AD723 Analog Devices, AD723 Datasheet - Page 4

• Manufacturer Part Number: AD723
• Description: 2.7 V to 5.5 V RGB-to-NTSC/PAL Encoder with Load Detect and Input Termination Switch
• Manufacturer: Analog Devices

AD723
Pin
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
Mnemonic
STND
SA
CE
TERM
RIN
GIN
BIN
AGND
RT
GT
BT
TGND
DVDD
DGND
HSYNC
VSYNC
4FSC
TVDET
CVSET
CV
YTRAP
AVDD
C
CSET
AVDD1
Y
YSET
AGND
15
16
17
1
2
3
4
POS
Description
Encoding Standard Pin. A Logic HIGH signal is used for NTSC encoding, a Logic LOW
signal signifies PAL.
When SA is high, phase alternation accompanies NTSC bandwidths and timing for
support of PAL (M) and “combination N” standards used in South America.
Chip Enable. A Logic HIGH input enables the encode function. A Logic LOW input
powers down the chip when not in use. Requires active HSYNC signal to activate.
Can be raised briefly to perform power-down load check.
Terminate. A Logic HIGH enables terminate function. RT, GT, and BT terminals are
tied to the termination ground, TGND. A Logic Low leaves these terminals floating.
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.
Analog Ground Connection. (Main Ground Connection.)
Input Terminal for RED Termination Switch. Can be left unconnected when switchable
input termination option is not used.
Input Terminal for GREEN Termination Switch. Can be left unconnected when switchable Circuit F
input termination option is not used.
Input Terminal for BLUE Termination Switch. Can be left unconnected when switchable
input termination option is not used.
Termination Switch Ground Connection.
Digital Positive Supply Connection.
Digital Ground Connection.
Horizontal Sync Signal (or CSYNC signal).
Vertical Sync Signal.
4FSC Clock Input. For NTSC: 14.318 180 MHz, for PAL: 17.734 475 MHz.
Output Flag for TV Presence Detection. LOW signal signifies no TV present.
Composite Video Gain Setting Resistor.
Composite Video Output.
Luminance Trap Filter Tap. Attach L-C resonant network to reduce cross-color artifacts.
Analog Positive Supply Connection.
Chrominance Output.
Chrominance Gain Setting Resistor.
Analog Positive Supply Connection.
Luminance Output (with CSYNC).
Luminance Gain Setting Resistor.
Analog Ground Connection.
POS
5
6
7
DPOS
DGND
DPOS
DGND
PIN FUNCTION DESCRIPTIONS
1k
DPOS
DGND
18
10
11
9
APOS
APOS
AGND
TGND
19
20
23
24
26
27
APOS
AGND
1k
APOS
AGND
21
Equivalent Circuit
Circuit A
Circuit A
Circuit A
Circuit A
Circuit B
Circuit B
Circuit B
Circuit F
Circuit F
Circuit A
Circuit A
Circuit A
Circuit E
Circuit C
Circuit C
Circuit D
Circuit C
Circuit C
Circuit C
Circuit C