- USART, UART, RS232, USB, SPI, I2C, TTL, etc. what are all of these and . . .
Often any 5V logic is called TTL, although most circuits nowadays are built as CMOS Today there are also many circuits that work at 3 3V, which is no longer TTL With respect to the internal levels the levels on the RS-232 line are inverted, +12V corresponds to logical low and -12V corresponds to logical high, which can be confusing
- 什么叫TTL电平？ - 知乎
ttl电平信号被利用的最多是因为通常数据表示采用二进制规定，+5v等价于逻辑"1"，0v等价于逻辑"0"，这就被称做ttl(晶体管-晶体管逻辑电平)信号系统，这是计算机处理器控制的设备内部各部分之间通信的标准技术。
- microcontroller - How does TTL serial work? - Electrical Engineering . . .
Which would be different if it were really TTL, as in your question (the microcontroller is HCMOS) TTL outputs are highly asymmetrical: they can only supply little current, typically 0 4mA Sinking current is OK, at 8mA The low source current may be a problem if the line has a high capacitance and is high speed
- ttl - RS485 signal transmission - Electrical Engineering Stack Exchange
My suspicion is that after the first TTL-485-TTL conversion, the clock-to-data timing is drifting RS485 is inherently multi-drop, so I'd suggest that rather than daisy-chaining the signals you try paralleling all of the receivers up on each transmission pair
- digital logic - What is meant by TTL in this context? - Electrical . . .
Additionally, a user might think that a high signal means "100%", and that a low signal means "0% " Depending on the specific TTL driver, this is not true because of the effective voltages The Chapter "CHANGE THE ANALOG INPUT MODULATION TRANSFER FUNCTION" on page 15 of the linked data sheet shows an example control circuit
- ttl - Tachometer IC that does not require zero-crossings? - Electrical . . .
But what if I have a square, 0-5V TTL input waveform? Can this IC even trigger off of a non-VR input frequency, or do I need to find another tachometer? I can only think to use an op-amp to convert the 0 to 5 V TTL square wave to a -5 to 5 V But that requires a negative voltage supply to the -Vcc rail of the op-amp, which I will not have
- ttl - How do I build an RC-base negative edge detector, that makes a . . .
Here is the trace showing the positive edge pulse too, chopped off by D1 The problem of this is that it works with the switch application that Ben Eater uses, but it might not work driven directly by a TTL device since the momentary current it needs to sink to discharge C3 (a whopping full ampere) is not possible with a TTL device
- ttl - Hardware debouncing using 74LS14 - Electrical Engineering Stack . . .
The 10k impedances are just too high for a LS TTL chip input, the chip input will source current out via the series 10k resistor when the pushbutton is pushed The values would be fine for a chip with CMOS input So the resitors should be in the 1k to 4k7 range
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