CX31993 Datasheet — Digest Product overview
Part: CX31993 Device class: Single-chip, high-performance NTSC/PAL analog video decoder (composite/S-Video/YC and CVBS), with integrated ADCs and video processing. Typical application: Set-top boxes, DVD players, DVRs, video capture cards, CCTV front-ends, multimedia appliances needing analog video input and digitization.
Key features
Inputs: Composite video (CVBS), S-Video (Y/C), typically supports multiple input channels (check variant). Video standards: NTSC (including NTSC-M/J), PAL (B/G/H/I/D/K/N), SECAM — automatic standard detection and switching. Analog-to-digital conversion: Integrated high-speed ADC(s) for luminance and chrominance. Resolution & formats: Supports standard-definition interlaced formats (720×480 NTSC, 720×576 PAL) with programmable output formats (YCbCr/RGB) and output bus configurations. Output interfaces: Parallel video data bus (8/10/12/16-bit configurable), ITU-R BT.656 compliant output, optional CCIR/ITU timing modes. Video processing: Built-in comb filters, luma/chroma separation, color transient improvement, automatic gain control (AGC), brightness/contrast/saturation/hue controls, color space conversion, white/black level restoration. Sync and timing: On-chip sync separator, support for external/internal clocking, gen-lock or free-run modes. Audio: May include audio ADC or I2S interface for audio pass-through (verify variant). Controls & configuration: I2C (Two-Wire) control interface for register programming and status readback; programmable registers for image adjustments and feature enable/disable. Power: Single low-voltage supply (commonly 3.3V core and I/O domains; check datasheet for exact rails and recommended decoupling). Package: Commonly available in QFP or BGA packages — refer to mechanical drawing for pinout and thermal recommendations. Temperature range: Commercial and industrial variants (e.g., 0–70°C and −40–85°C respectively). cx31993 datasheet
Performance specs (typical)
Signal-to-noise ratio (SNR): High SNR in luma/chroma paths (specific dB figures vary by revision; consult full datasheet). Input clamp and black-level restoration: On-chip clamp with programmable timing and thresholds. Sampling clock rates: Internal PLL generating required sampling clocks (e.g., 27 MHz/54 MHz multiples or derived rates) — configurable for different output bus widths and formats. Color space conversion accuracy: Programmable coefficients for RGB↔YCbCr with fixed-point math; typical error and chroma phase specs provided in full datasheet.
Functional blocks (high level)
Input conditioning: Video input termination, clamping, anti-alias filtering. ADC stage: Luma/chroma ADCs with sample-and-hold. Digital video processor: Demodulation, comb filtering, matrixing, scaling, de-interlacing (basic), and timing generation. Output formatter: Bus alignment, FIFO/buffer (if present), optional embedded sync insertion. Control & status: I2C registers, status bits for video detection, lock status, signal presence, error flags.
Typical register/control capabilities
Input selection and enable/disable per port. Standard detection enable and override (force NTSC/PAL). Gain/AGC settings, fine brightness/contrast/hue/saturation adjustments. Video filter enable: comb filter, noise reduction, peaking. Output format selection: YCbCr/RGB, bit depth, bus width, polarity control for syncs and data. PLL and clock dividers configuration. Interrupts/status for V_SYNC lock, field/frame detection, signal loss. CX31993 Datasheet — Digest Product overview Part: CX31993
Power, thermal, and PCB considerations
Provide recommended decoupling on each supply pin; follow datasheet layout examples for analog/digital separation. Keep analog input traces short, with controlled impedance and proper termination. Use star routing for sensitive analog grounds; keep digital switching noise away from ADC inputs. Thermal pad and copper pour recommendations available in mechanical section — follow for correct thermal dissipation.