Multimedia ICs Color TV Signal Encoder BH7236AF The BH7236AF converts analog RGB signals into color TV signals in the NTSC and PAL formats. From inputs of analog RGB signals, a composite synch signal, burst pulses and a color carrier, this IC generates a color TV signal, and can be adapted for either NTSC or PAL standards, which are selected externally. When set to PAL, chroma phase is switched for each line. The chroma signals and luminosity signals can be combined into a color TV signal or output separately, making this IC suitable for S pins. There are also pins for analog RGB signal output, and each output pin has its own internal 75Ω driver. •TVApplications peripherals •1)Features Can be adapted for NTSC and PAL formats. 5) Analog RGB signal output pins. 6) Internal 75Ω driver. (outputs color TV signals, luminosity signals, chroma signals and analog RGB signals) 7) Adaptable for color subcarrier pulse input. 2) Internal burst timing signal generator with half-H killer. 3) Internal flip-flop for PAL phase switching. 4) Separate Y / C output pins. •Block diagram GND1 1 RIN 2 CLAMP 24 GND2 75Ω 23 ROUT 75Ω 22 GOUT 75Ω 21 BOUT 75Ω 20 VOUT 19 VCC2 18 N. C. 17 YTRAP 75Ω 16 YOUT 75Ω 15 COUT SYNC GIN 3 CLAMP SYNC CLAMP BFPOUT 8 DELAY 7 Y/C MIX NT / PAL BFP 6 B-Y MOD. SCIN F·F 5 MATRIX PHASE SIFTER N. C. FILTER SYNC BPF 4 R-Y MOD. BIN SYNC MIX BFP N. C. 9 SYNCIN 10 SYNCOUT 11 14 N. C. VCC1 12 13 N. C BFP GEN. 1 Multimedia ICs BH7236AF •Pin descriptions Pin No. Pin name 1 GND1 2 Function Ground for all drivers other than the 75Ω driver. 2 RIN Analog R signal input. Drive at low impedance. 3 GIN Analog G signal input. Drive at low impedance. 4 BIN Analog B signal input. Drive at low impedance. 5 N. C. This pin is not connected inside the IC. 6 SCIN Color subcarrier input. Input a 3.579545MHz (NTSC) or 4.433619MHz (PAL) sign wave or pulse wave (50% duty). Do not exceed the range of GND-Vcc. 7 NT / PAL Selecting the type of color TV signal output. The high level selects NTSC, the low level PAL. Internally pulled up to 50kΩ. 8 BFPOUT Burst timing output. Burst timing is generated inside the IC when the subcarrier and composite synchronization signal. 9 N. C. 10 SYNCIN 11 SYNCOUT 12 VCC1 Power supply pin for all except the 75Ω driver. 13 N. C. This pin is not connected inside the IC. 14 N. C. This pin is not connected inside the IC. 15 COUT Chroma signal output. Internal 75Ω driver. 16 YOUT This pin is not connected inside the IC. Composite synchronization signal input. When the low level is input, the synchronization signal is output to both YOUT and VOUT, and inputs to RIN, GIN and BIN are clamped. This pin is internally pulled up to 100kΩ. Composite synchronization signal output. Luminance signal output. Internal 75Ω driver. Attached luminance trap filter. Attaching a trap filter reduces chroma signal cross-color caused by the luminance signal. Output impedance is approximately 2kΩ. 17 YTRAP 18 N. C. This pin is not connected inside the IC. 19 VCC2 Power supply pin for the 75Ω driver. 20 VOUT Color TV signal output. Internal 75Ωdriver. 21 BOUT Analog B signal output. Internal 75Ω driver. 22 GOUT Analog G signal output. Internal 75Ω driver. 23 ROUT Analog R signal output. Internal 75Ω driver. 24 GND2 Ground for the 75Ω driver. Multimedia ICs BH7236AF •Absolute maximum ratings (Ta = 25°C) Parameter Symbol Limits Unit Power supply voltage VCC Power dissipation Pd 550∗ mW Operating temperature Topr – 20 ~ + 70 °C Storage temperature Tstg – 55 ~ + 125 °C 7 V ∗ When mounted on a 50 × 50 × 1.6mm glass epoxy board. Reduced by 5.5mW for each increase in Ta of 1°C over 25°C. •Recommended operating conditions (Ta = 25°C) Parameter Symbol Limits Unit VCC 4.5 ~ 5.5 V RIN input level υRI 0 ~ 1.0 VP-P GIN input level υGI 0 ~ 1.0 VP-P Power supply voltage BIN input level υBI 0 ~ 1.0 VP-P SCIN input level υSC 0.4 ~ 5.0 VP-P 3 Multimedia ICs BH7236AF •Electrical characteristics (unless otherwise noted, Ta = 25°C, V CC Parameter Supply current Luminance level Symbol Min. Typ. = 5V, NTSC format) Max. Unit Conditions ICC — 42 55 mA υRI = υGI = υBI = 1.0VP-P υL 0.63 0.70 0.77 VP-P υRI = 1.0VP-P∗1 Luminance level R υL (R) 0.19 0.21 0.23 VP-P υGI = 1.0VP-P∗1 YOUT Luminance level G υL (G) 0.37 0.41 0.45 VP-P υBI = 1.0VP-P∗1 VOUT Luminance level B υL (B) 0.07 0.08 0.09 VP-P Synchronization level υS 0.27 0.30 0.33 VP-P Synchronization / Luminance level ratio R / burst level ratio RS / L 0.38 0.43 0.48 — RR / BU 2.84 3.16 3.48 — θR 94 104 114 deg RG / BU 2.65 2.95 3.25 θG 231 241 251 deg RB / BU 2.01 2.24 2.47 — B phase θB 337 347 357 deg Burst level υBU 0.23 0.29 0.35 VP-P ∗2 PAL burst phase ( + ) θBU+ 125 135 145 deg PAL∗1 PAL burst phase ( – ) θBU– 215 225 235 deg PAL∗1 PAL burst level ratio RBU 0.9 1.0 1.1 — PAL∗1 Carrier leak υCL — — 35 mVP-P — 3.90 — — V R phase G / burst level ratio G phase COUT VOUT B / burst level ratio SYNCOUT, "H" level RYO = υS / υL υRI = 1.0VP-P∗1 υGI = 1.0VP-P∗1 υBI = 1.0VP-P∗1 ∗2 SYNCOUT, "L" level — — — 0.80 V ROUT output level υRO 0.63 0.70 0.77 VP-P υRI = 1.0VP-P GOUT output level υGO 0.63 0.70 0.77 VP-P υGI = 1.0VP-P BOUT output level υBO 0.63 0.70 0.77 VP-P υBI = 1.0VP-P YOUT DC voltage VYO 1.30 1.70 2.10 V COUT DC voltage VCO 2.00 2.40 2.80 V VOUT DC voltage VVO 1.15 1.55 1.95 V ROUT DC voltage VRO 1.40 1.80 2.20 V GOUT DC voltage VGO 1.40 1.80 2.20 V BOUT DC voltage VBO 1.40 1.80 2.20 V Input volt. SYNCIN, NT / PAL, "H" level VH 2.2 — — V Input volt. SYNCIN, NT / PAL, "L" level VL — — 0.8 V Input curr. SYNCIN, NT / PAL, "H" level IH — — 300 µA Input current when applied = 5V Input curr. SYNCIN, NT / PAL, "L" level IL — — 200 µA Input current when applied = 0V ∗1 Guaranteed performance. ∗2 Measured with a 3.58MHz BPF. 䊊 Not designed for radiation resistance. 4 Multimedia ICs BH7236AF •Measurement circuit 1 24 Analog R signal 2 CLAMP 75Ω 23 SYNC Analog G signal 3 CLAMP 75Ω 22 SYNC Analog B signal 4 CLAMP + 75 75 75Ω 21 + 75 75 220µ MATRIX PHASE SIFTER + 75 75 ROUT measurement point GOUT measurement point BOUT measurement point VOUT measurement point VCC Y/C MIX 19 DELAY BFP 7 F·F VCC 20 75 220µ BPF 6 75Ω B - Y MOD. Color subcarrier FILTER SYNC 5 R - Y MOD. 0.1µ BGPOUT 75 220µ 0.1µ NT / PAL selector + 220µ 0.1µ 8 18 N.C. 17 N.C. 9 BFP GEN. SYNC MIX BFP 75Ω 16 + 75 220µ Composite SYNCH 75 75 10 75Ω 15 0.47µ SYNCOUT measurement point 11 75 YOUT measurement point COUT measurement point 14 N.C. SYNC VCC 12 operation •(1)Circuit SYNCIN is for composite synch input. During low input, the synchronization signal is output to YOUT, VOUT and SYNCOUT. This signal also controls the timing of the pedestal clamps of R IN , GIN and B IN . (The pedestal levels of RIN, GIN and BIN are kept constant by charging an attached capacitor.) (2) SCIN is for color subcarrier input. Set input to a pulse wave or sine wave (3.579545MHz for NTSC and 4.433619MHz for PAL). (3) NT / PAL is the NTSC / PAL selector pin, and connects to Vcc when set to NTSC and to GND when set to PAL. Chroma phase is switched for each line when the IC is set to PAL. (4) Using the composite synch and subcarrier inputs, the IC generates a burst flag signal, according to which 13 N.C. a burst signal is output to COUT and VOUT. The half-H killer presents the burst signal from being output at the wrong points. (5) PAL chroma phases are also switched at a regular cycle (1H) during vertical synchronization. (6) COUT and YOUT are for output of chroma signals and luminosity signals, respectively. Because the chroma signal and luminosity signals can be output separately, the IC can be adapted for S pins. Each has a 75Ω driver. (7) VOUT is for color TV signal output, and has an internal 75Ω driver. (8) ROUT, GOUT and BOUT are for analog RGB signal output, and have an internal 75Ω driver. 5 Multimedia ICs BH7236AF •Application example (NTSC color TV signal) 1 24 Analog R input 2 CLAMP 75Ω 23 ROUT 3 SYNC CLAMP 75Ω 22 GOUT 4 SYNC CLAMP 75Ω 21 BOUT 75Ω 20 0.1µ Analog G input 0.1µ Color TV signal 19 DELAY F·F VCC BGPOUT 75 VCC BFP Y/C MIX 6 7 + 220µ B - Y MOD. Color subcarrier input MATRIX PHASE SIFTER 5 FILTER N.C. SYNC BPF 0.1µ R - Y MOD. Analog B input 8 18 N.C. 17 N.C. BFP GEN. 9 Composite SYNC input 10 SYNCOUT low as possible as the analog RGB signal is clamped there. (2) The color subcarrier should have a duty of 50%. Duty fluctuation will affect chroma phase. •External dimensions (Units: mm) 15.0 ± 0.2 0.11 1.8 ± 0.1 0.4 ± 0.1 0.3Min. 0.15 SOP24 6 0.15 ± 0.1 5.4 ± 0.2 7.8 ± 0.3 13 1.27 75Ω 15 COUT 13 N.C. notes •(1)Operation Input impedance at the input terminals should be as 12 16 YOUT SYNC 12 1 75Ω 14 N.C. 11 VCC 24 SYNC MIX BFP (3) Composite synch and burst flag pulse inputs should conform to their respective standards, as input of an off-standard signal will shift the burst position and cause other problems that may prevent the TV from displaying color images. For input, use the TTL level and an impedance of 8kΩ.