The LM3914 is an
integrated circuit
An integrated circuit or monolithic integrated circuit (also referred to as an IC, a chip, or a microchip) is a set of electronic circuits on one small flat piece (or "chip") of semiconductor material, usually silicon. Large numbers of tiny ...
(IC), designed by
National Semiconductor
National Semiconductor was an American semiconductor manufacturer which specialized in analog devices and subsystems, formerly with headquarters in Santa Clara, California. The company produced power management integrated circuits, display drive ...
in the late 1970s, used to operate displays that visually show the
magnitude
Magnitude may refer to:
Mathematics
*Euclidean vector, a quantity defined by both its magnitude and its direction
*Magnitude (mathematics), the relative size of an object
*Norm (mathematics), a term for the size or length of a vector
*Order of ...
of an
analog signal
An analog signal or analogue signal (see spelling differences) is any continuous signal representing some other quantity, i.e., ''analogous'' to another quantity. For example, in an analog audio signal, the instantaneous signal voltage varies c ...
.
It can drive up to 10
LED
A light-emitting diode (LED) is a semiconductor Electronics, device that Light#Light sources, emits light when Electric current, current flows through it. Electrons in the semiconductor recombine with electron holes, releasing energy i ...
s,
LCD
A liquid-crystal display (LCD) is a flat-panel display or other electronically modulated optical device that uses the light-modulating properties of liquid crystals combined with polarizers. Liquid crystals do not emit light directly but in ...
s, or
vacuum fluorescent displays
A vacuum fluorescent display (VFD) is a display device once commonly used on consumer electronics equipment such as video cassette recorders, car radios, and microwave ovens.
A VFD operates on the principle of cathodoluminescence, roughly ...
on its outputs. The linear scaling of the output thresholds makes the device usable, for example, as a voltmeter. In the basic configuration it provides a ten step scale which is expandable to over 100 segments with other LM3914 ICs in series.
Features
The LM3914 / LM3915 / LM3916 are identical except for the ten
resistor divider
In electronics, a voltage divider (also known as a potential divider) is a passive linear circuit that produces an output voltage (''V''out) that is a fraction of its input voltage (''V''in). Voltage division is the result of distributing the in ...
inside each part.
* LM3914 - linear steps, scaled by a resistor divider consisting of ten 1000 ohm resistors.
[LM3914 Datasheet; National Semiconductors; 1988.](_blank)
/ref>
* LM3915 - 3 dB logarithmic steps, scaled by a resistor divider consisting of 6630, 4690, 3310, 2340, 1660, 1170, 830, 590, 410, 1000 ohm resistors.[LM3915 Datasheet; National Semiconductors; 1988.](_blank)
/ref>
* LM3916 - VU-meter steps, scaled by a resistor divider consisting of 1087, 970, 864, 769, 1298, 1031, 819, 923, 1531, 708 ohm resistors.[LM3916 Datasheet; National Semiconductors; 1988.](_blank)
/ref>
All the devices in this group operate with a range of voltages from 3-25 V, can drive LED
A light-emitting diode (LED) is a semiconductor Electronics, device that Light#Light sources, emits light when Electric current, current flows through it. Electrons in the semiconductor recombine with electron holes, releasing energy i ...
and VFD
VFD may refer to:
* Factory Workers' Union of Germany, (german: Verband der Fabrikarbeiter Deutschlands, link=no), a former trade union in Germany
* Vacuum fluorescent display, a display device on consumer electronics equipment
* Variable-freque ...
displays. They can provide a regulated output current between 2-30 mA to directly drive displays.
Internally, each device contains ten comparators and a resistor scaling network, as well as a 1.25 volt reference source. As the input voltage increases, each comparator turns on. The device can be configured for either a bar-graph mode, where all lower-output terminals switch on, or "dot" mode in which only one output goes on. [R. M. Marston ''Audio IC Users Handbook'' Newnes, 1997 , pp. 177-192 ] The device is packaged in an 18 pin dual in-line package
In microelectronics, a dual in-line package (DIP or DIL), is an electronic component package with a rectangular housing and two parallel rows of electrical connecting pins. The package may be through-hole mounted to a printed circuit board (P ...
or in a surface mount leadless chip carrier.
See also
* List of LM-series integrated circuits
The following is a list of LM-series integrated circuits. Many were among the first analog integrated circuits commercially produced since late 1965; some were groundbreaking innovations. As of 2007, many are still being used. The LM series orig ...
References
{{Reflist
External links
LM3914 Datasheet
- Texas Instruments
Display drivers
Linear integrated circuits