Simtek 5962-9459901MXA

Overview

5962-9459901MXA from Cypress Semiconductor is a military-grade 64 Kbit (8 K × 8) nonvolatile SRAM with QuantumTrap™ technology, supporting 35 ns access time, AutoStore™ on power-down, and software/hardware-controlled STORE/RECALL operations. It operates at single 5 V ±10%, features 1,000,000 STORE cycles and 100-year data retention, and is used in avionics black boxes requiring deterministic nonvolatile write-back during uncontrolled power loss.

For engineers reviewing the 5962-9459901MXA datasheet, 5962-9459901MXA pinout, 5962-9459901MXA application, or 5962-9459901MXA equivalent, key selection criteria include VCAP capacitor sizing (68 µF), HSB-driven hardware STORE timing (tDELAY), AutoStore inhibit configuration, and compatibility with MIL-PRF-38535 Class B screening requirements.

Technical Context

The device integrates parallel SRAM and QuantumTrap nonvolatile cells per bit, enabling simultaneous STORE/RECALL across all 8,192 bytes. STORE is triggered by power collapse (VCC < VSWITCH ≈ 3.6 V), HSB assertion, or six-cycle software address sequence (0x0000→0x1555→0x0AAA→0x1FFF→0x10F0→0x0F0F); RECALL occurs automatically at power-up or via software sequence ending at 0x0F0E.

During STORE, SRAM reads/writes are inhibited for tSTORE (max 10 ms); during RECALL, SRAM is cleared then loaded, taking tRECALL (max 10 ms). The HSB pin serves dual role: open-drain busy indicator (driven LOW during STORE) and active-LOW STORE trigger, with internal weak pull-up enabling optional disconnection.

Key Specifications

Pinout & Package

Package: 28-pin Ceramic Dual In-line Package (CDIP), 300 mil width, hermetically sealed, MIL-PRF-38535 compliant.

Key Features

Applications

Equivalent & Alternatives

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

Compared with AS4C16M16SA-7TCN and FM24CL64-G, 5962-9459901MXA uniquely delivers deterministic sub-10-ms STORE on uncontrolled power loss using only a passive capacitor-no external controller, clock, or firmware intervention required.

Availability

5962-9459901MXA is available at Aetrix Electronics and suitable for flight-critical data logging, secure key management, and radiation-hardened satellite payloads requiring stable component supply under MIL-PRF-38535 sourcing constraints.

Supply support for 5962-9459901MXA 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

Cypress Semiconductor (now part of Infineon Technologies) designs high-reliability memory and programmable solutions for automotive, industrial, and aerospace markets.

The STK12C68 nvSRAM product line targets applications demanding guaranteed nonvolatile storage without batteries-specifically avionics, defense electronics, and industrial control systems with uncontrolled power environments.

FAQ

What is the minimum VCAP capacitance required for reliable AutoStore operation?

The datasheet specifies a minimum of 68 µF ±20% at 6 V rating. Using less capacitance risks incomplete STORE execution if VCC drops faster than 20 µs/volt, as insufficient energy remains to complete the 10 ms tSTORE cycle. Derating to 100 µF is recommended for systems with high ESR PCB traces or wide temperature swings.

Can the HSB pin be left unconnected in systems that only use AutoStore or software STORE?

Yes-the HSB pin has an internal weak pull-up resistor and is fully optional. Leaving it unconnected disables hardware STORE initiation but does not affect AutoStore on power-down or software STORE/RECALL sequences. No external pull-up is required unless the system monitors HSB for STORE progress indication.

How does the device prevent STORE corruption during brownout conditions?

The device inhibits all STORE operations when VCC falls below VSWITCH (~3.6 V) *unless* a valid STORE is already in progress. Additionally, AutoStore and HSB STORE are suppressed unless at least one SRAM write occurred since the last STORE or RECALL-ensuring only meaningful data is preserved during marginal power conditions.

Is the 5962-9459901MXA compatible with commercial-grade STK12C68-5 designs?

Yes-pinout, timing, and command sequences are identical. The 5962-9459901MXA adds MIL-PRF-38535 Class B screening, extended temperature testing (−55°C to +125°C), and enhanced lot traceability. Commercial STK12C68-5 layouts require no changes, but VCAP capacitor derating and board-level conformal coating are recommended for full military compliance.