LM1247 National Semiconductor, LM1247 Datasheet
LM1247
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LM1247 Summary of contents
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... DAC outputs which are well matched to the LM2479 and LM2480 integrated bias clamp ICs. The LM1247 preamp is also designed to be compatible with the LM246x high gain driver family. Black level clamping of the video signal is carried out directly ...
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... Absolute Maximum Ratings If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications. Supply Voltage V , Pins 10 and 18 CC Peak Video DC Output Source Current (Any One Amp) Pins 19 Voltage at Any Input Pin ( Video Inputs (pk-pk) Thermal Resistance to Ambient (θ ...
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Video Signal Electrical Characteristics Unless otherwise noted 25˚ numbers refer to the definitions in Table 1. See (Note 7) for Min and Max parameters and (Note 6) for Typicals. Symbol Parameter V TH ABL Control Range ...
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DAC Output Electrical Characteristics Unless otherwise noted 25˚ for Min and Max parameters and (Note 6) for Typicals. DAC parameters apply to all 4 DACs. Symbol Parameter ∆V Variation in voltage of DAC with Max DAC ...
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... Note 15: A minimum pulse width of 200 ns is the guaranteed minimum for a horizontal line of 15 kHz. This limit is guaranteed by design lower line rate is used then a longer clamp pulse may be required. Note 16: Adjust input frequency from 10 MHz (A Note 17: Once the spot killer has been activated, the LM1247 remains in the off state until V Hexadecimal and Binary Notation Hexadecimal numbers appear frequently throughout this document, representing slave and register addresses, and register values. These appear in the format “ ...
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... At that time the protection is applied to all pins, including SDA and SCL. If any signal other than these two is applied to the LM1247 while the V is near zero, such as horizontal and vertical deflection pulses of sufficient amplitude, this protection will activate and pre- vent any communication on the I LM1247, until the other signal or signals are removed ...
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Typical Performance Characteristics FIGURE 2. Logic Horizontal Blanking FIGURE 3. Logic Vertical Blanking FIGURE 4. Deflection Horizonal Blanking 25˚C unless otherwise specified CC A 20048402 FIGURE 5. Deflection Vertical Blanking 20048403 FIGURE 6. Logic Clamp ...
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... LM2467 driver. ABL GAIN REDUCTION The ABL function reduces the contrast level of the LM1247 as the voltage on pin 22 is lowered from V shows the amount of gain reduction as the voltage is lowered from V the knee anound 3.7V, where the slope increases. Many system designs will require about gain reduction in full beam limiting ...
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... External resistor, 10k 1%, sets the internal bias current level for optimum performance of the LM1247. This resistor should be placed as close to pin 3 and the pin 4 ground return as possible. This is the ground for the input analog portions of the LM1247 internal circuitry. ...
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... ESD protection. Ground pin for the output analog portion of the LM1247 circuitry, and power supply pin for all the analog of the LM1247. Note the recommended charge storage and high frequency capacitors which should be as close to pins 17 and 18 as possible ...
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... CRT capacitance (averaged by C begins to turn off and the voltage at pin 22 begins to drop. The LM1247 then lowers the gain of the three video channels until the beam current reaches an equilibrium value. This pin accepts either TTL or CMOS logic levels ...
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Schematic Diagram FIGURE 9. LM123x/LM124x-LM246x Demo Board Schematic www.national.com 12 20048424 ...
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Schematic Diagram FIGURE 10. LM123x/LM124x-LM246x Demo Board Schematic (continued) 13 20048425 www.national.com ...
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PCB Layout FIGURE 11. LM123x/LM124x-LM246x Demo Board Layout www.national.com 14 20048426 ...
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... RAM, 0x00 (End-of-Screen) and 0x01 (End-of-Line). The first must be used to terminate a window and the second to terminate a line. The LM1247 is different from the LM1253A and LM1237 in that these are now not actually encoded into ROM, but are instead detected by the logic as the OSD image is read from page RAM ...
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OSD Generator Operation 2 varied under I C compatible control, but the total number of characters that can be stored and displayed on the screen is WINDOWS Two separate windows can be opened, utilizing the data stored in the page ...
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... Because each four-color character has two bits, the LM1247 internally has a matrix of two planes of ROM as shown in Figure 16. In that figure, dark pixels indicate a logic “1” and light pixels which indicate a logic “ ...
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OSD Generator Operation FOUR COLOR FONT AS TWO 2-COLOR Using a 4 color character as two 2 color characters is achieved by careful assignment of the four colors. When two 2 color characters are combined, there will be four pixel ...
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OSD Generator Operation FIGURE 18. Displaying Each Character Individually ATTRIBUTE TABLES Each character has an attribute value assigned the page RAM. The attribute value is 4 bits wide, making each character entry in the page RAM 12 ...
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OSD Generator Operation www.national.com (Continued) FIGURE 19. Button Box Detail FIGURE 20. On-Screen Effect of Button Boxes FIGURE 21. Shadowing 20 20048434 20048435 20048436 ...
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... Acknowledge bit. The next 8 bits will be the read data driven out by the LM1247 preamp associated with the address indicated by the two address bytes. Subsequent read data bytes will correspond to the next increment address loca- tions. Data should only be read from the LM1247 when both OSD windows are disabled. 2 FIGURE 23. I ...
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... Microcontroller Interface LM1247 Address Map CHARACTER ROM The 512 font characters from 0x0000 to 0x7FFF can be read from ROM by addressing the individual pixel rows of the desired character. Since the characters have 12 columns, it takes two bytes to read a given row of pixels within one character. Since the characters have 18 rows, a total of 36 bytes are needed to read the entire character ...
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... LM1247 Address Map Register Fonts - 2 Color Fonts - 4 Color Fonts - 2 Color Fonts - 4 Color DISPLAY PAGE RAM This address range (0x8000–0x81FF) contains the 512 characters which comprise the displayable OSD screens. There must be at least one End-of-Screen code (0x00) in this range to prevent unpredictable behaviour. NOTE: To avoid any unpredictable behaviour, this range should be cleared by writing bit 3 of the FRMCTRL1 Register, 0x8400, immediately after power up ...
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... LM1247 Address Map ATTRIBUTE CODE ATT[3:0] Bits 7-6 determine which Bank Select Register is used to look up the 3 bit address of the bank where the character will be called from. Bits 5-0 determine which of the 64 characters is called from that bank. Bits 11-8 address one of the 16 attributes in the table containing the colors and enhanced features to be used for this particular character ...
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... LM1247 Address Map END-OF-SCREEN CODE To signify the end of the window, a special End-of-Screen (EOS) code is used in place of a End-of-Line (EOL) code. There must be at least one EOS code in the Page RAM to avoid unpredictable behaviour. This can be accomplished by clearing the RAM by writing bit 3 of the FRMCTRL1 Register, 0x8400, immediately after power up ...
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... CLMP X A/D[0] X Address = 0x8440 + (N * 0x4 where Attribute number (0x0 ≤ N ≤ 0xF Attribute byte number (0x0 ≤ B ≤ 0x3) TABLE 16. LM1247 Two-Color Attribute Registers C0B[1:0] C1B[0] C1G[2: Address = 0x8500 + (N 0x8 where Attribute number (0x0 ≤ N ≤ 0xF Attribute byte number (0x0 ≤ ...
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... The Display Page RAM contains all of the 8-bit display character codes and their associated 4-bit attribute codes, and the special 12-bit page control codes — the End-of-Line, skip-line parameters and End-of-Screen characters. The LM1247 has a distinct advantage over many OSD Generators that it allows variable size and format windows. The window size is not dictated by a fixed geometry area of RAM ...
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... For this example, bank 4 is selected by Bank Select Register 0, and therefore the two upper bits of the character codes are both 0. • The data shown in Table 18 is sent to the LM1247 in two transmissions, one for the attribute and one for the Page data. Also, additional data will need to be sent to position the OSD window and turn it on. ...
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... SL value for the next line, unless the window contains just one line. • The last character in a display window is an EOS code. The EOS must NOT follow an EOL character. • Table 19 shows the data sent to the LM1247 for the entire image transmissions. Data Sent ...
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... Skip 3 lines Command stop condition start condition 0xBA LM1247 Slave Write Address 0x06 Address LSB www.national.com (Continued) Description Background (Color 0): Red = 000b, Green = 000b and Blue = 000b. Foreground (Color 1): Red = 111b, Green = 111b, Blue = 111b, and Enhanced Feature = 0000b. ...
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... Frame Control Register (See Control Register Definitions section). • If instead we used attributes 8 and 9 for this example, the black would not be transparent, since transparency only operates on black colors in the first 8 attributes. • The data shown in Table 20 is sent to the LM1247 in two I (Continued) Description 2 C transmissions ...
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... Building Display Pages Data Sent start condition 0xBA LM1247 Slave Write Address 0x40 Two-color attribute location 0 address LSB 0x84 Two-color attribute location 0 address MSB 0x00 Attribute Byte 0xFE Attribute Byte 0x03 Attribute Byte 0x00 Attribute Byte ...
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Control Register Definitions Bit 0 On-Screen Display Enable. The On-Screen Display will be disabled when this bit is a zero. When this bit is a one the On-Screen Display will be enabled. This controls both Window 1 and Window 2. ...
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Control Register Definitions Bits 6–0 This register determines the duration of the vertical blanking signal in scan lines. When vertical blanking is enabled recommended that this register be set to a number greater than 0x0A. Bit 7 Reserved. ...
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... Window 1 at the beginning of the Page Ram (0x8000). This register is new for the LM1247 and allows Window 1 to start anywhere in the Page RAM rather than just at 0x8000. Note that the address this points to in Page RAM must always contain the SL code for the first line of Window 1. Bits 15– ...
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Control Register Definitions Display Window 2 Horizontal Start Position: Bits 7–0 This register determines the horizontal start position of Window 2 in OSD pixels (not video signal pixels). The actual position, to the right of the horizontal flyback pulse, is ...
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Control Register Definitions Bits 6–4 This three bit field determines the ROM bank (0-7) selected when the upper two bits of the character address in Page RAM are 01 (Character Address = 01xxxxxxb) Bit 7 This bit is reserved and ...
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Pre-Amplifier Interface Registers Blue Channel Gain: Res’d X Bits 6–0 This register determines the gain of the blue video channel. This affects only the blue channel whereas the contrast register (0x8433) affects all channels. Bit 7 Reserved and should be ...
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Pre-Amplifier Interface Registers Bits 7–0 This register determines the output of DAC 3. The full-scale output is determined by bit 5 of the DAC Config, OSD Contrast & DC Offset Register (0x8438). DAC 4 Output Level: Bits 7–0 This register ...
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... Signal” and “Input Signal Out of Range”, to avoid seeing unsynchronized video. Bit 4 Reserved and should be set to zero. Bit 5 This is the Clamp Polarity bit. When set the LM1247 expects a positive going clamp pulse. When set the expected pulse is negative going. Bits 7–6 Reserved and should be set to zero. ...
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Attribute Table and Enhanced Features Bits 21–18 0000b Normal Display 0001b Blinking 0010b Shadowing 0011b Bordering 0100b RESERVED 0101b RESERVED 0110b RESERVED 0111b RESERVED 1000b Raised Box 1001b Blinking and Raised Box 1010b Depressed Box 1011b Blinking and Depressed Box ...
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Attribute Table and Enhanced Features TABLE 25. Attribute Tables and Corresponding Addresses (Continued) Attribute Number, (n) Two-Color Attribute Table Address 0100b 0101b 0110b 0111b 1000b 1001b 1010b 1011b 1100b 1101b 1110b 1111b BUTTON BOX FORMATION The value of the most ...
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... LM1237 ROM where they were reserved for the End-of- Screen (EOS) and End-of-Line (EOL) codes respectively. In the case of the LM1247, these two locations can be used for displayable characters as long as they are not needed when this bank is addressed from Bank Select Register addressed from Bank Select Registers then these two lower characters will be usable ...
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Attribute Table and Enhanced Features www.national.com (Continued) FIGURE 30. ROM Bank 1 Two Color Character Font FIGURE 31. ROM Bank 2 Two Color Character Font 44 20048445 20048446 ...
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Attribute Table and Enhanced Features FIGURE 32. ROM Bank 3 Four Color Character Font FIGURE 33. ROM Bank 4 Two Color Character Font (Continued) 45 20048447 20048448 www.national.com ...
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Attribute Table and Enhanced Features www.national.com (Continued) FIGURE 34. ROM Bank 5 Two Color Character Font FIGURE 35. ROM Bank 6 Two Color Character Font 46 20048449 20048450 ...
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Attribute Table and Enhanced Features FIGURE 36. ROM Bank 7 Four Color Character Font (Continued) 47 20048451 www.national.com ...
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... NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR SYSTEMS WITHOUT THE EXPRESS WRITTEN APPROVAL OF THE PRESIDENT AND GENERAL COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein: 1. Life support devices or systems are devices or systems which, (a) are intended for surgical implant ...