# integrated-circuit's questions - English 1answer

1.629 integrated-circuit questions.

### 7 What happens to components which stop being manufactured?

When a component/IC stops being manufactured, due to newer, and maybe more efficient, etc, chips becoming available, what happens to the designs? Are they released, so that somebody else can ...

### USB type-B sockets vs USB Mini-B sockets

Most Programmers hardware equipped with USB type-B connectors for connecting to PC. USB Mini-B connectors are much less used in device programmers. Have the USB type-B connectors any advantages or ...

### 2 LM339 Incorrect Behaviour for Two Elements

1 answers, 65 views integrated-circuit comparator
I am designing a monitoring circuit for a battery powered device that is charged from a solar panel. The circuit uses an LM339 to indicate the input voltages via two dual colour LEDs, one for the ...

### Question about using variable reluctance sensor

I am integrating a variable reluctance sensor into my project. These take the the signals produced by inductive pickups and convert them into nice square signals that a processor can use. Quite often, ...

### Quadrature encoder interface loses count

I am trying to read the encoder signal of a drive amplifier using an ARM (TM4C). The amplifier has differential outputs (+- 5V), the MCU has 2 QEIs (Quadrature Encoder Interfaces). First I have ...

### 1 What are those components?

0 answers, 118 views integrated-circuit identification
I am doing a reverse engineer project but I can't find what these components are. Can someone help me? The components have the folowing text on it: IC #1 = 7HUH 7HUH IC #2 = AAPQ AAPQ Here you ...

### DC-DC step up from 3V to over 100V

3 answers, 10.688 views integrated-circuit high-voltage boost
I'm currently building a DC-DC step up circuit to step up 3V to 100V. I don't want to use transformer because i want to keep the circuit as small as possible. My thought is ... building a 30V-output ...

### Wire to VDD or GND?

In the circuit below, there are four LTC485 ICs, one input (left), three for output (right). Pins 2, 3 and 8 are going to +5V, as well as GND. So where should I connect them to? Should I wire them all ...

1 answers, 164 views amplifier integrated-circuit cmos
I have designed amplifiers, using potential division method. What are the steps to design differential amplifier using inversion coefficient based design methodology? Please provide links/...

### -1 Building a device to reduce pulse frequency by a variable amount

A speed sensor on the wheel of a mini motorcycle sends pulses as the wheel rotates. It may send 1, 2 or 4 pulses per tire revolution, so let's say that at top speed, it may have 10, 20 or as many as ...

### Stepper Motor Accel/Decel Ramp for Fixed Frequency Input

1 answers, 266 views integrated-circuit stepper-motor
I have a reasonable working knowledge of electronics but am trying to find a solution to a puzzle I've come across and have not been able to find a complete answer. This involves a stepper motor and I ...

### Damaging BCD-to-decimal decoders?

1 answers, 56 views integrated-circuit high-voltage nixie
(ACTUAL QUESTION IS AT THE BOTTOM) I am a beginner in electronics and am learning more day-by-day to my best. I first got interested in Nixie tubes a few years back, so those are what I play around ...

### 1 Question about equation for LT3750 capacitor charger IC

I have a question about the equation for minimum primary inductance on page 8 of the data sheet for the LT3750 high voltage capacitor charging IC. The equation in question: L_{\text{pri}} \geq \...

### -2 Negative voltage regulator with up to 100 mA current

I want to reverse a board and design a similar one. It is written on its negative regulator eadrfo (in some cases eadrbc). I ...

### -2 Radio Control IC for Firework Detonator [closed]

At the moment I'm attempting to create a fireworks "detonator" for my dad, who thinks it would be neat. I need a way to set off the fireworks remotely with some kind of radio control, ideally from at ...

### SC16IS740IPW alternative - want DIP housing

I am working on Infrared receiver based on Vishay's TFBS4711 and I've added SC16IS740 Single UART with I2C-bus/SPI interface for simplyfing communication with ...

### STP16CPS05 Sink Driver External Resistor does not change output current

1 answers, 51 views led integrated-circuit
Have a 10 x 10 LED array sourced with CD74HC154 Decoder/Demultiplexer to PNP Transistors (rows) and sinked with STP16CPS05 Sink Driver (columns). This is driven with an Atmega328P. Rows and columns ...

### -1 Input impedance of Op amp calculation

1 answers, 65 views integrated-circuit input-impedance
As a part of my project I created an CMOS Op amp and I want to go through all parameters. In Op amps data sheet there are terms like input bias current and input impedance. How this terms are ...

### 6 Is there a lower limit on operating frequency of CMOS SRAM?

3 answers, 629 views integrated-circuit ram
I study computer science, and so I am in the deep end here. I have set upon designing a machine which requires RAM. I found a listing for Toshiba's 128KB (8 bit per word) SRAM (TC551001BPL). I intend ...

### 1 Cannot successfully setup LM741 op amp

I've been trying to setup this op amp for the past couple of hours, and I can't seem to do it successfully. I have a single supply, so I created a voltage divider with resistors to get +ve and -ve. I ...

### Synchronizing IC Temperatures

2 answers, 76 views integrated-circuit heat heatsink
I have several separate identical PCBs with identical ICs on them. It's fairly critical for this application that all the IC's are synchronized in regards to temperature. E.g. if one increases by 1 ...

### 1 How to display 2 digit number in binary adder circuit.?

2 answers, 1.363 views digital-logic integrated-circuit
I've made 4 bit adder circuit using 4008ic. And the sum output of the two 4 bit numbers from that Ic was feed to one bcd to 7seg decoder(74ls47) so that i can get decimal output. But since i cant ...

### 2 Longest, thinnest trace length to decoupling capacitor before capacitor is effectively useless

I was told time and time again to always put decoupling capacitors as close to the IC pin's VCC as possible. Sometimes when I make complex boards, I try my best to put the capacitor lead so close to ...

### 1 VLSI channel routing: Why only route through channels?

1 answers, 30 views integrated-circuit routing vlsi metal
I know that after placement you have your blocks and channels between the blocks. Now, the routing only takes place in the channels. My question is: Why can't we just route 'over' the blocks by ...

### High Side Driver IC - Application Information

I have a question regarding VN5025AJ-E: High side driver IC. Datasheet link - https://www.st.com/resource/en/datasheet/vn5025aj-e.pdf In the figure you can see the application schematic. In the ...

### 8 What capacitors are available in chip design?

2 answers, 1.240 views capacitor integrated-circuit
I've heard of MIM caps and MOM caps in chip design; what are the differences between them? What, if any, other capacitor types available to chip designers? What are the relative advantages and ...

### -4 Knowledge of electronic devices is hard to learn？ [closed]

I want to learn about more about electronics，but I don't know where to start, because there are too many electronic devices out there. If I can, I am willing to learn integrated circuits first, but I ...

### -12v supply from +12v

Part of my circuit needs -12v. What would be the simplest way to get this, considering I have a +12v supply already available in the circuit? I need ~500ma I searched for -12v regulators on Mouser, ...

### 1 Which IC can support LED debug of logical circuits?

1 answers, 68 views integrated-circuit debugging
I am new to electronics, and am playing with some ICs (555, 74393, 74595 and logics like 7400) on the breadboard. To see what happens, I would like to put LEDs at various places in the circuit. But I ...

### 1 I2C monitoring without Microcontroller [closed]

I am trying to read data from an I2C connected touch sensor. Specifically the Azotec IQS266. I plan to preprogram all of the settings the way I want them, and then not touch them again after that. In ...

### -3 Astable 555 not oscillating [closed]

I've been struggling with building a 555 timer for a project. I get the expected voltage at pin 3 (output), but the problem is that it's not oscillating. The Vout is constantly 8.4V, while I expected ...

### HX711 amplifier

I have one of the HX711 ADC devices that I want to use for a weighing application. I've fitted it to a breadboard and used demo firmware to poll the chip for readings. The behaviour is as follows: The ...

### TP4056-42 Without battery temperature sensor

1 answers, 198 views integrated-circuit battery-charging
I would like to create an integrated circuit with the IC TP4056-42 but without the battery temperature sensor. The datasheet speaks that when we do not use temperature sensor we must ground the pin 1 ...

### 4 SOIC -16 IC Orientation

4 answers, 1.174 views integrated-circuit soic
I've just soldered a SOIC-16 am26c32 on to a breakout board. The datasheet shows the orientation of the chip by means of a semi circle at one end (http://www.ti.com/lit/ds/symlink/am26c32.pdf). ...

### How do they make photo lithography lens so accurate?

2 answers, 89 views integrated-circuit circuit-design
How are the lenses and other apparatus required for projecting a miniaturized version of the circuit using photo lithographic technique for IC manfuacture made? Its known that even the tiniest spec ...

### Energy Meter energy calculation from power

I have interfaced a smart energy meter IC (ADE7878) to a microcontroller. The datasheet of the IC can be found here, http://www.analog.com/media/en/technical-documentation/data-sheets/...

### HBQ-i7 Bluetooth Chip Identification

I was recently in Hong Kong and decided to purchase a knockoff Airpod to tear it down and see how it was engineered to help me in my own design process. I got to the mainboard and found the single ...

### Integrated Circuit Epoxy Outer Molding [duplicate]

I'd like to know whether flame retardant epoxy resins, the FR-4 brominated type for instance, are used in the outer molding for integrated circuits or whether it's just a plain epoxy resin. ...

### 7 How to manufacture chip on board?

2 answers, 1.169 views integrated-circuit cmos ttl production cob
I am a developer of a cheap product and i have no experience in mass production. Device is fully functional and represents a single sided PCB, a microcontroller, a bunch of diodes and a few passive ...

### 8-bit shift register Master Reset button not working

I'm using the 74HC595. The datasheet can be found here. Everything works, just the only problem is the Master Reset button is not working. Pressing it to LOW doesn't do anything. I measured the ...

### What's the best internal SoC bus?

1 answers, 86 views fpga integrated-circuit interface soc amba
As far as I know there are two major buses - AMBA/AXI and Wishbone. While AMBA/AXI has proven itself in almost every ARM chip, I didn't find some numbers for Wishbone. Are there any benchmarks or real ...

### Help to identify Video Amp IC - 4 channel used for Analogue RGB video buffer

2 answers, 49 views amplifier integrated-circuit video
Way back some 10 yrs ago I used a Chip for RGB video buffer amplifier.it only provided some 3dB gain. It required no external components , had 4 internal video amplifiers in a 14 pin dil package. I ...

### Is my approach for the RL circuit correct?

For the image above, i(0+) = i(0-) = 0A, and to get the IL(t) function, you solve for Rth, which is 50ohms. Afterwards, i'm confused with how to approach getting IL(t).

### Question concerning equivalent capacitance

For the question above, i'm confused as to why the 6uF and 3uF capacitors have the same charge. Also, for part b, would you have to find v(t) at the 10uF capacitor? If not, what would be the other ...

### Diode vs diode-connected transistor [duplicate]

0 answers, 49 views transistors diodes integrated-circuit
Are there any differencies in functionality between those two or any advantages of one over the other? The only thing that comes to mind why someone would use diode-connected transistors over diodes ...

### Need help to design voltage regulator circuit with LT1959

I am planning to use LT1959 IC for making a voltage regulator circuit for 3V 1A output. The datasheet does not mention maximum allowed value for input capacitor for the circuit. In order to meet the ...

### Design an SMPS to provide 5V – Transformer [closed]

I'm trying to design an integrated IoT device that will replace standard light switches. Currently I'm using a Switching Power Supply from eBay: HLK-PM01, just to have an working prototype. Now I ...

### Optimal method to drive a pair of 10W 28V 0.35A LEDs using PWM for dimming

0 answers, 31 views led integrated-circuit pwm boost led-driver
Using DC/DC boost converter is inevitable because the power supply will be 12V, so the voltage has to be stepped up to at least 28-30 volts. The biggest aspect I am looking at is to have as few ...

### 2 TDA7294 100W Audio Amplifier Causing Unexpected Problems

This is the circuit I will be referring in this question: TDA7294 is described in this data sheet. Upper IC with added external components is a well-known circuit and can be found on many websites ...

### 2 Total Device vs Total Package Dissipation

For my design I need a bunch of 2222A transistors with each transistor dissipating at maximum ~500mW of power. The transistors come in single packages, dual packages, and quad packages. The datasheet ...