LM1237BDBC/NA National Semiconductor, LM1237BDBC/NA Datasheet - Page 7

• Manufacturer Part Number: LM1237BDBC/NA
• Description: Video ICs, 150MHz I2C Compatible RGB Preamplifier with Internal 254 Character OSD and 4 DACs
• Manufacturer: National Semiconductor

Typical Performance Characteristics
Figure 4 and Figure 5 show the case where the horizontal and vertical inputs are from deflection. Figure 4 shows the pin 24
voltage which is derived from a horizontal flyback pulse of 35 volts peak to peak with R
shows the pin 1 voltage which is derived from a vertical flyback pulse of 55 volts peak to peak with C
Figure 6 shows the pin 23 clamp input voltage superimposed on the neck board clamp logic input pulse. R
chosen to limit the pin 23 voltage to about 2.5V peak to peak. This corresponds to the application circuit given in Figure 9.
Cathode Response
Figure 7 shows the response at the red cathode for the application circuit in Figures 9, 10. The input video risetime is 1.5
nanoseconds. The resulting leading edge has a 7.1 nanosecond risetime and a 7.6% overshoot, while the trailing edge has a 7.1
nanosecond risetime and a 6.9% overshoot with an LM2467 driver.
FIGURE 4. Deflection Horizonal Blanking
FIGURE 6. Logic Clamp Pulse
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V
CC
7
= 5V, T
A
= 25˚C unless otherwise specified (Continued)
FIGURE 5. Deflection Vertical Blanking
FIGURE 7. Red Cathode Response
H
= 8.2K and C
4
= 1500pF and R
31
17
= 1K and should be
jumpered. Figure 5
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V
= 120K.
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