Semtech Corporation GS1528-CTAE3Z

Overview

GS1528-CTAE3Z from Gennum is a dual-output, multi-rate SDI cable driver IC designed for SMPTE 259M/344M/292M-compliant serial digital video transmission. It features selectable slew rate (SD/HD pin), 50Ω differential PECL input, 75Ω coaxial cable drive capability, and delivers 800 mV_p-p output swing into 75Ω at up to 1.485 Gb/s - used in broadcast-grade HD/SD video routing and distribution equipment.

For engineers reviewing the GS1528-CTAE3Z datasheet, pinout, applications, or equivalent options, key selection criteria include SMPTE compliance verification, dual-slew-rate configuration flexibility, RSET-controlled output amplitude tuning, and SOIC-8 thermal/power performance under 0°C–70°C industrial operation.

Technical Context

The GS1528-CTAE3Z implements a bipolar current-mode output stage with on-chip biasing and external RSET resistor control for precise output voltage swing adjustment (600–1040 mV_p-p). Its dual differential outputs support independent 75Ω coaxial cable driving with matched rise/fall times (400–800 ps) depending on SD/HD logic level.

Input interfacing uses self-biased 50Ω differential PECL architecture accepting 300–2200 mV_p-p AC-coupled signals; no external termination or bias resistors are required. The device operates from a single 3.3 V supply with typical power consumption of 160 mW and meets SMPTE return loss ≥15 dB from 5 MHz to 1.485 GHz.

Key Specifications

Pinout & Package

GS1528-CTAE3Z is housed in an 8-pin SOIC package (JEDEC MS-012, 150 mil width) with standard lead pitch (1.27 mm), gull-wing leads, and RoHS-compliant matte tin plating. Package dimensions: 4.9 × 6.0 × 1.75 mm (L × W × H).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar SDI cable driver applications.

Compared with THS8200IPFP and LMH0384SQ/NOPB, the GS1528-CTAE3Z uniquely provides dual independent outputs with user-selectable slew rate and externally adjustable amplitude - making it optimal for compact, multi-channel, standards-flexible broadcast hardware where layout efficiency and SMPTE version agility are critical.

Availability

GS1528-CTAE3Z is available at Aetrix Electronics and suitable for broadcast video routing switchers, HDTV camera interface modules, medical imaging endoscopy systems, and professional video production recorders requiring stable component supply across extended production cycles.

Supply support for GS1528-CTAE3Z includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Gennum Corporation was a Canadian fabless semiconductor company specializing in high-speed analog and mixed-signal ICs for video, communications, and timing applications before its acquisition by Semtech in 2013.

The GS1528-CTAE3Z belongs to Gennum's HD-LINX II family - engineered specifically for SMPTE-compliant serial digital video interfaces, emphasizing low jitter, flexible rate support, and robust coaxial cable drive performance in broadcast and pro-AV systems.

FAQ

What SMPTE standards does the GS1528-CTAE3Z support?

The GS1528-CTAE3Z supports SMPTE 259M (270 Mb/s), SMPTE 344M (540 Mb/s), and SMPTE 292M (1.485 Gb/s) standards. Its dual slew-rate capability - controlled by the SD/HD pin - allows it to meet the distinct rise/fall time requirements of each standard. At SD/HD = LOW, it achieves 400–800 ps edges compliant with SMPTE 292M; at SD/HD = HIGH, it meets SMPTE 259M/344M timing masks. This makes GS1528-CTAE3Z suitable for multi-standard video infrastructure.

How is output amplitude adjusted on the GS1528-CTAE3Z?

Output amplitude on the GS1528-CTAE3Z is set using an external resistor connected to the RSET pin. A 750 Ω ±1% resistor yields a nominal 800 mV_p-p differential output swing into a 75 Ω load. Table 3-1 in the datasheet shows RSET values from 573 Ω to 1100 Ω corresponding to output swings from 1040 mV_p-p down to 600 mV_p-p. The resistor must be placed adjacent to the RSET pin with minimized PCB parasitic capacitance - including removal of ground plane beneath the node - to maintain high-frequency accuracy. GS1528-CTAE3Z requires RSET ≥ 573 Ω for full-temperature-range reliability.

Does the GS1528-CTAE3Z require external input termination or biasing?

No, the GS1528-CTAE3Z does not require external input termination or biasing resistors. Its SDI/SDI differential inputs are self-biased and high-impedance, designed for direct AC-coupling with a minimum 4.7 µF tantalum capacitor. The input common-mode voltage range is specified as 1.6 V + ΔV_SDI/2 to V_CC − ΔV_SDI/2, accommodating differential swings from 300 mV_p-p to 2200 mV_p-p. This eliminates discrete bias networks and simplifies interface design - a key feature confirmed in Section 3.1 of the GS1528-CTAE3Z datasheet.

What is the recommended PCB layout practice for the GS1528-CTAE3Z RSET pin?

For the GS1528-CTAE3Z RSET pin, Gennum specifies strict layout rules: the RSET resistor must be placed as close as possible to the pin, and the PCB ground plane must be removed beneath both the RSET pin and the resistor body to minimize parasitic capacitance. This is critical because RSET forms part of the high-speed output current-setting circuit; excess capacitance degrades amplitude accuracy and high-frequency response. Additionally, a 1% SMT resistor is mandatory, and values below 573 Ω are prohibited to ensure stable operation across 0°C–70°C. These guidelines are explicitly detailed in Section 3.5 and Figure 3-4 of the GS1528-CTAE3Z datasheet.

Is the GS1528-CTAE3Z pin-compatible with other HD-LINX II family members?

Yes, the GS1528-CTAE3Z shares identical pinout and footprint with other HD-LINX II dual-output drivers such as the GS1538 and GS1548, enabling drop-in replacement in existing designs targeting different data rate or feature sets. All use the same 8-pin SOIC package, with matching SDI/SDI, SDO/SDO, VCC, VEE, RSET, and SD/HD pin assignments. However, functional differences exist - for example, the GS1538 adds input equalization, while the GS1548 supports 3 Gb/s. So while GS1528-CTAE3Z is physically compatible, system-level validation is required when substituting across family variants.