K4A8G085WC-BCTD - 8Gb DDR4 SDRAM 2666Mbps 1.2V | Samsung
MPN: K4A8G085WC-BCTD ⚠ Last Time Buy| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $60.05 | $60.05 |
| 10 | $58.25 | $582.50 |
| 100 | $55.6 | $5,560.00 |
| 500 | $53.1 | $26,550.00 |
| 1,000 | $50.85 | $50,850.00 |
K4A8G085WC-BCTD Overview
DDR4 SDRAM (Double Data Rate 4 Synchronous Dynamic Random-Access Memory) is the fourth generation of DDR memory and a successor to DDR3 within the DRAM family of volatile semiconductor memory. DDR4 achieves higher data rates and densities at lower operating voltage (1.2V versus 1.5V for DDR3) through a redesigned bank architecture, on-die termination (ODT), and a pseudo-open-drain I/O interface, making it the mainstream memory standard for servers, desktops, and embedded computing platforms.
Key features of the K4A8G085WC-BCTD include the 2666 Mbps (PC4-2133) speed grade, 1G x 8 organization suited to ECC and registered DIMM designs, CRC for command/address integrity, and ZQ calibration with dynamic ODT for improved signal integrity at high data rates. Auto precharge and an asynchronous reset input simplify controller timing management, while the data mask function enables selective byte writes during bursts.
Technically, the device is built on Samsung's advanced DRAM process technology with a supply range of 1.14V to 1.26V per distributor listings. The 78FBGA package uses a 0.8mm ball pitch, providing compact footprints and good electrical and thermal performance for high-density memory subsystems. Burst length 8 and burst chop 4 modes, along with programmable CAS latency and additive latency, give memory-controller designers flexible timing control.
Typical applications include main memory for enterprise servers and cloud infrastructure, high-end desktop platforms, networking switches and routers, and embedded computing boards that require 8Gb DDR4 with a x8 data bus. The 2666 Mbps grade balances bandwidth and power for mainstream system designs.
Design considerations: provide stable 1.2V rails for VDD and VDDQ with decoupling capacitors close to the balls, follow the Samsung datasheet PCB layout and fly-by routing guidelines, and respect the JEDEC power-up sequence to avoid latch-up or damage. Note this part carries a last_time_buy lifecycle status - plan migration to the pin-compatible K4A8G085WC-BIWE industrial-grade variant.
This page synthesizes distributor pricing and stock, drop-in alternatives, EOL migration guidance, and practical design notes not found in the manufacturer datasheet.
Drop-in alternatives for K4A8G085WC-BCTD — 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 K4A8G085WC-BCTD (same form factor and footprint) — differing in Package, Data Rate, Operating Temperature, Burst Length, Refresh.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
K4A8G085WC-BIWE
✅ Drop-In✓ In Stock
$6.29 / Unit
View Datasheet →K4A8G085WB-BCTD
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$7.5 / Unit
View Datasheet →K4A8G085WB-BIWE
✅ Drop-In ⚠️ Specs Unverified✓ In Stock
$6.5 / Unit
View Datasheet →MT40A1G8SA-075:E
✅ Drop-In✓ In Stock
$6.3 / Unit
View Datasheet →H5AN8G6NAFR-UHC
✅ Drop-In✓ In Stock
$5.7422 / Unit
View Datasheet →NT6AN8T1GA4H1-H1
✅ Drop-In📋 Reference alternative (not in catalog)
K4A8G085WC-BCTD Maximum Ratings & Electrical Characteristics
| Memory Type | DDR4 SDRAM |
| Density | 8 Gb |
| Organization | 1G x 8 |
| Data Rate | 2666 Mbps (PC4-2133) |
| Supply Voltage (VDD/VDDQ) | 1.2 V (1.14 V to 1.26 V) |
| Package | 78-ball FBGA (78FBGA) |
| Ball Pitch | 0.8 mm |
| Operating Temperature | 0C to +95C |
| Standard Operating Temp Range | 0C to +85C |
| Burst Length | 8 (chop 4) |
| Auto Precharge | Yes |
| Asynchronous Reset | Yes |
| CRC Function | Yes |
| ZQ Calibration | Yes |
| Dynamic ODT | Yes |
| Data Mask | Yes |
| Interface Type | Synchronous, parallel |
| Mounting Type | Surface Mount |
K4A8G085WC-BCTD 78-ball fbga (78fbga) Pin Configuration Guide
Pin configuration for K4A8G085WC-BCTD (78-ball fbga (78fbga) package). This digital IC includes GPIO, communication interfaces (UART, SPI, I2C), and power pins. Refer to the manufacturer datasheet for alternate pin functions and configuration options. Essential for embedded system design and PCB layout.
No detailed pinout data available for K4A8G085WC-BCTD.
Refer to the datasheet for full pin configuration.
Typical Applications
K4A8G085WC-BCTD is suitable for 6 applications: Enterprise Server Main Memory, Networking Switches and Routers, Cloud Computing Infrastructure, High-End Desktop Platforms, Embedded Computing and IPC, Test and Measurement Equipment.
Enterprise Server Main Memory
The K4A8G085WC-BCTD's 8Gb density in a 1G x 8 organization makes it a natural fit for ECC RDIMM and LRDIMM designs, where x8 devices enable single-bit error correction per DRAM. Its 2666 Mbps speed grade matches mainstream server memory controllers, and CRC plus ZQ calibration maintain command/address and signal integrity in multi-rank, high-population memory channels. In DIMM designs, dynamic ODT compensates for loading as ranks are added, and the 1.2V rails reduce power versus DDR3 by roughly 25% per transfer. Systems must implement JEDEC fly-by routing and per-rank termination for reliable operation at full speed.
Recommended
Networking Switches and Routers
Networking platforms use the K4A8G085WC-BCTD as packet-buffer and control-plane memory, where the 8Gb density supports deep burst buffers in switching ASICs. The 2666 Mbps rate provides the sustained bandwidth needed for line-rate packet processing, and the data mask function allows selective buffer updates during partial packet writes, reducing read-modify-write overhead. The 0C to +95C operating range covers equipment room environments, while CRC protects address integrity in electrically noisy backplanes. Designers should verify controller timing tables include this speed bin and reserve the asynchronous reset input for system-level brown-out recovery.
Recommended
Cloud Computing Infrastructure
Cloud server and storage nodes standardize on 8Gb DDR4 components like the K4A8G085WC-BCTD to reach high capacity per socket while keeping power budgets in check. The 1.2V operation and DDR4 bank-group architecture deliver the bandwidth-per-watt improvement over DDR3 that hyperscale operators require, and the 1G x 8 organization supports the ECC schemes mandatory in multi-tenant infrastructure. Its last-time-buy status is a key procurement consideration: fleets built on this MPN should qualify the pin-compatible K4A8G085WC-BIWE as a second source, validating JEDEC timings in BMC, BIOS, and U-Boot before fleet-wide rollout.
Recommended
High-End Desktop Platforms
Desktop motherboards using 2666-class memory controllers pair directly with the K4A8G085WC-BCTD in UDIMM or soldered-down configurations. The 8Gb, 1G x 8 organization enables 8GB-per-module capacities with x8 chips, and programmable CAS and additive latency let firmware optimize performance across speed bins. Dynamic ODT and ZQ calibration keep signal integrity stable across two-DIMM-per-channel topologies at 2666 Mbps. For consumer designs, note the commercial temperature grade and the last-time-buy status: consumer replacement BOMs should qualify the WC-BIWE industrial variant, which fits the same layout and provides longer supply continuity.
Recommended
Embedded Computing and IPC
Industrial PCs and embedded controllers using BGA-down DDR4 memory adopt the K4A8G085WC-BCTD for its balance of 8Gb density and 2666 Mbps bandwidth at 1.2V. The 0.8mm-ball 78FBGA footprint suits compact baseboards, and the asynchronous reset supports the robust brown-out behavior industrial systems demand. Because industrial environments exceed the commercial temperature grade, embedded designers typically specify the pin-compatible K4A8G085WC-BIWE from the start; existing designs validated on BCTD can migrate with zero PCB redesign but must re-run JEDEC timing validation in the boot firmware. Careful VDD/VDDQ decoupling near the balls is essential in electrically noisy factory settings.
Recommended
Test and Measurement Equipment
Bench instruments and automated test systems use the K4A8G085WC-BCTD as capture and waveform memory, exploiting the 8Gb density and 2666 Mbps streaming bandwidth to sustain deep acquisition records. The 1G x 8 organization simplifies 64-bit memory-controller interfaces using eight devices, and ZQ calibration with dynamic ODT maintains eye margins across temperature drift during long measurement sessions. Designers should validate the full JEDEC power-up sequence in FPGA-based memory controllers, since FPGA DDR4 PHYs require correct MR register programming for this speed bin, and should qualify the WC-BIWE variant given the BCTD's last-time-buy procurement risk.
Recommended
Recommended Products Summary
Engineering reference data for K4A8G085WC-BCTD — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | K4A8G085WC-BIWE | K4A8G085WB-BCTD | MT40A1G8SA-075:E | H5AN8G6NAFR-UHC | NT6AN8T1GA4H1-H1 |
|---|---|---|---|---|---|---|
| Package | 78-ball FBGA | 78-ball FBGA - same | 78-ball FBGA - same | 78-ball FBGA - same | 78-ball FBGA - same | 78-ball FBGA - same |
| Brand | Samsung Electronics | Samsung Electronics | Samsung Electronics | Micron Technology | SK Hynix | Nanya Technology |
| Density | 8 Gb | 8 Gb | 8 Gb | 8 Gb | 8 Gb | 8 Gb |
| Organization | 1G x 8 | 1G x 8 | 1G x 8 | 1G x 8 | 1G x 8 | 1G x 8 |
| Supply Voltage | 1.2 V (1.14-1.26 V) | 1.2 V | 1.2 V | 1.2 V | 1.2 V | 1.2 V |
| Firmware/SPD Compatibility | Baseline JEDEC 2666 bin | Timing validation required (not firmware drop-in) | Same JEDEC bin family | SPD and sequencing differences - validate | SPD validation required | SPD validation required |
Key Differentiators
- Migration path exists within same footprint (vs K4A8G085WC-BIWE)
- 2666 Mbps mainstream speed bin with CRC and dynamic ODT (vs MT40A1G8SA-075:E)
- Trade-off: last-time-buy limits future supply (vs H5AN8G6NAFR-UHC)
Design Notes
For soldered-down 78FBGA designs, route address/command in fly-by topology with per-DIMM or per-device termination and keep DQS/DQ length matching within JEDEC skew budgets for 2666 Mbps (tCK ~0.75 ns class). Place 0.1uF decoupling capacitors at every VDD/VDDQ ball pair plus bulk capacitance per rail; the 1.14-1.26V VDDQ tolerance leaves little margin at speed, so measure rails under burst load during bring-up.
Substituting DDR4 across die revisions or brands is not a firmware drop-in even when the 78-ball footprint matches. The K4A8G085WC-BIWE is pin- and layout-compatible, but sources warn that down-clocking or changing die requires strict JEDEC timing validation in U-Boot or BIOS, including MR register programming and SPD updates. Similarly, IC-Components notes the BCTD is not a direct drop-in for Micron 062E-class parts due to timing, VDDQ tolerance, and power-up sequencing differences.
Follow the JEDEC DDR4 power-up sequence: apply VDD before or with VDDQ/ VPP per datasheet ramp-rate requirements, hold RESET_n low until rails stabilize, then run controller initialization and ZQ calibration (ZQCL) before first access. The asynchronous reset input should be driven by a supervisor or the memory controller, not left floating, to guarantee recovery from brown-out conditions in server and networking environments.
Procurement risk: this part is in last-time-buy and Samsung EOL notifications were widely reported in 2026. Small-quantity stock (e.g., 20 pcs at LCSC as of Sep 2026) is quickly depleted and broker lots carry date-code and authenticity risk. Design new BOMs around the pin-compatible K4A8G085WC-BIWE (industrial grade) and buy last-batch BCTD only with full traceability documentation.
Compliance Information
Retrieved web data does not state RoHS/REACH/lead-free status for this MPN. Verify via Samsung certificate of conformance or the LCSC product page (C2920071).
