LM311 Voltage Comparator with Strobe
Voltage Comparator, DIP-8/SOIC-8
Aliase:311 Comparator, High Speed Comparator
DIP-8 Top View
8 Pins
Pinout Table8
| Pin | Signal / Name | Type | Alternative Functions |
|---|---|---|---|
| 1 | GND | Ground | Output Emitter (Ground) — emitter of open-collector output transistor; connect to GND for single-supply or to negative rail for bipolar supply |
| 2 | INA+ | Analog | Non-Inverting Input (+) — output goes HIGH when IN+ > IN- |
| 3 | INA- | Analog | Inverting Input (-) — output goes LOW when IN- > IN+ |
| 4 | V- | Ground | Negative Supply — connect to negative rail (bipolar operation, e.g. -15V)Ground (0V) — connect to GND for single-supply operation |
| 5 | BAL | Analog | Offset Balance / Strobe — connect with pin 6 via 20kΩ pot between V+ and V- to null input offset; when used as strobe, driving LOW forces output LOW regardless of input; leave NC if unused |
| 6 | BAL | Analog | Offset Balance — second balance pin; used together with pin 5 for offset null adjustment; leave NC if unused |
| 7 | OUT | Digital | Comparator Output (Open-Collector) — requires external pull-up resistor to desired voltage; output LOW when IN+ < IN-, high-Z (HIGH via pull-up) when IN+ > IN- |
| 8 | V+ | Power | Positive Supply Voltage (+5V to +36V single-supply, or ±15V bipolar) |