In the datasheet, the input rise and fall times of general-purpose CMOS logic ICs are specified in the operating ranges in which their functional operation is guaranteed.
Use CMOS logic ICs within the operating ranges to prevent a malfunction due to output oscillation etc.
If a slowly rising or falling signal (a low slew rate signal) is applied to an input, a current spike occurs during switching, causing VCC and GND bounce, which might result in output oscillation or a malfunction.
Use ICs with a Schmitt-trigger input for slowly changing inputs. However, in the case of excessively slowly changing inputs, even ICs with a Schmitt-trigger input might not be able to suppress noise on power supply or signal lines, resulting in output oscillation or instability.
The following table shows the rise and fall times of a typical IC*1 in each series.
Type | Series Name | Series No. | One-Gate Logic (L-MOS) Equivalents | Operating Voltage Range (V) | Propagation Delay Times*1, tpLH and tpHL (ns) | Output Current*2, IOUT (mA) | Rise and Fall Times at 3.3 V | Rise and Fall Times at 5 V |
---|---|---|---|---|---|---|---|---|
For 5-V Systems |
Standard | TC40xxB TC45xxB |
TC4S TC4W |
3 to 18 | 200 (at 5.0 V) |
±0.51 (at 5.0 V) |
0 to 10000 ns *6 | 0 to 5000 ns *6 |
High Speed | TC74HC | TC7S TC7W |
2 to 6 | 23 (at 4.5 V) |
±4.0 or 6.0 (at 4.5 V) (±2.0 in the case of TC7S) |
0 to 1000 ns at 2 V |
0 to 500 ns at 4.5 V |
|
TC74HCT | TC7WT | 4.5 to 5.5 | 28 (at 4.5 V) |
- | 0 to 500 ns | |||
Advanced |
TC74AC | - | 2 to 5.5 | 8.5 (at 4.5 V) |
±24 (at 4.5 V) |
0 to 100 ns/V | 0 to 20 ns/V | |
TC74ACT | - | 4.5 to 5.5 | 9.0 (at 5.0 V) |
- | 0 to 10 ns/V | |||
Very High Speed |
TC74VHC 74VHC |
TC7SH TC7WH |
2 to 5.5 | 8.5 (at 5.0 V) |
±8.0 (at 4.5 V) |
0 to 100 ns/V | 0 to 20 ns/V | |
TC74VHC9 74VHC9 |
10 (at 5.0 V) |
- *5 | - *5 | |||||
TC74VHCT 74VHCT |
TC7SET | 4.5 to 5.5 | 9.5 (at 5.0 V) |
- | 0 to 20 ns/V | |||
TC74VHCV 74VHCV |
- | 1.8 to 5.5 | 8.5 (at 5.0 V) |
±16 (at 4.5 V) |
0 to 20 ms/V | 0 to 1 ms/V | ||
For low-voltage systems |
Medium Speed | TC74LCX 74LCX |
TC7SZ TC7PZ TC7WZ |
1.65 to 3.6 (1.65 to 5.5 in the case of TC7SZ/PZ/WZ) |
6.5 (at 5.0 V) |
±24 (at 3.0 V) |
0 to 10 ns/V | - |
High Speed | TC74VCX | 7UL | 1.2 to 3.6 (0.9 to 3.6 in the case of 7UL) |
4.2 (at 2.3 V) |
±24 (at 3.0 V) (±8.0 in the case of 7UL) |
0 to 10 ns/V | - |
*1: Maximum propagation delay time of typical ICs (TC4001, TC74HC244, TC74AC244, TC74VHC244, TC74LCX244, and TC74VCX244) at 85°C, except for the TC4001 for which the maximum propagation delay time at 25°C is shown
*2: Output current values are specified in the DC Characteristics table shown in the datasheet. Absolute maximum rated output current is specified separately.
*3: The TC7SET series does not have an output power-down protection function.
*4: The ICs of the TC7SZ series in the fSV package do not have an output power-down protection function except those with an open-drain output.
*5: Rise and fall times are not specified because the TC74VHC9 and 74VHC9 series provide Schmitt-trigger inputs.
*6: Rise and fall times are not specified in the datasheet. The values shown above should be considered only as a guide for creating a design.