EPM7256SQC208-7 - 256 Macrocell 5V CPLD | Altera | 208-PQFP
MPN: EPM7256SQC208-7 ✗ Cuối đờiEPM7256SQC208-7 Tóm tắt
A CPLD (Complex Programmable Logic Device) is a programmable logic IC built from an array of macrocells connected by a programmable interconnect matrix. Unlike an FPGA, which uses fine-grained lookup-table logic and volatile SRAM configuration, a CPLD uses non-volatile EEPROM cells and coarse-grained product-term logic, giving deterministic timing, instant-on operation, and high immunity to single-event upsets. In the logic hierarchy, a CPLD sits between discrete glue logic and full FPGAs: CPLD -> programmable logic device (PLD) -> digital logic IC -> semiconductor.
The MAX 7000S architecture is based on EEPROM cells, so the EPM7256SQC208-7 retains its configuration without an external boot device and is in-system programmable (ISP) through the IEEE 1149.1 JTAG interface. Each macrocell provides programmable flip-flops, product-term logic, and I/O control, allowing the device to implement address decoding, bus bridging, state machines, and glue logic with fixed, predictable propagation delays.
Key specifications include 256 macrocells, 164 I/O pins, 5,000 usable gates, 7.5 ns tPD, 128.2 MHz fMAX, and 5.0 V VCC operation with 3.3 V-compatible I/O options. The 208-pin PQFP package measures 28 x 28 mm with 0.5 mm lead pitch and is rated for commercial temperature operation.
Typical applications include PCI and ISA bus interface logic, address decoding and chip-select generation, DSP and microcontroller glue logic, industrial control backplanes, and legacy system replacement where 5 V logic levels and deterministic timing are required.
When designing with this device, note that the MAX 7000S family is a mature, non-volatile 5 V CPLD family; verify lifecycle status and consider pin-compatible MAX 7000S speed-grade variants or MAX 7000B/7000A family members before committing to new production. This page synthesizes distributor availability, drop-in speed-grade alternatives, and practical design notes not found in the manufacturer datasheet.
Bộ thay thế dễ dàng lắp đặt cho EPM7256SQC208-7 — cùng gói, chân-to-chân tương thích. Các bộ phận yêu cầu hàn PCB bị loại trừ.
Các biến thể trong loạt này
Các mẫu cùng loạt có thể lắp đặt dễ dàng tương thích với EPM7256SQC208-7 (cùng hình factor và footprint) — khác nhau ở Package, Speed Grade, Device Type, Operating Temperature, RoHS Status.
EPM7256SQC208-10
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →EPM7256SQC208-15
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →EPM7256SQC208-15N
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →EPM7256SQC208-7N
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →EPM7256BQC208-7
✅ Drop-InLiên hệ để biết giá
Xem tài liệu →EPM7256SQC208-7 Tỷ lệ tối đa & tính chất điện
| Device Family | MAX 7000S (EPM7256S) |
| Macrocells | 256 |
| Usable Gates | 5,000 |
| User I/O Pins | 164 |
| Propagation Delay (tPD) | 7.5 ns |
| Maximum Operating Frequency (fMAX) | 128.2 MHz |
| Supply Voltage (VCC) | 5.0 V |
| Configuration Technology | EEPROM (non-volatile) |
| In-System Programmability | Yes (IEEE 1149.1 JTAG) |
| Hộp | 208-pin PQFP (28 x 28 mm, 0.5 mm pitch) |
| Kiểu lắp đặt | Surface Mount |
| Khoảng nhiệt độ hoạt động | Commercial (0C to +70C) |
| Minimum DC Input Voltage | -0.5 V |
| Input Undershoot Tolerance | -2.0 V for <100 mA, <20 ns |
| Speed Grade | -7 (7.5 ns) |
| Logic Levels | 5.0 V CMOS/TTL compatible |
Hướng dẫn cấu hình chân EPM7256SQC208-7 208-pin pqfp (28 x 28 mm, 0.5 mm pitch)
Cấu hình chân cho EPM7256SQC208-7 (208-pin pqfp (28 x 28 mm, 0.5 mm pitch) gói). IC số này bao gồm chân GPIO, giao diện truyền thông (UART, SPI, I2C) và chân nguồn. Tham khảo tài liệu thông số kỹ thuật của nhà sản xuất để biết các chức năng chân thay thế và tùy chọn cấu hình. Cực kỳ quan trọng cho thiết kế hệ thống tích hợp và lập trình PCB.
Không có dữ liệu chân cụ thể sẵn có cho EPM7256SQC208-7.
Tham khảo: tài liệu kỹ thuật cho cấu hình chân đầy đủ.
Ứng dụng tiêu biểu
EPM7256SQC208-7 phù hợp cho 6 Áp dụngs: PCI and ISA Bus Interface Logic, Address Decoding and Chip-Select Generation, DSP and Microcontroller Glue Logic, Industrial Control Backplanes, Legacy 5V System Replacement, Test and Measurement Instrumentation.
PCI and ISA Bus Interface Logic
The EPM7256SQC208-7 fits PCI and ISA bus interface designs because its 7.5 ns pin-to-pin propagation delay and 128.2 MHz fMAX provide the deterministic timing needed for bus arbitration, target decoding, and wait-state generation. With 256 macrocells and 164 I/O pins, it can absorb the address decode, chip-select, and handshake logic that would otherwise require dozens of discrete 74-series devices. The 5.0 V VCC operation matches legacy PCI/ISA signaling directly, avoiding level shifters. Placed between the host bus and peripheral devices, the CPLD implements configurable target and initiator state machines; the trade-off is that its EEPROM macrocells are coarse-grained, so very wide datapath functions are better mapped to an FPGA.
Được đề xuất
Address Decoding and Chip-Select Generation
The EPM7256SQC208-7 is well suited to address decoding and chip-select generation because its 7.5 ns tPD keeps decode latency well inside a single 5 V memory or peripheral bus cycle. The 256 macrocells can implement multiple address comparators, bank decoders, and wait-state generators simultaneously, while the 164 I/O pins allow direct connection to wide address and control buses without external glue. The device is typically placed between the processor address bus and memory/peripheral chip-select inputs, where its non-volatile EEPROM configuration provides instant-on operation at power-up with no boot sequence. The trade-off is fixed product-term logic depth, so extremely complex decode trees may need pipelining.
Được đề xuất
DSP and Microcontroller Glue Logic
The EPM7256SQC208-7 serves as glue logic around DSPs and microcontrollers because it consolidates interrupt prioritization, wait-state generation, and peripheral chip-select logic into one 208-pin PQFP device. Its 5.0 V VCC and TTL-compatible I/O interface directly with legacy 5 V DSPs and MCUs, and the 128.2 MHz fMAX supports high-speed host-port and serial-port handshaking. With 256 macrocells, designers can implement multiple independent state machines in a single device, reducing board area and part count. The device is placed between the processor and its peripherals, translating control signals and generating timing strobes; the trade-off is that the EEPROM-based architecture is optimized for control logic rather than arithmetic datapaths.
Được đề xuất
Industrial Control Backplanes
The EPM7256SQC208-7 is used in industrial control backplanes because its non-volatile EEPROM configuration provides instant-on operation and immunity to the power glitches common in factory environments. The 164 I/O pins and 256 macrocells can implement backplane arbitration, slot addressing, and handshake logic for multi-card systems, while the 5.0 V signaling matches legacy industrial I/O racks. The device is placed on the controller card, where it manages bus grants and interrupt routing between slots. Its deterministic 7.5 ns timing simplifies worst-case timing analysis compared with SRAM-based FPGAs. The trade-off is commercial temperature rating, so extended-temperature industrial variants should be evaluated for harsh environments.
Được đề xuất
Legacy 5V System Replacement
The EPM7256SQC208-7 is a common choice for replacing obsolete 5 V glue-logic boards because it integrates the function of many discrete 74-series and PAL devices into a single 208-pin PQFP. Its 5.0 V VCC and TTL-compatible inputs allow direct drop-in replacement of legacy logic without level shifting, and the EEPROM configuration means no configuration PROM is required. The device is placed on the existing board footprint, where it re-implements address decoding, state machines, and bus interfacing in programmable logic. Because the MAX 7000S family is mature, designers should verify lifecycle status and stock before committing to new production. The trade-off is that the 208-pin PQFP requires a larger land pattern than modern fine-pitch packages.
Được đề xuất
Test and Measurement Instrumentation
The EPM7256SQC208-7 is used in test and measurement instrumentation for trigger logic, timing generation, and front-panel interface control. Its 7.5 ns propagation delay and 128.2 MHz fMAX support precise event sequencing, while the 256 macrocells can implement multiple counters, comparators, and state machines in one device. The 5.0 V I/O interfaces directly with legacy instrument buses and discrete front-panel controls. The device is placed on the instrument control board, where it coordinates acquisition timing and host communication. Non-volatile EEPROM configuration ensures the instrument boots immediately without a configuration load. The trade-off is that the commercial temperature grade limits use in environmental chambers without derating.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho EPM7256SQC208-7 — so sánh, hướng dẫn thiết kế và thông tin tuân thủ.
Hướng dẫn chọn lựa
So sánh với các sản phẩm thay thế
| Tham số | Sản phẩm này | EPM7256SQC208-10 | EPM7256SQC208-15 | EPM7256SQC208-7N | EPM7256BQC208-7 |
|---|---|---|---|---|---|
| Package | 208-pin PQFP | 208-pin PQFP - same | 208-pin PQFP - same | 208-pin PQFP - same | 208-pin PQFP - same |
| Brand | Altera | Altera | Altera | Altera | Altera |
| Propagation Delay (tPD) | 7.5 ns | 10 ns | 15 ns | 7.5 ns | 7.5 ns |
| Macrocells | 256 | 256 | 256 | 256 | 256 |
| User I/O Pins | 164 | 164 | 164 | 164 | 164 |
| Supply Voltage (VCC) | 5.0 V | 5.0 V | 5.0 V | 5.0 V | 3.3 V-compatible |
| Configuration Technology | EEPROM (non-volatile) | EEPROM (non-volatile) | EEPROM (non-volatile) | EEPROM (non-volatile) | EEPROM (non-volatile) |
| Speed Grade | -7 | -10 | -15 | -7 | -7 |
Bảo phân biệt quan trọng
- Fastest speed grade in the 208-pin MAX 7000S family (vsEPM7256SQC208-10)
- Higher maximum operating frequency (vsEPM7256SQC208-15)
- Non-volatile EEPROM configuration (vsEPM7256BQC208-7)
Ghi chú thiết kế
Decouple every VCC pin of the EPM7256SQC208-7 with a 0.1 uF ceramic capacitor placed as close to the pin as possible, plus at least one 10 uF bulk capacitor per device. The MAX 7000S family draws transient current during macrocell switching, and the 208-pin PQFP has many VCC/GND pairs distributed around the perimeter; missing decoupling on any one pair can cause ground bounce and erratic JTAG programming. Estimated: at 5.0 V and typical 100 mA dynamic current, total device power is about 0.5 W, so no heatsink is required, but the copper plane under the device should be solid for return-current integrity.
Route the JTAG signals (TCK, TMS, TDI, TDO) as short, matched traces with a continuous ground reference, and keep TCK away from high-speed I/O to avoid clocking spurious JTAG states. Place the JTAG header within a few centimeters of the device and add a 10 kOhm pull-up on TMS and a 10 kOhm pull-down on TCK per the MAX 7000 family programming guidelines. The 208-pin PQFP uses 0.5 mm lead pitch, so verify solder-mask and stencil apertures against IPC land-pattern recommendations before fabrication.
Do not exceed the -0.5 V minimum DC input voltage; the datasheet permits brief undershoot to -2.0 V only for input currents below 100 mA and periods shorter than 20 ns. Series-terminate long I/O traces to control overshoot, especially on 5 V buses with fast edges. Also confirm the speed grade before substitution: replacing a -7 with a -10 or -15 changes tPD from 7.5 ns to 10 ns or 15 ns, which can violate setup/hold margins in bus-interface designs. Estimated: a 2.5 ns timing increase consumes roughly 20 percent of a 12.5 ns budget at 80 MHz.
Thông tin tuân thủ
Compliance data for the EPM7256SQC208-7 was not present in the verified web data. The 'N' suffix variant (EPM7256SQC208-7N) is referenced as a lead-free package option in distributor listings, but RoHS/REACH status for the base part could not be confirmed from the provided sources.
