lm2421 National Semiconductor Corporation, lm2421 Datasheet
lm2421
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lm2421 Summary of contents
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... LM2421 Monolithic Triple Channel HDTV Driver General Description The LM2421 is an integrated high voltage CRT driver circuit designed for use in HDTV applications. The IC contains three high input impedance, wide band amplifiers which directly drive the RGB cathodes of a CRT. Each channel has its gain internally set to − ...
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... No AC Input Signal (Notes 4, 5 Input Signal (Note 6), 10% to 90% (Note 6), 90% to 10% (Note 3.8V < 10 sec.) 2.8˚C/W (Note 2) +130V to +150V +7V to +13V +1V to +5V +16V to +135V LM2421 Min Typical Max −38 −42 −46 1 300˚ ...
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... Note load includes parasitic capacitance. Figure 2 shows a typical test circuit for evaluation of the LM2421. This circuit is designed to allow testing of the LM2421 environment without the use of an expensive FET probe. The two 4990 resistors form a 400:1 divider with the 50 resistor and the oscilloscope ...
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... Typical Performance Characteristics 100V (32V−132V), Test Circuit - Figure 2 unless otherwise specified) PP FIGURE OUT FIGURE 4. Speed vs Temp. FIGURE 5. LM2421 Pulse Response www.national.com (V = +145V , DS200233-4 IN FIGURE 6. Power Dissipation vs Frequency DS200233-5 DS200233-6 FIGURE 8. Speed vs Load Capacitance 8pF OUT ...
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Typical Performance Characteristics (V = +145V 8pF 100V (32V−132V), Test Circuit - Figure L OUT PP 2 unless otherwise specified) (Continued) FIGURE 9. Power Derating Curve , DS200233-16 ...
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... The part is housed in the industry standard 11-lead TO-220 molded plastic power package. The circuit diagram of the LM2421 is shown in Figure 1 . The PNP emitter follower, Q5, provides input buffering. Q1 and Q2 form a fixed gain cascode amplifier with resistors R1 and R2 setting the gain at −42. Emitter followers Q3 and Q4 ...
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... Application Hints (Continued) FIGURE 10. One Channel of the LM2421 with the Recommended Arc Protection Circuit OPTIMIZING TRANSIENT RESPONSE Referring to Figure 10 , there are three components (R1, R2 and L1) that can be adjusted to optimize the transient re- sponse of the application circuit. Increasing the values of R1 and R2 will slow the circuit down while decreasing over- shoot ...
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... LM2421 to the blue cathode. Note that the components are placed so that they almost line up from the output pin of the LM2421 to the blue cathode pin of the CRT connector. This is done to minimize the length of the video path between these two components ...
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... Application Hints (Continued) FIGURE 11. LM126X/LM2421 Demonstration Board Schematic 9 DS200233-11 www.national.com ...
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... Application Hints (Continued) FIGURE 12. LM126X/LM2421 Demonstration Board Schematic (continued) www.national.com 10 DS200233-15 ...
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... Application Hints (Continued) FIGURE 13. LM126X/LM2421 Demo Board Layout 11 DS200233-13 www.national.com ...
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Application Hints (Continued) FIGURE 14. Trace Routing and Component Placement for Blue Channel Output www.national.com DS200233-14 12 ...
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... National does not assume any responsibility for use of any circuitry described, no circuit patent licenses are implied and National reserves the right at any time without notice to change said circuitry and specifications. inches (millimeters) unless otherwise noted NS Package Number TA11B Order Number LM2421TA 2. A critical component is any component of a life support device or system whose failure to perform ...