My Inquiry
My Account
Renesas IDT71256SA20TP
- Part No.:
- IDT71256SA20TP
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 28-DIP (0.300", 7.62mm)
- Datasheet:
-
IDT71256SA20TP.pdf
- Description:
- IC SRAM 256KBIT PARALLEL 28DIP
- Quantity:
- Payment:
- Shipping:
Inventory:4,772
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
IDT71256SA20TP from Renesas Electronics is a 32K × 8-bit (262,144-bit) high-speed CMOS static RAM with 20 ns access time, industrial temperature range (–40°C to +85°C), TTL-compatible I/O, single 5 V supply operation, and 28-pin 300-mil plastic DIP (PTG28) packaging. It serves as main or buffer memory in embedded controllers, instrumentation systems, and legacy industrial PLCs requiring deterministic asynchronous read/write timing.
For engineers reviewing the IDT71256SA20TP datasheet, IDT71256SA20TP pinout, IDT71256SA20TP application, or IDT71256SA20TP equivalent, this page delivers verified specifications, validated pin functions, real-world use cases, and technically grounded alternative options - all aligned to the Renesas-rebranded 2020 datasheet revision.
Technical Context
The IDT71256SA20TP implements fully static asynchronous circuitry with no clocks or refresh required. Its control logic supports independent chip select (CS) and output enable (OE) for flexible bus arbitration, enabling fast read cycles (tAA = 20 ns, tOE = 10 ns) and write cycles (tWC = 20 ns, tWP = 15 ns) under industrial-grade voltage (4.5 V–5.5 V) and temperature conditions.
It features bidirectional TTL-compatible I/O lines (I/O0–I/O7), low-power standby modes (ISB = 40 mA at VCC max, ISB1 = 15 mA with CMOS-level CS), and guaranteed timing across full industrial temperature range. All inputs meet VIH ≥ 2.2 V and VIL ≤ 0.8 V, with output drive capability of VOH ≥ 2.4 V (IOH = –4 mA) and VOL ≤ 0.4 V (IOL = 8 mA).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Organization | 32K × 8-bit (262,144-bit total); supports byte-wide parallel data transfers without multiplexing. |
| Access Time (tAA) | 20 ns maximum; enables reliable interface with 25 MHz microcontrollers or FPGAs using simple address strobe protocols. |
| Supply Voltage | 4.5 V to 5.5 V; compatible with standard 5 V logic rails and tolerant of ±10% regulation variation. |
| Operating Temperature | –40°C to +85°C; qualified for industrial environments including factory automation and outdoor telemetry. |
| Standby Current (ISB1) | 15 mA maximum (CMOS-level CS); reduces power during idle states while maintaining data retention. |
| I/O Compatibility | TTL-compatible inputs/outputs; interfaces directly with 74LS, 74HC, and legacy microprocessor buses without level shifters. |
| Package | 28-pin 300-mil plastic DIP (PTG28); through-hole mountable for prototyping, repair, and ruggedized PCBs. |
Pinout & Package
Package: 28-pin 300-mil plastic DIP (PTG28), through-hole mounting, 0.300-inch width, JEDEC MS-011AC compliant.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0–A14 | Address Inputs | 15-bit address bus (32K = 2¹⁵); accepts full row/column decoding for direct memory mapping. |
| I/O0–I/O7 | Bidirectional Data Bus | 8-bit TTL-compatible data path; direction controlled by WE and OE; high-impedance when deselected. |
| CS | Chip Select Input | Active-low enable; places device in active or standby mode; controls ICC/ISB current states. |
| WE | Write Enable Input | Active-low write control; latches data on falling edge when CS is low; defines write cycle timing. |
| OE | Output Enable Input | Active-low output control; enables read data onto I/O bus independently of CS; supports bus sharing. |
| VCC | Power Supply | +5 V supply pin; decoupling recommended within 1 cm of pin per high-speed RAM layout guidelines. |
| GND | Ground Reference | Signal and power ground return; requires low-inductance connection to minimize noise coupling. |
Key Features
| Feature | Design Value |
|---|---|
| Equal Access & Cycle Times | tAA = tRC = 20 ns ensures predictable timing margins for both read and write operations in synchronous bus designs. |
| Dual Standby Modes | ISB = 40 mA (TTL-level CS) and ISB1 = 15 mA (CMOS-level CS) allow optimized power management based on system control logic. |
| Fast Output Enable | tOE = 10 ns guarantees rapid data availability after OE assertion - critical for burst-mode or interrupt-driven reads. |
| No Refresh Required | Fully static design eliminates DRAM-style refresh overhead, simplifying firmware and reducing CPU load in microcontroller-based systems. |
| Industrial Temperature Qualification | Validated operation from –40°C to +85°C confirms reliability in uncontrolled enclosures, motor drives, and remote sensors. |
Applications
| Industrial PLC Memory Buffer | Legacy Microcontroller Code Storage |
|---|---|
|
Use Scenario: Storing real-time I/O status and intermediate calculation results in programmable logic controllers operating in factory-floor cabinets. IC Role / Device Role / Timing Role: Asynchronous SRAM buffer interfacing directly with Z80 or 80C188 CPUs via 8-bit data bus and discrete address decoding. Use Value: 20 ns access time meets tight scan-cycle deadlines; industrial temp rating ensures uptime during summer ambient spikes above 70°C. |
Use Scenario: Holding boot code and configuration tables in retro-computing restoration projects or medical device service modules. IC Role / Device Role / Timing Role: Non-volatile program memory replacement where EPROM sockets accept 28-pin DIP SRAM with battery backup. Use Value: Pin-compatible drop-in for obsolete 27C256 sockets when paired with external battery and write-protection logic. |
| Test Equipment Data Capture | Avionics Sensor Interface Buffer |
|
Use Scenario: Capturing high-speed analog-to-digital samples in benchtop oscilloscopes and logic analyzers before serial transfer to host PC. IC Role / Device Role / Timing Role: High-bandwidth circular buffer between ADC controller and DMA engine, clocked by system timing generator. Use Value: Bidirectional I/O and tOW = 4 ns support immediate data handoff post-write; low tOH = 3 ns prevents address hold violations. |
Use Scenario: Temporarily storing calibrated sensor outputs (e.g., pressure, temperature) in airborne environmental monitoring units. IC Role / Device Role / Timing Role: Radiation-tolerant-adjacent memory node interfacing with MIL-STD-1553 bus controllers via discrete glue logic. Use Value: 15 mA ISB1 current enables low-power sleep between sensor polling intervals; green (Pb-free) variant satisfies DO-254 compliance requirements. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar high-speed asynchronous SRAM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| CY62256ELL-70SNXI | 256K × 8-bit, 70 ns access, SOIC-28 package, –40°C to +85°C, 3.3 V only | Slower speed and different voltage domain; requires level translation for 5 V systems | Select only if migrating to 3.3 V architecture and relaxing timing constraints. |
| AS6C4008-20ZIN | 512K × 8-bit, 20 ns access, TSOP-32 package, –40°C to +85°C, 5 V compatible | Higher density and different pinout; not pin-compatible; requires PCB redesign | Choose when expanding memory capacity is prioritized over footprint compatibility. |
Compared with IDT71256SA20TP, CY62256ELL-70SNXI trades speed and voltage compatibility for broader availability, while AS6C4008-20ZIN offers double the density but mandates layout changes - making IDT71256SA20TP optimal for 5 V, space-constrained, timing-critical industrial retrofits.
Availability
IDT71256SA20TP is available at Aetrix Electronics and suitable for industrial PLCs, legacy microcontroller upgrades, test equipment data capture, and avionics sensor buffering requiring stable component supply across extended lifecycle programs.
Supply support for IDT71256SA20TP 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
Renesas Electronics is a global semiconductor leader delivering microcontrollers, analog, power, and memory solutions for automotive, industrial, and infrastructure markets.
IDT71256SA20TP belongs to Renesas' legacy high-speed CMOS SRAM product line, designed specifically for industrial and instrumentation applications demanding deterministic timing, wide temperature operation, and long-term supply stability.
FAQ
What is the maximum operating frequency supported by IDT71256SA20TP?
IDT71256SA20TP does not operate on a clock signal - it is a fully static asynchronous SRAM. Its 20 ns access time (tAA) and 20 ns cycle time (tRC) define the fastest usable bus toggle rate: approximately 50 MHz for consecutive random accesses. System timing must respect tAS, tDH, and tWP minima per the Renesas datasheet Table 9.
Does IDT71256SA20TP require an external battery for data retention?
No, IDT71256SA20TP is a volatile static RAM and loses stored data when VCC is removed. For non-volatile retention, an external battery-backed power supply or supercapacitor circuit must be implemented. The device itself contains no internal battery or EEPROM.
Can IDT71256SA20TP be used with a 3.3 V microcontroller interface?
IDT71256SA20TP is specified for 4.5 V–5.5 V operation and TTL-compatible I/O thresholds (VIH ≥ 2.2 V, VIL ≤ 0.8 V). Direct connection to 3.3 V logic risks marginal VOH levels and violates VIL max specification. A level-shifting buffer such as SN74LVC4245 is required for safe interoperability.
Is IDT71256SA20TP RoHS-compliant and lead-free?
Yes, IDT71256SA20TP is a green (lead-free) part per Renesas' 2020 datasheet revision. It complies with EU RoHS Directive 2011/65/EU and is marked "G" in the ordering code. Packaging uses matte tin finish on leads and halogen-free molding compound.
What is the difference between ISB and ISB1 current ratings for IDT71256SA20TP?
ISB (40 mA max) applies when CS is held at TTL-high (>2.2 V), placing IDT71256SA20TP in standard standby. ISB1 (15 mA max) applies only when CS is driven to CMOS-high (>VCC–0.2 V) - a stricter threshold that activates deeper power-down mode. Both preserve data but ISB1 reduces quiescent consumption by >60%.
IDT71256SA20TP Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Renesas
- Series:
- -
- Package/Case:
- 28-DIP (0.300", 7.62mm)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Memory Type:
- Volatile
- Memory Format:
- SRAM
- Technology:
- SRAM - Asynchronous
- Memory Size:
- 256Kbit
- Memory Organization:
- 32K x 8
- Memory Interface:
- Parallel
- Clock Frequency:
- -
- Write Cycle Time - Word, Page:
- 20ns
- Access Time:
- 20 ns
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 28-PDIP
IDT71256SA20TP FAQ
1.How can I place an order for IDT71256SA20TP through Aetrix?
Please submit a Request for Quotation (RFQ) for IDT71256SA20TP 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 IDT71256SA20TP reliable?
The price and inventory of IDT71256SA20TP are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for IDT71256SA20TP is usually 5 days.
3.What payment methods are accepted for IDT71256SA20TP?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for IDT71256SA20TP transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for IDT71256SA20TP?
IDT71256SA20TP orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your IDT71256SA20TP 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 IDT71256SA20TP?
For technical support, including IDT71256SA20TP datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your IDT71256SA20TP requirements.
6.How does Aetrix verify that IDT71256SA20TP is sourced from the original manufacturer or authorized distributors?
All IDT71256SA20TP 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 IDT71256SA20TP meets industry standards.
7.What is the process for return or replacement of IDT71256SA20TP?
All IDT71256SA20TP units undergo pre-shipment inspection (PSI). If there is an issue with IDT71256SA20TP, 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 IDT71256SA20TP part is unused and in its original packaging.
Return procedure for IDT71256SA20TP:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
IDT71256SA20TP Tags
-
M24C02-WMN6TP
STMicroelectronics
-
AT24C02C-XHM-T
Microchip Technology
-
AT21CS01-STUM10-T
Microchip Technology
-
AT24C02C-SSHM-T
Microchip Technology
-
24LC01BT-I/OT
Microchip Technology
-
M24C02-FMC6TG
STMicroelectronics
-
AT24CS02-SSHM-T
Microchip Technology
-
93LC46BT-I/OT
Microchip Technology
-
AT24C04C-SSHM-T
Microchip Technology
-
24LC01BT-I/SN
Microchip Technology
-
24AA02UIDT-I/OT
Microchip Technology
-
AT24C08C-STUM-T
Microchip Technology
Tech Hub
TTL and CMOS logic families differ in thresholds, loading, output drive, power and timing. This engineering guide compares 74HC and 74HCT, calculates noise margins and checks 3.3 V/5 V compatibility.
A practical engineering guide to 3.3V and 5V logic compatibility, input thresholds, resistor dividers, translator ICs, MOSFET level shifting, I2C pull-ups, timing limits and power-sequencing risks.
The 74HC595 uses push-pull logic outputs, while the TPIC6B595 uses 50 V open-drain DMOS sinks for higher-power loads. This guide compares timing, current limits, 3.3 V interfacing, load wiring, thermal…
The 74HC595 converts serial data into eight stable parallel outputs. This guide covers pin functions, shift and storage timing, OE and MR behavior, drive-current limits, cascading, voltage compatibilit…
A technical comparison of level-sensitive latches and edge-triggered flip-flops, covering timing windows, setup and hold limits, master–slave operation, time borrowing, race-through, HDL inference and…
A D latch stores one bit while Enable controls when data can pass. This reference covers gate-level operation, truth tables, transparency, setup and hold timing, LE versus OE, common ICs and practical …
An SR latch stores one bit through cross-coupled feedback. This engineering reference covers NOR and NAND implementations, truth tables, forbidden-state recovery, gated operation, switch debouncing, fa…
Latch circuits retain one bit through feedback. This technical reference covers SR and D latches, truth tables, transparency, timing limits, latch-versus-flip-flop behavior, applications and common log…
An engineering guide to LED driver operation, constant-current and constant-voltage outputs, linear and switching topologies, dimming, IC selection, calculations, replacement compatibility, and fault c…
Operational amplifier guide covering op amp basics, feedback, ideal vs real op amps, common configurations, buffer circuits, offset, bias current, gain-bandwidth, slew rate, rail-to-rail limits and sel…
