1. Home
  2. Electronic Components
  3. T PHL and T PLH: why can they be different?

T PHL and T PLH: why can they be different?

Hi,

Consider the propagation time from H (high) to L (low): T PHL. Consider the propagation time from L to H: T PLH. Why are they generally different (in value)? Note that I'm not here speaking about the propagation delay, T PD defined as max(T PHL, T PLH).

Thanks.

Reply to
Merciadri Luca
Loading thread data ...

Did you read anything about how the circuits work? Look for asymmetries in the device properties and circuit topology.

Hint: the physics of PMOS and NMOS devices are not as similar as they might seem.

Cheers

Phil Hobbs

--
Dr Philip C D Hobbs
Principal
ElectroOptical Innovations
55 Orchard Rd
Briarcliff Manor NY 10510
845-480-2058

email: hobbs (atsign) electrooptical (period) net
http://electrooptical.net
Reply to
Phil Hobbs

s
t

Thanks!

Reply to
Merciadri Luca

Generally, because bipolar transistors aren't symmetrical, top to bottom.

These days, with CMOS, that difference is being eroded.

Hope This Helps! Rich

Reply to
Rich Grise

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.