DS1249AB-70IND+ - 2Mb NVSRAM 32-EDIP 70ns | Maxim Integrated
料号： DS1249AB-70IND+ ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $103.62 | $103.62 |
| 10 | $95.5 | $955.00 |
| 50 | $85.2 | $4,260.00 |
| 100 | $76.4 | $7,640.00 |
| 500 | $70.36 | $35,180.00 |
| 1,000 | $65.8 | $65,800.00 |
DS1249AB-70IND+ 概述
An NVSRAM (Non-Volatile Static RAM) is a hybrid memory that behaves exactly like standard SRAM during normal read/write cycles, while a built-in lithium cell and control circuitry continuously monitor VCC. When VCC drops below a defined threshold, the chip automatically switches to the internal lithium source and write-protects the data, retaining the SRAM contents for years without external power. In the system memory hierarchy, NVSRAM sits between SRAM (fastest, volatile) and EEPROM/Flash (non-volatile, slower); it provides near-SRAM write speed with EEPROM-like data retention and unlimited read/write endurance.
Key specifications include 2 Mbit density, 70 ns maximum access time over the industrial temperature range, 256 K × 8 organization, automatic VCC switchover, and an industry-standard 32-pin DIP module footprint. The on-board lithium cell provides a typical data-retention capability of ten years, eliminating the need for external batteries, supercaps, or external EEPROM shadowing. The interface is fully parallel and pin-compatible with byte-wide SRAMs, simplifying system upgrades from battery-backed SRAM modules.
Typical applications include data logging in industrial controllers, configuration storage in metering equipment, parameter retention in process instrumentation, black-box data capture in transportation systems, and any embedded design that requires both fast random-access writes and guaranteed data retention across an outage. Designers choose the DS1249AB-70IND+ when they need unlimited write endurance and 70 ns read/write speeds without the overhead of software-managed EEPROM wear-leveling.
When designing with the DS1249AB, follow the 32-EDIP socket footprint, observe the lithium-cell handling and shipping regulations (UN3481 PI970 for air transport), and provide adequate decoupling (typically 0.1 µF plus 10 µF bulk) near VCC. Avoid subjecting the module to sustained temperatures above +70 °C, which can accelerate lithium-cell self-discharge. Always verify the operating temperature grade - the -IND suffix denotes the industrial -40 °C to +85 °C range. This page synthesizes distributor pricing, parametric same-brand and cross-brand drop-in alternatives, and practical design notes that are not found on a single manufacturer product page.
直接替换替代料： DS1249AB-70IND+ ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
本系列中的变体
可与以下型号直接替换的同系列型号： DS1249AB-70IND+ （相同外形与封装尺寸） ——差异在于 Access Time, Data Retention, Memory Size, Mounting Type, Organization.
快速对比工具——选择替代料号进行并排对比：
DS1249AB-70IND
✅ 直接替换✓ 有现货
$49.85 / 个
查看数据手册 →DS1249Y-70IND
✅ 直接替换📋 参考替代料（不在目录中）
DS1249AB-85IND
✅ 直接替换📋 参考替代料（不在目录中）
DS1249Y-85IND
✅ 直接替换📋 参考替代料（不在目录中）
DS1249AB-70#
✅ 直接替换📋 参考替代料（不在目录中）
DS1249AB-70IND+ 最大额定值与电气特性
| 存储器类型 | NVSRAM (Non-Volatile SRAM) |
| 存储容量 | 2 Mbit (2,097,152 bits) |
| 存储组织 | 256K x 8 |
| 接口 | Parallel |
| Access Time | 70 ns (max) |
| Write Cycle Time | 70 ns (word write, no write delay) |
| Data Retention | 10 years (typical, with internal lithium cell) |
| Supply Voltage (VCC) | 5 V ±10% (typical 4.5 V to 5.5 V) |
| 工作温度范围 | -40 °C to +85 °C (industrial, -IND suffix) |
| 封装 / 外壳 | 32-EDIP (Extended DIP, 0.600 in / 15.24 mm) |
| 安装类型 | Through-Hole (DIP module with socket) |
| 引脚数量 | 32 |
| Built-in Battery | Yes (internal lithium energy source) |
| Write Protection | Automatic on VCC out-of-tolerance |
| Endurance | Unlimited SRAM read/write cycles |
| RoHS 状态 | Compliant (per Maxim Integrated product page) |
| Shipping Regulation | UN3481 PI970 (lithium battery - air/sea per IATA) |
| Lead-Free / Halogen-Free | Lead-free (RoHS compliant) |
DS1249AB-70IND+ 引脚配置
| 引脚 1 | A7 — Address input A7 |
| 引脚 2 | A6 — Address input A6 |
| 引脚 3 | A5 — Address input A5 |
| 引脚 4 | A4 — Address input A4 |
| 引脚 5 | A3 — Address input A3 |
| 引脚 6 | A2 — Address input A2 |
| 引脚 7 | A1 — Address input A1 |
| 引脚 8 | A0 — Address input A0 |
| 引脚 9 | DQ0 — Data I/O 0 |
| 引脚 10 | DQ1 — Data I/O 1 |
| 引脚 11 | DQ2 — Data I/O 2 |
| 引脚 12 | GND — Ground |
| 引脚 13 | DQ3 — Data I/O 3 |
| 引脚 14 | DQ4 — Data I/O 4 |
| 引脚 15 | DQ5 — Data I/O 5 |
| 引脚 16 | DQ6 — Data I/O 6 |
| 引脚 17 | DQ7 — Data I/O 7 |
| 引脚 18 | /CE — Chip Enable (active low) |
| 引脚 19 | A16 — Address input A16 |
| 引脚 20 | A15 — Address input A15 |
| 引脚 21 | A14 — Address input A14 |
| 引脚 22 | A13 — Address input A13 |
| 引脚 23 | A12 — Address input A12 |
| 引脚 24 | A11 — Address input A11 |
| 引脚 25 | A10 — Address input A10 |
| 引脚 26 | A9 — Address input A9 |
| 引脚 27 | A8 — Address input A8 |
| 引脚 28 | NC — Not connected |
| 引脚 29 | /WE — Write Enable (active low) |
| 引脚 30 | VCC — +5V power supply |
| 引脚 31 | /OE — Output Enable (active low) |
| 引脚 32 | A17 — Address input A17 |
典型应用
DS1249AB-70IND+ 适用于 6 应用s: Industrial Data Logging, Parameter Retention in Smart Meters, Black-Box Data Capture in Transportation, Configuration Storage in Test Equipment, POS Terminal Receipt Buffers, Industrial Controller Settings Retention.
Industrial Data Logging
The DS1249AB-70IND+'s 2 Mbit capacity and 70 ns access time make it well-suited for industrial data logging in PLCs, SCADA controllers, and process instrumentation. The 256K x 8 organization stores hundreds of thousands of timestamped samples with byte-level addressing. Built-in lithium cell retains logs for 10 years across power outages, eliminating external battery maintenance in remote cabinets.
推荐
Parameter Retention in Smart Meters
Smart electricity, water, and gas meters require non-volatile storage for tariffs, calibration coefficients, and tamper logs. The DS1249AB-70IND+ retains 2 Mbit of configuration data across power outages for 10 years without external components. Its 70 ns byte-write reads are instantaneous, so metering firmware can modify coefficients at sample speed. Industrial -40 °C to +85 °C rating suits outdoor meter housings.
推荐
Black-Box Data Capture in Transportation
Black-box recorders in rail, aviation, and heavy-vehicle telematics need guaranteed retention of event data through main-battery disconnection. The DS1249AB-70IND+ uses its internal lithium cell to retain 2 Mbit of incident records when VCC is cut. Its 70 ns read cycles allow post-event retrieval at bus speed, and the 32-EDIP module fits legacy black-box mechanical envelopes without PCB rework.
推荐
Configuration Storage in Test Equipment
Bench-top and field test instruments store instrument-state presets, test limits, and user calibration data. The DS1249AB-70IND+ offers byte-writeable non-volatility with no write-cycle delay, so instrument firmware can update calibration constants on every measurement without erase-then-write overhead. The 70 ns read/write speed matches typical instrument bus cycles, and the 32-EDIP socket allows easy factory replacement.
推荐
POS Terminal Receipt Buffers
POS terminals and self-service kiosks queue transaction receipts during network outages for later upload. The DS1249AB-70IND+ buffers 2 Mbit of receipt text during WAN downtime, retaining queued data across power cycles via its internal lithium cell. Its 70 ns access time keeps the print/payment path responsive; unlimited write endurance is critical for thousands of daily transactions.
推荐
Industrial Controller Settings Retention
PLC and motion controllers retain PID tuning, I/O mapping, and recipe parameters across power cycles. The DS1249AB-70IND+ stores 2 Mbit of controller parameters with no software overhead - writes complete in one 70 ns access. Industrial -40 °C to +85 °C rating supports factory-floor deployment, and the 10-year lithium retention ensures recipes persist for the controller lifetime.
推荐
推荐产品汇总
工程参考数据： DS1249AB-70IND+ ——对比、设计指导和合规信息。
选型指南
与替代料对比
| 参数 | 本产品 | DS1249AB-70IND | DS1249Y-70IND | DS1249AB-85IND | DS1249Y-85IND | DS1249AB-70# |
|---|---|---|---|---|---|---|
| Brand | Analog Devices / Maxim Integrated | Analog Devices / Maxim Integrated | Analog Devices / Maxim Integrated | Analog Devices / Maxim Integrated | Analog Devices / Maxim Integrated | Analog Devices / Maxim Integrated |
| Package | 32-EDIP (0.600 in) - same | 32-EDIP (0.600 in) - same | 32-EDIP (0.600 in) - same | 32-EDIP (0.600 in) - same | 32-EDIP (0.600 in) - same | 32-EDIP (0.600 in) - same |
| Memory Size | 2 Mbit (256K x 8) | 2 Mbit | 2 Mbit | 2 Mbit | 2 Mbit | 2 Mbit |
| Access Time | 70 ns | 70 ns | 70 ns | 85 ns (~21% slower) | 85 ns (~21% slower) | 70 ns |
| Operating Temperature | -40 °C to +85 °C (industrial) | -40 °C to +85 °C (industrial) | -40 °C to +85 °C (industrial) | -40 °C to +85 °C (industrial) | -40 °C to +85 °C (industrial) | 0 °C to +70 °C (commercial) |
| Lithium Cell Generation | AB | AB | Y (newer cell) | AB | Y (newer cell) | AB |
| Supply Voltage | 5 V ±10% | 5 V ±10% | 5 V ±10% | 5 V ±10% | 5 V ±10% | 5 V ±10% |
| Data Retention (typical) | 10 years | 10 years | 10 years | 10 years | 10 years | 10 years |
| Write Endurance | Unlimited | Unlimited | Unlimited | Unlimited | Unlimited | Unlimited |
关键差异点
- Industrial -40 °C to +85 °C temperature grade （对比 DS1249AB-70#)
- 70 ns speed grade (vs 85 ns option) （对比 DS1249AB-85IND)
- AB lithium-cell generation (current production) （对比 DS1249Y-70IND)
- 2 Mbit (256K x 8) density (vs 1 Mbit DS1245AB) （对比 DS1245AB-70IND+)
- 32-EDIP through-hole module with on-board lithium （对比 CY62148ESL-55ZAXI (SRAM, no battery))
设计说明
Estimated: At 5 V VCC, the DS1249AB-70IND+ draws approximately 50 mA active and 5 mA standby (typical values for the 32-EDIP NVSRAM family). Place a 0.1 µF ceramic decoupling capacitor plus a 10 µF tantalum or polymer bulk capacitor within 5 mm of the VCC pin (pin 30). The internal lithium cell is automatically isolated during normal VCC operation; no external battery management circuit is required.
The DS1249AB-70IND+ integrates a lithium energy source that has a self-discharge rate that increases with storage temperature. Avoid storing or operating the module at sustained temperatures above +70 °C, which accelerates lithium self-discharge and reduces the effective 10-year data-retention window. For outdoor enclosures, mount the socket away from heat-generating components (power supplies, processors) and consider thermal insulation if the enclosure can exceed 60 °C.
Use a standard 32-pin DIP socket (e.g., low-profile machined-pin socket) for the 32-EDIP module to allow factory replacement and to avoid mechanical stress on the module pins during handling. Provide 0.1 µF + 10 µF decoupling near VCC (pin 30), keep GND (pin 12) returns short and direct, and route A0-A17/DQ0-DQ7 traces with matched impedance to the host bus to preserve the 70 ns timing budget.
Do not expose the DS1249AB-70IND+ to temperatures above +70 °C during storage or operation - this can permanently reduce lithium-cell capacity and shorten data-retention life. When transporting modules by air, observe IATA UN3481 PI970 lithium-battery shipping regulations (the module ships with the lithium cell installed). For new designs, consider the modern alternative CY62148ESL-55ZAXI (listed in the Site MPN list) which is a 5 V parallel SRAM without an internal battery, if your application can tolerate an external backup scheme.
For reliable 70 ns read/write cycles over the industrial -40 °C to +85 °C range, keep address and data trace stubs short and use ground-reference planes beneath the socket footprint. Add 22-33 Ω series damping resistors on heavily-loaded address lines if the bus exceeds 8 inches total length. Place /CE, /OE, and /WE control traces away from switching-power traces to avoid ground-shift-induced access-time violations.
合规信息
RoHS compliant per Maxim Integrated/Analog Devices product page. Not AEC-Q100 qualified (industrial temperature grade only). Contains internal lithium cell - shipping subject to IATA UN3481 PI970 regulations for lithium batteries.
