LM3916N-1 National Semiconductor, LM3916N-1 Datasheet - Page 13

• Manufacturer Part Number: LM3916N-1
• Description: LED BAR GRAPH DRIVER, 3916, DIP18
• Manufacturer: National Semiconductor

Specifications of LM3916N-1

• Led Driver Application: VU Meter, Power Meters
• No. Of Outputs: 10
• Output Current: 30mA
• Output Voltage: 17V
• Input Voltage: 3V To 25V
• Dimming Control Type: Analogue
• Operating: RoHS Compliant
• Topology: Linear

Application Hints
LM3916’s reference 16 dB higher or 7.89V. Variation in the
two on-chip references and resistor tolerance may cause a
objectionable, R2 can be trimmed.
The drawback of the aforementioned approach is that the
threshold of LED #1 on the LM3915 is only 56 mV. Since
V
±
REF2
1 dB error in the −10 dB to −13 dB transition. If this is
. 7.89V
(Continued)
FIGURE 8. Low Cost Circuit for 40 dB Display
FIGURE 9. Improved Circuit for 40 dB Display
13
comparator offset voltage may be as high as 10 mV, large
errors can occur at the first few thresholds. A better ap-
proach, as shown in Figure 9, is to keep the reference the
same for both drivers (10V in the example) and amplify the
input signal by 16 dB ahead of the LM3915. Alternatively,
instead of amplifying, input signals of sufficient amplitude
can be fed directly to the LM3916 and attenuated by 16 dB to
drive the LM3915.
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