component
NA555DR
Public Made by Adomby adom
Texas Instruments Timers / Clock Oscillators, SOIC-8. Datasheet-verified pinout, KiCad symbol/footprint/3D.
3D Model
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Symbol & Footprint
Schematic Symbol
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PCB Footprint
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Datasheet
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README
markdownNA555DR
Texas Instruments · Timers / Clock Oscillators · SOIC-8
NA555DR from Texas Instruments, in a SOIC-8. Pinout and pin descriptions extracted from the manufacturer datasheet by ds2sf; symbol, footprint, and 3D from KiCad-official CAD.
Pinout
| Pin | Name | Type | Function |
|---|---|---|---|
| 1 | GND | power_in | Ground reference (0 V). All voltages in the datasheet are with respect to this pin. |
| 2 | TRIG | input | Start-of-timing input. When TRIG falls below 1/2 of CONT (nominally 1/3 VCC), the internal flip-flop is set: OUT goes high and DISCH is released (open). |
| 3 | OUT | output | High-current timer output signal. Can sink or source up to 200 mA; TTL-compatible logic levels with a 5 V supply. |
| 4 | RESET | input | Active-low reset. Forces OUT low and DISCH low regardless of other inputs. Threshold ~0.7 V (min 0.3 V, max 1 V). Tie high (to VCC) when unused. |
| 5 | CONT | bidirectional | Control-voltage pin. Internally biased to 2/3 VCC and sets the comparator thresholds; can be overdriven by an external voltage or bypassed to GND with a 10 nF capacitor to reject supply noise. |
| 6 | THRES | input | End-of-timing input. When THRES rises above CONT (nominally 2/3 VCC), the flip-flop is reset: OUT goes low and DISCH is pulled low. Input current typ 30 nA (max 250 nA). |
| 7 | DISCH | output | Open-collector discharge output. Provides a low-impedance path to GND to discharge the external timing capacitor whenever OUT is low. On-state VCE ~0.15 V typ at 8 mA. |
| 8 | VCC | power_in | Positive supply. Recommended operating range 4.5 V to 16 V (SE555 up to 18 V). Absolute maximum 18 V. |
Key specifications
| Parameter | Value |
|---|---|
| Manufacturer | Texas Instruments |
| Package | SOIC-8 |
| Category | RTC |
| Pins | 8 |
Ordering variants
Same part, different packaging or reel option.
NA555DRNA555DRDNA555DRP
CAD (KiCad official)
- Symbol:
NA555DR - Footprint:
Package_SO:SOIC-8_3.9x4.9mm_P1.27mm - 3D model: SOIC-8 (KiCad packages3D, STEP)
Provenance
Data extracted from the manufacturer datasheet, not a distributor listing:
- Datasheet: Texas Instruments datasheet (39 pp, sha256
c6f5275b8c31eb1d, retrieved 2026-08-17, tier: manufacturer) - Extractor:
ds2sf(Claude). Every pin and dimension is cited to a datasheet page; it refuses to fabricate. - CAD: KiCad official libraries (CC-BY-SA 4.0).