LM1291N ,Video PLL System for Continuous-Sync MonitorsLM1291VideoPLLSystemforContinuous-SyncMonitorsJune1995LM1291VideoPLLSystemforContinuous-SyncMonitor ..
LM1291N ,Video PLL System for Continuous-Sync MonitorsFeaturesYWide continuous autosync rangeÐ22 kHz to 125 kHzThe LM1291 is an integrated horizontal tim ..
LM1292N ,Video PLL System for Continuous-Sync MonitorsLM1292 Video PLL System for Continuous-Sync MonitorsApril 1999LM1292Video PLL System for Continuous ..
LM1295 ,DC Controlled Geometry Correction System for Continuous Sync MonitorsapplicationsTheICprovidestwooutputscomposedofthesummationofflexibilityDC controlled 1st and 2nd ord ..
LM1295N ,DC Controlled Geometry Correction System for Continuous Sync MonitorsLM1295 DC Controlled Geometry Correction System for Continuous Sync MonitorsApril 1999LM1295DC Cont ..
LM1296 ,Raster Geometry Correction System for Multi-Frequency DisplaysElectrical CharacteristicsSee Test Circuit (Figure 2), V = 12V; V = 4V; V = 4V; V = 0V (Note 6); T ..
LM393AD ,Low power dual voltage comparatorFeatures 3 DescriptionThese devices consist of two independent voltage1• Single-Supply or Dual Supp ..
LM393ADG4 ,Dual Differential Comparator 8-SOIC 0 to 70Maximum Ratings.. 49 Power Supply Recommendations.... 146.2 ESD Ratings........ 410 Layout.... 146. ..
LM393ADGKR ,Dual, General Purpose Differential Comparator SLCS005Z–OCTOBER 1979–REVISED OCTOBER 2017Changes from Revision W (July 2010) to Revision X Page• ..
LM393ADGKRG4 ,Dual Differential Comparator 8-VSSOP 0 to 70Support & ReferenceProduct Order Tools &TechnicalCommunityDesignFolder Now Documents SoftwareLM193, ..
LM393ADR ,Dual, General Purpose Differential ComparatorMaximum Ratings.. 49 Power Supply Recommendations.... 146.2 ESD Ratings........ 410 Layout.... 146. ..
LM393ADRG4 ,Dual Differential Comparator 8-SOIC 0 to 70Features. 1• Removed Ordering Information table....... 3• Added ESD warning.... 15Copyright 1979–2 ..
LM1291N
Video PLL System for Continuous-Sync Monitors
TL/H/12323
LM1291
Video
PLL
System
for
Continuous-Sync
Monitors
June 1995
LM1291
Video PLL System for Continuous-Sync Monitors
General Description
The LM1291isan integrated horizontal time base solution
specifically designedto operatein continuous-sync video
monitors.It automatically synchronizestoanyH frequency
from22kHzto125kHzand providesthe drive pulsetothe
high power deflection circuit.
Available sync processing includes avertical sync separator
anda compositevideo sync stripper.An internalsync selec-
tionscheme gives highest priorityto separateHandV sync,
then composite sync,and finally syncon video;no external
switching between sync sourcesis necessary.The LM1291
provides polarity-normalized H/HV andV sync outputs,
along with logic flags which showthe respective input polar-
ities.
The design usesan on-chip FVC (Frequency-to-Voltage
Converter)tosetthe center frequencyof theVCO (Voltage-
Controlled Oscillator). This technique allows autosync oper-
ation overthe entire frequency range usingjust one opti-
mizedsetof external components.
The system includesa second phase detector which com-
pensatesfor storage time variationinthe horizontal output
transistor;the picture’s horizontal positionis thus indepen-
dentof temperatureand component variance.
The LM1291 providesDC controlpins forHDrive duty cycle
and flyback phase.
Features Wide continuous autosync rangeÐ22 kHzto 125 kHz
(1:5.7) withno component switchingor external adjust-
mentsNo manufacturing trims requiredÐinternal VCO capaci-
tor trimmedon chipNo costly high-precision components needed Low phase jitter(1.3nsat 100 kHz)DC controlledH phaseand duty cycle Video mute pulsefor blanking duringH frequency
transitions Input sync prioritization Clamp pulse positionand width control Continuous clamp pulse output, even withno sync input Resistor-programmable minimum and maximum VCO
frequency X-ray input disablesH drive and mutes video until VCC
powered downH drive disabledfor VCCk 9.5V Horizontal output transistor protected against accidental
turn-on during flyback Capacitor-programmable frequency ramping, dfVCO/dt,
protectsH output transistor during scanning mode
changes
Connection Diagram
TL/H/12323–1
FIGURE1
Order Number LM1291N
SeeNS PackageNumberN28B
C1995National SemiconductorCorporation RRD-B30M115/PrintedinU.S.A.
