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Details, datasheet, quote on part number:AD725AR
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Datasheet text preview:
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FEATURES Composite Video Output: Both NTSC and PAL Chrominance and Luminance (S-Video) Outputs Luma Trap Port to Eliminate Cross Color Artifacts TTL Logic Levels Integrated Delay Line and Auto-Tuned Filters Drives 75 Reverse-Terminated Loads Low Power +5 V Operation Power-Down to <1 A Very Low Cost APPLICATIONS RGB/VGA to NTSC/PAL Encoding Personal Computers/Network Computers Video Games Video Conference Cameras Digital Still Cameras
Low Cost RGB to NTSC/PAL Encoder with Luma Trap Port AD725
PRODUCT DESCRIPTION
The AD725 is a very low cost general purpose RGB to NTSC/ PAL encoder that converts red, green and blue color component signals into their corresponding luminance (baseband amplitude) and chrominance (subcarrier amplitude and phase) signals in accordance with either NTSC or PAL standards. These two outputs are also combined on-chip to provide a composite video output. All three outputs are available separately at voltages of twice the standard signal levels as required for driving 75 , reverse-terminated cables. The AD725 features a luminance trap (YTRAP) pin that provides a means of reducing cross color generated by subcarrier frequency components found in the luminance signal. For portable or other power-sensitive applications, the device can be powered down to less than 1 µA of current consumption. All logic levels are TTL compatible thus supporting the logic requirements of 3 V CMOS systems. The AD725 is packaged in a low cost 16-lead SOIC and operates from a +5 V supply.
FUNCTIONAL BLOCK DIAGRAM
NTSC/PAL HSYNC VSYNC 4FSC CLOCK XNOR 4FSC SYNC SEPARATOR CSYNC BURST NTSC/PAL FSC 90 C/270 C 180 C (PAL ONLY) CLOCK AT 8FSC SAMPLEDDATA DELAY LINE 2-POLE LP POSTFILTER
CSYNC
FSC 90 C 4FSC QUADRATURE +4 DECODER FSC 0 C CSYNC 3-POLE LP PREFILTER
RED
DC CLAMP
Y
X2
LUMINANCE OUTPUT LUMINANCE TRAP
R GREEN
DC CLAMP
RGB-TO-YUV ENCODING MATRIX
U
4-POLE LPF
U CLAMP BALANCED MODULATORS
NTSC/PAL 4-POLE LPF
X2
COMPOSITE OUTPUT CHROMINANCE OUTPUT
X2
BLUE
DC CLAMP
V
4-POLE LPF BURST
V CLAMP
EV. 0
Information furnished by Analog Devices is believed to be accurate and reliable. However, no responsibility is assumed by Analog Devices for its use, nor for any infringements of patents or other rights of third parties which may result from its use. No license is granted by implication or otherwise under any patent or patent rights of Analog Devices. One Technology Way, P.O. Box 9106, Norwood, MA 02062-9106, U.S.A. Tel: 781/329-4700 World Wide Web Site: http://www.analog.com Fax: 781/326-8703 © Analog Devices, Inc., 1997
AD725SPECIFICATIONS 150
Parameter SIGNAL INPUTS (RIN, GIN, BIN) Input Amplitude Black Level1 Input Resistance2 Input Capacitance
(Unless otherwise noted, VS = +5, TA = +25 C, using 4FSC synchronous clock. All loads are 5% at the IC pins. Outputs are measured at the 75 reverse terminated load.)
Conditions Full Scale 0.8 RIN, GIN, BIN TTL Logic Levels 1 2 1 1 V V µA µA 1 5 Min Typ Max 714 Units mV p-p V M pF
LOGIC INPUTS (HSYNC, VSYNC, 4FSC, CE, STND) Logic Low Input Voltage Logic High Input Voltage Logic Low Input Current (DC) Logic High Input Current (DC) VIDEO OUTPUTS3 Luminance (LUMA) Bandwidth, 3 dB Gain Error Nonlinearity Sync Level DC Black Level Luminance Trap (YTRAP) Output Resistance DC Black Level Chrominance (CRMA) Bandwidth, 3 dB Color Burst Amplitude Color Burst Width Chroma Level Error4 Chroma Phase Error5 DC Black Level Chroma Feedthrough Composite (COMP) Absolute Gain Error Differential Gain Differential Phase DC Black Level Chroma/Luma Time Alignment POWER SUPPLIES Recommended Supply Range Quiescent Current--Encode Mode Quiescent Current--Power Down
NTSC PAL 7 max p-p NTSC PAL 252 264
4.4 5.2 2 0.3 279 291 1.3 1.0 1.0
+7 310 325
MHz MHz % % mV mV V k V MHz MHz mV p-p mV p-p µs µs % Degrees V mV p-p % % Degrees V ns
NTSC PAL NTSC PAL NTSC PAL
206 221
R, G, B = 0 With Respect to Luma With Respect to Chroma With Respect to Chroma S-Video Single Supply +4.75 5
1.2 1.5 255 291 2.51 2.28 4 ±3 2.0 15 1 0.5 1.5 1.4 20
305 362
40 +3
30 <1
+5.25 V 36 mA µA
NOTES 1 R, G, and B signals are inputted via an external ac coupling capacitor. 2 Except during dc restore period (back porch clamp). 3 All outputs measured at a 75 reverse-terminated load; ac voltages at the IC output pins are twice those specified here. 4 Difference between ideal and actual color bar subcarrier amplitudes. 5 Difference between ideal and actual color bar subcarrier phases. Specifications are subject to change without notice.
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AD725
ABSOLUTE MAXIMUM RATINGS*
Supply Voltage, APOS to AGND . . . . . . . . . . . . . . . . . . +6 V Supply Voltage, DPOS to DGND . . . . . . . . . . . . . . . . . . +6 V AGND to DGND . . . . . . . . . . . . . . . . . . . . . 0.3 V to +0.3 V Inputs . . . . . . . . . . . . . . . . . . . DGND 0.3 to DPOS + 0.3 V Internal Power Dissipation . . . . . . . . . . . . . . . . . . . . . . 800 mW Operating Temperature Range . . . . . . . . . . . . 40°C to +85°C Storage Temperature Range . . . . . . . . . . . . . 65°C to +125°C Lead Temperature Range (Soldering 30 sec) . . . . . . . . +230°C
*Stresses above those listed under Absolute Maximum Ratings may cause permanent damage to the device. This is a stress rating only; functional operation of the device at these or any other conditions above those indicated in the operational section of this specification is not implied. Exposure to absolute maximum rating conditions for extended periods may affect device reliability. Thermal Characteristics: 16-Pin SOIC Package: JA = 100°C/W.
PIN CONFIGURATION 16-Lead Wide Body (SOIC) (R-16)
STND 1 AGND 4FSC APOS CE RIN GIN BIN 2 3 4
16 HSYNC 15 VSYNC 14 DPOS
13 DGND TOP VIEW 5 (Not to Scale) 12 YTRAP 6 7 8 11 LUMA 10 COMP 9 CRMA
AD725
ORDERING GUIDE Temperature Range Package Description 16-Lead SOIC 16-Lead SOIC 16-Lead SOIC Evaluation Board Package Option R-16 R-16 R-16
Model
AD725AR 40°C to +85°C AD725AR-Reel 40°C to +85°C AD725AR-Reel7 40°C to +85°C AD725-EB
CAUTION ESD (electrostatic discharge) sensitive device. Electrostatic charges as high as 4000 V readily accumulate on the human body and test equipment and can discharge without detection. Although the AD725 features proprietary ESD protection circuitry, permanent damage may occur on devices subjected to high energy electrostatic discharges. Therefore, proper ESD precautions are recommended to avoid performance degradation or loss of functionality.
WARNING!
ESD SENSITIVE DEVICE
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AD725
PIN DESCRIPTIONS
Pin 1
Mnemonic STND
Description Encoding Standard Pin. A Logic HIGH input selects NTSC encoding. A Logic LOW input selects PAL encoding. TTL Logic Levels. Analog Ground Connection. 4FSC Clock Input. For NTSC: 14.318 180 MHz. For PAL: 17.734 475 MHz. TTL Logic Levels. Analog Positive Supply (+5 V ± 5%). Chip Enable. A Logic HIGH input enables the encode function. A Logic LOW input powers down chip when not in use. TTL Logic Levels. Red Component Video Input. 0 mV to 714 mV AC-Coupled. Green Component Video Input. 0 mV to 714 mV AC-Coupled. Blue Component Video Input. 0 mV to 714 mV AC-Coupled. Chrominance Output.* Approximately 1.8 V peak-to-peak for both NTSC and PAL. Composite Video Output.* Approximately 2.5 V peak-to-peak for both NTSC and PAL. Luminance plus CSYNC Output.* Approximately 2 V peak-to-peak for both NTSC and PAL. Luminance Trap Filter Tap. Attach L-C resonant network to reduce cross-color artifacts. Digital Ground Connection. Digital Positive Supply (+5 V ± 5%). Vertical Sync Signal (if using external CSYNC set at > +2 V). TTL Logic Levels. Horizontal Sync Signal (or CSYNC signal). TTL Logic Levels.
Equivalent Circuit Circuit A
2 3
A GND 4FSC
Circuit A
4 5
APOS CE
Circuit A
6 7 8 9 10 11 12 13 14 15 16
RIN GIN BIN CRMA COMP LUMA YTRAP DGND DPOS VSYNC HSYNC
Circuit B Circuit B Circuit B Circuit C Circuit C Circuit C Circuit D
Circuit A Circuit A
*The Luminance, Chrominance and Composite Outputs are at twice normal levels for driving 75 reverse-terminated lines.
APOS DPOS DPOS APOS DPOS 1k 12 1 3 5 15 16 DGND 6 7 8 DGND VCLAMP AGND DGND 9 10 11 AGND DGND DPOS
Circuit A
Circuit B
Circuit C
Circuit D
Figure 1. Equivalent Circuits
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Typical CharacteristicsAD725
+5V TEKTRONIX TG2000 SIGNAL GENERATION PLATFORM COMPOSITE SYNC OMPOSITE VIDEO
AD725
RGB 3 75 4FSC C RGB TO NTSC/PAL ENCODER
SONY MONITOR MODEL PVM-1354Q 7 5
GENLOCK FSC (3.579545MHz OR 4.433618MHz) OSCILLATOR
FSC
HP3314A 4 PLL
TEKTRONIX VM700A WAVEFORM MONITOR
Figure 2. Evaluation Setup
1.0
1.0
APL = 50.8% 525 LINE NTSC NO FILTERING SLOW CLAMP TO 0.00V @ 6.63 s
APL = 50.6% 625 LINE PAL NO FILTERING SLOW CLAMP TO 0.00V @ 6.72 s
100
0.5
0.5
VOLTS
50
VOLTS
0.0
0
IRE
0.0
50 0.5 0 10 20 30 µs 40 50 60
0.5 0
10
20
30 s
40
50
60
Figure 3. 100% Color Bars, NTSC
Figure 5. 100% Color Bars, PAL
Figure 4. 100% Color Bars on Vector Scope, NTSC
Figure 6. 100% Color Bars on Vector Scope, PAL
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