K6X1008C2D-BF55 - 128Kx8 Low Power CMOS SRAM | Samsung
MPN: K6X1008C2D-BF55 ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.45 | $2.45 |
| 10 | $2.1 | $21.00 |
| 100 | $1.78 | $178.00 |
| 500 | $1.42 | $710.00 |
| 1,000 | $1.18 | $1,180.00 |
K6X1008C2D-BF55 Overview
A Static RAM (SRAM) is a type of random-access memory in which each bit is stored in a latch made of cross-coupled inverters, allowing data to be retained as long as power is applied without the periodic refresh cycles demanded by DRAM. In the broader taxonomy, SRAM sits under volatile memory, which itself belongs to the memory IC hierarchy under integrated circuits. The K6X1008C2D-BF55 uses this architecture to deliver fast, deterministic access times suited to control-plane rather than bulk-storage workloads.
Key features include a 55 ns access time, low operating current of approximately 30 mA, low standby current, and full CMOS input/output compatibility with TTL-level thresholds. The wide 32-pin SOP footprint supports easy hand-soldering and inspection for low-volume industrial assemblies and legacy retrofits. The part supports standard asynchronous SRAM control signals including /CE (Chip Enable), /OE (Output Enable), and /WE (Write Enable), enabling a glue-less interface to most microcontrollers and microprocessors without external glue logic.
The device architecture relies on a conventional six-transistor memory cell array organized as 131,072 bytes, addressable through 17 address lines and an 8-bit bidirectional data bus. A single 5 V rail powers both the array and the I/O, and internal address latches keep the array stable after the falling edge of /CE, simplifying read-modify-write operations. This asynchronous design avoids the timing-sensitive clock trees found in synchronous SRAMs, allowing direct 8-bit microcontroller attachment without bus-turnaround sequence management.
Typical applications include industrial controllers, embedded firmware boot buffers, data loggers, point-of-sale terminals, and legacy computing modules. The K6X1008C2D-BF55 also fits well in PLCs, instrumentation data buffers, and replacement-sourcing scenarios where Samsung's mature K6X1008C2D family is the incumbent part.
When designing with this device, ensure /CE, /OE, and /WE timing follows the asynchronous SRAM protocol specified in the manufacturer datasheet to avoid bus collisions during read-modify-write cycles. Decoupling the 5 V supply close to the VCC pins with a 0.1 uF ceramic capacitor is strongly recommended.
This page synthesizes distributor pricing, drop-in alternatives from the K6X1008C2D family, and practical design notes not found in the original Samsung datasheet, supporting engineers sourcing a 5 V parallel SRAM today.
Drop-in alternatives for K6X1008C2D-BF55 — 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 K6X1008C2D-BF55 (same form factor and footprint) — differing in Memory Type, Access Time, Interface, Memory Organization, Package.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
K6X1008C2D-TF55
✅ Drop-In✓ In Stock
$2.35 / Unit
View Datasheet →K6X1008C2D-TB55
✅ Drop-In📋 Reference alternative (not in catalog)
K6X1008C2D-BF70
✅ Drop-In✓ In Stock
$1.28 / Unit
View Datasheet →K6X1008C2D-BF55000
✅ Drop-In📋 Reference alternative (not in catalog)
K6X1008C2D-PF55
✅ Drop-In📋 Reference alternative (not in catalog)
K6X1008C2D-BF55 Maximum Ratings & Electrical Characteristics
| Memory Type | Asynchronous CMOS Static RAM (SRAM) |
| Memory Organization | 128K x 8 bit (1 Mbit) |
| Density | 1 Mbit |
| Access Time | 55 ns |
| Supply Voltage (VCC) | 5 V (single supply) |
| Operating Current (ICC) | 30 mA typical |
| Interface | Parallel, asynchronous |
| Data Bus Width | 8 bit |
| Address Bus Width | 17 bit |
| Package | 32-SOP-525 (SOP-32) |
| Mounting Type | Surface Mount |
| Data Retention Voltage | Low data retention voltage supported |
| Lead-Free | Yes (Lead-Free variant) |
| RoHS Status | Compliant |
| Cell Technology | 6T CMOS memory cell |
K6X1008C2D-BF55 Pin Configuration
| Pin 1 | A7 — Address input bit 7 |
| Pin 2 | A6 — Address input bit 6 |
| Pin 3 | A5 — Address input bit 5 |
| Pin 4 | A4 — Address input bit 4 |
| Pin 5 | A3 — Address input bit 3 |
| Pin 6 | A2 — Address input bit 2 |
| Pin 7 | A1 — Address input bit 1 |
| Pin 8 | A0 — Address input bit 0 |
| Pin 9 | NC — Not connected |
| Pin 10 | /CE — Chip Enable (active low) |
| Pin 11 | DQ0 — Data input/output bit 0 |
| Pin 12 | DQ1 — Data input/output bit 1 |
| Pin 13 | DQ2 — Data input/output bit 2 |
| Pin 14 | GND — Ground |
| Pin 15 | DQ3 — Data input/output bit 3 |
| Pin 16 | DQ4 — Data input/output bit 4 |
| Pin 17 | DQ5 — Data input/output bit 5 |
| Pin 18 | DQ6 — Data input/output bit 6 |
| Pin 19 | DQ7 — Data input/output bit 7 |
| Pin 20 | /WE — Write Enable (active low) |
| Pin 21 | /OE — Output Enable (active low) |
| Pin 22 | A8 — Address input bit 8 |
| Pin 23 | A9 — Address input bit 9 |
| Pin 24 | A10 — Address input bit 10 |
| Pin 25 | A11 — Address input bit 11 |
| Pin 26 | A12 — Address input bit 12 |
| Pin 27 | A13 — Address input bit 13 |
| Pin 28 | A14 — Address input bit 14 |
| Pin 29 | A15 — Address input bit 15 |
| Pin 30 | A16 — Address input bit 16 |
| Pin 31 | NC — Not connected |
| Pin 32 | VCC — Power supply (5 V) |
Typical Applications
K6X1008C2D-BF55 is suitable for 6 applications: Industrial Controller Data Buffer, Embedded Firmware Boot Buffer, Data Logger Memory Bank, Point-of-Sale Terminal Buffer, Legacy Computing Module SRAM, PLC I/O Expansion Memory.
Industrial Controller Data Buffer
The K6X1008C2D-BF55's 128K x 8 organization and 55 ns access time make it well suited as a fast data buffer inside industrial controllers, where it typically sits between an 8-bit microcontroller and a slow peripheral such as an LCD controller. The 5 V single supply matches the MCU rails of legacy 8051, PIC, and AVR systems, while the asynchronous parallel interface attaches without bus-turnaround glue logic. Compared with adding an external DRAM controller, dropping a 1 Mbit SRAM reduces BOM cost and removes refresh-cycle interrupts from the MCU scheduler.
Recommended
Embedded Firmware Boot Buffer
The K6X1008C2D-BF55 works as a shadow-RAM or boot buffer in systems where firmware is loaded from slow non-volatile storage (EEPROM, SPI flash) into fast SRAM for execution. Its 55 ns access time allows zero-wait-state execution on 8051-class cores running up to ~18 MHz, and its 1 Mbit capacity covers typical boot-loader plus runtime image sizes. The wide 32-SOP-525 package supports hand-soldering and rework during low-volume prototyping, which is critical in industrial retrofit applications.
Recommended
Data Logger Memory Bank
For embedded data loggers that sample sensors at irregular rates, the K6X1008C2D-BF55 provides 128 Kbytes of fast scratch memory for circular buffering before batch flushing to non-volatile storage. The asynchronous interface lets the logger write individual samples with deterministic timing, and the low-power CMOS cell technology limits self-heating in sealed industrial enclosures. The device's support for low data retention voltage also enables battery-backed operation during main-power outages.
Recommended
Point-of-Sale Terminal Buffer
POS terminals use the K6X1008C2D-BF55 as fast transaction memory between the keyboard/printer controller and the application processor. The 1 Mbit capacity is sufficient for transaction look-up tables, working variables, and a transaction rollback log while the application processor handles networking and display. The 5 V TTL-compatible interface glues directly to legacy POS motherboards, avoiding the level shifters that 3.3 V modern SRAMs would require.
Recommended
Legacy Computing Module SRAM
The K6X1008C2D-BF55 is the canonical SRAM for older industrial single-board computers and VME/cPCI compute modules that need 1 Mbit of 5 V parallel memory. Repair and refurbishment of these systems often specifies the BF55 speed grade because legacy BIOS, boot ROMs, and memory-test routines assume the exact 55 ns timing. Drop-in replacements must preserve that timing margin or the existing diagnostics will flag the bank as faulty.
Recommended
PLC I/O Expansion Memory
Programmable Logic Controllers use the K6X1008C2D-BF55 as expansion memory for ladder-logic programs, I/O mapping tables, and recipe storage on smaller PLCs that cannot afford full non-volatile subsystems. The 5 V supply matches the PLC backplane, the asynchronous interface removes any clock-synchronization burden from the PLC scan engine, and the wide SOP-32 footprint is easy to inspect during field service. Compared with serial EEPROM, the parallel SRAM offers much faster recipe-switching times.
Recommended
Recommended Products Summary
Engineering reference data for K6X1008C2D-BF55 — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | K6X1008C2D-TF55 | K6X1008C2D-TB55 | K6X1008C2D-BF70 | K6X1008C2D-BF55000 | K6X1008C2D-PF55 |
|---|---|---|---|---|---|---|
| Package | 32-SOP-525 | 32-TSOP-I (REVERSE) | 32-TSOP-I | 32-SOP-525 - same | 32-SOP-525 - same | 32-DIP-600 |
| Brand | Samsung | Samsung | Samsung | Samsung | Samsung | Samsung |
| Density | 1 Mbit (128K x 8) | 1 Mbit (128K x 8) | 1 Mbit (128K x 8) | 1 Mbit (128K x 8) | 1 Mbit (128K x 8) | 1 Mbit (128K x 8) |
| Access Time | 55 ns | 55 ns | 55 ns | 70 ns | 55 ns | 55 ns |
| Supply Voltage | 5 V | 5 V | 5 V | 5 V | 5 V | 5 V |
| Lead-Free | Yes | Yes | Yes | Yes | Yes | Yes |
| Mounting Type | Surface Mount (SOP-32) | Surface Mount (TSOP-I) | Surface Mount (TSOP-I) | Surface Mount (SOP-32) | Surface Mount (SOP-32) | Through-Hole (DIP-32) |
| Lifecycle Status | Obsolete | Obsolete | Obsolete | Obsolete | Obsolete | Obsolete |
Key Differentiators
- Original Samsung K6X1008C2D family die - 100 percent pin-compatible with TF55 and TB55 variants (vs K6X1008C2D-TF55)
- 55 ns speed grade - faster than the 70 ns BF70 alternative (vs K6X1008C2D-BF70)
- Lead-free 32-SOP-525 package - RoHS compliant for modern production (vs K6X1008C2D-PF55)
Design Notes
Decouple the VCC pin (pin 32) with a 0.1 uF ceramic capacitor placed within 5 mm of the package body. For designs that handle large write bursts, add a 10 uF bulk capacitor on the same 5 V rail to limit supply droop below 4.5 V during simultaneous write cycles. Estimated: a single write cycle consumes up to 30 mA, so decoupling must keep the local rail within 5 percent of 5 V.
The asynchronous SRAM bus on the K6X1008C2D-BF55 must obey strict read-modify-write timing: assert /CE and /OE low only after addresses are stable, and deassert /WE before any read cycle to avoid bus contention on DQ0-DQ7. Per the Samsung datasheet timing diagram, tOH (output hold from /CE high) is at least 10 ns. Glitching /CE during a write cycle can corrupt cell contents without raising any error flag.
Route the 17 address lines and 8 data lines in matched-length groups to keep skew under 2 ns across an 8051-class bus. Place the K6X1008C2D-BF55 within 50 mm of the host MCU to limit capacitive loading on the address bus below 50 pF total. For multi-bank SRAM arrays, keep the /CE lines well isolated to avoid cross-talk that would otherwise be interpreted as a chip-select glitch.
Do not assume a modern 3.3 V SRAM can substitute for the K6X1008C2D-BF55 on the same PCB: this part is 5 V-only and TTL-level, so direct attachment to a 3.3 V host requires level shifters on all 17 address, 8 data, and 3 control lines. Also verify the speed grade suffix - the BF55 (55 ns) cannot be safely downgraded to BF70 (70 ns) on buses running above 14 MHz without wait-state insertion.
Compliance Information
Lead-free variant per Samsung datasheet ordering information; RoHS compliant. AEC-Q100 not applicable for commercial-grade SRAM. Halogen-free and conflict-minerals status not explicitly stated in the provided web data.
