LM1296
Raster Geometry Correction System for Multi-Frequency Displays
General Description
The LM1296is a monolithic IC for use in the raster scanning circuitry of a multi-frequency CRT monitor.The IC provides an S-corrected sawtooth waveform and a variable DC output voltage.These two outputs drive the vertical deflection am-plifier.It also provides another waveform for East-West ge-ometry correction which includes pincushion,corner,and trapezoid controls.The geometry correction is controlled by DC input voltages from 0V to 4V.
The raster height and the raster vertical position can be con-trolled by two DC voltage input pins that adjust the sawtooth waveform amplitude and the variable DC output voltage.The East-West correction of the LM1296has height tracking and vertical position tracking capabilities.As the height or posi-tion of the raster is adjusted the geometry correction is main-tained by the chip automatically.
The LM1296is packaged in a 16-pin plastic DIP package.薄膜生产线 Features
n Vertical scanning frequency 50Hz–165Hz
n Accepts either polarity of V sync n DC-controlled correction terms n Raster vertical position control
n Vertical S-correction (linearity)control n East-West pincushion control n East-West trapezoid control n East-West corner control
n Provides both polarities of correction output
n
East-West correction tracks raster vertical position and height
n Compatible with LM1290and LM1292horizontal PLL
Applications
n Vertical deflection of monitors
尼龙扣
Connection Diagram
DS012894-1
FIGURE 1.
Order Number LM1296N See NS Package Number N16A
February 1998
LM1296Raster Geometry Correction System for Multi-Frequency Displays
©1998National Semiconductor Corporation DS012894www.national
Absolute Maximum Ratings(Notes3,1) If Military/Aerospace specified devices are required, please contact the National Semiconductor Sales Office/ Distributors for availability and specifications.
Supply Voltage(V CC)15V Input Voltage(V IN)
Pins1,2,8,9,10,160V≤V IN≤5V Power Dissipation(P D)
Above25˚C,Derate
Based onθJA and T J(Note4) 1.5W Thermal Resistance(θJA)81˚C/W Junction Temperature(T JMAX)150˚C ESD Susceptibility(Note5)2kV Storage Temperature−65˚C to+150˚C Lead Temperature(Soldering10sec.)265˚C
Operating Ratings(Note2)
Supply Voltage(V CC)10.8V≤V CC≤13.2V Input Voltage(V IN)
Pins1,2,8,9,10,160V≤V IN≤4V Output Current(I OUT)
Pins11,13,15−2mA≤I OUT≤2mA Temperature Range(T A)0˚C to+70˚C
Electrical Characteristics
See Test Circuit(Figure2),V CC=12V;V2=4V;V16=4V;V RDCV=0V(Note6);T A=25˚C unless otherwise specified Symbol Parameter Conditions Min Typ Max Units
(Note8)(Note7)(Note8)
I CC Supply Current Pins11,13,15Loaded,2mA2632mA V SYNC Vertical Sync Input Sensitivity(Pin7)1%or99%Duty Cycle
Rectangular Waveform1V PP
AC-Coupled to Pin7
Through0.01µF Cap.
f MIN Minimum Lock Frequency C OSC=0.15µF50Hz f MAX Maximum Lock Frequency C OSC=0.15µF165Hz f FR Free Run Frequency V7=4V or0V40Hz R IN1Input Resistance(Pin1)25kΩR IN2Input Resistance(Pin2)V2=1V12kΩR IN3Input Resistance(Pins8,9,10)50kΩR IN4Input Resistance(Pin16)50kΩV O15SAWTOOTH OUT(Pin15)V2=4V,V16=0V 1.8
Output Amplitude(R L15=5kΩ)V2=4V,V16=4V 3.1V PP
V2=0V,V16=0V1
V2=0V,V16=4V 1.7
V DC15SAWTOOTH OUT(Pin15)V2=0V to4V,V16=0V to4V 3.9V Output DC Voltage(R L15=5kΩ)
k TEMP SAWTOOTH OUT(Pin15)(Note9) 1.5% Temperature Stability
k S S-Correction of Sawtooth Output(Pin15)V2=4V,V16=4V0.5%
V2=4V,V16=0V2
V RDCV Relative DC Voltage between V1=4V−200mV DC OUT(Pin13)and V1=1.5V200
SAWTOOTH OUT(Pin15)
V RDCV=V13−V DC15
(R L13=5kΩ)
V TRAP Trapezoid Correction V2=4V,V8=0V0.87V PP Output Waveform Amplitude V2=4V,V8=4V0.73
(Pin11,R L11=5kΩ)Pincushion and Corner
Corrections are Null
V PIN Pincushion Correction V2=4V,V10=0V 1.9V PP Output Waveform Amplitude V2=4V,V10=4V 1.45
(Pin11,R L11=5kΩ)Trapezoid and Corner
Corrections are Null
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Electrical Characteristics
(Continued)
See Test Circuit (Figure 2),V CC =12V;V 2=4V;V 16=4V;V RDCV =0V (Note 6);T A =25˚C unless otherwise specified
Symbol Parameter
Conditions
Min Typ Max Units
(Note 8)
(Note 7)(Note 8)
V CNR
Corner Correction
V 2=4V,V 9=0V 1.1V PP Output Waveform Amplitude V 2=4V,V 9=4V 0.8
(Pin 11,R L11=5k Ω)
Trapezoid and Pincushion Corrections are Null V DC11
E-W OUT
Trapezoid,Pincushion,and 4.1
Output Offset Voltage Corner Correction Waveforms (Pin 11,R L11=5k Ω)
are Null
10 18 100 101
Note 1:Absolute Maximum Ratings indicate limits beyond which damage to the device may occur.
Note 2:Operating Ratings indicate conditions for which the device is functional,but do not guarantee specific performance limits.For guaranteed specifications and test conditions,see the Electrical Characteristics.The guaranteed specifications apply only for the test conditions listed.Some performance characteristics may de-grade when the device is not operated under the listed test conditions.
Note 3:All voltages are measured with respect to GND,unless otherwise specified.
Note 4:The maximum power dissipation must be derated at elevated temperatures and is dictated by T JMAX ,θJA and the ambient temperature,T A .The maximum allowable power dissipation at any elevated temperature is P D =(T JMAX –T A )/θJA or the number given in the Absolute Maximum Ratings,whichever is lower.For this device,T JMAX =150˚C.The typical thermal resistance (θJA )of the LM1296is 81˚C/W.Note 5:Human Body model,100pF capacitor discharged through a 1.5k Ωresistor.Note 6:Adjust V 1until V RDCV =0V,where V RDCV =V 13−V DC15.张英森
Note 7:Typical specifications are specified at T A =25˚C and represent most likely parametric norm.Note 8:Tested limits are guaranteed to National’s AOQL (Average Outgoing Quality Level).
Note 9:Amplitude stability versus ambient temperature is defined by |V 70−V 25|/V 25x 100%,where
V 70and V 25are the output sawtooth peak-to-peak amplitudes at 70˚C and 25˚C respectively.
Test Circuit
Typical Performance Characteristics
T A =25˚C,f v =60Hz,V 2=4V,V 16=4V,V RDCV =0V,V 8,9,10=Set for null correction waveforms,unless otherwise specified
DS012894-2
FIGURE 2.
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Typical Performance Characteristics
(Continued)
E-W Out (Pin 11)
DS012894-3E-W Out (Pin 11)
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E-W Out (Pin 11)DS012894-5E-W Out (Pin 11)
DS012894-6
E-W Out (Pin 11)DS012894-7E-W Out (Pin 11)
DS012894-8
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Block Diagram
Functional Description包边带
The LM1296outputs a sawtooth and a variable DC voltage for the vertical deflection amplifier.It also provides the hori-zontal deflection output circuit with a waveform for Trap-ezoid,Pincushion and Corner correction.
Referring to Figure 3,pin 7(V SYNC)goes to the Sync Po-larity Correction Block that accepts either positive-going or negative-going sync signals.The polarity-corrected sync is sent to the Injection-Locked Oscillator so that the sawtooth generated is synchronized with the vertical sync.With no sync signal AC-coupled to pin 7,the oscillator free runs at typically 40Hz.
There are three capacitors and one control pin connected to the Sawtooth Waveform Generation Block.C OSC is the tim-ing capacitor for the Injection-Locked Oscillator.C F is the fil-ter capacitor for an internal circuit that detects the existence of vertical sync and prevents the Injection-Locked Oscillator from locking at twice the vertical sync frequency.C ALC is for the automatic level control (ALC)circuit.The ALC circuit maintains the sawtooth output amplitude,which is set by the DC voltage at pin 2(HEIGHT),regardless of the vertical sync frequency.Since the output sawtooth goes to the geometry correction circuit as well,the correction waveform generated tracks the sawtooth ,the height of the CRT raster.
The S Correction block shapes the linear sawtooth into an S-shape sawtooth.Pin 15(SAWTOOTH OUT)outputs the buffered S-shape sawtooth.The amount of S correction is controlled by the DC voltage at pin 16(S).
Referring to Figure 4,the extent of S correction is defined by the following equation.
k S =(∆A 1+∆A 2)/2A x 100%
The LM1296is designed to drive an external vertical deflec-tion amplifier that is operating with positive and negative power supplies.The LM1296outputs an S-corrected saw-tooth with a DC level that is typical 3.85V.Pin 13(DC OUT)provides a DC voltage of 3.85V ±200mV.By applying a DC control voltage to pin 1(POSITION),the output voltage at pin 13can be varied.This sets the output DC current from the vertical deflection amplifier,which in turn sets the raster ver-tical position.
DS012894-9
FIGURE 3.
DS012894-10
FIGURE 4.
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