LM556 Dual Precision Timer
Dual Timer, DIP-14/SOIC-14
Aliase:556 Timer, NE556, Dual 555
DIP-14 Top View
14 Pins
Pin-Tabelle14
| Pin | Signal / Name | Typ | Alternative Funktionen |
|---|---|---|---|
| 1 | DISCH | Analog | Discharge A — open-collector switch; connects timing capacitor to GND during output LOW phase; connect to RC timing network |
| 2 | THRES | Analog | Threshold A — comparator input; when voltage rises above 2/3 VCC, output goes LOW and discharge transistor turns ON |
| 3 | CONT | Analog | Control Voltage A — direct access to internal 2/3 VCC voltage divider; connect 10nF cap to GND to filter noise; can be used to modulate threshold externally |
| 4 | RST | Digital | Reset A (Active Low) — forces output LOW and discharge ON regardless of other inputs; tie to VCC if unused |
| 5 | OUT | Digital | Timer A Output — HIGH when triggered and in timing period; LOW when threshold exceeded or reset active; can source/sink up to 200mA |
| 6 | TRIG | Analog | Trigger A — when voltage falls below 1/3 VCC, output goes HIGH and timing begins; active-low pulse input |
| 7 | GND | Ground | System Ground (0V) — shared by both timer halves |
| 8 | TRIG | Analog | Trigger B — when voltage falls below 1/3 VCC, output goes HIGH and timing begins; active-low pulse input |
| 9 | OUT | Digital | Timer B Output — HIGH when triggered and in timing period; LOW when threshold exceeded or reset active; can source/sink up to 200mA |
| 10 | RST | Digital | Reset B (Active Low) — forces output LOW and discharge ON regardless of other inputs; tie to VCC if unused |
| 11 | CONT | Analog | Control Voltage B — direct access to internal 2/3 VCC voltage divider; connect 10nF cap to GND to filter noise |
| 12 | THRES | Analog | Threshold B — comparator input; when voltage rises above 2/3 VCC, output goes LOW and discharge transistor turns ON |
| 13 | DISCH | Analog | Discharge B — open-collector switch; connects timing capacitor to GND during output LOW phase; connect to RC timing network |
| 14 | VCC | Power | Positive Power Supply (+5V to +15V; add 100nF bypass capacitor to GND near pin) |