Current location - Plastic Surgery and Aesthetics Network - Plastic surgery and beauty - 100 points for help, how to convert LVTTL and TTL grades?
100 points for help, how to convert LVTTL and TTL grades?
TTL output is higher than 2.4V, and the output is low; =2.0V, input low level.

Attention in TTL use: Generally, TTL level overshoot will be serious, and a 22 ohm or 33 ohm resistor may be connected in series at first; When the TTL level input pin is suspended, it is considered high internally. If you want to pull down, use a resistor below 1k to pull down. TTL output cannot drive CMOS input.

Precautions for ECL, PECL and LVPECL: Different levels cannot be directly driven. The middle can be converted by AC coupling, resistance network or special chip.

The above three types are emitter follower output structures, and a resistor must be pulled to DC bias voltage. (such as LVPECL, often used for clocks: used for DC matching.

Pull up 130 Euro and pull down 82 Euro; Ac matching time

Start with 82 Euler and use 130 Euler at the same time. However, after two modes of operation, the DC level is about1.95v. )