Multimedia ICs Color TV signal encoder BA7242F The BA7242F is an IC which converts analog RGB signals to NTSC and PAL color TV signals. In addition to composite output, luminance output, chrominance output, and analog RGB output are available. Each type of output is equipped with an internal 75Ω driver. •TVApplications peripheral devices •1)Features Supports both NTSC and PAL systems. 4) Internal 75Ω driver 5) Supports subcarrier pulse for color input 2) Internal flip-flop circuit for PAL common mode switching 3) Equipped with Y / C separated output pin. CLAMP BFP GIN 2 CLAMP RIN 3 Y/C MIX BFP SYNC MIX 1 MATRIX BIN VCC SYNC •Block diagram CLAMP 14 VCC2 13 YOUT 12 VOUT 11 GND2 10 COUT 9 NT / PAL 8 SCIN GND NT / PAL GND F•F 7 NT / PAL GND1 FILTER 6 CHROMA GEN BFP B-Y MOD 5 R-Y MOD VCC SYNC PHASE GEN 4 BURST FLAG VCC1 SYNC BFP 1 Multimedia ICs BA7242F •Absolute maximum ratings (Ta = 25°C) Parameter Symbol Limits Unit Power supply voltage VCC 7 V Power dissipation Pd 450∗ mW Operating temperature Topr – 20 ~ + 70 °C Storage temperature Tstg – 55 ~ + 125 °C ∗ Reduced by 4.5mW for each increase in Ta of 1°C over 25°C. (When mounted on a 70mm × 70mm × 1.6mm glass epoxy board.) •Recommended operating conditions (Ta = 25°C) Parameter Symbol Limits Unit VCC 4.5 ~ 5.5 V RIN input level υRI 0 ~ 0.7 VP–P GIN input level υGI 0 ~ 0.7 VP–P 0 ~ 0.7 VP–P Power supply voltage BIN input level υBI SCIN input level υSC 0.45 ~ 0.60 VP–P •Pin descriptions 2 Pin No. Pin name Function 1 BIN Input for analog B signal. Operate with low impedance. 2 GIN Input for analog G signal. Operate with low impedance. 3 RIN Input for analog R signal. Operate with low impedance. 4 VCC1 VCC for all except 75Ω driver. 5 SYNC Input for composite SYNC signal. Outputs SYNC signal to VOUT and YOUT pins when input is LOW. 6 BFP Input for burst timing signal. Simultaneously performs the burst output and initiates the pedestal clamp for the RIN, GIN, and BIN input signals when input is LOW. 7 GND1 GND for all except 75Ω driver. 8 SCIN 3.58MHz or 4.43MHz pulse signal input. 9 NT / PAL 10 COUT Video signal output mode setting. HIGH level = NTSC, LOW level = PAL. 11 GND2 12 VOUT Composite video signal output. Internal 75Ω driver. 13 YOUT Luminance signal output. Internal 75Ω driver. 14 VCC2 VCC for 75Ω driver. Chrominance signal output. Internal 75Ω driver. GND for 75Ω driver. Multimedia ICs BA7242F •Electrical characteristics (unless otherwise noted, Ta = 25°C, V CC Parameter Symbol Min. Typ. = 5V, SCIN = 3.579545MHz, NT / PAL = 5V) Max. Conditions Unit ICC 23 34 45 mA υL 0.63 0.70 0.77 VP-P υRI = υ GI = υ BI = 0.7VP-P Luminance level R υL(R) 0.19 0.21 0.23 VP-P υRI = 0.7VP-P∗2 Luminance level G υL(G) 0.37 0.41 0.45 VP-P υGI = 0.7VP-P∗2 Luminance level B υL(B) 0.07 0.08 0.09 VP-P υBI = 0.7VP-P∗2 Synchronization level υS 0.27 0.30 0.33 VP-P Synchronization / luminance level ratio R S/L 0.38 0.43 0.48 — RYO = υYS / υYL Red / burst level ratio R R / BU 2.84 3.16 3.48 — υRI = 0.7VP-P∗2 Green / burst level ratio R G / BU 2.65 2.95 3.25 — υGI = 0.7VP-P∗2 Blue / burst level ratio R B / BU 2.01 2.24 2.47 — υBI = 0.7VP-P∗2 Red phase θR 94 104 114 deg ∗2 Green phase θG 231 241 251 deg ∗2 Blue phase θB 337 347 357 deg ∗2 Burst level υBU 0.26 0.29 0.32 VP-P ∗4 Carrier leak υCL — — 35 mVP-P ∗3 θBU + 125 135 145 deg NT / PAL = 0V∗2 θBU – 215 225 235 deg NT / PAL = 0V∗2 R BU 0.9 1.0 1.1 — NT / PAL = 0V∗2 YOUT DC voltage V YO 1.60 2.00 2.40 V COUT DC voltage V CO 2.20 2.60 3.00 V VOUT DC Voltage V VO 1.35 1.75 2.15 V High level input voltage SYNC, BFP, NT / PAL V IH 2.0 — — V Low level input voltage SYNC, BFP, NT / PAL V IL — — 0.8 V Input current during high SYNC, BFP, NT / PAL V IH — — 300 µA With 5V applied Input current during low SYNC, BFP, NT / PAL V IL — — 200 µA With 0V applied Current consumption Luminance level YOUT VOUT COUT VOUT PAL burst phase PAL burst ratio ∗2 Guaranteed design with these parameters ∗3 Measured using a 3.58MHz BPF for 3.5µs after the burst. ∗4 Measured using a 3.58MHz BPF. 䊊 Not designed for radiation resistance 3 Multimedia ICs BA7242F SYNC •Measurement circuit 2 CLAMP 14 75 YOUT measurement point 13 220µ 75 BFP 3 75 Y/C MIX 0.1µ RIN input SYNC MIX BFP 0.1µ MATRIX CLAMP 1 GIN input VCC VCC 0.1µ BIN input CLAMP VOUT measurement point 12 220µ 75 BFP GND CHROMA GEN B-Y MOD 75 0.47µ description •(1)Operation The composite SYNC is input to the SYNCIN pin. During Low level input, the SYNC signal is output to the YOUT, VOUT, and SYNCOUT pins. (2) The burst flag pulse is input to the BFPIN pin. During Low level input, the burst signal is output to the COUT and VOUT pins. For PAL, the phase inversion of the chroma signal occurs according to this signal. Furthermore, this signal also acts as the timing for the pedestal clamp for the RIN, GIN, and BIN pins. By using an external condenser for charging during Low level input, the pedestal levels for the RIN, GIN, and BIN pins are maintained at a uniform level. (3) The NT / PAL pin is for selecting either NTSC or 4 FILTER PHASE GEN GND NT / PAL (BFP) 7 COUT measurement point 75 Vcc 9 NT / PAL R-Y MOD VCC 6 11 10 F•F Burst flag pulse 5 BURST FLAG Composite SYNC 4 SYNC VCC 0.1µ 8 560 4.7k Color subcarrier PAL. For NTSC, this pin is connected to VCC and for PAL, this pin is connected to GND. (4) The SCIN pin is the color subcarrier input pin. Input either a pulse wave or a sine wave of frequency 3.579545MHz for NTSC or of frequency 4.433619MHz for PAL. (5) The COUT pin is the output pin for the chroma signal, and the YOUT pin is the output pin for the luminance signal. This is compatible with the S pin because the chroma signal and the luminance signal can be output separately. Both pins have internal 75Ω drivers. (6) The VOUT pin is the output pin for a color TV signal and has an internal 75Ω driver. Multimedia ICs BA7242F SYNC •Application example (When using NTSC color TV signal) 1 CLAMP 3 CLAMP 13 Y/C MIX BFP 0.1µ Analog R signal 14 SYNC MIX BFP 2 MATRIX CLAMP 0.1µ Analog G signal VCC VCC 0.1µ Analog B signal 12 75 + Color TV signal output 220µ BFP GND 10 4.7k Color subcarrier 560 14 8 1 7 1.27 0.15 ± 0.1 4.4 ± 0.2 6.2 ± 0.3 8.7 ± 0.2 1.5 ± 0.1 input pin, input them with a low impedance. (2) Input a signal of duty 50% for the color subcarrier. If the duty fluctuates, it will affect the chroma phase. Furthermore, for the application example, a voltagedividing resistor is assumed for the CMOS input of 5VP-P. For other input formats, regulate the SCIN pin for 0.5VP-P. (3) Input the composite SYNC and burst flag pulse according to the standard value. If the timing is off, the TV receiver may not show any color. As well, set the input level the same as the TTL level. The input impedance is 8kΩ. 0.1µ 8 •External dimensions (Units: mm) 0.11 notes •(1)Operation Since analog RGB signals perform clamping at the 9 NT / PAL FILTER PHASE GEN GND NT / PAL (BFP) 7 VCC F•F 6 11 CHROMA GEN Burst flag pulse B-Y MOD 5 R-Y MOD VCC Composite SYNC BURST FLAG 4 SYNC VCC 0.4 ± 0.1 0.3Min. 0.15 SOP14 5