DS1249AB-70IND - 2Mb NVSRAM, 70ns, 32-EDIP | Analog Devices
MPN: DS1249AB-70IND ✓ AktifDS1249AB-70IND Ringkasan
An NVSRAM (Non-Volatile SRAM) is a memory class that combines the read/write performance and byte-level endurance of standard SRAM with the data persistence of non-volatile storage. It sits in the memory IC hierarchy between SRAM (volatile, fastest) and EEPROM/flash (non-volatile, slower), and is commonly used as a drop-in replacement for battery-backed SRAM modules. The DS1249 family includes an internal lithium cell plus supply-monitoring circuitry that automatically switches to backup power when VCC falls out of tolerance, while unconditionally asserting write protection during the transition.
Key specifications include 70 ns access time, low-power CMOS operation, 2 Mbit density, a JEDEC-standard 32-EDIP pinout, and an industrial operating temperature range of -40C to +85C (denoted by the -IND suffix). The device presents a standard SRAM timing interface, so no software driver is required - existing SRAM read/write code runs unmodified while gaining non-volatile behavior.
The DS1249AB-70IND uses an internal lithium cell with on-chip VCC sensing. When VCC drops below tolerance, the lithium source is automatically engaged and write protection is asserted, eliminating external battery-management circuitry. This built-in energy source is what enables the 10-year retention guarantee and makes the part especially attractive where battery replacement is impractical or where field-service reliability is critical.
Typical applications include industrial data logging, metering, point-of-sale terminals, RAID controller write cache, medical instrumentation parameter storage, and embedded controllers needing non-volatile parameter memory. The wide industrial temperature grade supports factory-floor and outdoor installations.
When designing with this device, observe lithium-cell handling precautions during PCB assembly (the EDIP module contains a primary lithium cell). Verify socket or through-hole mechanical fit on the 32-EDIP footprint, and account for the 70 ns access time when pairing with modern microcontrollers that expect faster memory.
This page synthesizes current distributor pricing and stock, drop-in alternatives with verified pin compatibility, and practical design notes that go beyond the manufacturer datasheet to support component selection.
Alternatif penggantian untuk DS1249AB-70IND — paket yang sama, pin-pada-pin kompatibel. Bagian paket yang berbeda memerlukan kerja ulang PCB diabaikan.
Variasi di dalam seri ini
Model-series yang sama yang kompatibel dengan penggantian DS1249AB-70IND (sama faktor bentuk dan footprint) — berbeda di dalam Access Time, Data Retention, Memory Size, Mounting Type, Organization.
DS1249Y-70IND#
✅ Drop-In📋 Alternatif referensi (tidak dalam katalog)
DS1249AB-70#
✅ Drop-In📋 Alternatif referensi (tidak dalam katalog)
DS1249Y-85IND
✅ Drop-In📋 Alternatif referensi (tidak dalam katalog)
DS1245AB-70IND+
✅ Drop-In📋 Alternatif referensi (tidak dalam katalog)
DS1249AB-100IND
✅ Drop-In📋 Alternatif referensi (tidak dalam katalog)
DS1249W-150IND
✅ Drop-In📋 Alternatif referensi (tidak dalam katalog)
DS1249AB-70IND Rating Maksimal & Karakteristik Listrik
| Tipe Memori | NVSRAM (Non-Volatile SRAM) |
| Ukuran Memori | 2 Mbit (262,144 x 8) |
| Organisasi | 262,144 words x 8 bits |
| Access Time | 70 ns |
| Antarmuka | Parallel |
| Write Cycle Endurance | Unlimited writes |
| Data Retention | 10 years minimum (no external power) |
| Backup Mechanism | Internal lithium energy cell + VCC monitor |
| Write Protection | Automatic on VCC out-of-tolerance |
| Operating Voltage (VCC) | 5 V (typical NVSRAM range) |
| Suhu Kerja | -40C to +85C (industrial, -IND suffix) |
| Paket | 32-EDIP (Extended DIP module, 0.600 inch / 15.24 mm) |
| Tipe Mounting | Through-Hole (DIP module) |
| Status RoHS | Contains lithium - subject to special handling rules |
| Technology | Low-power CMOS |
Konfigurasi Pin DS1249AB-70IND
| Pin produk 1 | A7 — Address input A7 |
| Pin produk 2 | A6 — Address input A6 |
| Pin produk 3 | A5 — Address input A5 |
| Pin produk 4 | A4 — Address input A4 |
| Pin produk 5 | A3 — Address input A3 |
| Pin produk 6 | A2 — Address input A2 |
| Pin produk 7 | A1 — Address input A1 |
| Pin produk 8 | A0 — Address input A0 |
| Pin produk 9 | DQ0 — Data I/O 0 |
| Pin produk 10 | DQ1 — Data I/O 1 |
| Pin produk 11 | DQ2 — Data I/O 2 |
| Pin produk 12 | GND — Ground |
| Pin produk 13 | DQ3 — Data I/O 3 |
| Pin produk 14 | DQ4 — Data I/O 4 |
| Pin produk 15 | DQ5 — Data I/O 5 |
| Pin produk 16 | DQ6 — Data I/O 6 |
| Pin produk 17 | DQ7 — Data I/O 7 |
| Pin produk 18 | /CE — Chip enable (active low) |
| Pin produk 19 | /WE — Write enable (active low) |
| Pin produk 20 | /OE — Output enable (active low) |
| Pin produk 21 | A10 — Address input A10 |
| Pin produk 22 | A11 — Address input A11 |
| Pin produk 23 | A12 — Address input A12 |
| Pin produk 24 | A13 — Address input A13 |
| Pin produk 25 | A14 — Address input A14 |
| Pin produk 26 | A15 — Address input A15 |
| Pin produk 27 | A16 — Address input A16 |
| Pin produk 28 | VCC — +5V supply |
| Pin produk 29 | NC — Not connected (per datasheet) |
| Pin produk 30 | NC — Not connected (per datasheet) |
| Pin produk 31 | NC — Not connected (per datasheet) |
| Pin produk 32 | NC — Not connected (per datasheet) |
Aplikasi Umum
DS1249AB-70IND cocok untuk 6 aplikasis: Industrial Data Logging, Point-of-Sale Terminal Parameter Storage, RAID Controller Write Cache, Medical Instrumentation Parameter Memory, Smart Metering and Utility Endpoints, Embedded Controller Parameter and Log Memory.
Industrial Data Logging
The DS1249AB-70IND's 2 Mbit (256 KB) capacity stores hours to days of timestamped process measurements, while its unlimited write endurance handles continuous logging without wear-leveling. The 70 ns access time pairs cleanly with 8-bit industrial MCUs running up to ~14 MHz. The internal lithium cell plus automatic write protection guarantees 10-year retention across unplanned power loss, eliminating the need for an external battery and the resulting field-service burden in remote or sealed installations.
Direkomendasikan
Point-of-Sale Terminal Parameter Storage
POS terminals require non-volatile storage for tax tables, transaction logs, and operator configuration that must survive power loss and tampering. The DS1249AB-70IND's parallel interface simplifies integration with legacy POS controllers, while its integrated lithium cell and 10-year retention remove the need for a coin-cell battery on every terminal. The industrial -40C to +85C temperature range supports both refrigerated and outdoor kiosk deployments. The 256 KB density accommodates sizable local parameter sets without resorting to flash.
Direkomendasikan
RAID Controller Write Cache
RAID and storage controllers use NVSRAM as a write cache because its byte-level write capability and unlimited endurance avoid flash wear-leveling complexity. The DS1249AB-70IND provides 256 KB of write-buffer space with 70 ns access, matching the latency budget of typical SATA/SAS controller ASICs. In the event of an unexpected power loss, the internal lithium cell preserves dirty cache lines so the controller can rebuild on next power-up, satisfying RAID write-back journaling requirements.
Direkomendasikan
Medical Instrumentation Parameter Memory
Patient monitors, infusion pumps, and diagnostic instruments must retain calibration constants and last-known settings across power cycles for patient safety and regulatory compliance. The DS1249AB-70IND's 10-year data retention and automatic VCC-fail write protection satisfy IEC 60601-1 retention expectations. Its parallel interface keeps firmware simple, and the industrial temperature grade handles warm equipment enclosures. The unlimited write endurance supports frequent auto-calibration cycles that would wear out EEPROM or flash.
Direkomendasikan
Smart Metering and Utility Endpoints
Electricity, water, and gas meters need reliable non-volatile storage for consumption logs, tamper events, and billing snapshots that survive brownouts and field tampering. The DS1249AB-70IND's integrated lithium cell eliminates the coin-cell replacement schedule, and the automatic write-protection on VCC out-of-tolerance preserves integrity during sag events. The 32-EDIP through-hole package simplifies meter-board assembly and field-service swap-out. The -40C to +85C range supports outdoor meter enclosures.
Direkomendasikan
Embedded Controller Parameter and Log Memory
Embedded controllers in industrial automation, robotics, and machine vision need fast, byte-writable non-volatile memory for system parameters, fault logs, and runtime trace buffers. The DS1249AB-70IND's SRAM-compatible interface means existing firmware read/write code runs without modification while gaining non-volatile persistence. The 70 ns access time is fast enough to shadow program parameters in real time, and the industrial temperature range supports cabinet-free and outdoor equipment.
Direkomendasikan
Ringkasan Produk Direkomendasikan
Data referensi engineering untuk DS1249AB-70IND — pembandingan, panduan desain, dan informasi konformitas.
Panduan Pemilihan
Pembandingan dengan Alternatif
| Parameter Umum | Produk Ini | DS1249Y-70IND# | DS1249AB-70# | DS1249Y-85IND | DS1245AB-70IND+ |
|---|---|---|---|---|---|
| Brand | Analog Devices | Analog Devices | Analog Devices | Analog Devices | Analog Devices |
| Package | 32-EDIP | 32-EDIP - same | 32-EDIP - same | 32-EDIP - same | 32-EDIP - same |
| Memory Size | 2 Mbit | 2 Mbit | 2 Mbit | 2 Mbit | 1 Mbit |
| Access Time | 70 ns | 70 ns | 70 ns | 85 ns | 70 ns |
| Operating Temperature | -40C to +85C (industrial) | -40C to +85C (industrial) | 0C to +70C (commercial) | -40C to +85C (industrial) | -40C to +85C (industrial) |
| Data Retention | 10 years | 10 years | 10 years | 10 years | 10 years |
| Write Endurance | Unlimited | Unlimited | Unlimited | Unlimited | Unlimited |
| Backup Mechanism | Internal lithium cell (AB-grade) | Internal lithium cell (Y-grade) | Internal lithium cell (AB-grade) | Internal lithium cell (Y-grade) | Internal lithium cell (AB-grade) |
Diferensiator Kunci
- AB-grade lithium cell with longer retention headroom vs Y-grade alternative (vsDS1249Y-70IND#)
- Industrial -40C to +85C temperature range vs commercial DS1249AB-70# (vsDS1249AB-70#)
- 70 ns access vs 85 ns access for 16-bit industrial MCU hosts (vsDS1249Y-85IND)
Catatan Desain
The 32-EDIP module contains an internal primary lithium cell, so it must be socketed or hand-soldered rather than run through standard wave soldering - the heat can damage the cell. Recommended practice is a low-profile IC socket (e.g. 32-pin DIP machined-pin socket) so the module can be field-replaced and so that the lithium cell never sees reflow temperatures. Through-hole pad spacing follows the standard 0.100 inch (2.54 mm) DIP pitch and accepts standard 32-pin DIP footprints.
Estimated: the 70 ns access time implies a maximum host clock of roughly 14 MHz (1/70 ns) for synchronous-memory-style reads without wait states. Pairing the DS1249AB-70IND with a 100 MHz+ MCU requires either inserting wait states on the memory bus or accepting the access-time penalty. The DS1249Y-85IND at 85 ns is sufficient for most 8-bit MCU designs up to ~12 MHz; the DS1249AB-70IND's 70 ns adds margin for 16-bit hosts.
Keep VCC decoupling local to pin 28 of the EDIP module - a 0.1 uF ceramic in parallel with a 10 uF tantalum placed within 5 mm of the pin is recommended. The automatic write-protection circuit monitors VCC for an out-of-tolerance condition, so a noisy or slowly-rising VCC rail can cause spurious write-protect events; ensure the upstream 5 V regulator has clean transient response and adequate bulk capacitance. The four NC pins (29-32) on the AB-grade module should be left floating per the datasheet.
Informasi Konformitas
The DS1249AB-70IND EDIP module contains an internal primary lithium cell and is therefore generally not RoHS compliant under the lead exemption rules for primary batteries; consult the manufacturer datasheet for the latest hazardous-materials shipping classification. REACH, AEC-Q100, lead-free, halogen-free, and conflict-minerals status were not present in the Verified Web Data and are marked unknown.
