EPC2L20U - 1.6Mb Configuration PROM 20-PLCC | Altera
MPN: EPC2L20U ⚠ Last Time Buy| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $18.5 | $18.50 |
| 10 | $16.75 | $167.50 |
| 100 | $14.2 | $1,420.00 |
| 500 | $12.1 | $6,050.00 |
| 1,000 | $10.55 | $10,550.00 |
EPC2L20U Overview
A configuration PROM is a non-volatile serial memory device that stores the FPGA bitstream and loads it into the FPGA's SRAM configuration cells at power-up or after a reconfiguration command. In the broader component hierarchy, an EPC PROM sits below non-volatile memory ICs, within the FPGA configuration subsystem; it eliminates the need for a separate boot PROM on the board and supports multi-device configuration daisy-chains.
Key features include 1.6 Mbit of storage (sufficient for the largest Stratix and APEX II bitstreams), in-system programmability through the IEEE Std 1532 interface, 3.3V single-supply operation, and JTAG-based boundary-scan test. The low-power 'L' suffix denotes the 3.3V core variant (vs the 5V-only EPC2 family), making it compatible with modern low-voltage FPGA rails. The PLCC-20 package supports socket mounting for field-replaceable designs and through-hole rework.
The EPC2L20U uses a serial configuration interface (nCONFIG, nSTATUS, CONF_DONE, DCLK, DATA0) and supports cascade mode where multiple PROMs can be combined for very large bitstreams. The device supports optional decompression, allowing the FPGA bitstream to be compressed in PROM and decompressed by the FPGA during configuration - effectively doubling the usable capacity.
Typical applications include configuration boot memory for APEX II/20K, Stratix, Cyclone, Mercury and ACEX 1K FPGAs, multi-FPGA configuration chains, in-field firmware updates via JTAG, and embedded systems requiring non-volatile bitstream storage. The JTAG programmability also makes it suitable for prototyping and low-volume production.
When designing with the EPC2L20U, ensure that the JTAG chain is properly terminated and that the nCONFIG signal is correctly driven by the system reset logic. The PLCC-20 socket allows easy field replacement but should be socketed only when mechanical stress is a concern - for high-shock environments, soldering the PLCC directly is preferred.
Drop-in alternatives for EPC2L20U — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Variants in this series
Same-series models that are drop-in compatible with EPC2L20U (same form factor and footprint) — differing in Package, Mounting Type, Memory Type, JTAG Support, Supported FPGA Families.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
EPC2LC20N
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$7.4 / Unit
View Datasheet →EPC2L20N
✓ In Stock
$17.2 / Unit
View Datasheet →EPC2LI20N
✅ Drop-In✓ In Stock
$5.1 / Unit
View Datasheet →EPC2L120N
✅ Drop-In ⚠️ 参数待验证✓ In Stock
$7.85 / Unit
View Datasheet →EPC2L20
✅ Drop-In✓ In Stock
$25.8 / Unit
View Datasheet →EPC2L20U Maximum Ratings & Electrical Characteristics
| Memory Size | 1.6 Mbit |
| Supply Voltage (VCC) | 3.0 V to 3.6 V |
| Interface Type | Serial configuration (DCLK/DATA0) |
| Programmability | In-system programmable via IEEE 1532 / JTAG |
| Supported FPGAs | APEX II, APEX 20K, Mercury, Stratix, Cyclone, ACEX 1K |
| Configuration Mode | Single + Cascade (multi-PROM daisy chain) |
| Compression Support | Yes (FPGA decompresses bitstream) |
| Operating Temperature | -40C to +85C (industrial) |
| Package | 20-PLCC (PLCC-20) |
| Mounting Type | Surface Mount / Socket |
| JTAG Support | Yes (IEEE Std 1149.1 boundary scan) |
| Pin Count | 20 |
EPC2L20U Pin Configuration
| Pin 1 | VCC — 3.3V power supply |
| Pin 2 | DATA0 — Configuration data output to FPGA |
| Pin 3 | DCLK — Configuration clock input from FPGA |
| Pin 4 | nCS — Chip select (cascaded mode) |
| Pin 5 | nCASC — Cascade output (next PROM enable) |
| Pin 6 | OE — Output enable |
| Pin 7 | GND — Ground |
| Pin 8 | GND — Ground |
| Pin 9 | TDI — JTAG test data in |
| Pin 10 | TMS — JTAG test mode select |
| Pin 11 | TCK — JTAG test clock |
| Pin 12 | TDO — JTAG test data out |
| Pin 13 | nCONFIG — Configuration control from system |
| Pin 14 | nSTATUS — Configuration status to system |
| Pin 15 | CONF_DONE — Configuration complete to system |
| Pin 16 | nINIT_CONF — Initiate reconfiguration |
| Pin 17 | PADD[1] — Address/program pin |
| Pin 18 | PADD[2] — Address/program pin |
| Pin 19 | PADD[3] — Address/program pin |
| Pin 20 | PADD[4] — Address/program pin |
Typical Applications
EPC2L20U is suitable for 6 applications: Stratix FPGA Boot Memory, APEX II Configuration Storage, Cyclone FPGA Bitstream Backup, Multi-FPGA Configuration Daisy Chain, In-Field Firmware Update via JTAG, Legacy Industrial Control Systems.
Stratix FPGA Boot Memory
The EPC2L20U stores the Stratix FPGA configuration bitstream in non-volatile memory and serially loads it at power-up via the nCONFIG/nSTATUS/DCLK/DATA0 interface. Its 1.6 Mbit capacity covers most Stratix EP1S10 to EP1S25 device bitstreams, and 3.3V operation matches Stratix I/O rails directly. The 20-PLCC socket allows easy field upgrade when new firmware revisions are released. Designers can also enable compression mode to fit larger Stratix bitstreams by exploiting the FPGA's built-in decompressor.
Recommended
APEX II Configuration Storage
For APEX II designs, the EPC2L20U provides reliable boot storage with 1.6 Mbit of capacity, sufficient for the largest APEX II EP2A70 bitstreams. The serial passive configuration interface is natively supported by APEX II without external logic. Cascade mode allows two or more EPC2L20U devices to be chained for even larger designs. The 20-PLCC package is compatible with APEX II reference design board layouts from the original Altera APEX II development kit.
Recommended
Cyclone FPGA Bitstream Backup
Although Cyclone devices primarily use active serial EPCQ configuration flash, the EPC2L20U can serve as a backup boot source in passive serial mode for first-generation Cyclone designs. The 3.3V supply aligns with Cyclone's VCCIO requirements. In-system JTAG programmability of the EPC2L20U enables field updates via the standard JTAG chain that also programs the Cyclone. This dual-device configuration scheme provides redundancy for safety-critical industrial applications.
Recommended
Multi-FPGA Configuration Daisy Chain
In systems with multiple SRAM-based FPGAs, the EPC2L20U's cascade mode allows two or more PROMs to be chained so the combined capacity exceeds 1.6 Mbit. Each PROM contributes a portion of the bitstream; the chain delivers data sequentially until CONF_DONE is asserted. This is essential for multi-FPGA signal processing boards and high-density prototyping where a single PROM is insufficient. The 20-PLCC package standardizes the PCB footprint across cascade members.
Recommended
In-Field Firmware Update via JTAG
The EPC2L20U supports IEEE Std 1532 JTAG in-system programming, allowing firmware updates without removing the PROM from the board. Combined with the JTAG-programmable FPGA, this enables full system reprogramming via a single JTAG header - critical for deployed telecom, military, and industrial equipment. The 20-PLCC socket allows quick swap if a corrupted bitstream bricks the device. Update time is approximately 2-4 seconds per Mbit via JTAG at typical TCK rates.
Recommended
Legacy Industrial Control Systems
Long-lifecycle industrial automation, medical imaging, and military systems that were designed around APEX 20K, APEX II, or first-generation Stratix FPGAs often still require the EPC2L20U for spare parts and field replacement. The part's -40C to +85C industrial temperature range supports harsh factory environments. Obsolescence management requires sourcing through distributors stocking last-time-buy inventory or migrating to EPCQ serial NOR with a small PCB adapter for the configuration interface change.
Recommended
Recommended Products Summary
Engineering reference data for EPC2L20U — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | EPC2LC20N | EPC2L20N | EPC2LI20N | EPC2L20 |
|---|---|---|---|---|---|
| Package | 20-PLCC | 20-PLCC | 20-PLCC | 20-PLCC | 20-PLCC |
| Brand | Altera | Altera | Altera | Altera | Altera |
| Memory Size | 1.6 Mbit | 1.6 Mbit | 1.6 Mbit | 1.6 Mbit | 1.6 Mbit |
| Supply Voltage | 3.0V to 3.6V | 3.0V to 3.6V | 3.0V to 3.6V | 3.0V to 3.6V | 3.0V to 3.6V |
| JTAG Programming | Yes (IEEE 1532) | Yes (IEEE 1532) | Yes (IEEE 1532) | Yes (IEEE 1532) | Yes (IEEE 1532) |
| Cascade Mode | Yes | Yes | Yes | Yes | Yes |
| Temperature Grade | Industrial -40C to +85C | Commercial 0C to +70C | Industrial | Industrial | Commercial |
| Lifecycle Status | Last Time Buy | Last Time Buy | Last Time Buy | Last Time Buy | Last Time Buy |
Key Differentiators
- Surface-mount PLCC-20 variant (vs EPC2L20N)
- 3.3V low-voltage operation (vs EPC2 (5V original))
- Industrial temperature screening (vs EPC2L20 (commercial))
Design Notes
The EPC2L20U is the 3.3V 'L' variant; substituting a 5V EPC2 part will damage the device. Verify the 'L' suffix is present before PCB assembly. APEX II designs on 5V rails require the original EPC2 (no 'L'), while Stratix/Cyclone on 3.3V rails require the EPC2L.
Place the EPC2L20U within 50 mm of the FPGA's configuration pins to minimize DCLK/DATA0 trace length mismatch. Use series termination (33 ohm) on DCLK if traces exceed 25 mm. Keep JTAG signals (TDI/TMS/TCK/TDO) away from switching power rails to avoid programming errors during in-field updates.
Decouple VCC with a 0.1 uF ceramic capacitor placed within 3 mm of pin 1, plus a 10 uF bulk capacitor on the same supply rail. The EPC2L20U draws approximately 50 mA peak during configuration and 10 mA in standby. Provide adequate bulk capacitance on the 3.3V rail if multiple PROMs are cascaded.
Estimated: Configuration time for a 1.6 Mbit bitstream at 40 MHz DCLK is approximately 40 ms; with JTAG programming at 10 MHz TCK the program time is approximately 4-6 seconds. Plan system reset hold time accordingly. CONF_DONE must remain low until all cascaded PROMs complete - a missing CONF_DONE pull-up causes configuration failures.
Compliance Information
Compliance data not present in verified web sources. Altera EPC2 family parts are typically lead-free by modern revisions; verify with manufacturer documentation before Pb-free assembly.
