LM3914DWF National Semiconductor Corporation, LM3914DWF Datasheet - Page 4

• Manufacturer Part Number: LM3914DWF
• Description: LM3914 - Dot/bar Display Driver, Package: Mdip, Pin Nb=18
• Manufacturer: National Semiconductor Corporation

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Electrical Characteristics
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 +10.000 V
significant error.
Note 4: Pin 5 input current must be limited to
Note 5: Bar mode results when pin 9 is within 20 mV of V
10 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 di-
vider so that resistor ratio matching error predominates over
comparator offset voltage.
Adjust Pin Current: Current flowing out of the reference ad-
just 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.
Typical Performance Characteristics
Supply Current vs
Temperature
LED
3 V
−0.015V
3 V
−0.015V
) to the change in input voltage (V
DC
DC
V
V
+
LED
V
V
RLO
RHI
20 V
V
+
12 V
DC
12 V
DC
0V
DC
V
REF
V
IN
T
, V
A
RHI
= +25˚C, I
V
DS007970-2
+
, V
− 1.5V
RLO
±
3 mA. The addition of a 39k resistor in series with pin 5 allows
L(REF)
(V
IN
DC
+
) required to pro-
(Notes 2, 4) (Continued)
− 1.5V)
= 0.2 mA, V
at pin 6, with 0.000 V
Operating Input Bias
Current vs Temperature
+
. Dot mode results when pin 9 is pulled at least 200 mV below V
LED
LED
.
= 3.0V, pin 9 connected to pin 3 (Bar Mode).
DC
4
at pin 4. At lower full-scale voltages, buffer and comparator offset voltage may add
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 volt-
age 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 re-
gion. Most significant error when the voltage across the in-
ternal voltage divider is small. Specified and tested with pin
6 voltage (V
REF
) over the specified range of load current (I
DS007970-20
RHI
) equal to pin 4 voltage (V
±
Reference Voltage vs
Temperature
100V signals without damage.
+
or left open circuit. LED No. 10 (pin
RLO
).
L(REF)
LED
+
).
).
DS007970-21
) as