LM1237BAAF/NA National Semiconductor, LM1237BAAF/NA Datasheet - Page 37

• Manufacturer Part Number: LM1237BAAF/NA
• Description: IC PREAMP CMOS 150MHZ 24-DIP
• Manufacturer: National Semiconductor
• Type: Preamplifierr

Specifications of LM1237BAAF/NA

• Applications: OSD Monitors, Drivers
• Mounting Type: Through Hole
• Package / Case: 24-DIP (0.300", 7.62mm)
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Other names: *LM1237BAAF/NA; *LM1237BAAF/NA/NOPB; LM1237BAAF/NA/NOPB; LM1237BAAF/NANOPB; LM1237BAAF/NANOPB

Pre-Amplifier Interface Registers
DAC 3 REGISTER
Register Name (address): DAC3CTRL (0x8436)
DAC 4 REGISTER
Register Name (address): DAC4CTRL (0x8437)
DAC CONFIG, OSD CONTRAST & DC OFFSET REGISTER
Register Name (address): DACOSDDCOFF (0x8438)
GLOBAL VIDEO CONTROL REGISTER
Register Name (address): GLOBALCTRL (0x8439)
PLL RANGE REGISTER
Register Name (address): PLLFREQRNG (0x843E)
Bits 7–0
Bits 7–0
Bits 7–0
Bits 2–0
Bits 4–3
Bit 5
Bit 6
Bit 7
Bit 0
Bit 1
Bits 1–0
Bit 2
RSV
RSV
RSV
RC7
BA7
7
7
7
7
7
DCF1
This register determines the output of DAC 2. The full-scale output is determined by bit 5 of the DAC
Config, OSD Contrast & DC Offset Register.
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.
This register determines the output of DAC 4. The output of this DAC can be scaled and mixed with the
outputs of DACs 1–3 as determined by bit 6 of the DAC Config, OSD Contrast & DC Offset Register.
These determine the DC offset of the three video outputs, blue, red and green.
These determine the contrast of the internally generated OSD.
When this bit is a 0, the full-scale outputs of DACs 1–3 are 4.5V. When it is a 1 the full-scale level is
2.5V.
When this bit is a 0, the DAC 4 output is independent. When it is a 1, the DAC 4 output is scaled by
50% and added to the outputs of DACs 1–3.
Reserved and should be set to zero.
When this bit is a 1, the video outputs are blanked (set to black level). When it is a 0, video is not
blanked.
When this bit is a 1, the analog sections of the preamplifier are shut down for low power consumption.
When it is a 0, the analog sections are enabled.
These determine the optimum frequency range of the Phase Locked Loop. Please see Table 3. OSD
Register recommendations for recommended register values for various horizontal scan rates.
This is the Vertical Blanking register. When this bit is a 1, vertical blanking is gated to the video outputs.
When set to a 0, the video outputs do not have vertical blanking.
RC6
RSV
RSV
BA6
6
6
6
6
6
CLMP
DCF0
RSV
RC5
BA5
5
5
5
5
5
OSD1
RSV
RSV
RC4
BA4
4
4
4
4
4
(Continued)
37
OSD0
OOR
RC3
RSV
BA3
3
3
3
3
3
RC2
DC2
RSV
BA2
VBL
2
2
2
2
2
PFR1
RC1
DC1
BA1
PS
1
1
1
1
1
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PFR0
RC0
DC0
BA0
BV
0
0
0
0
0