CD74HCT240: SN74HCT240

Danny Yamashiro

Prodigy 10 points

Part Number: CD74HCT240
Other Parts Discussed in Thread: SN74HCT240, , SN74HCS240

Tool/software:

What is the difference between CD74HCT240 and SN74HCT240

3 months ago

0 Clemens Ladisch 3 months ago

Guru 316760 points

CD devices were originally made by RCA, then acquired by Harris and later by TI. SN devices were always made by TI.

Nowadays, they are identical.

0 Danny Yamashiro 3 months ago in reply to Clemens Ladisch

Prodigy 10 points

The data sheets for the CD and SN additional current for inputs not at 0 or Vcc is different. Almost triple, although the CD specifies the input voltage at Vcc-2.1 V and the SN is at 2.4V.

0 Malcolm Lyn 3 months ago in reply to Danny Yamashiro

TI__Mastermind 26100 points

Hi Danny,

CD devices are all going to be on older processes. Most SN devices will be on more modern CMOS processes which is why the spec is better.

Best,

Malcolm

+1 Clemens Ladisch 3 months ago in reply to Danny Yamashiro

Guru 316760 points

For voltages further away from V_CC, the shoot-through current is higher. The graph below shows typical values for the SN74HCS240 (which uses the same process, but has more hysteresis):

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CD74HCT240: SN74HCT240