NA556DR from Texas Instruments, in a SOIC-14. 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	1DISCH	output	Timer 1 discharge pin. Open-collector output used to discharge the external timing capacitor C_T when the timer output is low.
2	1THRES	input	Timer 1 threshold input. End-of-timing input; when THRES > CONT (nominally 2/3 Vcc) the output goes low and the discharge transistor turns on.
3	1CONT	input	Timer 1 control voltage. Sets the comparator thresholds (nominally 2/3 Vcc); can be tied to a bypass capacitor for noise immunity or driven to modulate the timing.
4	1RESET	input	Timer 1 active-low reset input. Overrides all other inputs; forces output and discharge low. Tie to Vcc when unused. V_RESET typ 0.7 V, max 1 V.
5	1OUT	output	Timer 1 output. High-current TTL-compatible timer output; can sink or source up to 200 mA.
6	1TRIG	input	Timer 1 trigger input. Start-of-timing input; when TRIG < 1/2 CONT (nominally 1/3 Vcc) the output goes high and the discharge transistor turns off.
7	GND	power_in	Ground / device negative supply reference.
8	2TRIG	input	Timer 2 trigger input. Start-of-timing input; when TRIG < 1/2 CONT (nominally 1/3 Vcc) the output goes high and the discharge transistor turns off.
9	2OUT	output	Timer 2 output. High-current TTL-compatible timer output; can sink or source up to 200 mA.
10	2RESET	input	Timer 2 active-low reset input. Overrides all other inputs; forces output and discharge low. Tie to Vcc when unused.
11	2CONT	input	Timer 2 control voltage. Sets the comparator thresholds (nominally 2/3 Vcc); can be tied to a bypass capacitor for noise immunity or driven to modulate the timing.
12	2THRES	input	Timer 2 threshold input. End-of-timing input; when THRES > CONT (nominally 2/3 Vcc) the output goes low and the discharge transistor turns on.
13	2DISCH	output	Timer 2 discharge pin. Open-collector output used to discharge the external timing capacitor C_T when the timer output is low.
14	VCC	power_in	Positive supply voltage. Recommended 4.5 V to 16 V (NA556/NE556/SA556); absolute maximum 18 V. Bypass to GND with a local ceramic capacitor.

Key specifications

Parameter	Value
Manufacturer	Texas Instruments
Package	SOIC-14
Category	RTC
Pins	14

Ordering variants

Same part, different packaging or reel option.

NA556DR
NA556DRD
NA556DRN

CAD (KiCad official)

Symbol: NA556DR
Footprint: Package_SO:SOIC-14_3.9x8.7mm_P1.27mm
3D model: SOIC-14 (KiCad packages3D, STEP)

Provenance

Data extracted from the manufacturer datasheet, not a distributor listing:

Datasheet: Texas Instruments datasheet (31 pp, sha256 63e3e49f1c2acba3, 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).

Datasheet PDF