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Infineon Technologies STK12C68-5C55M
- Part No.:
- STK12C68-5C55M
- Manufacturer:
- Infineon Technologies
- Category:
- Memory
- Package:
- 28-CDIP (0.300", 7.62mm)
- Datasheet:
-
STK12C68-5C55M.pdf
- Description:
- IC NVSRAM 64KBIT PARALLEL 28CDIP
- Quantity:
- Payment:
- Shipping:
Inventory:2,516
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Product details
Overview
STK12C68-5C55M from Cypress Semiconductor is a 64 Kbit (8K × 8) nonvolatile static RAM with QuantumTrap™ technology, delivering 55 ns access time, single 5V±10% operation, and AutoStore™ functionality triggered by power loss using an external 68 µF capacitor. It serves as a drop-in SRAM replacement in mission-critical systems requiring guaranteed data retention during unexpected power failure - e.g., industrial PLCs, avionics black boxes, and medical device configuration storage.
For engineers reviewing the STK12C68-5C55M datasheet, STK12C68-5C55M pinout, STK12C68-5C55M application, or STK12C68-5C55M equivalent, key selection criteria include VCAP capacitor sizing (68–220 µF), HSB-driven hardware store timing (tDELAY), STORE cycle endurance (1 million cycles), and compatibility with military temperature range (−55°C to +125°C).
Technical Context
The STK12C68-5C55M integrates parallel SRAM and QuantumTrap nonvolatile cells per memory location, enabling simultaneous STORE/RECALL across all 8,192 bytes. Its dual-mode control supports software-initiated STORE via six-address CE-read sequence (0x0000 → 0x0F0F) and hardware-initiated STORE via HSB pin assertion.
AutoStore activation relies on internal charge pump driving VCAP to 5V during normal operation; when VCC drops below VSWITCH (~3.6V), the chip isolates VCAP and executes STORE using stored energy. During STORE or RECALL, SRAM read/write is inhibited, and HSB is driven low open-drain to signal busy status.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 64 Kbit (8K × 8), directly replaceable for standard 28-pin SRAM sockets without address/data bus redesign. |
| Access Time | 55 ns max, ensuring compatibility with legacy 5V microcontroller buses running ≤18 MHz. |
| Nonvolatile Endurance | 1,000,000 STORE cycles, limiting field replacement frequency in high-write-logging applications. |
| Data Retention | 100 years at +25°C, validated for long-term archival of calibration constants or firmware boot flags. |
| Operating Voltage | 5V ±10% (4.5V–5.5V), compatible with legacy 5V logic rails and eliminating need for voltage translation. |
| Temperature Range | −55°C to +125°C, qualified per MIL-PRF-38535 for aerospace and defense embedded systems. |
| VCAP Capacitor | 68 µF minimum (220 µF max, +20%), defines minimum power-loss hold-up time for reliable STORE completion. |
Pinout & Package
STK12C68-5C55M is supplied in a 28-pin ceramic leadless chip carrier (LCC) package with 300-mil body size and J-lead terminations, suitable for hermetic sealing and high-reliability PCB assembly.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A12 | Address Inputs | 13-bit address bus selecting one of 8,192 SRAM locations; no internal latching - requires stable setup before CE/WE assertion. |
| DQ0–DQ7 | Bidirectional Data I/O | 8-bit multiplexed data path; tri-stated when OE = HIGH or during STORE/RECALL to prevent bus contention. |
| CE (E) | Chip Enable | Active-low enable controlling device selection; required LOW with OE/WE for valid read/write - used in software STORE sequence. |
| WE (W) | Write Enable | Active-low write strobe; must remain HIGH during STORE/RECALL to avoid corruption; pulled up externally at power-up. |
| OE (G) | Output Enable | Active-low output driver control; disables DQ drivers when HIGH, essential for bus sharing in multi-chip systems. |
| HSB | Hardware Store Busy | Open-drain status/output pin: driven LOW during any STORE (Auto/Hardware/Software); initiates STORE when externally pulled LOW. |
| VCAP | AutoStore Capacitor Terminal | Internal charge-pump output; connects to external 68–220 µF capacitor - sole energy source for power-loss STORE operation. |
| VCC | Power Supply | +5V ±10% main supply; disconnected from VCAP internally when VCC < VSWITCH (~3.6V) to trigger AutoStore. |
| VSS | Ground | System ground reference; must be low-impedance connection to minimize noise coupling into sensitive nv cell programming. |
Key Features
| Feature | Design Value |
|---|---|
| AutoStore on Power Loss | Zero-software intervention STORE triggered by VCC drop below VSWITCH, using only external capacitor - eliminates firmware dependency for fail-safe logging. |
| QuantumTrap Nonvolatile Cell | Embedded per-cell nonvolatility enables full-array parallel STORE/RECALL in tSTORE/tRECALL time - no block erase or page management overhead. |
| Three STORE Initiation Modes | Hardware (HSB pin), software (6-address CE-read sequence), and AutoStore provide flexible integration across safety-critical, firmware-controlled, and passive systems. |
| Unlimited RECALL Cycles | Enables repeated cold-boot restoration of configuration without degrading nonvolatile elements - critical for field-upgradable devices. |
| Military Temperature Qualification | Qualified per MIL-PRF-38535 Class K, supporting deployment in uncontrolled environments like engine bays or satellite payloads. |
Applications
| Industrial Control Loggers | Aerospace Flight Recorders |
|---|---|
Use Scenario: Continuous timestamped sensor data logging in programmable logic controllers during mains power interruption. IC Role / Device Role / Timing Role: Nonvolatile SRAM buffer storing last 10 seconds of analog input history prior to brownout. Use Value: Guarantees zero-data-loss logging without battery backup or complex power-fail interrupt handling. | Use Scenario: Storing flight parameter snapshots (altitude, attitude, engine RPM) in aircraft black box recorders. IC Role / Device Role / Timing Role: Primary configuration and transient state memory with 100-year retention for post-crash forensic analysis. Use Value: Eliminates need for EEPROM wear-leveling or flash endurance management in certified DO-178C systems. |
| Medical Diagnostic Calibration Storage | Defense Communications Secure Boot |
Use Scenario: Retaining factory-calibrated ADC offset/gain coefficients and user-adjusted diagnostic thresholds across equipment power cycles. IC Role / Device Role / Timing Role: Tamper-resistant nonvolatile memory holding cryptographic keys and calibration signatures verified at power-on self-test. Use Value: Prevents recalibration drift after unplanned shutdowns while meeting IEC 62304 Class C software safety requirements. | Use Scenario: Storing encrypted boot images and secure boot keys in tactical radios operating in extreme thermal environments. IC Role / Device Role / Timing Role: Trusted execution environment (TEE) root-of-trust memory with −55°C to +125°C operation and anti-tamper STORE inhibit capability. Use Value: Enables secure cold-start without external crypto co-processor or battery-backed SRAM vulnerabilities. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar nonvolatile SRAM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| CY14B108L-SP25XI | 8 Mbit density, 25 ns access, SPI interface, integrated VCAP switch; no HSB pin or AutoStore on power loss. | Requires SPI host controller and firmware-managed STORE; unsuitable for legacy parallel-bus systems. | Select when migrating to higher-density, lower-power SPI-based designs with active firmware control. |
| FM24CL64-G | 64 Kbit, I²C interface, 1 MHz clock, no AutoStore; relies on external power-fail detection circuitry. | Lacks autonomous power-loss response - needs external supervisor IC and GPIO coordination. | Choose for cost-sensitive consumer applications where firmware complexity and external components are acceptable. |
Compared with CY14B108L-SP25XI and FM24CL64-G, the STK12C68-5C55M uniquely delivers autonomous 55 ns parallel SRAM replacement with hardware-triggered STORE, military temp rating, and zero-external-component AutoStore - making it irreplaceable in legacy avionics and industrial control retrofits.
Availability
STK12C68-5C55M is available at Aetrix Electronics and suitable for industrial control loggers, aerospace flight recorders, and medical diagnostic calibration storage requiring stable component supply across extended product lifecycles.
Supply support for STK12C68-5C55M 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) is a U.S.-based semiconductor company specializing in high-reliability memory, PSoC, and USB solutions for industrial, automotive, and aerospace markets.
The STK12C68-5C55M belongs to Cypress's QuantumTrap nvSRAM product line, engineered specifically for fail-safe data retention in systems where battery backup is prohibited, unreliable, or subject to regulatory restrictions.
FAQ
What is the minimum VCAP capacitance required for reliable AutoStore operation?
The STK12C68-5C55M requires a minimum 68 µF tantalum or polymer capacitor on VCAP, rated ≥6V and +20% tolerance. This value ensures sufficient energy to complete the tSTORE cycle (≤10 ms) when VCC drops below VSWITCH (~3.6V). Using less capacitance risks incomplete STORE and data loss; values up to 220 µF are supported for extended hold-up time.
Can STK12C68-5C55M operate without the VCAP capacitor?
No - VCAP is mandatory for AutoStore functionality. If VCAP is omitted or shorted, AutoStore fails silently during power loss. However, the device can still perform software or HSB-initiated STORE operations if VCAP is replaced with a regulated +5V supply (AutoStore Inhibit mode), but this disables autonomous power-loss response and requires firmware coordination.
How does the STK12C68-5C55M prevent unintended STORE during brown-out conditions?
The device monitors VCC against VSWITCH (~3.6V). When VCC falls below this threshold, all externally initiated STORE and write operations are automatically inhibited. Additionally, the HSB pin must be actively driven LOW (not just floating) to initiate hardware STORE - preventing noise-induced false triggers. Internal circuitry also holds WE high at power-up to block inadvertent writes.
Is the STK12C68-5C55M pin-compatible with standard 28-pin SRAMs like the HM62256?
Yes - it uses identical 28-pin LCC pinout and electrical signaling (TTL/CMOS-compatible inputs, 3-state outputs), allowing direct replacement of HM62256 and similar 8K×8 SRAMs. However, VCAP must be added externally, and HSB should be left unconnected or pulled up if unused; OE/CE/WE timing margins must meet tACE/tDOE specs per the datasheet.
STK12C68-5C55M Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Infineon Technologies
- Series:
- -
- Package/Case:
- 28-CDIP (0.300", 7.62mm)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Memory Type:
- Non-Volatile
- Memory Format:
- NVSRAM
- Technology:
- NVSRAM (Non-Volatile SRAM)
- Memory Size:
- 64Kbit
- Memory Organization:
- 8K x 8
- Memory Interface:
- Parallel
- Clock Frequency:
- -
- Write Cycle Time - Word, Page:
- 35ns
- Access Time:
- 35 ns
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -55°C ~ 125°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 28-CDIP
STK12C68-5C55M FAQ
1.How can I place an order for STK12C68-5C55M through Aetrix?
Please submit a Request for Quotation (RFQ) for STK12C68-5C55M on Aetrix. Our sales agent will provide a competitive quotation and guide you through the order confirmation once you accept the terms.
2.Are the price and stock information for STK12C68-5C55M reliable?
The price and inventory of STK12C68-5C55M are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for STK12C68-5C55M is usually 5 days.
3.What payment methods are accepted for STK12C68-5C55M?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for STK12C68-5C55M transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for STK12C68-5C55M?
STK12C68-5C55M orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your STK12C68-5C55M order is processed, you will receive an email with the shipment details and tracking number.
Note: Tracking information may take up to 24 hours to appear. Express delivery typically takes 3–5 business days.
5.How can I obtain technical support or documentation for STK12C68-5C55M?
For technical support, including STK12C68-5C55M datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your STK12C68-5C55M requirements.
6.How does Aetrix verify that STK12C68-5C55M is sourced from the original manufacturer or authorized distributors?
All STK12C68-5C55M products on Aetrix are procured from qualified distributors and authorized channels. Our dedicated quality assurance team conducts strict verification, including traceability checks and, if necessary, third-party testing. This ensures that STK12C68-5C55M meets industry standards.
7.What is the process for return or replacement of STK12C68-5C55M?
All STK12C68-5C55M units undergo pre-shipment inspection (PSI). If there is an issue with STK12C68-5C55M, returns or replacements are accepted under the following conditions:
1.Quantity discrepancies, incorrect items, or visible external defects (such as breakage or corrosion), acknowledged by Aetrix.
2.The issue is reported within 90 days of delivery.
3.The STK12C68-5C55M part is unused and in its original packaging.
Return procedure for STK12C68-5C55M:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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