Texas Instruments BQ4013YMA-85N

Overview

BQ4013YMA-85N from Texas Instruments is a 128 k × 8 nonvolatile SRAM with integrated lithium backup, designed for industrial temperature operation (–40°C to +85°C), 5-V ±10% supply tolerance, and 85 ns access time. It provides automatic write-protection during power-up/down, data retention ≥10 years without external power, and industry-standard 32-pin DIP pinout - used in embedded controllers requiring persistent memory across brownouts.

For engineers reviewing the BQ4013YMA-85N datasheet, BQ4013YMA-85N pinout, BQ4013YMA-85N application, or BQ4013YMA-85N equivalent, key selection criteria include VPFD = 4.37 V (for 10% 5-V systems), tCER = 85 ms (3.3-V mode) / 120 ms (5-V mode), and MA-package compatibility with legacy 1-Mb SRAM footprints.

Technical Context

The BQ4013YMA-85N integrates a CMOS SRAM core, power-fail detection circuitry, and a sealed lithium coin cell within a single 32-pin DIP module. Its control logic monitors VCC continuously and triggers automatic write-protection when voltage falls below VPFD = 4.37 V (typ), switching seamlessly to internal backup power before VCC drops to VSO ≈ 3 V.

During valid power, it behaves identically to a standard 128 k × 8 asynchronous SRAM with CE/OE/WE control and full address/data bus (A0–A16, DQ0–DQ7). The internal isolation switch disconnects the lithium cell until first VCC application, limiting self-discharge to ~0.5%/year prior to activation.

Key Specifications

Pinout & Package

32-pin dual in-line package (DIP), MA package type, through-hole mounting. Pin 1 is bottom-left corner (pin 1 marker adjacent to notch on top edge).

Key Features

Applications

Equivalent & Alternatives

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

Compared with STK15C88-85I and AS6C1008-85ZIN, the BQ4013YMA-85N delivers true single-component nonvolatility with guaranteed 10-year retention and hardware-enforced write-protection - reducing design complexity, test coverage, and field failure risk in industrial and medical applications.

Availability

BQ4013YMA-85N is available at Aetrix Electronics and suitable for industrial control systems, medical instrumentation, avionics data recorders, and telecom infrastructure requiring stable component supply across extended product lifecycles.

Supply support for BQ4013YMA-85N 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 leader specializing in analog, embedded processing, and power management technologies, with over 50 years of innovation in reliable, high-performance components.

The BQ4013YMA-85N belongs to TI's legacy nonvolatile SRAM product line, engineered specifically for mission-critical data retention in industrial and medical equipment where firmware-based backup solutions are insufficient or prohibited.

FAQ

What is the operating temperature range for the BQ4013YMA-85N?

The BQ4013YMA-85N is rated for industrial temperature operation from –40°C to +85°C. This specification is validated per TI's recommended operating conditions and applies to all electrical parameters including access time, VPFD threshold, and standby current. The device maintains full functionality across this range without derating, making it suitable for deployment in harsh environments such as factory floors or vehicle-mounted systems.

Does the BQ4013YMA-85N require external circuitry to function as nonvolatile memory?

No, the BQ4013YMA-85N requires no external circuitry to deliver nonvolatile operation. Its integrated lithium cell, power-fail detection logic, and automatic write-protection circuitry are fully self-contained within the MA-package DIP module. Engineers can replace standard SRAMs on existing PCBs without modifying support components - provided the 32-pin footprint and 5-V supply are maintained.

How does the BQ4013YMA-85N handle power-up sequencing and stabilization?

Upon power-up, the BQ4013YMA-85N enforces a chip-enable recovery time (tCER) of up to 120 ms in 5-V systems to allow processor stabilization before permitting writes. During this window, the SRAM remains write-protected even if CE is asserted. This prevents spurious writes caused by undervoltage or clock instability during boot - a behavior confirmed in TI's SLUS121A datasheet Figure 10 timing diagrams.

Is the lithium cell in the BQ4013YMA-85N replaceable or serviceable?

No, the lithium cell in the BQ4013YMA-85N is permanently sealed inside the DIP module and not user-replaceable. TI specifies ≥10 years of data retention under normal conditions after first power application. The cell is electrically isolated until initial VCC application, limiting pre-activation self-discharge to ~0.5% per year - a design feature confirmed in the Functional Description section of the datasheet.

What is the significance of the "N" suffix in BQ4013YMA-85N?

The "N" suffix in BQ4013YMA-85N denotes industrial temperature grade (–40°C to +85°C), distinguishing it from commercial-grade variants like BQ4013YMA-85 (0°C to +70°C). This suffix is defined in TI's official part numbering guide and correlates directly to the TOPR specification in the Recommended Operating Conditions table - not to packaging, RoHS status, or pin count.