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Microchip Technology AT45D161-RI
- Part No.:
- AT45D161-RI
- Manufacturer:
- Microchip Technology
- Category:
- Memory
- Package:
- 28-SOIC (0.342", 8.69mm Width)
- Datasheet:
-
AT45D161-RI.pdf
- Description:
- IC FLASH 16MBIT SPI 15MHZ 28SOIC
- Quantity:
- Payment:
- Shipping:
Inventory:1,275
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Product details
Overview
AT45D161-RI from Microchip Technology is a 16-Mbit, 5V-only serial DataFlash® memory IC optimized for in-system reprogramming via SPI interface. It features 4096 pages × 528 bytes (17,301,504 bits), dual 528-byte SRAM buffers, and hardware page write protection. Used in digital voice, image, and embedded data logging systems requiring low-pin-count nonvolatile storage with concurrent buffer access.
For engineers reviewing the AT45D161-RI datasheet, AT45D161-RI pinout, AT45D161-RI application, or AT45D161-RI equivalent, this page delivers verified technical context, real-world timing behavior (7 ms page program, 120 µs page-to-buffer transfer), SPI Mode 0/3 compatibility, and precise pin-level functional mapping - all validated against Microchip's official documentation Rev. 1081C–01/01.
Technical Context
The AT45D161-RI implements a serial flash architecture with two independent 528-byte SRAM buffers enabling simultaneous data reception into one buffer while reprogramming a page in main memory. Its command set supports page/block erase, main memory-to-buffer transfer/compare, and auto-page rewrite - all internally self-timed without external high-voltage programming signals.
It operates exclusively at 4.5V–5.5V, uses SPI-compatible three-wire serial interface (CS/SCK/SI/SO), and integrates hardware write protection (WP pin) and ready/busy status reporting (RDY/BUSY open-drain output). The device defaults to SPI Mode 3 on power-up/reset and supports both Mode 0 and Mode 3 timing waveforms.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Memory Density | 16 Mbit (4096 × 528-byte pages = 17,301,504 bits) |
| Supply Voltage | 4.5V–5.5V only - no multi-voltage support; requires stable 5V rail |
| Max Clock Frequency | 15 MHz - enables up to ~1.875 MB/s theoretical serial throughput |
| Page Program Time | 7 ms typical - full erase+program cycle per 528-byte page |
| Page-to-Buffer Transfer | 120 µs typical - enables rapid preload of buffers during background operations |
| Active Read Current | 15 mA typical at 5.5V/15 MHz - defines power budget for continuous streaming reads |
| Standby Current | 10 µA typical - critical for battery-backed or low-power wake-on-event designs |
Pinout & Package
AT45D161-RI is available in 28-pin SOIC, 28-pin TSOP-I, and 32-pin PLCC packages. Pin functions are identical across packages; NC pins vary by package but serve no electrical role. All packages share identical signal mapping for CS, SCK, SI, SO, WP, RESET, RDY/BUSY, VCC, and GND.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| CS | Chip Select | Active-low enable for instruction decoding; must remain low during full command sequence |
| SCK | Serial Clock | Controls bit timing for SI input and SO output; supports Mode 0 (CPOL=0) and Mode 3 (CPOL=1) |
| SI | Serial Input | Receives opcodes, addresses, and data MSB-first; sampled on SCK rising edge in Mode 0, falling in Mode 3 |
| SO | Serial Output | Drives read data/status register bits MSB-first; tri-stated when CS is high |
| WP | Hardware Page Write Protect | Low = protects first 256 pages from program/erase; internal pull-up allows omission if unused |
| RESET | Chip Reset | Active-low aborts ongoing operation and resets state machine; internal pull-up allows omission |
| RDY/BUSY | Open-drain Status Indicator | Pulled low during self-timed operations (e.g., tEP = 20 ms max); requires external pull-up resistor |
| VCC / GND | Power Supply | Single 4.5–5.5V supply; decoupling capacitor required within 1 cm of pins |
Key Features
| Feature | Design Value |
|---|---|
| Dual 528-byte SRAM buffers | Enables pipelined operation: receive new data into one buffer while programming another page to flash |
| Single-cycle page program | Integrated erase+program eliminates separate erase step - simplifies firmware and reduces latency |
| SPI Mode 0 and Mode 3 support | Compatible with broad range of microcontrollers without clock polarity inversion logic |
| Hardware page write protection | Physical WP pin blocks reprogramming of first 256 pages - prevents accidental corruption of boot code |
| Ready/Busy status pin | RDY/BUSY provides hardware flow control - avoids polling overhead and improves deterministic timing |
Applications
| Digital Voice Recorder | Industrial Data Logger |
|---|---|
Use Scenario: Embedded voice prompt storage in HVAC controllers, medical devices, or security systems with limited PCB space. IC Role / Device Role / Timing Role: Nonvolatile serial storage for pre-recorded WAV/ADPCM audio; accessed via SPI at ≤15 MHz during playback initialization. Use Value: 528-byte page granularity matches typical audio frame sizes; dual buffers allow seamless looped playback with zero-gap transitions. |
Use Scenario: Long-term environmental sensor data capture (temperature, humidity, voltage) in remote industrial nodes powered by energy harvesting. IC Role / Device Role / Timing Role: Low-power, high-reliability flash storage interfaced to an ultra-low-power MCU; programmed in bursts during wake cycles. Use Value: 10 µA standby current extends battery life; hardware WP prevents firmware corruption during brown-out events. |
| Medical Diagnostic Imager | POS Terminal Firmware Storage |
Use Scenario: Storing calibration tables and image metadata in portable ultrasound or ECG devices where EMI resilience is critical. IC Role / Device Role / Timing Role: SPI-connected configuration memory holding device-specific coefficients; read once at boot and cached in RAM. Use Value: Serial interface minimizes switching noise vs. parallel flash; CMOS/TTL-compatible I/O ensures robust signal integrity on noisy boards. |
Use Scenario: Secure firmware image storage in payment terminals requiring field-upgradable bootloader and application code. IC Role / Device Role / Timing Role: Primary nonvolatile storage for signed firmware binaries; accessed during secure boot verification and OTA updates. Use Value: Page-level erase enables atomic firmware updates; built-in program timer eliminates need for software timeout management. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar serial flash memory applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| AT45DB161B | Enhanced revision with improved endurance (100K cycles vs. 10K), faster tP (5 ms typ), and extended temperature range (–40°C to 85°C industrial) | Required for new designs per Microchip recommendation; supports higher reliability and longer product lifecycle | Select AT45DB161B for production releases; AT45D161-RI remains valid for legacy repair or existing stock utilization |
| W25Q16JVSSIQ | 16 Mbit Quad SPI NOR flash (Winbond); supports standard/dual/quad I/O, 100 MHz clock, 3V supply (2.7–3.6V) | Not pin-compatible; requires different driver stack and layout due to quad I/O and voltage mismatch | Consider only if migrating to 3V system architecture and needing higher bandwidth; not a drop-in replacement |
Compared with AT45DB161B and W25Q16JVSSIQ, the AT45D161-RI offers proven stability in 5V legacy systems but lacks endurance and speed upgrades - making it suitable for cost-sensitive, low-volume, or maintenance-only deployments where design change is constrained.
Availability
AT45D161-RI is available at Aetrix Electronics and suitable for digital voice recorders, industrial data loggers, medical diagnostic imagers, and POS terminal firmware storage requiring stable component supply across extended product lifecycles.
Supply support for AT45D161-RI 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
Microchip Technology is a leading provider of microcontroller, analog, FPGA, and memory solutions, delivering reliable, secure, and scalable semiconductor products for industrial, automotive, and consumer markets.
The AT45D161-RI belongs to Microchip's DataFlash® family - designed specifically for embedded systems needing serial-interface nonvolatile memory with integrated SRAM buffers to enable concurrent data streaming and flash reprogramming.
FAQ
What is the maximum clock frequency supported by the AT45D161-RI?
The AT45D161-RI supports a maximum serial clock (SCK) frequency of 15 MHz, as specified in its AC characteristics table. This timing enables efficient data transfer rates while maintaining signal integrity across standard PCB traces. Operation above 15 MHz is not guaranteed and may result in command failures or data corruption. The AT45D161-RI must be operated within this limit to ensure reliable page reads, buffer transfers, and program cycles.
Does the AT45D161-RI support both SPI Mode 0 and Mode 3?
Yes, the AT45D161-RI is explicitly compatible with both SPI Mode 0 (CPOL = 0, CPHA = 0) and Mode 3 (CPOL = 1, CPHA = 0), as confirmed in its datasheet features and timing diagrams. The device automatically detects the inactive clock polarity on each CS falling edge. This dual-mode support allows direct interfacing with diverse host MCUs without requiring clock inversion logic or firmware workarounds - a key advantage of the AT45D161-RI in heterogeneous design environments.
How does the hardware page write protect (WP) pin function on the AT45D161-RI?
The WP pin on the AT45D161-RI, when driven low, permanently disables program and erase operations on the first 256 pages (pages 0–255) of main memory. This protection remains active until WP is returned high. The pin has an internal pull-up, so it may be left unconnected if protection is unnecessary. This feature safeguards critical boot code or calibration data stored in early pages - a design-critical capability unique to the AT45D161-RI's hardware-level security model.
What is the purpose of the RDY/BUSY pin on the AT45D161-RI?
The RDY/BUSY pin on the AT45D161-RI is an open-drain output that goes low during any self-timed internal operation - including page program (tEP), page erase (tPE), block erase (tBE), and page-to-buffer transfer (tXFR). It provides hardware flow control, eliminating the need for software polling of the status register. An external pull-up resistor is required. This real-time signaling ensures deterministic timing for the host MCU and is integral to the AT45D161-RI's ability to manage concurrent buffer and flash operations reliably.
Can the AT45D161-RI be used in industrial temperature applications?
Yes, the AT45D161-RI is rated for industrial temperature operation from –40°C to +85°C, as defined in its DC operating range specification. This rating applies to all package variants (SOIC, TSOP, PLCC) and is validated across electrical parameters including standby current (10 µA typ), active read current (15 mA typ), and timing margins. Designers deploying the AT45D161-RI in motor drives, factory automation, or outdoor instrumentation can rely on its specified performance across this full industrial range without derating.
AT45D161-RI Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Microchip Technology
- Series:
- -
- Package/Case:
- 28-SOIC (0.342", 8.69mm Width)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Memory Type:
- Non-Volatile
- Memory Format:
- FLASH
- Technology:
- FLASH
- Memory Size:
- 16Mbit
- Memory Organization:
- 528 Bytes x 4096 pages
- Memory Interface:
- SPI
- Clock Frequency:
- 15 MHz
- Write Cycle Time - Word, Page:
- 15ms
- Access Time:
- -
- Voltage - Supply:
- 4.5V ~ 5.5V
- Operating Temperature:
- -40°C ~ 85°C (TC)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
- 28-SOIC
AT45D161-RI FAQ
1.How can I place an order for AT45D161-RI through Aetrix?
Please submit a Request for Quotation (RFQ) for AT45D161-RI 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 AT45D161-RI reliable?
The price and inventory of AT45D161-RI are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for AT45D161-RI is usually 5 days.
3.What payment methods are accepted for AT45D161-RI?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for AT45D161-RI transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for AT45D161-RI?
AT45D161-RI orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your AT45D161-RI 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 AT45D161-RI?
For technical support, including AT45D161-RI datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your AT45D161-RI requirements.
6.How does Aetrix verify that AT45D161-RI is sourced from the original manufacturer or authorized distributors?
All AT45D161-RI 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 AT45D161-RI meets industry standards.
7.What is the process for return or replacement of AT45D161-RI?
All AT45D161-RI units undergo pre-shipment inspection (PSI). If there is an issue with AT45D161-RI, 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 AT45D161-RI part is unused and in its original packaging.
Return procedure for AT45D161-RI:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
AT45D161-RI Tags
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