KM681000ALT-10L - 128Kx8 5V Low-Power CMOS SRAM | Samsung
MPN: KM681000ALT-10L ✗ End of Life| Qty | Unit Price | Extended |
|---|---|---|
| 1 | $2.95 | $2.95 |
| 10 | $2.6 | $26.00 |
| 100 | $2.25 | $225.00 |
| 500 | $1.95 | $975.00 |
| 1,000 | $1.7 | $1,700.00 |
KM681000ALT-10L Overview
A static RAM (SRAM) is a type of volatile semiconductor memory that uses bistable latching circuitry (typically 6 transistors per cell) to store each bit, eliminating the need for periodic refresh cycles required by dynamic RAM (DRAM). SRAM occupies the role of cache, scratchpad, and buffer memory in the broader memory hierarchy: register file -> SRAM cache -> DRAM main memory -> storage. Its random-access nature and byte-level write granularity make it ideal for control logic, lookup tables, and small data buffers where speed and simplicity outweigh density-per-cost.
Key features of the KM681000ALT-10L include 128K x 8 organization, 5V single-supply operation, low standby current, fully static operation requiring no clock or refresh, and TTL-compatible I/O. The device supports common asynchronous SRAM control signals (chip enable, output enable, write enable) and operates over commercial (0C to +70C) or industrial (-40C to +85C) temperature ranges depending on the device grade. The 'ALT' suffix denotes a specific package and operating-mode variant within the KM681000 family.
Architecturally, the KM681000ALT-10L uses a 6T CMOS SRAM cell array, internal address decoding, and an 8-bit bidirectional data bus. The die is offered in a small-outline surface-mount package to support compact PCB layouts. The asynchronous interface simplifies integration with microcontrollers and legacy logic that do not provide dedicated SDRAM controllers.
Typical applications include industrial control PLCs and HMI panels, networking equipment buffer memory, point-of-sale terminals, instrumentation data logging, automotive infotainment subsystems, and legacy embedded computing where deterministic low-latency read/write access and high endurance are required. The wide temperature tolerance and 5V supply simplify designs replacing older SRAMs in long-lifecycle products.
When designing with this device, ensure the address and data lines have adequate decoupling near the device and that the chip-enable access timing (tCE) is respected in worst-case read cycles. Designers upgrading from older 5V SRAMs should confirm the pinout matches their existing footprint, as different Samsung speed grades (e.g., -8, -10, -12) share the same functional pinout but differ in access time.
Drop-in alternatives for KM681000ALT-10L — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
Quick Comparison Tool — Select alternative parts for side-by-side comparison:
KM681000ALT-8
✅ Drop-In📋 Reference alternative (not in catalog)
KM681000ALT-12
✅ Drop-In📋 Reference alternative (not in catalog)
KM681000ALT-15
✅ Drop-In📋 Reference alternative (not in catalog)
HY628100ALLT1-55I
✅ Drop-In📋 Reference alternative (not in catalog)
AS6C1008-55PCN
✅ Drop-In📋 Reference alternative (not in catalog)
KM681000ALT-10L Maximum Ratings & Electrical Characteristics
| Memory Type | Volatile SRAM (Static RAM) |
| Memory Organization | 128K x 8 (1 Mbit) |
| Number of Words | 131,072 words |
| Bits per Word | 8 bits |
| Supply Voltage (Vcc) | 5 V |
| Access Time | 100 ns (suffix -10) |
| Operating Mode | Asynchronous, fully static |
| Refresh Requirement | None (static, no refresh) |
| Interface | Parallel asynchronous, TTL-compatible I/O |
| Output Enable Pin | Yes (/OE) |
| Write Enable Pin | Yes (/WE) |
| Chip Enable Pin | Yes (/CE1, CE2) |
| Operating Temperature Range | Commercial / Industrial (L grade) |
| Package Type | Surface Mount (ALT suffix indicates package variant) |
| Process Technology | High-speed low-power CMOS |
KM681000ALT-10L Pin Configuration
| Pin 1 | NC — Not connected (per datasheet) |
| Pin 2 | A16 — Address input 16 (highest) |
| Pin 3 | A14 — Address input 14 |
| Pin 4 | A12 — Address input 12 |
| Pin 5 | A7 — Address input 7 |
| Pin 6 | A6 — Address input 6 |
| Pin 7 | A5 — Address input 5 |
| Pin 8 | A4 — Address input 4 |
| Pin 9 | A3 — Address input 3 |
| Pin 10 | A2 — Address input 2 |
| Pin 11 | A1 — Address input 1 |
| Pin 12 | A0 — Address input 0 (lowest) |
| Pin 13 | I/O0 — Data I/O 0 |
| Pin 14 | I/O1 — Data I/O 1 |
| Pin 15 | I/O2 — Data I/O 2 |
| Pin 16 | GND — Ground |
| Pin 17 | I/O3 — Data I/O 3 |
| Pin 18 | I/O4 — Data I/O 4 |
| Pin 19 | I/O5 — Data I/O 5 |
| Pin 20 | I/O6 — Data I/O 6 |
| Pin 21 | I/O7 — Data I/O 7 |
| Pin 22 | /CE1 — Chip enable 1 (active low) |
| Pin 23 | A10 — Address input 10 |
| Pin 24 | /OE — Output enable (active low) |
| Pin 25 | A11 — Address input 11 |
| Pin 26 | A9 — Address input 9 |
| Pin 27 | A8 — Address input 8 |
| Pin 28 | A13 — Address input 13 |
| Pin 29 | /WE — Write enable (active low) |
| Pin 30 | CE2 — Chip enable 2 (active high) |
| Pin 31 | A15 — Address input 15 |
| Pin 32 | Vcc — Power supply +5V |
Typical Applications
KM681000ALT-10L is suitable for 6 applications: Industrial PLC and HMI Buffer Memory, Networking Equipment Packet Buffer, Point-of-Sale Terminal Scratchpad, Instrumentation Data Acquisition Memory, Automotive Infotainment Scratchpad, Legacy Embedded Computer Expansion Memory.
Industrial PLC and HMI Buffer Memory
The KM681000ALT-10L fits industrial PLC buffer memory roles because its 128K x 8 organization, 5V supply, and 100 ns access time are compatible with legacy 8/16-bit microcontrollers used in factory automation. Its fully static, no-refresh asynchronous interface eliminates the need for a memory controller, simplifying the PCB. The L-grade industrial temperature range (-40C to +85C) supports factory floor conditions including motor cabinets and outdoor enclosures. With standby current in the low-uA range, the SRAM preserves state across power cycles when paired with a battery or supercap backup.
Recommended
Networking Equipment Packet Buffer
The KM681000ALT-10L is well-suited as a packet buffer in routers, switches, and serial-protocol converters because its 100 ns access time keeps up with 10 Mbps Ethernet bridging without dropping packets. The 8-bit wide data bus matches typical network processor datapaths, while the 5V TTL interface simplifies level shifting to legacy logic. Its low standby current makes it appropriate for always-on buffering in low-power network nodes. With 131,072 addressable bytes, it can hold approximately 800 Ethernet frames at 128 bytes each for store-and-forward applications.
Recommended
Point-of-Sale Terminal Scratchpad
The KM681000ALT-10L works as a transaction scratchpad in point-of-sale (POS) terminals where it temporarily buffers receipt line items, printer buffers, and keyboard scan codes between the host CPU and peripherals. Its 5V supply matches legacy POS controller platforms, and the 128K x 8 capacity holds extended receipt data plus operating parameters. The asynchronous, no-clock interface simplifies integration with 8051, Z80, or 6800-family POS controllers. Industrial temperature grading supports deployment in unheated retail back rooms.
Recommended
Instrumentation Data Acquisition Memory
The KM681000ALT-10L serves as a high-speed sample buffer in digital oscilloscopes, data loggers, and spectrum analyzers. Its 100 ns access time matches ADC throughput at sampling rates up to 5 MSPS when used as a half-period ping-pong buffer. The fully static operation means there is no risk of data corruption from refresh arbitration during long captures. With 128K x 8 storage, the device can hold approximately 65,000 12-bit ADC samples (when paired with packing logic), suitable for transient capture in bench instruments.
Recommended
Automotive Infotainment Scratchpad
The KM681000ALT-10L provides volatile scratchpad memory for automotive infotainment head units, dashboard displays, and HVAC controllers where deterministic read/write access is required. Its 5V supply and asynchronous interface simplify interface to legacy automotive microcontrollers. Although not AEC-Q100 qualified itself, it has been used in commercial-grade automotive subsystems where the host MCU provides qualification coverage. The 1 Mbit capacity comfortably buffers navigation waypoint data, audio equalizer presets, and user interface state.
Recommended
Legacy Embedded Computer Expansion Memory
The KM681000ALT-10L acts as expansion memory for legacy industrial PCs, embedded single-board computers, and VME/cPCI peripheral cards that use asynchronous SRAM sockets. Its 100 ns access time pairs well with ISA-bus-style timing (8 MHz AT-bus clocks). The 32-pin surface-mount ALT package occupies a small board footprint suitable for retrofits of legacy cards. Designers upgrading 1980s-1990s equipment often spec the KM681000ALT-10L as a like-for-like replacement when modern SDRAM is incompatible with vintage memory controllers.
Recommended
Recommended Products Summary
Engineering reference data for KM681000ALT-10L — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | KM681000ALT-8 | KM681000ALT-12 | HY628100ALLT1-55I | AS6C1008-55PCN |
|---|---|---|---|---|---|
| Brand | Samsung Electronics | Samsung Electronics | Samsung Electronics | SK Hynix | Alliance Memory |
| Package | TSOP-32 (ALT) | TSOP-32 (ALT) - same | TSOP-32 (ALT) - same | TSOP-32 (ALT-equivalent) - same | PDIP-32 (32-lead, pin-compatible) |
| Memory Density | 1 Mbit (128K x 8) | 1 Mbit | 1 Mbit | 1 Mbit | 1 Mbit |
| Access Time | 100 ns | 85 ns (faster) | 120 ns (slower) | 55 ns (faster) | 55 ns (faster) |
| Supply Voltage | 5V | 5V | 5V | 5V | 5V |
| Interface | Asynchronous, parallel | Asynchronous | Asynchronous | Asynchronous | Asynchronous |
| Refresh Required | No (static) | No | No | No | No |
Key Differentiators
- Samsung brand legacy and proven long-term reliability (vs AS6C1008-55PCN)
- Mid-range 100 ns speed grade balances cost and performance (vs KM681000ALT-8)
- Compatible with broader 5V asynchronous SRAM ecosystem (vs HY628100ALLT1-55I)
Design Notes
Place a 0.1 uF ceramic decoupling capacitor as close as possible to the Vcc pin (pin 32) of the KM681000ALT-10L, with a 10 uF tantalum or aluminum bulk capacitor on the supply rail. SRAM switching transients on the address bus can couple through the supply; bulk capacitance reduces Vcc droop during burst reads. Estimated: a 5V supply with a 100 ns access cycle at 10 MHz draws approximately 30-50 mA continuous, so the 10 uF bulk cap should have low ESR to handle the di/dt spikes. Tie unused address and data pins to known states via pull-ups/pull-downs if your MCU drives them only when active.
Do not assume the KM681000ALT-10L is 3.3V-tolerant - it requires 5V Vcc and its inputs are TTL-level only. Driving I/O pins with 3.3V CMOS logic from a modern MCU typically works for reads (logic-high threshold ~2V), but the SRAM's output high level (Voh) at 3.3V Vcc may not meet 3.3V CMOS Vih reliably. Use a 5V-tolerant MCU or a level translator. Estimated: a 3.3V MCU driving Voh of 2.7V into the KM681000ALT-10L's Vih of 2.2V will work for reads, but writing requires full 5V TTL levels on the data bus.
Route address and data lines with matched trace lengths to avoid skew-induced access-time violations. Keep /WE, /OE, and /CE1 control traces short and well-shielded from noisy digital signals. Place a ground plane beneath the SRAM to provide a low-impedance return path. Estimate: every 1 cm of unmatched trace on a 100 ns bus introduces roughly 0.5-0.7 ns of delay; with tAA = 100 ns and tCO = 50 ns, you have only ~50 ns of setup margin, so keep total trace mismatch under 5 cm.
Compliance Information
KM681000ALT-10L is a legacy Samsung product. RoHS, REACH, and lead-free status were not explicitly stated in the verified web data; consult Samsung legacy documentation or the original datasheet for compliance history. Not AEC-Q100 qualified for automotive.
