Texas Instruments BQ4011YMA-150N

Overview

BQ4011YMA-150N from Texas Instruments is a 32 k × 8 nonvolatile SRAM with integrated lithium backup, 150 ns access time, industrial temperature range (–40°C to +85°C), and 5 V ±10% operation. It functions as a standard SRAM during normal power and automatically preserves data during power loss in embedded instrumentation and industrial control systems.

For engineers reviewing the BQ4011YMA-150N datasheet, BQ4011YMA-150N pinout, BQ4011YMA-150N application, or BQ4011YMA-150N equivalent, key selection considerations include VPFD threshold (4.37 V), write-protection timing (tWPT ≤ 150 µs), data retention duration (≥10 years), and DIP-28 compatibility with legacy 256-kb SRAM footprints.

Technical Context

The BQ4011YMA-150N integrates a CMOS SRAM core, power-fail detection circuitry, and a sealed lithium coin cell within a single 28-pin DIP module. Its VPFD threshold is fixed at 4.37 V (typical) for 5-V systems with ±10% tolerance, triggering automatic write-protection and battery switchover when VCC falls below this level.

During power-up, the device enforces a 85 ms chip-enable recovery time (tCER) before enabling writes, ensuring processor stabilization. The internal isolation switch disconnects the lithium cell until first power application, limiting self-discharge to ~0.5% per year prior to use.

Key Specifications

Pinout & Package

28-pin plastic dual-in-line package (DIP), MA package type, 0.6-inch width, through-hole mounting. Pin 1 is A14 (top-left corner, notch up); pin 14 is VSS (ground); pin 28 is VCC (5 V supply).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar nonvolatile SRAM applications.

Compared with STK15C88-150I, BQ4011YMA-150N reduces BOM count and layout complexity by integrating battery and control logic; compared with BQ4013YMA-150N, it offers identical functionality at lower cost and shorter lead time for commercial-industrial use.

Availability

BQ4011YMA-150N is available at Aetrix Electronics and suitable for industrial data loggers, programmable logic controllers (PLCs), and smart metering systems requiring stable component supply and guaranteed long-term data retention.

Supply support for BQ4011YMA-150N includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Texas Instruments is a global semiconductor company headquartered in Dallas, Texas, specializing in analog, embedded processing, and power management technologies since 1930.

The BQ4011YMA-150N belongs to TI's bq40xx nonvolatile SRAM product line, designed specifically to replace battery-backed static RAM subsystems in industrial and instrumentation applications where data integrity during power loss is mission-critical.

FAQ

What is the power-fail detect (VPFD) threshold for BQ4011YMA-150N?

The BQ4011YMA-150N has a fixed VPFD threshold of 4.37 V (typical), optimized for 5-V systems with ±10% supply tolerance. This value is factory-trimmed and not user-adjustable. When VCC falls below this level, the device immediately initiates write-protection and switches to lithium backup. The BQ4011YMA-150N datasheet specifies VPFD min/max as 4.30 V to 4.50 V across temperature and process variation.

Does BQ4011YMA-150N require external components to operate?

No, the BQ4011YMA-150N is a fully self-contained module requiring only VCC, VSS, and standard parallel bus connections. It integrates the SRAM core, lithium coin cell, power-fail detection circuitry, and backup switchover logic into a single 28-pin DIP package. No external capacitors, diodes, or controllers are needed - unlike discrete SRAM + battery solutions such as the STK15C88 series.

How long does BQ4011YMA-150N retain data without power?

The BQ4011YMA-150N guarantees ≥10 years of data retention in the absence of VCC at TA = 25°C, based on accelerated life testing of the integrated lithium cell and ultra-low standby current (≤2 µA). Retention time decreases at elevated temperatures; the datasheet specifies 10-year minimum under typical industrial storage conditions, with the lithium cell electrically isolated until first power application to minimize shelf-life discharge.

Is BQ4011YMA-150N pin-compatible with standard 256-kb SRAMs?

Yes, the BQ4011YMA-150N uses an industry-standard 28-pin DIP (MA package) footprint matching JEDEC 256-kb SRAMs such as the AS6C4008 or IS61LV25616. All address, data, and control signals (A0–A14, DQ0–DQ7, CE, OE, WE, VCC, VSS) align directly. No PCB modification is required for drop-in replacement in existing designs using 32 k × 8 parallel SRAM layouts.

What happens to BQ4011YMA-150N outputs during power failure?

When VCC falls below VPFD, the BQ4011YMA-150N places all DQ0–DQ7 pins in high-impedance state and ignores CE, OE, and WE inputs (treated as "don't care"). This prevents bus contention and unintended writes. Outputs remain in high-Z until VCC rises above VPFD and tCER (85 ms max) expires, after which normal read/write operation resumes. The BQ4011YMA-150N truth table explicitly defines this behavior under "Power" mode.