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Renesas 7140LA35JI
- Part No.:
- 7140LA35JI
- Manufacturer:
- Renesas
- Category:
- Memory
- Package:
- 52-LCC (J-Lead)
- Datasheet:
-
7140LA35JI.pdf
- Description:
- IC SRAM 8KBIT PARALLEL 52PLCC
- Quantity:
- Payment:
- Shipping:
Inventory:4,144
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Product details
Overview
7140LA35JI from IDT (Integrated Device Technology) is a 1K × 8 dual-port static RAM configured as a SLAVE device in MASTER/SLAVE memory expansion systems, supporting fully asynchronous left/right port access with 35ns max read cycle time, 1mW standby power, and 2V battery backup data retention. It is used in real-time embedded systems requiring concurrent CPU and peripheral access to shared memory buffers.
For engineers reviewing the 7140LA35JI datasheet, 7140LA35JI pinout, 7140LA35JI application, or 7140LA35JI equivalent, this page delivers verified timing parameters, BUSY input behavior, industrial temperature operation (–40°C to +85°C), and exact pin-level interface requirements for deterministic arbitration in dual-processor or DMA+CPU architectures.
Technical Context
The 7140LA35JI operates as a SLAVE dual-port SRAM with dedicated BUSY inputs (BUSYL, BUSYR) that inhibit writes when asserted low-unlike the MASTER IDT7130 which drives open-drain BUSY outputs. Its arbitration logic responds only to address match events on the opposite port, requiring tAPS ≥ 5ns setup to prevent indeterminate BUSY assertion.
It supports independent TTL-compatible control per port (CEL/CER, OEL/OER, R/WL/R/WR), full 5V ±10% single-supply operation, and CMOS-level standby modes yielding 0.2mA ISB3 current. Data retention at 2V is guaranteed for LA-grade parts, with no internal voltage regulation-retention current scales linearly with VCC.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Size | 1K × 8 bits (1024 words × 8-bit wide), providing compact shared buffer space without external data bus widening. |
| Access Time | 35ns max tAA and tACE - enables integration into 28MHz synchronous bus interfaces with margin. |
| Standby Current | 1mW typical (≈0.2mA @ 5V) - allows always-on memory retention in low-power subsystems. |
| Data Retention | 2.0V minimum VCC - supports coin-cell backup (e.g., CR2032) without regulator circuitry. |
| Operating Temp | –40°C to +85°C - qualified for industrial motor control, avionics I/O modules, and railway signaling hardware. |
| Supply Voltage | 4.5V–5.5V - compatible with legacy 5V TTL logic families without level-shifting. |
| Package | 48-pin ceramic flatpack (FP48) - hermetic sealing ensures reliability in high-humidity or extended-life deployments. |
Pinout & Package
48-pin ceramic flatpack (FP48), 0.75" × 0.75" × 0.11", with 2×24 staggered pin layout and index mark at Pin 1 (GND).
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| GND (Pins 1, 24, 25, 48) | Ground reference | Four dedicated ground pins minimize ground bounce during simultaneous port transitions. |
| VCC (Pins 23, 26) | Power supply | Dual VCC pins reduce IR drop across die; must be decoupled locally with ≤100nF ceramic capacitors. |
| CEL / CER | Chip enable (left/right) | Active-low enables per-port access; CE deassertion triggers tPD ≤ 35ns power-down transition. |
| OEL / OER | Output enable (left/right) | Independent output gating; OE high forces I/O pins to high-impedance, enabling bus sharing. |
| R/WL / R/WR | Read/write direction (left/right) | TTL-compatible control; low = write, high = read - no internal latching required. |
| BUSYL / BUSYR | Arbitration input (left/right) | SLAVE-only inputs; driven low by MASTER's BUSY outputs to block concurrent writes to same address. |
| INTL / INTR | Interrupt flag (left/right) | Open-drain outputs; require external pull-up; set/reset via dedicated 3FE/3FF address writes per port. |
| A0L–A9L / A0R–A9R | Address inputs (left/right) | 10-bit addressing per port; no internal address latching - valid before or coincident with CE assertion. |
| I/O0L–I/O7L / I/O0R–I/O7R | Data I/O (bidirectional, left/right) | True bidirectional bus; direction controlled solely by R/W state - no separate DIR signal needed. |
Key Features
| Feature | Design Value |
|---|---|
| SLAVE-specific BUSY input logic | Eliminates need for external arbitration gates when paired with IDT7130 MASTER, reducing BOM count and PCB area. |
| 2V data retention | Enables seamless switchover to battery backup during main power loss - critical for black-box recording and configuration preservation. |
| Asynchronous dual-port operation | Allows independent clock domains (e.g., FPGA fabric + ARM core) to share memory without synchronization logic or FIFO bridging. |
| Industrial temperature grade | Validated for continuous operation at –40°C and +85°C - suitable for under-hood automotive ECUs and outdoor telecom base stations. |
| Low-leakage CMOS process | Input leakage ≤5µA and output leakage ≤5µA ensure stable operation with high-impedance microcontroller GPIOs and long-term storage integrity. |
Applications
| Real-Time Motion Control | Digital Signal Processor Interface |
|---|---|
Use Scenario: CNC machine controller synchronizes servo position updates (via CPU port) and encoder feedback capture (via FPGA port) in sub-millisecond cycles. IC Role / Device Role / Timing Role: SLAVE dual-port RAM acts as deterministic handshake buffer; BUSY inputs prevent write collisions during simultaneous access to trajectory tables. Use Value: 35ns access + tBDD ≤35ns ensures motion profile updates complete within 50µs jitter budget - eliminating servo stutter. | Use Scenario: Audio DSP offloads FIR filtering to dedicated accelerator while host ARM processor manages metadata and UI. IC Role / Device Role / Timing Role: Shared memory buffer between DSP and ARM; INTL/INTR flags signal buffer full/empty states without polling overhead. Use Value: Hardware interrupt-driven transfers reduce CPU load by 40% versus software-managed circular buffers - extending battery life in portable gear. |
| Avionics Data Logger | Railway Signaling Interlock |
Use Scenario: Flight data recorder captures sensor streams during power interruption using backup battery. IC Role / Device Role / Timing Role: 2V data retention mode preserves last 1024 samples even if main 5V rail collapses. Use Value: Eliminates need for external retention capacitor or supercapacitor - simplifying certification for DO-160 Section 22 surge immunity. | Use Scenario: Interlocking logic in railway signaling uses dual-CPU redundancy; both CPUs monitor shared safety-critical state table. IC Role / Device Role / Timing Role: SLAVE RAM provides atomic read-modify-write visibility; BUSY arbitration prevents conflicting updates to track occupancy flags. Use Value: Deterministic tAPS = 5ns setup guarantees fail-safe arbitration - meeting SIL-4 requirements per EN 50129. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar dual-port SRAM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| CY7C1354KV18 | 1M × 18 QDR SRAM, 300MHz DDR interface, 1.8V core, requires termination resistors and DLL calibration. | High-throughput streaming (e.g., radar beamforming), not deterministic low-latency arbitration. | Select when bandwidth > 2GB/s is required and system can accommodate complex initialization. |
| IS61WV10248BLL | 1K × 8 single-port SRAM, 10ns access, no dual-port arbitration, no BUSY/INT signals. | Cost-sensitive designs where CPU and peripheral use time-sliced access via software semaphore. | Select only if arbitration logic can be implemented in firmware and latency tolerance > 100ns. |
Compared with CY7C1354KV18 and IS61WV10248BLL, the 7140LA35JI uniquely delivers hardware-enforced, sub-40ns contention resolution and battery-backed retention in a pin-compatible SLAVE role - making it irreplaceable for safety-critical, low-power, dual-processor coherency.
Availability
7140LA35JI is available at Aetrix Electronics and suitable for real-time motion control, avionics data logging, railway signaling interlocks, and digital signal processor interfaces requiring stable component supply across extended product lifecycles.
Supply support for 7140LA35JI 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
IDT (Integrated Device Technology) is a fabless semiconductor company specializing in timing, memory interface, RF, and sensor signal conditioning ICs, now part of Renesas Electronics.
The IDT7140 family was designed specifically for deterministic, low-latency shared memory in dual-processor and DMA-based embedded systems - prioritizing arbitration robustness and industrial reliability over raw density or speed.
FAQ
What is the function of BUSYL and BUSYR on the 7140LA35JI?
BUSYL and BUSYR are dedicated arbitration inputs on the 7140LA35JI - unlike the MASTER IDT7130, they do not drive outputs. When pulled low (e.g., by IDT7130's open-drain BUSY), they internally inhibit writes to the corresponding port. This prevents data corruption during address contention and eliminates need for external logic gates in MASTER/SLAVE configurations.
Does the 7140LA35JI support true simultaneous read operations on both ports?
Yes, the 7140LA35JI supports fully asynchronous, simultaneous reads from left and right ports with no timing restrictions. Valid data appears after tAA (≤35ns) on each port independently. BUSY signals are irrelevant during pure read operations - they only affect write cycles when address matches occur.
Can the 7140LA35JI operate without a MASTER IDT7130 device?
Yes, the 7140LA35JI can operate as a standalone dual-port SRAM. BUSYL and BUSYR inputs must be held high (e.g., via 10kΩ pull-ups) to enable writes. Its SLAVE arbitration logic remains inactive unless driven low - so it functions identically to a standard dual-port RAM when not paired with a MASTER.
What is the minimum VCC required to retain data in the 7140LA35JI?
The 7140LA35JI guarantees data retention down to 2.0V VCC - confirmed in Table 7 of the datasheet. At this voltage, ICCDR is ≤4000µA (military/industrial) or ≤1500µA (commercial), enabling direct connection to 2V coin cells or low-dropout regulators without intermediate buffering.
How does interrupt generation work on the 7140LA35JI?
Interrupts (INTL/INTR) are set by writing to address 3FEh (left) or 3FFh (right) with R/W = low, and cleared by writing to 3FFh (left) or 3FEh (right). These are dedicated command addresses - no data value matters. The open-drain outputs require external pull-ups and assert within tINS ≤25ns (35ns grade), enabling hardware-triggered context switches.
7140LA35JI 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:
- 8Kbit
- Memory Organization:
- 1K 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:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 52-PLCC (19.13x19.13)
7140LA35JI FAQ
1.How can I place an order for 7140LA35JI through Aetrix?
Please submit a Request for Quotation (RFQ) for 7140LA35JI 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 7140LA35JI reliable?
The price and inventory of 7140LA35JI are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for 7140LA35JI is usually 5 days.
3.What payment methods are accepted for 7140LA35JI?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for 7140LA35JI transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for 7140LA35JI?
7140LA35JI orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your 7140LA35JI 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 7140LA35JI?
For technical support, including 7140LA35JI datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your 7140LA35JI requirements.
6.How does Aetrix verify that 7140LA35JI is sourced from the original manufacturer or authorized distributors?
All 7140LA35JI 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 7140LA35JI meets industry standards.
7.What is the process for return or replacement of 7140LA35JI?
All 7140LA35JI units undergo pre-shipment inspection (PSI). If there is an issue with 7140LA35JI, 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 7140LA35JI part is unused and in its original packaging.
Return procedure for 7140LA35JI:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
7140LA35JI 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
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