Saturday, June 23, 2018

CD4060 Binary Counter Divider Oscillator

The CD4020BC, CD4060BC are 14-stage ripple carry binary counters, and the CD4040BC is a 12-stage ripple carry binary counter. The counters are advanced one count on the negative transition of each clock pulse. The counters are reset to the zero state by a logical "1" at the reset input independent of clock.

CD4060 Binary Counter Divider Oscillator

CD4040BC, 12-Stage Ripple Carry Binary Counters
CD4060BC, 14-Stage Ripple Carry Binary Counters

CD4060 - 14-Stage Ripple Carry Binary Counters
you can also use a crystal between pin 10 and 11 with two caps 22pF from 10, 11 to gnd and a 10M resistor between 10 and 11 in place of R C network for more precision.

Tuesday, June 12, 2018

ADuCM360 - Precision Analog Microcontroller

ADuCM360 is a Low power precision analog microcontroller, ARM cortex M3 with dual sigma-delta ADCs. There is an Application note and Evaluation Kit from Analog Devices. This solutions helps you evaluate a part of a Process Control or Data Acquisition module that you may wish to design.

"In the circuit, the ADuCM360 is connected to a Type T thermocouple and a 100 Ω platinum resistance temperature detector (RTD). The RTD is used for cold junction compensation. The low power Cortex-M3 core converts the ADC readings to a real temperature value. The Type T temperature range supported is −200°C to +350°C, and this temperature range is converted to an output current range of 4 mA to 20 mA."

12-Bit, 4-20mA Loop-Powered Thermocouple Measurement System

12-Bit, 4-20mA Loop-Powered System

The thermocouple used in this application is a Type T (copper-constantan) that has a temperature range of −200°C to +350°C. Its sensitivity is approximately 40 μV/°C, which means that the ADC in bipolar mode, with a PGA gain of 32, can cover the entire temperature range of the thermocouple.

The RTD was used for cold junction compensation. The particular one used in this circuit was a platinum 100 Ω RTD, Enercorp PCS 1.1503.1. It is available in a 0805, surface-mount package. This RTD has a temperature variation of 0.385 Ω/°C.

Saturday, June 09, 2018

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

LM3914 - Dot/Bar Display Driver

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.

Millivolt Meter using a LM3914 LED Dot Display

Millivolt Meter using a LM3914 LED Dot Display

More Reading

Tuesday, May 22, 2018

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.

LF398 - Monolithic Sample and Hold Circuit

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.

LF398 - Monolithic Sample and Hold Circuit

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.

Monday, May 21, 2018

LM2575 - Buck Adjustable Switching Regulator

"The buck-boost regulator circuit delivers -5V output. I hoped this would a nice way to generate a negative voltage for e.g. an LCD-display. However this circuit requires component values that are similar to the buck regulator at high load."

The TI Datasheet Layout Guidelines

LM2575 Switching Regulator
LM2575 - Step-Down Adjustable Voltage Switching Regulator with Output Enable

The LM2575 represents a superior alternative to  popular three-terminal linear regulators. Due to its
high efficiency, it significantly reduces the size of the heat sink.

The device also offers internal frequency compensation, a fixed-frequency oscillator, cycle-by-cycle current limiting, and thermal shutdown.

Saturday, May 19, 2018

LM723 Power Electronics Workhorse

This is another versatile and flexible chip. I could design current sources, voltage to current transmitters, level translation and many more. You can think of applications beyond the Power Electronics Scope with this.

LM723 Power Electronics Workhorse

"The circuit provides internal current limiting. When the output current exceeds 150mA an external NPN or PNP pass element may be used. Provisions are made for adjustable current limiting and remote shutdown."

LM723 Power Electronics Workhorse

The LM723/LM723C is also useful in a wide range of other applications such as a shunt regulator, a current regulator or a temperature controller

Some Specs -

Input voltage up to 40V, Output voltage adjustable from 2 to 37V, Output current to 150mA without external pass transistor and Adjustable current limiting.

Friday, March 23, 2018

STMicroelectronics - Industrial and Automotive Semiconductors

STMicroelectronics was created in 1987 by the merger of SGS Microelettronica of Italy and Thomson Semiconducteurs of France. It is well know to engineers for very reliable and robust Power Devices and Integrated Circuits from Analog and Mixed-Power Signal to Embedded Devices.

STMicroelectronics - Industrial and Automotive Semiconductors

Segments include semiconductors for industrial applications, MEMS (Micro-Electro-Mechanical Systems), Sensors and chips for wireless and mobile applications. IC Interface and Management Solutions that are part of computing and embedded Systems.
  • Transistors, Analog & Mixed Signal ICs
  • EMI Filtering & Conditioning
  • Automotive Devices and Systems.
  • Microcontrollers, ARM, ASIC
  • Power Devices and Motor Control
  • Thyristors & ACSwitches and Motor Control
EVAL6235PD demonstration board

EVAL6235PD demonstration board

Fully integrated DMOS three-phase brushless DC motor driver. Used in conjunction with the EVALPRACTISPIN interface board and practiSPIN software, the board provides an evaluation platform to test the features of the L6235 device. In particular, the board provides a means to evaluate the power dissipation performance of the IC in the PowerSO package.

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