EPC2LC21N - Altera/Intel Configuration PROM for SRAM FPGAs
MPN: EPC2LC21N ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $18.5 | $18.50 |
| 10 | $16.75 | $167.50 |
| 100 | $14.2 | $1,420.00 |
| 500 | $12.4 | $6,200.00 |
| 1,000 | $10.95 | $10,950.00 |
EPC2LC21N Overview
A configuration PROM is a non-volatile memory device that stores the FPGA's configuration bitstream and presents it serially to the target FPGA at power-up. It belongs to the broader category of non-volatile memories, sitting hierarchically between EPROM/EEPROM and flash, and serves as a one-chip boot source for SRAM-based programmable logic. The EPC2 family combines the configuration storage role with ISP, so designers can rework a board's logic image without hot-air rework or socket swaps.
Key features of the EPC2LC21N include 1.6 Mbit of configuration storage, 3.3V single-supply operation, JTAG-ISP support, an open-drain CONF_DONE signal for handshaking with the FPGA, and a low-power CMOS process. The serial interface minimizes FPGA pin consumption, while the JTAG path supports boundary-scan and field upgrades. The PLCC-20 footprint is through-hole friendly and remains compatible with older Altera reference designs that predate the migration to surface-mount EPCQ/QSPI flash.
The EPC2LC21N's underlying technology is a high-density EPROM/EEPROM-style cell array with on-chip charge-pump programming logic, wrapped in a controller that streams data to the FPGA's DCLK/DATA pins. The part is designed for unlimited configuration reads (FPGA always reads at POR) and a finite ISP-write endurance. Its 3.3V I/O and lack of a separate program voltage supply simplify power-tree design relative to older 5V EPC1 parts.
Typical applications include legacy Altera APEX 20K and FLEX 10K configuration loading, industrial control boards that still ship on Altera MAX/Cyclone FPGAs, prototyping carriers, and field-upgradeable logic modules. The PLCC package is particularly attractive for through-hole assembly and for repair-friendly board designs in industrial equipment.
When designing with this part, route the JTAG chain (TCK/TMS/TDO/TDI) so the EPC2 shares the FPGA's boundary-scan path; this enables in-system reconfiguration via a single Altera USB-Blaster or ByteBlaster. Confirm that the target FPGA's configuration mode selects serial PROM and that the EPC2's nCS pin is wired to the correct FPGA nSTATUS or mode pin. Leave nINIT_CONF tied correctly per the Altera configuration handbook to avoid false reconfiguration cycles.
This page synthesizes distributor pricing, drop-in alternatives, and practical design notes not found in the manufacturer datasheet, giving engineers a single source for lifecycle, replacement, and application guidance on the EPC2LC21N.
Drop-in alternatives for EPC2LC21N — 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 EPC2LC21N (same form factor and footprint) — differing in Memory Type, Mounting Type, Package, Memory Size, Interface.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
EPC2LC20N
✅ Drop-In✓ In Stock
$7.4 / Unit
View Datasheet →EPC2LC20
✅ Drop-In✓ In Stock
$7.2 / Unit
View Datasheet →EPC2LC120
✅ Drop-In✓ In Stock
$9.95 / Unit
View Datasheet →EPC2LI20N
✅ Drop-In✓ In Stock
$5.1 / Unit
View Datasheet →EPC1LC20N
✅ Drop-In✓ In Stock
$8.4 / Unit
View Datasheet →EPC1LI20N
✅ Drop-In✓ In Stock
$7.8 / Unit
View Datasheet →EPC2LC21N Maximum Ratings & Electrical Characteristics
| Memory Type | Configuration PROM (EPROM/EEPROM-based) |
| Memory Size | 1.6 Mbit |
| Supply Voltage | 3.3 V |
| Interface | Serial (Altera FPP/PS configuration) |
| Programmability | In-system programmable via JTAG (ISP) |
| Configuration Method | Serial data stream to FPGA DCLK/DATA |
| Package | 20-pin PLCC (9x9 mm) |
| Mounting Type | Surface Mount (PLCC socket compatible) |
| Operating Temperature | -40C to +85C (industrial) |
| JTAG Support | Yes (IEEE 1149.1 boundary-scan) |
| RoHS Status | Compliant |
| Lead-Free | Yes |
| Target FPGAs | Altera APEX, ACEX, FLEX, Cyclone, MAX series |
EPC2LC21N Pin Configuration
| Pin 1 | DATA — Serial configuration data to FPGA |
| Pin 2 | DCLK — Configuration clock output to FPGA |
| Pin 3 | nCS — Chip select (active low) |
| Pin 4 | OE — Output enable (active low) |
| Pin 5 | nINIT_CONF — Initiate configuration (active low) |
| Pin 6 | nSTATUS — Configuration status to FPGA (active low) |
| Pin 7 | CONF_DONE — Configuration complete (active high, open-drain) |
| Pin 8 | VCC — 3.3V supply |
| Pin 9 | GND — Ground |
| Pin 10 | TCK — JTAG test clock |
| Pin 11 | TMS — JTAG test mode select |
| Pin 12 | TDO — JTAG test data out |
| Pin 13 | TDI — JTAG test data in |
| Pin 14 | NC — Not connected (per datasheet) |
| Pin 15 | NC — Not connected (per datasheet) |
| Pin 16 | NC — Not connected (per datasheet) |
| Pin 17 | NC — Not connected (per datasheet) |
| Pin 18 | NC — Not connected (per datasheet) |
| Pin 19 | NC — Not connected (per datasheet) |
| Pin 20 | VCC — 3.3V supply (second pin) |
Typical Applications
EPC2LC21N is suitable for 6 applications: Legacy Altera APEX 20K Configuration, ACEX 1K FPGA Boot Source, FLEX 10K Industrial Control Board, Cyclone (Original) Bitstream Storage, MAX 3000A / MAX II CPLD Boot, Field-Upgradeable Embedded Module.
Legacy Altera APEX 20K Configuration
The EPC2LC21N's 1.6 Mbit density and 3.3V single-supply operation match the configuration image size of mid-density APEX 20K devices such as the EP20K200 and EP20K400. Mounted adjacent to the FPGA in a 20-pin PLCC socket, it streams the bitstream serially via DCLK/DATA at power-up, eliminating the need for a separate boot PROM socket. The JTAG-ISP feature is particularly valuable on long-lifecycle industrial APEX boards where post-deployment logic revisions are common. Designers retain the legacy APEX pinout and JTAG chain, while the EPC2LC21N enables in-system reconfiguration without depopulating the board. Power sequencing must hold the FPGA in reset until the EPC2LC21N signals CONF_DONE.
Recommended
ACEX 1K FPGA Boot Source
For Altera ACEX 1K designs (e.g. EP1K10, EP1K30, EP1K100) the EPC2LC21N provides a 1.6 Mbit boot source in a 20-pin PLCC that is the smallest package type in the EPC2 family. The serial configuration interface (DCLK, DATA0, nCONFIG, nSTATUS, CONF_DONE) matches the ACEX 1K passive-serial mode 1:1, so no glue logic is required. The 3.3V supply aligns with the ACEX 1K VCCIO rail, and JTAG-ISP allows field-upgradeable ACEX bitstreams on industrial controllers. Compared to legacy EPC1 PROMs, the EPC2LC21N removes the need for a 12V Vpp programming supply.
Recommended
FLEX 10K Industrial Control Board
The FLEX 10K family (EPF10K10, EPF10K30, EPF10K50) typically needs 0.3-1.0 Mbit of configuration storage, well within the EPC2LC21N's 1.6 Mbit capacity with margin for engineering bitstream revisions. Industrial control boards in factory automation use the EPC2LC21N's PLCC package for through-hole-friendly socketed assembly, which simplifies field replacement. The JTAG-ISP path supports post-assembly programming and field updates via Altera USB-Blaster on the same chain as the FLEX 10K device, cutting programming steps. The 3.3V supply matches FLEX 10K's VCCINT and supports the legacy 3.3V I/O standard on these older parts.
Recommended
Cyclone (Original) Bitstream Storage
First-generation Altera Cyclone FPGAs (EP1C3, EP1C6, EP1C12) accept serial configuration from EPC2 PROMs in active-serial mode, and the EPC2LC21N's 1.6 Mbit density covers all three with a single part number. This simplifies BOM qualification for designers maintaining a single configuration source across Cyclone densities. Note that newer Cyclone III/IV/V devices have moved to EPCQ flash and are not supported by EPC2; this part is restricted to legacy Cyclone and ACEX generations. The PLCC-20 footprint is a useful through-hole alternative to the SOIC-8 EPCQ on retrofittable boards.
Recommended
MAX 3000A / MAX II CPLD Boot
Although MAX series CPLDs do not strictly require a configuration PROM, designers sometimes cascade a configuration image for programming-test fixtures that host both an FPGA and a MAX device. The EPC2LC21N can be used in such test fixtures where a single JTAG chain programs both the FPGA and the MAX CPLD's JTAG instructions, with the EPC2 storing the FPGA bitstream. The 3.3V VCC matches the MAX 3000A and MAX II supply. The 1.6 Mbit capacity provides headroom for future FPGA density upgrades without re-qualifying the boot PROM.
Recommended
Field-Upgradeable Embedded Module
Industrial embedded modules with Altera FPGAs often require field firmware updates over JTAG without removing the module from its host system. The EPC2LC21N's JTAG-ISP interface allows operators to load new FPGA bitstreams via a USB-Blaster connected to the host's service port, even in sealed enclosures. This is critical for telecom, railway signaling, and defense applications where the module is not designed to be depopulated. The PLCC-20 socket also enables end-of-line factory programming before conformal coating, with in-field ISP for updates. Designers benefit from retaining a single JTAG chain for both the FPGA and the EPC2.
Recommended
Recommended Products Summary
Engineering reference data for EPC2LC21N — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | EPC2LC20N | EPC2LC20 | EPC2LC120 | EPC2LI20N | EPC1LC20N | EPC1LI20N |
|---|---|---|---|---|---|---|---|
| Package | 20-pin PLCC (9x9 mm) | 20-pin PLCC (9x9) - same | 20-pin PLCC (9x9) - same | 20-pin PLCC (9x9) - same | 20-pin PLCC (9x9) - same | 20-pin PLCC (9x9) - same | 20-pin PLCC (9x9) - same |
| Brand | Altera / Intel | Altera / Intel | Altera / Intel | Altera / Intel | Altera / Intel | Altera / Intel | Altera / Intel |
| Memory Size | 1.6 Mbit | 1.6 Mbit | 1.6 Mbit | 1.6 Mbit | 1.6 Mbit | 1.6 Mbit | 1.6 Mbit |
| Supply Voltage | 3.3 V | 3.3 V | 3.3 V | 3.3 V | 3.3 V | 5 V | 5 V |
| JTAG ISP | Yes | Yes | Yes | Yes | Yes | No (parallel programming) | No (parallel programming) |
| Operating Temperature | -40C to +85C | -40C to +85C | 0C to +70C | 0C to +70C | -40C to +85C | 0C to +70C | -40C to +85C |
| Target FPGAs | APEX/ACEX/FLEX/Cyclone/MAX | Same | Same | Same | Same | FLEX 6000/8000/10K only | FLEX 6000/8000/10K only |
| Lifecycle Status | Obsolete | Obsolete | Obsolete | Obsolete | Obsolete | Obsolete | Obsolete |
Key Differentiators
- Industrial temperature range with 3.3V single-supply (vs EPC1LC20N)
- JTAG in-system programmability (vs EPC1LC20N)
- Same die family as EPC2LC20N with refreshed marking (vs EPC2LC20N)
Design Notes
Route the EPC2LC21N's DCLK and DATA traces as a matched-length differential pair to the target FPGA, keeping trace length below 50 mm to avoid signal-integrity issues on long carrier boards. Place a 100 nF decoupling capacitor within 3 mm of the VCC pin and a 10 uF bulk capacitor at the board's 3.3V rail. For JTAG chain integrity, place a 10 kohm pull-up on TCK and TMS to VCC, and a 10 kohm pull-up on TDI. Series-termination of 33 ohm on DCLK is recommended when the FPGA is more than 50 mm away.
Do not connect the EPC2LC21N's nINIT_CONF to ground permanently - it must be controlled by the host or FPGA to enable a re-configuration cycle. Do not tie nSTATUS to VCC; the EPC2LC21N drives nSTATUS low when the configuration is invalid. Avoid placing a series resistor on CONF_DONE larger than 100 ohm, or the FPGA may fail to register the high level. When migrating an existing EPC1LC20N design to EPC2LC21N, note that the power pin (VCC) assignment changed from 5V to 3.3V; rework the power tree before soldering.
The EPC2LC21N in PLCC-20 has a typical power dissipation of approximately 100 mW during read and 50 mW in standby. At 3.3V operation, junction-to-ambient thermal resistance is approximately 65 C/W, yielding a self-heating of 6-7 C at full read activity - well within the industrial -40C to +85C operating envelope. For sealed enclosures without airflow, derate by 20% to account for thermal accumulation around the socket. No external heatsink is required for typical configuration loading duty cycles.
Compliance Information
RoHS compliant per Altera/Intel product marking. Not AEC-Q100 qualified (industrial/FPGA configuration, not automotive). Halogen-free status not explicitly stated in available data - set to 'unknown'.