lm3914-mdc National Semiconductor Corporation, lm3914-mdc Datasheet - Page 4

• Manufacturer Part Number: lm3914-mdc
• Description: Dot/bar Display Driver
• Manufacturer: National Semiconductor Corporation

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Electrical Characteristics
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:
For higher power dissipations, pulse testing is used.
Note 3: Accuracy is measured referred to +10.000V
significant error.
Note 4: Pin 5 input current must be limited to
Note 5: Bar mode results when pin 9 is within 20mV of V
output current) is disabled if pin 9 is pulled 0.9V or more below V
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
(I
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
3 V
3 V
−0.015V ≤ V
−0.015V ≤ V
) to the change in input voltage (V
DC
DC
≤ V
≤ V
+
LED
≤ 20 V
RLO
RHI
≤ V
≤ 12 V
≤ 12V
+
DC
DC
DC
0V ≤ V
V
REF
T
IN
, V
A
≤ V
= +25˚C, I
RHI
+
, V
− 1.5V
RLO
±
L(REF)
3mA. The addition of a 39k resistor in series with pin 5 allows
≤ (V
IN
DC
+
) required to pro-
(Notes 2, 4) (Continued)
− 1.5V)
= 0.2 mA, V
at pin 6, with 0.000 V
+
. Dot mode results when pin 9 is pulled at least 200mV below V
LED
LED
.
= 3.0V, pin 9 connected to pin 3 (Bar Mode).
DC
at pin 4. At lower full-scale voltages, buffer and comparator offset voltage may add
4
LED Current Regulation: The change in output current
over the specified range of LED supply voltage (V
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
(V
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
REF
) over the specified range of load current (I
RHI
) equal to pin 4 voltage (V
±
100V signals without damage.
+
or left open circuit. LED No. 10 (pin 10
RLO
).
L(REF)
LED
+
).
).
) as