collage.

RF Microwave and Wireless Data Communication

This RF is also a Tough Science and needs Authentic and Highly Skilled Engineers to design and develop the technologies for the future. The Budget of the Average consumer will be less, the appetite enormous. The Business Models complex and very challenging. The customer potential is 100% and it will work only if it is affordable and planned carefully. It is not as easy as it looks.

Read and Learn More –

Time and Frequency Circuits and Articles including frequency synthesis and conversion.Spreadsheets/ Programs to calculate pll response, phase noise under vibration, and others.Wenzel Associates Technical Library

Resources for Radio, Radar, RF, Microwave, & Wireless Engineering. Collection of links to various application notes for different RF Vendors. Links to RF equations, technical data sheets, math notes and much more. RF Cafe – Microwave & Wireless Engineering

Cellular and PCS phones, pagers and two-way radios, radio spectrum. Wireless Telecommunications FCC

“The IEEE WCET certification shows that the individual has demonstrated mastery of the internationally recognized body of wireless communication knowledge…” IEEE WCET – Wireless Communications

RF chips, white papers, FCC, a variety of specialty books on various wireless/ spread spectrum / RF areas, and a wide range of other information.Spread Spectrum Scene Online

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. Spread Spectrum and RF Resources

More Reading

With the Wi-Fi and WiMAX becoming essential in Intranet and Internet Networks, and as new low power consumption tablets, netbooks and webbooks become commonplace; RF Microwave learning is important for designers.

It is almost like, every person is a potential user for a Handheld Computer. Which is not only a communicator but more important, News, Knowledge and Information is at his fingertips. This is an empowerment that makes a better worker, student, citizen or a businessman.

delabs Technologies

Basic Analog for Digital Designers

“There is a long gap between engineering college and mid career in a non-engineering position, but technology marches on so a simple method of keeping abreast with the latest developments is required. This application note starts with an overview of the basic laws of physics, progresses through circuits 1 and 2, and explains op amp operation through the use of feedback principles.”

Basic Analog for Digital Designers – Application Note

Basic Analog for Digital Designers

AN9510.2 October 19, 2004 – This is an Analog Reference for the Embedded Engineer. An Application Note from Intersil Tech Reference.

  1. Basic Physics Laws, Circuit Theorems and Analysis
  2. Ohm’s and Kirchoff’s Laws
  3. Voltage and Current Dividers
  4. Thevenin’s and Norton’s Theorems
  5. Networks in the Feedback Path
  6. Types of Opamp Configurations
  7. Video Amplifiers


Some algebra, the basic laws of physics, and the basic circuit laws are adequate to gain an understanding of op amp circuits. By applying these tools to various circuit configurations it is possible to predict performance. Further in-depth knowledge is required to do op amp design, and there are many sources where this knowledge can be obtained. Don’t hesitate to try some of these tricks on your local circuit design engineer, but be aware that it may result in a long lecture about circuit design.

Visual Embedded RAD

Just like an electronic circuit is a graphical representation of what will be on the PCB. Firmware development should be a 2D graphical diagram of what goes into eeprom.

An example is the Ladder Logic software that can program 80C51 types in a Fanuc, Allen Bradley or Siemens PLCs. Then many people can do at least restricted firmware programming for some embedded solutions.

Build a DMM or digital multi meter

Visual Embedded RAD. This is more like code snippets inserted in code in the background when user drags and drops a Hardware Function or Program Method. The Environment is Visual, but Code is compact as same modules or blocks used. There is no C or Intermediate Language. Visual to Binary Hex Direct.

(Idea – Mar-04, Revised again – 4 April 2008, Nature – Open Source Anantha Narayan )

The Motor Bicycle

At late 40s I am into riding Geared Cycles. A Cycle Guru says it is the ‘Cadence’ in pedaling speed. What I need is a ‘Mentor’ for the Methodology behind Optimum Gear usage.

Mixed Circuits Analog with Digital

But some people are developing what will become well known as The Motor Bicycle, funny names.

Updated Nov 2015

Constant LED Brightness and LDS8711

The LDS8711 is a fixed frequency current mode boost converter with internal rectifier and cycle-by- cycle switch current limit specifically designed to drive a string of up to 10 White LEDs.

Constant LED Brightness and LDS8711

Aa Switching Converter Chip with hardly any external components driving a HB LED chain. HB – High Brightness LED. This IC is from IXYS Power Devices.

High efficiency boost converter with the input voltage range from 2.7 to 5.5 V . Drives one LED string with 10 LEDs in series up to 32 mA.

  • 250 mV current sense voltage
  • No external Schottky Required
  • 0.7 MHz Switching Frequency
  • Efficiency greater than 83%
  • PWM LED Brightness Control
  • Low Shutdown Current (<1µA)

LED Current Setting – The maximum current value in the LED string may be factory preset in the range from 10 to 30mAin 0.125mA steps, or set by Smart OneWire interface in the range from 0.125to 32 mA.The average LED string current that determines LED brightness may be controlled applying PWM signal to the EN/PWM pin.

74HCT373 Octal transparent D-type latches

CD74HCT373 – High Speed CMOS Logic Octal Transparent Latches with 3-State Outputs

The ‘HCT373 devices are octal transparent D-type latches. When the latch-enable (LE) input is high, the Q outputs follow the data (D) inputs. When LE is low, the Q outputs are latched at the logic levels of the D inputs.

From – 74HCT373 Texas Instruments

What it can do ?

This is like a Byte of Memory, A Byte means 8 Bits. A Bit Means one Input or Output Pin of an IC, Which understands Logic 1 is High and Logic 0 is Low.

74HCT373 Octal transparent D-type latches

The HCT works well with old TTL and CMOS families. This takes very less Power (battery lasts longer). It switches very fast (the computation is done faster). Its got good symmetrical output drive. Means Source and Sink both nice.

When you run out of ports I/O in your favorite uC, This guy will come to your rescue. Simple way is to Put four of this and Interconnect or Bus their Data inputs D0-D7. Then Connect this Bus to 8 Ports of our uC Chip. Enable the Output of all of them. Use 4 ports from your uC to latch each one with the data you want to be outputted. Now you have 8×4 32 Bits output. This comes at a small cost, the clock time, but negligible. In the same way you can enhance the Input ports, use the 373, the other way around with OE.

This all means more Keys, Sensors, Motors, Relays can be accommodated. By Multiplexing Matrix even more can be achieved. You can also expand Analog Inputs using Analog Multiplexers. Try CD4051 or even FETs.