NE555
xx555 Precision Timers
Manufacturer
Texas Instruments
Overview
Part: xx555 Precision Timers
Type: Precision Timer
Key Specs:
- Timing range: microseconds to hours
- Output current: up to 200mA (sink or source)
- Supply voltage: 5V to 15V
Features:
- Astable or monostable operation
- Adjustable duty cycle
- TTL-compatible output
- Timed interval controlled by a single external resistor and capacitor network
- Frequency and duty cycle controlled independently with two external resistors and a single external capacitor
- Trigger level: approximately one-third of the supply voltage
- Threshold level: approximately two-thirds of the supply voltage
- Control voltage pin (CONT) for altering levels
- Reset input (RESET) overrides all other inputs
Applications:
- Pulse-shaping circuits
- Missing-pulse detectors
- Pulse-width modulators
- Pulse-position modulators
- Sequential timers
- Pulse generators
- Frequency dividers
- Industrial controls
Package:
- D (SOIC, 8)
- P (PDIP, 8)
- PS (SO, 8)
- PW (TSSOP, 8)
- FK (LCCC, 20)
- JG (CDIP, 8)
Features
- Timing from microseconds to hours
- Astable or monostable operation
- Adjustable duty cycle
- TTL-compatible output can sink or source up to 200mA
- On products compliant to MIL-PRF-38535, all parameters are tested unless otherwise noted. On all other products, production processing does not necessarily include testing of all parameters.
Applications
- Pulse-shaping circuits
- Missing-pulse detectors
- Pulse-width modulators
- Pulse-position modulators
- Sequential timers
- Pulse generators
- Frequency dividers
- Industrial controls
Simplified Schematic
Pin Configuration
NA555...D OR P PACKAGE NE555...D, P, PS, OR PW PACKAGE SA555...D OR P PACKAGE SE555...D, JG, OR P PACKAGE (TOP VIEW)
NC - No internal connection
Table 4-1. Pin Functions
| | PIN |
|-----------------|----------------------------------------------------|------------------------------------------------|--------------|---------------------------------------------------------------------------------------|
| | NO | D . |
| NAME | D (SOIC), P (PDIP), PS (SO), PW (TSSOP), JG (CDIP) | | TYPE | DESCRIPTION |
| CONT | 5 | 12 | Input/output | Controls comparator thresholds, Outputs 2/3 × VCC, allows bypass capacitor connection |
| DISCH | 7 | 17 | Output | Open collector output to discharge timing capacitor |
| GND | 1 | 2 | _ | Ground |
| NC | _ | 1, 3, 4, 6, 8, 9,
11, 13, 14, 16,
18, 19 | _ | No internal connection |
| OUT | 3 | 7 | Output | High current timer output signal |
| RESET | 4 | 10 | Input | Active low reset input forces output and discharge low. |
| THRES | 6 | 15 | Input | End of timing input. THRES > CONT sets output low and discharge low |
| TRIG | 2 | 5 | Input | Start of timing input. TRIG < ½ CONT sets output high and discharge open |
| V CC | 8 | 20 | _ | Input supply voltage, 4.5V to 16V. SE555 maximum is 18V. |
Electrical Characteristics
at VCC = 5V to 15V and TA = 25°C (unless otherwise noted)
| PARAMETER | TEST CONDITIONS | | MIN | TYP | MAX | UNIT |
|--------------------------------|---------------------------------|---------------------|------|------|------|------|--|
| | | NA555, NE555, SA555 | 8.8 | 10 | 11.2 |
| | VCC = 15V | SE555 | 9.4 | 10 | 10.6 |
| THRES voltage level | | NA555, NE555, SA555 | 2.4 | 3.3 | 4.2 | V |
| | VCC = 5V | SE555 | 2.7 | 3.3 | 4 |
| THRES current(1) | | | | 30 | 250 | nA |
| | | NA555, NE555, SA555 | 4.5 | 5 | 5.6 |
| | VCC = 15V | SE555 | 4.8 | 5 | 5.2 |
| TRIG voltage level | VCC = 15V, TA = –55°C to +125°C | SE555
3 |
| | | NA555, NE555, SA555 | 1.1 | 1.67 | 2.2 | V |
| | VCC = 5V | SE555 | 1.45 | 1.67 | 1.9 |
| | VCC = 5V, TA = –55°C to +125°C | SE555 | | | 1.9 |
| | | NA555, NE555, SA555 | | 0.5 | 2 | μA |
| TRIG current | TRIG at 0V | SE555 | | 0.5 | 0.9 |
| RESET voltage level | | | 0.3 | 0.7 | 1 | V |
| | TA = –55°C to +125°C | SE555 | | | 1.1 |
| | RESET at VCC | | | 0.1 | 0.4 |
| RESET current | | NA555, NE555, SA555 | | –0.4 | –1.5 | mA |
| | RESET at 0V | SE555 | | –0.4 | –1 |
| DISCH switch off-state current | | | | 20 | 100 | nA |
| DISCH switch on-state voltage | VCC = 5V, IO = 8mA | NA555, NE555, SA555 | | 0.15 | 0.4 | V |
Absolute Maximum Ratings
over operating free-air temperature range (unless otherwise noted)(1)
| MIN | MAX | UNIT | |||
|---|---|---|---|---|---|
| VCC | Supply voltage(2) | 18 | V | ||
| VI | Input voltage | CONT, RESET, THRES, TRIG | VCC | V | |
| IO | Output current | ±225 | mA | ||
| TJ | Operating virtual junction temperature | 150 | °C | ||
| Case temperature for 60 seconds | FK package | 260 | °C | ||
| Lead temperature 1.6mm (1/16 inch) from case | JG package, 60 seconds | 300 | °C | ||
| Tstg | Storage temperature | –65 | 150 | °C |
(1) Operation outside the Absolute Maximum Ratings may cause permanent device damage. Absolute Maximum Ratings do not imply functional operation of the device at these or any other conditions beyond those listed under Recommended Operating Conditions. If used outside the Recommended Operating Conditions but within the Absolute Maximum Ratings, the device may not be fully functional, and this may affect device reliability, functionality, performance, and shorten the device lifetime.
Recommended Operating Conditions
over operating free-air temperature range (unless otherwise noted)
| MIN | MAX | UNIT | |||
|---|---|---|---|---|---|
| NA555, NE555, SA555 | 4.5 | 16 V | |||
| VCC | Supply voltage | SE555 | 4.5 | 18 | |
| IO | Output current | ±200 | mA | ||
| NA555 | –40 | 105 | |||
| NE555 | 0 | 70 | |||
| TA | Operating free-air temperature | SA555 | –40 | 85 | °C |
| SE555 | –55 | 125 | |||
| (2) All voltage values are with respect to GND. |
(2) JEDEC document JEP157 states that 250V CDM allows safe manufacturing with a standard ESD control process.
5.4 Thermal Information
| THERMAL METRIC(1) | NA556, NE556, SA555, SE555 | SE555 | NA555, NE555 | NE555 | UNIT | |||
|---|---|---|---|---|---|---|---|---|
| D (SOIC) | FK (LCCC) | JG (CDIP) | P (PDIP) | PS (SO) | PW (TSSOP) | |||
| 8 PINS | 20 PINS | 8 PINS | 8 PINS | 8 PINS | 8 PINS | |||
| RθJA | Junction-to-ambient thermal resistance | 125.4 | 92.2 | 125.0 | 98.5 | 124.5 | 164.2 | °C/W |
| RθJC(top) | Junction-to-case (top) thermal resistance | 64.9 | 67.6 | 73.3 | 77.8 | 61.2 | 70.5 | °C/W |
| RθJB | Junction-to-board thermal resistance | 73.2 | 66.7 | 114.9 | 61.0 | 79.3 | 104.8 | °C/W |
| ψJT | Junction-to-top characterization parameter | 14.3 | 61.6 | 44.4 | 43.9 | 16.5 | 8.2 | °C/W |
| Junction-to-board characterization ψJB parameter | 72.1 | 66.5 | 106.6 | 60.3 | 77.8 | 103.1 | °C/W | |
| RθJC(bot) | Junction-to-case (bottom) thermal resistance | N/A | 14.2 | 29.3 | N/A | N/A | N/A | °C/W |
(1) For more information about traditional and new thermal metrics, see the Semiconductor and IC package thermal metrics application report.
5.5 Electrical Characteristics
at VCC = 5V to 15V and TA = 25°C (unless otherwise noted)
| PARAMETER | TEST CONDITIONS | | MIN | TYP | MAX | UNIT |
|--------------------------------|---------------------------------|---------------------|------|------|------|------|--|
| | | NA555, NE555, SA555 | 8.8 | 10 | 11.2 |
| | VCC = 15V | SE555 | 9.4 | 10 | 10.6 |
| THRES voltage level | | NA555, NE555, SA555 | 2.4 | 3.3 | 4.2 | V |
| | VCC = 5V | SE555 | 2.7 | 3.3 | 4 |
| THRES current(1) | | | | 30 | 250 | nA |
| | | NA555, NE555, SA555 | 4.5 | 5 | 5.6 |
| | VCC = 15V | SE555 | 4.8 | 5 | 5.2 |
| TRIG voltage level | VCC = 15V, TA = –55°C to +125°C | SE555
3 |
| | | NA555, NE555, SA555 | 1.1 | 1.67 | 2.2 | V |
| | VCC = 5V | SE555 | 1.45 | 1.67 | 1.9 |
| | VCC = 5V, TA = –55°C to +125°C | SE555 | | | 1.9 |
| | | NA555, NE555, SA555 | | 0.5 | 2 | μA |
| TRIG current | TRIG at 0V | SE555 | | 0.5 | 0.9 |
| RESET voltage level | | | 0.3 | 0.7 | 1 | V |
| | TA = –55°C to +125°C | SE555 | | | 1.1 |
| | RESET at VCC | | | 0.1 | 0.4 |
| RESET current | | NA555, NE555, SA555 | | –0.4 | –1.5 | mA |
| | RESET at 0V | SE555 | | –0.4 | –1 |
| DISCH switch off-state current | | | | 20 | 100 | nA |
| DISCH switch on-state voltage | VCC = 5V, IO = 8mA | NA555, NE555, SA555 | | 0.15 | 0.4 | V |
Thermal Information
| THERMAL METRIC(1) | NA556, NE556, SA555, SE555 | SE555 | NA555, NE555 | NE555 | UNIT | |||
|---|---|---|---|---|---|---|---|---|
| D (SOIC) | FK (LCCC) | JG (CDIP) | P (PDIP) | PS (SO) | PW (TSSOP) | |||
| 8 PINS | 20 PINS | 8 PINS | 8 PINS | 8 PINS | 8 PINS | |||
| RθJA | Junction-to-ambient thermal resistance | 125.4 | 92.2 | 125.0 | 98.5 | 124.5 | 164.2 | °C/W |
| RθJC(top) | Junction-to-case (top) thermal resistance | 64.9 | 67.6 | 73.3 | 77.8 | 61.2 | 70.5 | °C/W |
| RθJB | Junction-to-board thermal resistance | 73.2 | 66.7 | 114.9 | 61.0 | 79.3 | 104.8 | °C/W |
| ψJT | Junction-to-top characterization parameter | 14.3 | 61.6 | 44.4 | 43.9 | 16.5 | 8.2 | °C/W |
| Junction-to-board characterization ψJB parameter | 72.1 | 66.5 | 106.6 | 60.3 | 77.8 | 103.1 | °C/W | |
| RθJC(bot) | Junction-to-case (bottom) thermal resistance | N/A | 14.2 | 29.3 | N/A | N/A | N/A | °C/W |
(1) For more information about traditional and new thermal metrics, see the Semiconductor and IC package thermal metrics application report.
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