SCHMITT TRIGGERS DUAL GATE/HEX INVERTER
The SN54LS/ 74LS13 and SN54LS / 74LS14 contain logic gates / inverters which accept standard TTL input signals and provide standard TTL output levels. They are capable of transforming slowly changing input signals into sharply defined, jitter-free output signals. Additionally, they have greater noise margin than conventional inverters. Each circuit contains a Schmitt trigger followed by a Darlington level shifter and a phase splitter driving a TTL totem pole output. The Schmitt trigger uses positive feedback to effectively speed-up slow input transitions, and provide different input threshold voltages for positive and negative-going transitions. This hysteresis between the positive-going and negative-going input thresholds (typically 800 mV) is determined internally by resistor ratios and is essentially insensitive to temperature and supply voltage variations. LOGIC AND CONNECTION DIAGRAMS
VCC 14 13 SN54 / 74LS13 12 11 10 9 8
SN54/74LS13 SN54/74LS14
SCHMITT TRIGGERS DUAL GATE/ HEX INVERTER
LOW POWER SCHOTTKY
J SUFFIX CERAMIC CASE 632-08
14 1
14 1
N SUFFIX PLASTIC CASE 646-06
1
2
3
4
5
6
7 GND
14 1
D SUFFIX SOIC CASE 751A-02
VCC 14 13
SN54 / 74LS14 12 11 10 9 8
ORDERING INFORMATION
SN54LSXXJ SN74LSXXN SN74LSXXD Ceramic Plastic SOIC
1
2
3
4
5
6
7 GND
GUARANTEED OPERATING RANGES
Symbol VCC TA IOH IOL Supply Voltage Operating Ambient Temperature Range Output Current — High Output Current — Low Parameter 54 74 54 74 54, 74 54 74 Min 4.5 4.75 – 55 0 Typ 5.0 5.0 25 25 Max 5.5 5.25 125 70 – 0.4 4.0 8.0 Unit V °C mA mA
FAST AND LS TTL DATA 5-24
SN54/74LS13 • SN54/74LS14
DC CHARACTERISTICS OVER OPERATING TEMPERATURE RANGE (unless otherwise specified)
Limits Symbol VT+ VT– VT+ – VT– VIK VOH Parameter Positive-Going Threshold Voltage Negative-Going Threshold Voltage Hysteresis Input Clamp Diode Voltage 54 Output HIGH Voltage 74 54, 74 VOL IT+ IT– IIH IIL IOS Output LOW Voltage 74 Input Current at Positive-Going Threshold Input Current at Negative-Going Threshold Input HIGH Current 0.1 Input LOW Current Short Circuit Current (Note 1) Power Supply Current LS13 Total, Output HIGH ICC Total, Output LOW LS14 LS13 LS14 2.9 8.6 4.1 12 6.0 16 7.0 21 mA VCC = MAX – 20 – 0.4 –100 0.35 – 0.14 – 0.18 1.0 20 0.5 V mA mA µA mA mA mA 2.7 3.4 0.25 0.4 V V 2.5 Min 1.5 0.6 0.4 0.8 – 0.65 3.4 – 1.5 Typ Max 2.0 1.1 Unit V V V V V Test Conditions VCC = 5.0 V VCC = 5.0 V VCC = 5.0 V VCC = MIN, IIN = – 18 mA VCC = MIN, IOH = – 400 µA, VIN = VIL VCC = MIN, IOL = 4.0 mA, VIN = 2.0 V VCC = MIN, IOL = 8.0 mA, VIN = 2.0 V VCC = 5.0 V, VIN = VT+ VCC = 5.0 V, VIN = VT– VCC = MAX, VIN = 2.7 V VCC = MAX, VIN = 7.0 V VCC = MAX, VIN = 0.4 V VCC = MAX, VOUT = 0 V
Note 1: Not more than one output should be shorted at a time, nor for more than 1 second.
AC CHARACTERISTICS (TA = 25°C)
Max Symbol tPLH tPHL Parameter Propagation Delay, Input to Output Propagation Delay, Input to Output LS13 22 27 LS14 22 22 Unit ns ns Test Conditions VCC = 5.0 V CL = 15 pF
3V VIN 0V tPHL tPLH 1.6 V 0.8 V
VOUT
1.3 V
1.3 V
Figure 1. AC Waveforms
FAST AND LS TTL DATA 5-25
SN54/74LS13 • SN54/74LS14
5 V O , OUTPUT VOLTAGE (VOLTS) 4
VCC = 5 V TA = 25°C
3
2
1
0
0
0.4
0.95 1.2 VIN, INPUT VOLTAGE (VOLTS)
1.8
2
Figure 2. VIN versus VOUT Transfer Function
2 V T , THRESHOLD VOLTAGE (VOLTS) ∆ V T, HYSTERESIS (VOLTS)
TA = 25°C VT+
1.6
1.2 VT– 0.8 ∆ VT
0.4
0 4.5
4.75 5 5.25 VCC, POWER SUPPLY VOLTAGE (VOLTS)
5.5
Figure 3. Threshold Voltage and Hysteresis versus Power Supply Voltage
1.9 V T , THRESHOLD VOLTAGE (VOLTS) ∆ V T, HYSTERESIS (VOLTS) 1.7 1.5 1.3 1.1 0.9 0.7 – 55° VT– ∆ VT 0° 25° 75° TA, AMBIENT TEMPERATURE (°C) VT+
125°
Figure 4. Threshold Voltage Hysteresis versus Temperature
FAST AND LS TTL DATA 5-26
