LM3914 datasheet(4/22 Pages) NSC

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Electrical Characteristics (Notes 2, 4) (Continued)

Note 1: Absolute Maximum Ratings indicate limits beyond which damage to the device may occur. Operating Ratings indicate conditions for which the device is

functional, but do not guarantee specific performance limits. Electrical Characteristics state DC and AC electrical specifications under particular test conditions which

guarantee specific performance limits. This assumes that the device is within the Operating Ratings. Specifications are not guaranteed for parameters where no limit

is given, however, the typical value is a good indication of device performance.

Note 2: Unless otherwise stated, all specifications apply with the following conditions:

3VDC ≤ V

+ ≤ 20 VDC

VREF,VRHI,VRLO ≤ (V

+ − 1.5V)

3VDC ≤ VLED ≤ V

≤ VIN ≤ V+ − 1.5V

−0.015V

≤ VRLO ≤ 12VDC

TA = +25˚C, IL(REF) = 0.2 mA, VLED = 3.0V, pin 9 connected to pin 3 (Bar Mode).

−0.015V

≤ VRHI ≤ 12 VDC

For higher power dissipations, pulse testing is used.

Note 3: Accuracy is measured referred to +10.000VDC at pin 6, with 0.000 VDC at pin 4. At lower full-scale voltages, buffer and comparator offset voltage may add

significant error.

Note 4: Pin 5 input current must be limited to ±3mA. The addition of a 39k resistor in series with pin 5 allows ±100V signals without damage.

Note 5: Bar mode results when pin 9 is within 20mV of V+. Dot mode results when pin 9 is pulled at least 200mV below V+ or left open circuit. LED No. 10 (pin 10

output current) is disabled if pin 9 is pulled 0.9V or more below VLED.

Note 6: The maximum junction temperature of the LM3914 is 100˚C. Devices must be derated for operation at elevated temperatures. Junction to ambient thermal

resistance is 55˚C/W for the molded DIP (N package).

Definition of Terms

Accuracy: The difference between the observed threshold

voltage and the ideal threshold voltage for each comparator.

Specified and tested with 10V across the internal voltage

divider so that resistor ratio matching error predominates

over comparator offset voltage.

Adjust Pin Current: Current flowing out of the reference

adjust pin when the reference amplifier is in the linear region.

Comparator Gain: The ratio of the change in output current

LED) to the change in input voltage (VIN) required to pro-

duce it for a comparator in the linear region.

Dropout Voltage: The voltage measured at the current

source outputs required to make the output current fall by

10%.

Input Bias Current: Current flowing out of the signal input

when the input buffer is in the linear region.

LED Current Regulation: The change in output current

over the specified range of LED supply voltage (V

LED)as

measured at the current source outputs. As the forward

voltage of an LED does not change significantly with a small

change in forward current, this is equivalent to changing the

voltage at the LED anodes by the same amount.

Line Regulation: The average change in reference output

voltage over the specified range of supply voltage (V

+).

Load Regulation: The change in reference output voltage

REF) over the specified range of load current (IL(REF)).

Offset Voltage: The differential input voltage which must be

applied to each comparator to bias the output in the linear

region. Most significant error when the voltage across the

internal voltage divider is small. Specified and tested with pin

6 voltage (V

RHI) equal to pin 4 voltage (VRLO).

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