October 2006

CD4093BC - Quad 2-Input 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. The difference between the positive (V_T⁺) and the negative voltage (V_T^-) is defined as hysteresis voltage (V_H).

• Wide supply voltage range: 3.0V to 15V
• Schmitt-trigger on each input
• Noise immunity greater than 50%
• Equal source and sink currents

STMicroelectronics | QUAD 2-INPUT NAND SCHMIDT TRIGGERS - HCF4093

CD4093 is a very useful chip, as it has a Schmitt-trigger and it is a nand, cmos, low power - ananth.

Quad, General Purpose Differential Comparator - LM339 - TI Product Folder




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 V_CC is at least 1.5 V more positive than the input common-mode voltage. Current drain is independent of the supply voltage. The outputs can be connected to other open-collector outputs to achieve wired-AND relationships.

• 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

Zero-Crossing-Triac-Driver-MOC3041

• Simplifies logic control of 115 VAC power
• Zero voltage crossing
• dv/dt of 2000 V/µs typical, 1000 V/µs guaranteed

Ananth -

These were used by me to make solid state relays. Look at the circuits here Power Electronics Circuits. The were used to control Heaters from DC control signal from a Proportional Temperature Controller. The Magnetic Contactors can be avoided for lower powers. At higher powers SCR banks become a bit expensive. The SSR has no mechanical wear and tear but heat up at high currents. So if we overrate by 5 Times then it is an excellent solution for lower power controls upto 5 Kilo Watts. The cycle time of Contactors must be 20-60 Seconds to make it last long. In a SSR a one second cycle time is possible as 10-20mS is the switching speed due to zero crossing.