My Inquiry
My Account
Renesas 71421LA35J
- Part No.:
- 71421LA35J
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 52-LCC (J-Lead)
- Datasheet:
-
71421LA35J.pdf
- Description:
- IC SRAM 16KBIT PARALLEL 52PLCC
- Quantity:
- Payment:
- Shipping:
Inventory:3,411
Please send an inquiry. Send us your inquiry, and we will respond immediately.
Product details
Overview
IDT71421LA35J from Integrated Device Technology is a 2K × 8 dual-port static RAM configured as a SLAVE device in MASTER/SLAVE memory expansion systems, supporting fully asynchronous port-to-port communication with BUSY input and interrupt flag (INTR) functionality. It delivers 35 ns max read cycle time, 1 mA typical standby current at 5 V, and 2 V battery backup data retention - enabling real-time interprocessor messaging in industrial control backplanes.
For engineers reviewing the IDT71421LA35J datasheet, IDT71421LA35J pinout, IDT71421LA35J application, or IDT71421LA35J equivalent, key selection criteria include SLAVE-side BUSY input timing (tWB = 0 ns), interrupt address mapping (7FFH for INTR set), 52-pin PLCC package compatibility, and industrial temperature support (–40°C to +85°C).
Technical Context
The IDT71421LA35J operates as a SLAVE dual-port SRAM with dedicated BUSY input (BUSYR) that internally inhibits writes during contention, eliminating need for external arbitration logic. Its interrupt function uses fixed mailbox addresses: writing to 7FFH from the left port asserts INTR, while reading 7FFH from the right port clears it.
It supports two independent asynchronous ports (left/right), each with separate CE/OE/R/W controls and 11-bit addressing (A0–A10), enabling concurrent access to any of 2048 × 8-bit locations. The LA suffix confirms low-power design with 2 V data retention capability and 1 µA full-standby current (ISB3) under CMOS-level inputs.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Organization | 2K × 8 (2048 words × 8 bits), fully random-access dual-port architecture |
| Max Read Cycle Time (tRC) | 35 ns - defines minimum interval between successive reads on same port |
| Standby Current (ISB1) | 25 mA max (TTL-level inputs, both ports disabled) - enables low-power idle operation in multi-port systems |
| Data Retention Voltage | 2.0 V - guarantees nonvolatile data hold during main power loss, critical for fail-safe industrial logging |
| Operating Temperature | –40°C to +85°C - qualified for industrial-grade embedded control and automation environments |
| Supply Voltage | 4.5 V to 5.5 V - TTL-compatible single 5 V ±10% rail simplifies power design |
| Interrupt Address | 7FFH - fixed right-port mailbox location for interprocessor signaling via INTR flag |
Pinout & Package
Package: 52-pin Plastic Leaded Chip Carrier (PLCC), body size ≈ 19.05 mm × 19.05 mm × 4.32 mm, lead pitch 0.635 mm, RoHS-compliant.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| A0R–A10R | Right-port address inputs | 11-bit address bus for accessing 2K locations on right port |
| I/O0R–I/O7R | Right-port bidirectional data lines | 8-bit parallel data path; high-impedance when OER = VIH or CER = VIH |
| R/WR | Right-port write enable | Active-low control: drives write cycle when R/WR = VIL and CER = VIL |
| CER | Right-port chip enable | Active-low master enable: disables all right-port functions and reduces current to ISB1/ISB2/ISB4 levels |
| OER | Right-port output enable | Active-low control: enables I/O0R–I/O7R drivers only when CER = VIL |
| BUSYR | Busy input (SLAVE) | External BUSY signal from MASTER (IDT71321); inhibits writes when driven LOW |
| INTR | Interrupt output (right port) | Open-drain flag asserted HIGH when left port writes to 7FFH; requires 270 Ω pull-up |
| VCC | Power supply | Single 5 V ±10% supply; all VCC pins must be connected to decoupled 5 V rail |
| GND | Ground reference | All GND pins must be connected to common system ground plane |
Key Features
| Feature | Design Value |
|---|---|
| SLAVE-specific BUSY input | Enables hardware write-inhibit without external logic when used with IDT71321 MASTER in width-expanded systems |
| Fixed interrupt mailbox (7FFH) | Provides deterministic interprocessor signaling: left-port write → INTR assertion; right-port read → INTR clear |
| 2 V data retention | Preserves memory contents during brownout or controlled shutdown using backup battery, reducing system recovery latency |
| Industrial temperature range | Validated operation from –40°C to +85°C ensures reliability in motor drives, PLCs, and outdoor telecom equipment |
| 52-pin PLCC packaging | Surface-mount compatible footprint with proven thermal and mechanical robustness for high-vibration industrial PCBs |
Applications
| Industrial PLC Backplane Memory | Dual-CPU Interprocessor Messaging |
|---|---|
Use Scenario: Two independent CPUs share status and command data across a ruggedized backplane in a programmable logic controller. IC Role / Device Role / Timing Role: IDT71421LA35J serves as SLAVE memory in a MASTER/SLAVE pair, accepting writes from CPU A and providing reads to CPU B with BUSY-controlled arbitration. Use Value: Eliminates software polling via hardware INTR flag (7FFH) and prevents data corruption through BUSYR-driven write inhibition during address contention. |
Use Scenario: Real-time embedded system with safety-critical and non-safety partitions exchanging sensor updates and actuator commands. IC Role / Device Role / Timing Role: IDT71421LA35J provides deterministic, low-latency mailbox memory where partition A writes to 7FFH to trigger INTR, notifying partition B of new data. Use Value: Achieves sub-35 ns inter-processor notification latency and guarantees atomic message delivery without OS intervention or shared-bus contention. |
| Motor Drive Control Co-Processor Buffer | Redundant Sensor Data Logger |
Use Scenario: High-speed motion controller uses dual processors: one handles trajectory calculation, the other manages PWM generation and feedback loops. IC Role / Device Role / Timing Role: IDT71421LA35J acts as SLAVE buffer, receiving interpolated position commands from the master processor and feeding them to the servo loop processor with precise timing alignment. Use Value: 35 ns tRC and asynchronous dual-port access ensure jitter-free command streaming, while 2 V data retention preserves last valid position during brief power dips. |
Use Scenario: Environmental monitoring node logs sensor readings continuously, retaining latest values during AC power failure using backup battery. IC Role / Device Role / Timing Role: IDT71421LA35J stores timestamped sensor snapshots in circular buffer mode; its 2 V retention mode maintains data integrity without refresh circuitry. Use Value: Reduces system BOM by eliminating external retention capacitor or EEPROM, with guaranteed 2 V hold and <1 µA ISB3 current during battery backup. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual-port SRAM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| CY7C1371BV33-167AXC | 3.3 V core, 167 MHz QDR interface, no BUSY/INT logic, 16-bit data bus | Requires level-shifting for 5 V systems; lacks hardware arbitration and mailbox interrupts | Select only if migrating to 3.3 V architecture and implementing software-based coherency |
| IDT71321LA35J | MASTER variant with BUSY output (open-drain), on-chip arbitration logic, and INTL flag | Used as primary controller in MASTER/SLAVE pairs; cannot substitute directly as SLAVE | Required when building custom dual-port arrays needing local arbitration; not drop-in for IDT71421LA35J roles |
Compared with CY7C1371BV33-167AXC and IDT71321LA35J, the IDT71421LA35J uniquely provides SLAVE-specific BUSY input and fixed 7FFH interrupt signaling in a 5 V, industrial-temp 2K×8 package - making it irreplaceable for legacy or cost-sensitive dual-CPU designs requiring hardware-coordinated memory access.
Availability
IDT71421LA35J is available at Aetrix Electronics and suitable for industrial PLC backplanes, dual-CPU interprocessor messaging, and motor drive control co-processor buffers requiring stable component supply, long-term lifecycle support, and RoHS-compliant packaging.
Supply support for IDT71421LA35J 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
Integrated Device Technology (IDT), now part of Renesas Electronics, is a fabless semiconductor company specializing in timing, memory interface, RF, and sensor signal conditioning ICs for communications, computing, and industrial markets.
The IDT71421LA series belongs to IDT's legacy dual-port SRAM product line, designed specifically for hardware-arbitrated, real-time interprocessor communication in industrial control, test equipment, and avionics subsystems.
FAQ
What is the role of IDT71421LA35J in a MASTER/SLAVE dual-port SRAM configuration?
IDT71421LA35J functions exclusively as the SLAVE device: it accepts BUSY input (BUSYR) from an IDT71321 MASTER to inhibit writes during address contention, and provides interrupt signaling via INTR flag triggered by left-port writes to address 7FFH. It does not generate BUSY signals or perform arbitration - those functions reside solely in the MASTER.
Does IDT71421LA35J support battery backup, and what voltage is required?
Yes, IDT71421LA35J supports battery backup data retention at 2.0 V (VDR), as specified in Table 6. This allows memory contents to be preserved during main power loss. The LA suffix explicitly denotes this low-power, retention-capable version - distinct from SA variants which lack 2 V hold capability.
What are the timing requirements for asserting INTR on IDT71421LA35J?
INTR is asserted when the left port performs a valid write to address 7FFH (CER = VIH, CEL = VIL, R/WL = VIL). Per Table 11b, tINS (interrupt set time) is ≤45 ns max. The flag remains asserted until the right port reads 7FFH with CER = VIL and OER = VIL - at which point INTR clears within tINR ≤45 ns.
Can IDT71421LA35J operate independently without a MASTER device?
Yes, IDT71421LA35J can operate as a standalone dual-port SRAM. In this mode, BUSYR must be held HIGH (e.g., via pull-up) since it is an input, and interrupt functionality remains active using 7FFH as the mailbox. All timing and electrical specs apply unchanged - only the hardware arbitration benefit of the MASTER/SLAVE pair is forfeited.
Which package options are available for IDT71421LA35J, and is the PLCC version lead-free?
IDT71421LA35J is offered in 52-pin PLCC (PLG52), 52-pin STQFP (PPG52), 64-pin TQFP (PNG64), and 64-pin STQFP (PPG64). The "J" suffix in IDT71421LA35J specifically denotes the 52-pin PLCC package. Per the datasheet's "Green parts available" note and ordering information, this variant is RoHS-compliant and lead-free.
71421LA35J Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Renesas
- Series:
- -
- Package/Case:
- 52-LCC (J-Lead)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Memory Type:
- Volatile
- Memory Format:
- SRAM
- Technology:
- SRAM - Dual Port, Asynchronous
- Memory Size:
- 16Kbit
- Memory Organization:
- 2K 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:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 52-PLCC (19.13x19.13)
71421LA35J FAQ
1.How can I place an order for 71421LA35J through Aetrix?
Please submit a Request for Quotation (RFQ) for 71421LA35J 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 71421LA35J reliable?
The price and inventory of 71421LA35J are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 71421LA35J is usually 5 days.
3.What payment methods are accepted for 71421LA35J?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 71421LA35J transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 71421LA35J?
71421LA35J orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 71421LA35J 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 71421LA35J?
For technical support, including 71421LA35J datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 71421LA35J requirements.
6.How does Aetrix verify that 71421LA35J is sourced from the original manufacturer or authorized distributors?
All 71421LA35J 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 71421LA35J meets industry standards.
7.What is the process for return or replacement of 71421LA35J?
All 71421LA35J units undergo pre-shipment inspection (PSI). If there is an issue with 71421LA35J, 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 71421LA35J part is unused and in its original packaging.
Return procedure for 71421LA35J:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
71421LA35J 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…
