XC7A35T-1CPG236C Datasheet, Pinout, Equivalents, and Specs

The XC7A35T-1CPG236C is a versatile Field-Programmable Gate Array (FPGA) from the AMD-Xilinx Artix-7 family, engineered to deliver an optimal balance of performance, low power consumption, and cost-effectiveness. It solves the problem of requiring significant parallel processing and custom logic in a compact, power-efficient footprint. This device is particularly well-suited for a wide range of applications, from industrial control and machine vision to software-defined radio and advanced consumer electronics, where both logic density and I/O flexibility are paramount.

What is the XC7A35T-1CPG236C?

The XC7A35T-1CPG236C is a member of the Xilinx (now part of AMD) Artix-7 family of FPGAs, built on a 28nm High-Performance Low-Power (HPL) process technology. This process node represents a significant advancement over previous generations, enabling a superior combination of logic density, processing throughput, and power efficiency. The device is specifically designed to meet the demands of cost-sensitive applications that cannot compromise on performance.

At its core, the XC7A35T-1CPG236C is a sea of programmable logic resources that can be configured by a hardware designer to implement virtually any digital circuit. The fundamental building block is the Configurable Logic Block (CLB). This device contains thousands of CLBs, each of which includes two "slices." Each slice is equipped with four 6-input Look-Up Tables (LUTs) and eight flip-flops. The 6-input LUT architecture is a key feature, as it can implement more complex logic functions per resource compared to older 4-input LUT architectures, leading to better device utilization and potentially higher performance. In total, the XC7A35T-1CPG236C provides 33,280 logic cells, 20,800 LUTs, and 41,600 flip-flops, offering substantial capacity for complex state machines, data processing pipelines, and custom processors.

Beyond general-purpose logic, the device integrates specialized hardware blocks to accelerate common functions. It includes 90 DSP48E1 slices, which are high-performance arithmetic blocks capable of performing 25x18 multiplication, accumulation, and other signal processing operations at very high speeds. This makes the XC7A35T an excellent choice for applications involving digital filtering, Fast Fourier Transforms (FFTs), and other computationally intensive algorithms. For on-chip data storage, it provides 1,800 Kbits of fast, dual-port Block RAM (BRAM). These BRAM blocks are essential for buffering data, implementing FIFOs, and creating on-chip memory for soft-core processors. Furthermore, the architecture includes advanced Clock Management Tiles (CMTs), each containing a Mixed-Mode Clock Manager (MMCM) and a Phase-Locked Loop (PLL). These CMTs provide sophisticated clock synthesis, jitter filtering, and deskew capabilities, which are critical for managing multiple clock domains in a complex system-on-chip (SoC) design.

Pinout Configuration and Packaging

The XC7A35T-1CPG236C is offered in the CPG236 package, which is a 236-ball Chip-Scale Package (CSP) with a 0.5mm ball pitch. This BGA (Ball Grid Array) package has a compact 10x10 mm footprint, making it highly suitable for space-constrained PCB designs. The CSP format provides excellent electrical performance and good thermal characteristics, but it requires careful PCB design and advanced assembly processes (e.g., X-ray inspection) due to the hidden solder connections.

The 236 pins are allocated to power, ground, configuration, JTAG, and user I/O. The device provides a total of 106 user I/O pins, which are organized into I/O banks. Each bank can be powered by a separate VCCO supply, allowing the FPGA to interface with logic families operating at different voltage levels (e.g., 1.8V, 2.5V, 3.3V) simultaneously. The I/O pins on Artix-7 devices are highly configurable and support a wide range of standards, including single-ended standards like LVCMOS and LVTTL, as well as differential standards like LVDS and TMDS, which are essential for high-speed data links.

Key pins that designers must pay close attention to during schematic capture and layout include:

• Power Pins: VCCINT (core logic voltage, nominally 1.0V), VCCAUX (auxiliary internal voltage), VCCO (I/O bank voltages), and numerous GND pins. A robust Power Delivery Network (PDN) with meticulous decoupling is non-negotiable for stable operation.
• Configuration Pins: PROG_B (program), DONE (configuration complete), and INIT_B (initialization error). These pins control the loading of the configuration bitstream from external flash memory.
• JTAG Pins: TCK, TMS, TDI, TDO. These provide a standard JTAG interface for programming, debugging, and boundary-scan testing.
• Clock Inputs: Dedicated clock-capable pins are routed directly to the global clocking resources (CMTs) to ensure low-skew, low-jitter clock distribution throughout the fabric.

Designers must consult the official Xilinx UG475 (7 Series FPGAs Packaging and Pinout User Guide) for the exact pin locations, bank assignments, and design rules for the CPG236 package.

Core Architectural Features

• Advanced 6-Input LUT Architecture: Provides a rich logic fabric with 20,800 Look-Up Tables. This architecture allows for the implementation of more complex combinatorial logic within a single LUT, reducing the number of logic levels required for a given function. This leads to improved performance, lower power, and more efficient routing.
• High-Throughput DSP48E1 Slices: Includes 90 dedicated Digital Signal Processing (DSP) slices. Each slice features a 25x18 multiplier, a pre-adder, and a 48-bit accumulator. These blocks are optimized for high-speed arithmetic and are critical for accelerating algorithms in applications like wireless communications, machine vision, and audio processing.
• Flexible Block RAM and Clock Management: Offers 1,800 Kbits of true dual-port Block RAM for efficient on-chip data buffering and storage. This is complemented by multiple Clock Management Tiles (CMTs), each with an MMCM and PLL, providing precise control over clock generation, frequency synthesis, and skew correction for robust system timing.
• Integrated Analog-to-Digital Converter (XADC): Features an on-chip dual 12-bit, 1 MSPS Analog-to-Digital Converter. The XADC can be used for system monitoring of on-chip temperature and supply voltages, or for digitizing up to 17 external analog inputs, potentially eliminating the need for a separate ADC component in some systems.
• Low Power Consumption and Multiple I/O Standards: Manufactured on a 28nm HPL process, the device is designed for low static and dynamic power. It supports various power-saving modes and fine-grained clock gating. The 106 user I/Os are organized in banks that support a wide variety of I/O standards, enabling direct connection to a multitude of external components.

Specifications Parameter Table

XC7A35T-1CPG236C Equivalents, Cross Reference & Lifecycle

The XC7A35T-1CPG236C is an active and widely deployed component within the Artix-7 family, with a long expected lifecycle. However, for procurement flexibility and design optimization, it's important to understand its variants and potential alternatives.

Speed Grade Variants: The "-1" in the part number denotes the slowest commercial speed grade. Faster, pin-for-pin compatible options exist, such as the XC7A35T-2CPG236C and XC7A35T-3CPG236C. These parts can meet more aggressive timing constraints but may have different power characteristics. A design that passes timing on a -1 grade will work on a -2 or -3 part, but the reverse is not guaranteed.

Temperature Grade Variants: The "C" indicates a commercial temperature range (0°C to 85°C junction). For applications requiring operation in harsher environments, an Industrial grade variant, XC7A35T-1CPG236I, is available, rated for -40°C to 100°C junction temperature. While functionally identical, it is not a direct "equivalent" if the application operates in the extended temperature range.

Family Alternatives: If a design requires more logic resources, the next step up within the Artix-7 family would be the XC7A50T. If a design is smaller and more cost-sensitive, the XC7A15T could be considered. It is critical to note that these are not pin-compatible and would require a complete redesign of the PCB.

When sourcing this component, it is crucial to verify the full part number to ensure the correct speed and temperature grade for your application. Check XC7A35T-1CPG236C Inventory & Pricing to see current availability and ordering options.

Typical Applications & Circuit Considerations

The XC7A35T-1CPG236C's blend of resources makes it a workhorse for a diverse set of applications. Its parallel processing nature is ideal for tasks that are inefficient on traditional microprocessors. Common use cases include:

• Machine Vision and Image Processing: The numerous DSP slices and BRAM blocks are perfect for implementing real-time image processing pipelines, including filtering, color space conversion, feature detection, and object tracking for industrial cameras and inspection systems.
• Industrial Automation and Motor Control: The low-latency, deterministic nature of FPGAs is ideal for high-precision motor control loops. The XC7A35T can generate multiple, synchronized PWM signals, decode quadrature encoder feedback, and implement industrial communication protocols like EtherCAT or Profinet in hardware.
• Software-Defined Radio (SDR): The DSP slices can be used to build digital front-ends for radio systems, performing tasks like digital down-conversion (DDC), digital up-conversion (DUC), and implementing modulation/demodulation schemes.
• Test and Measurement: The flexible I/O and high-speed logic allow for the creation of custom logic analyzers, arbitrary waveform generators, and protocol analyzers.

Circuit Design Considerations:

Successfully integrating the XC7A35T-1CPG236C requires careful attention to system-level design. The Power Delivery Network (PDN) is arguably the most critical aspect. The FPGA requires several distinct voltage rails (VCCINT, VCCAUX, VCCOs, VCCBRAM), each with specific noise and ripple requirements. A multi-stage approach using switching regulators for efficiency followed by LDOs for clean power, combined with a dense network of high-frequency ceramic decoupling capacitors placed directly under the BGA package, is standard practice. Referencing the Xilinx UG483 (7 Series FPGAs PCB Design Guide) is essential.

Configuration is another key area. As a SRAM-based device, the XC7A35T loses its configuration when powered off. A non-volatile configuration memory, typically a Quad-SPI flash chip, must be included on the board. The FPGA will automatically read its configuration bitstream from this flash upon power-up.

Finally, PCB layout for the CPG236 package demands expertise. Proper BGA fanout strategies (e.g., via-in-pad) are needed to access the inner balls. High-speed differential pairs (like LVDS) require controlled impedance routing with matched lengths. Clock traces must be carefully routed to minimize jitter and skew. A multi-layer PCB with dedicated power and ground planes is not optional; it is a requirement for reliable operation. For more options in this performance class, you can Browse Artix-7 Series components on our site.

Video Demonstration

Frequently Asked Questions (XC7A35T-1CPG236C FAQ)

What development tools are used for the XC7A35T-1CPG236C?

The primary development environment for the XC7A35T-1CPG236C is the AMD-Xilinx Vivado Design Suite. This comprehensive software package includes tools for HDL (VHDL/Verilog) synthesis, implementation (place and route), static timing analysis, and bitstream generation. It also integrates powerful debugging tools like the Vivado Logic Analyzer for real-time, on-chip signal inspection. A free version, Vivado ML Standard Edition (formerly WebPACK), provides full support for the entire Artix-7 family, making it accessible for students, hobbyists, and commercial projects.

What is the difference between the Artix-7 and Spartan-7 series?

While both Artix-7 and Spartan-7 families are built on the same 28nm process and share the same core 6-input LUT architecture, they target different application segments. The Artix-7 series, including the XC7A35T, is optimized for higher performance-per-watt, offering more DSP slices, more Block RAM, higher I/O speeds, and integrated transceivers in larger devices. The Spartan-7 series is optimized for the lowest cost and power consumption, focusing on I/O expansion, system connectivity, and sensor fusion in cost-sensitive applications.

How is the XC7A35T-1CPG236C programmed?

The XC7A35T is an SRAM-based FPGA, meaning its configuration is volatile and must be loaded each time the device is powered on. The most common method is "Master SPI" mode, where the FPGA acts as the bus master and automatically reads its configuration bitstream from an external non-volatile SPI or Quad-SPI flash memory chip. For development and debugging, the device can also be programmed directly via its JTAG interface using a programming cable like the Xilinx Platform Cable USB II.

What does the "-1CPG236C" suffix mean?

The part number suffix provides critical information about the specific device variant. For XC7A35T-1CPG236C: "-1" indicates the speed grade, which is the slowest commercial grade. "C" signifies the commercial temperature grade, rated for a junction temperature of 0°C to 85°C. "PG236" defines the package type, which is a 236-pin chip-scale BGA. The final "C" is often used by distributors to denote RoHS compliance (lead-free).

Can the XC7A35T-1CPG236C interface with DDR3 memory?

Yes, the Artix-7 family is fully capable of interfacing with external DDR3 SDRAM. This is accomplished using the Memory Interface Generator (MIG) core, a free IP block within the Vivado Design Suite. The MIG provides a wizard-based tool that generates a customized, high-performance memory controller and physical layer (PHY) tailored to the specific FPGA and memory device being used. This is essential for applications that require large data buffers, such as video processing or high-speed data acquisition.