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[FAQ] What are the performance specifications of the HCS logic family at 3.3V operation?

FAQ: Logic and Voltage Translation > Input Parameters >> Current FAQ

This question comes up fairly often because the HCS logic family is specified only at 2V, 4.5V, and 6V.

The following min / max values are interpolated from the datasheet tables, and thus are guaranteed by the datasheet specifications. Typical values are not guaranteed, however they are good estimates of performance under normal operating conditions.

HCS Family Electrical Characteristics

PARAMETER TEST CONDITIONS VCC MIN TYP MAX UNIT
VT+ Positive switching threshold   3.3 V 1.22 1.93 2.358 V
VT- Negative switching threshold   3.3 V 0.768 1.28 2.04 V
ΔVT Hysteresis (VT+ - VT-)   3.3 V 0.408 0.65 1.312 V
VOH High-level output voltage IOH = -20 uA 3.3 V 3.2 3.298   V
IOH = -4 mA 3.3 V   3.14  
VOL Low-level output voltage IOL = 20 uA 3.3 V   0.002 0.1 V
IOL = 4 mA 3.3 V   0.12  

PARAMETER VCC MIN TYP MAX UNIT
fmax Max switching frequency (HCS74) 3.3 32 64 MHz
fmax Max switching frequency (HCS165) 3.3 83 91 MHz
fmax Max switching frequency (HCS595) 3.3 40 74 MHz

Timing specifications are specific to each device -- please use linear interpolation for any timing parameters that need to be checked at 3.3V.

This related FAQ includes an Excel calculator to help speed this process: 

[FAQ] What method is best used for estimating specification values between those given in the datasheet? - Logic forum - Logic - TI E2E support forums