Datasheet

ManualsBrandsTEXAS INSTRUMENTS ManualsLinear ICsN/A Case type SO8 Type (misc.) Timer Case type SO8 Type (misc.) Timer

LM555

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SNAS548B –MAY 2004–REVISED JULY 2006

LM555 Timer

Check for Samples: LM555

FEATURES

APPLICATIONS

• Direct replacement for SE555/NE555

• Precision timing

• Timing from microseconds through hours • Pulse generation

• Operates in both astable and monostable • Sequential timing

modes

• Time delay generation

• Adjustable duty cycle

• Pulse width modulation

• Output can source or sink 200 mA

• Pulse position modulation

• Output and supply TTL compatible

• Linear ramp generator

• Temperature stability better than 0.005% per

°C

• Normally on and normally off output

• Available in 8-pin MSOP package

DESCRIPTION

The LM555 is a highly stable device for generating accurate time delays or oscillation. Additional terminals are

provided for triggering or resetting if desired. In the time delay mode of operation, the time is precisely controlled

by one external resistor and capacitor. For astable operation as an oscillator, the free running frequency and duty

cycle are accurately controlled with two external resistors and one capacitor. The circuit may be triggered and

reset on falling waveforms, and the output circuit can source or sink up to 200mA or drive TTL circuits.

SCHEMATIC DIAGRAM

Please be aware that an important notice concerning availability, standard warranty, and use in critical applications of

Texas Instruments semiconductor products and disclaimers thereto appears at the end of this data sheet.

2All trademarks are the property of their respective owners.

PRODUCTION DATA information is current as of publication date.

Products conform to specifications per the terms of the Texas

Instruments standard warranty. Production processing does not

necessarily include testing of all parameters.

Summary of content (20 pages)

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LM555 www.ti.com SNAS548B – MAY 2004 – REVISED JULY 2006 LM555 Timer Check for Samples: LM555 FEATURES APPLICATIONS • • • • • • • • • • 1 2 • • • • • • Direct replacement for SE555/NE555 Timing from microseconds through hours Operates in both astable and monostable modes Adjustable duty cycle Output can source or sink 200 mA Output and supply TTL compatible Temperature stability better than 0.
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LM555 SNAS548B – MAY 2004 – REVISED JULY 2006 www.ti.com Connection Diagram Dual-In-Line, Small Outline and Molded Mini Small Outline Packages Figure 1. Top View These devices have limited built-in ESD protection. The leads should be shorted together or the device placed in conductive foam during storage or handling to prevent electrostatic damage to the MOS gates.
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LM555 www.ti.com SNAS548B – MAY 2004 – REVISED JULY 2006 Electrical Characteristics (1) (2) (TA = 25°C, VCC = +5V to +15V, unless otherwise specified) Parameter Conditions Limits Units LM555C Min Supply Voltage Typ 4.5 Max 16 V 6 15 mA VCC = 5V, RL = ∞ VCC = 15V, RL = ∞ (Low State) (3) 3 10 1 % RA = 1k to 100kΩ, 50 ppm/°C Accuracy over Temperature 1.5 % Drift with Supply 0.1 %/V 2.25 % 150 ppm/°C 3.
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LM555 SNAS548B – MAY 2004 – REVISED JULY 2006 www.ti.com Electrical Characteristics (1) (2) (continued) (TA = 25°C, VCC = +5V to +15V, unless otherwise specified) Parameter Conditions Limits Units LM555C Min Typ ISOURCE = 100mA, VCC = 15V 12.75 13.3 V VCC = 5V 2.75 3.
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LM555 www.ti.com SNAS548B – MAY 2004 – REVISED JULY 2006 Typical Performance Characteristics Minimum Pulse Width Required for Triggering Supply Current vs. Supply Voltage High Output Voltage vs. Output Source Current Low Output Voltage vs. Output Sink Current Low Output Voltage vs. Output Sink Current Low Output Voltage vs.
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LM555 SNAS548B – MAY 2004 – REVISED JULY 2006 www.ti.com Typical Performance Characteristics (continued) Output Propagation Delay vs. Voltage Level of Trigger Pulse Output Propagation Delay vs. Voltage Level of Trigger Pulse Discharge Transistor (Pin 7) Voltage vs. Sink Current Discharge Transistor (Pin 7) Voltage vs. Sink Current APPLICATIONS INFORMATION MONOSTABLE OPERATION In this mode of operation, the timer functions as a one-shot (Figure 2).
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LM555 www.ti.com SNAS548B – MAY 2004 – REVISED JULY 2006 The voltage across the capacitor then increases exponentially for a period of t = 1.1 RA C, at the end of which time the voltage equals 2/3 VCC. The comparator then resets the flip-flop which in turn discharges the capacitor and drives the output to its low state. Figure 3 shows the waveforms generated in this mode of operation.
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LM555 SNAS548B – MAY 2004 – REVISED JULY 2006 www.ti.com Figure 5. Astable In this mode of operation, the capacitor charges and discharges between 1/3 VCC and 2/3 VCC. As in the triggered mode, the charge and discharge times, and therefore the frequency are independent of the supply voltage. Figure 6 shows the waveforms generated in this mode of operation. VCC = 5V TIME = 20μs/DIV. RA = 3.9kΩ RB = 3kΩ C = 0.01μF Top Trace: Output 5V/Div. Bottom Trace: Capacitor Voltage 1V/Div. Figure 6.
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LM555 www.ti.com SNAS548B – MAY 2004 – REVISED JULY 2006 Figure 7. Free Running Frequency FREQUENCY DIVIDER The monostable circuit of Figure 2 can be used as a frequency divider by adjusting the length of the timing cycle. Figure 8 shows the waveforms generated in a divide by three circuit. VCC = 5V Top Trace: Input 4V/Div. TIME = 20μs/DIV. Middle Trace: Output 2V/Div. RA = 9.1kΩ Bottom Trace: Capacitor 2V/Div. C = 0.01μF Figure 8.
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LM555 SNAS548B – MAY 2004 – REVISED JULY 2006 www.ti.com VCC = 5V Top Trace: Modulation 1V/Div. TIME = 0.2 ms/DIV. Bottom Trace: Output Voltage 2V/Div. RA = 9.1kΩ C = 0.01μF Figure 10. Pulse Width Modulator PULSE POSITION MODULATOR This application uses the timer connected for astable operation, as in Figure 11, with a modulating signal again applied to the control voltage terminal. The pulse position varies with the modulating signal, since the threshold voltage and hence the time delay is varied.
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LM555 www.ti.com SNAS548B – MAY 2004 – REVISED JULY 2006 LINEAR RAMP When the pullup resistor, RA, in the monostable circuit is replaced by a constant current source, a linear ramp is generated. Figure 13 shows a circuit configuration that will perform this function. Figure 13. Figure 14 shows waveforms generated by the linear ramp. The time interval is given by: (6) (7) VBE ≃ 0.6V VCC = 5V Top Trace: Input 3V/Div. TIME = 20μs/DIV. Middle Trace: Output 5V/Div.
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LM555 SNAS548B – MAY 2004 – REVISED JULY 2006 www.ti.com Figure 15. 50% Duty Cycle Oscillator Note that this circuit will not oscillate if RB is greater than 1/2 RA because the junction of RA and RB cannot bring pin 2 down to 1/3 VCC and trigger the lower comparator. ADDITIONAL INFORMATION Adequate power supply bypassing is necessary to protect associated circuitry. Minimum recommended is 0.1μF in parallel with 1μF electrolytic.
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PACKAGE OPTION ADDENDUM www.ti.
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PACKAGE OPTION ADDENDUM www.ti.com 9-Feb-2013 Green (RoHS & no Sb/Br): TI defines "Green" to mean Pb-Free (RoHS compatible), and free of Bromine (Br) and Antimony (Sb) based flame retardants (Br or Sb do not exceed 0.1% by weight in homogeneous material) (3) MSL, Peak Temp. -- The Moisture Sensitivity Level rating according to the JEDEC industry standard classifications, and peak solder temperature. (4) Only one of markings shown within the brackets will appear on the physical device.
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PACKAGE MATERIALS INFORMATION www.ti.com 17-Nov-2012 TAPE AND REEL INFORMATION *All dimensions are nominal Device Package Package Pins Type Drawing SPQ Reel Reel A0 Diameter Width (mm) (mm) W1 (mm) B0 (mm) K0 (mm) P1 (mm) W Pin1 (mm) Quadrant LM555CMM VSSOP DGK 8 1000 178.0 12.4 5.3 3.4 1.4 8.0 12.0 Q1 LM555CMM/NOPB VSSOP DGK 8 1000 178.0 12.4 5.3 3.4 1.4 8.0 12.0 Q1 LM555CMMX/NOPB VSSOP DGK 8 3500 330.0 12.4 5.3 3.4 1.4 8.0 12.
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PACKAGE MATERIALS INFORMATION www.ti.com 17-Nov-2012 *All dimensions are nominal Device Package Type Package Drawing Pins SPQ Length (mm) Width (mm) Height (mm) LM555CMM VSSOP DGK 8 1000 203.0 190.0 41.0 LM555CMM/NOPB VSSOP DGK 8 1000 203.0 190.0 41.0 LM555CMMX/NOPB VSSOP DGK 8 3500 349.0 337.0 45.0 LM555CMX SOIC D 8 2500 349.0 337.0 45.0 LM555CMX/NOPB SOIC D 8 2500 349.0 337.0 45.
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