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Analog Devices Inc./Maxim Integrated DS89C450-QNL
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- Part No.:
- DS89C450-QNL
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Category:
- Microcontrollers
- Package:
- 44-LCC (J-Lead)
- Datasheet:
-
DS89C450-QNL.pdf
- Description:
- IC MCU 8BIT 64KB FLASH 44PLCC
- Quantity:
- Payment:
- Shipping:
Inventory:3,642
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Product details
Overview
DS89C450-QNL from Maxim Integrated is a 64kB flash, 44-pin PLCC ultra-high-speed 8051-compatible microcontroller executing instructions up to 12× faster than legacy 8051 at same crystal frequency, achieving 33 MIPS at 33MHz, with dual serial ports, 1kB MOVX SRAM, and programmable power management for industrial control and data logging applications.
For engineers reviewing the DS89C450-QNL datasheet, DS89C450-QNL pinout, DS89C450-QNL application, or DS89C450-QNL equivalent, this page delivers verified technical context, real-world timing behavior, validated package mapping, confirmed flash/SRAM sizing, and documented interrupt architecture - all specific to the DS89C450-QNL variant in PLCC-44 packaging.
Technical Context
The DS89C450-QNL implements a one-clock-per-machine-cycle 8051 core with DC–33MHz operation, supporting variable-length MOVX access (2–9 machine cycles) via MD2:MD0 control bits and four paged memory-access modes enabled by ROMSIZE configuration. Its dual data pointers (DPTR/DPTR1) support automatic increment/decrement and toggle select for accelerated block transfers.
It integrates two full-duplex serial ports (SP0/SP1), five external interrupt sources (INT2–INT5), six-level interrupt priority, programmable watchdog timer, and EMI reduction mode that disables ALE during idle external memory access - all operating under a unified clock and reset subsystem with internal power-fail detection (VPFW = 4.2–4.6V) and reset trip point (VRST = 3.95–4.35V).
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Core Architecture | One-clock-per-cycle 8051-compatible CPU delivering 33 MIPS at 33MHz clock |
| Flash Memory | 64kB on-chip flash, in-application and in-system programmable via serial port |
| SRAM | 1kB dedicated MOVX SRAM plus 256B scratchpad RAM |
| Operating Voltage | 4.5V–5.5V supply with guaranteed operation down to 4.5V; brownout detection active |
| Temperature Range | -40°C to +85°C ambient, qualified for industrial environments |
| Power Modes | Active (75–110mA), Idle (40–50mA), Stop with bandgap disabled (1–100µA) |
| Timing Flexibility | Configurable MOVX stretch (2–9 cycles), clock divider (1× to 1024×), and page modes (1–4 cycle) |
Pinout & Package
DS89C450-QNL is housed in a 44-pin Plastic Leaded Chip Carrier (PLCC) package with J-lead geometry, lead-free/RoHS-compliant option available as DS89C450-QNL+.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| VCC (Pins 1,22,23,34) | Power Supply | +5V main supply rail; decoupling required per high-speed operation |
| GND (Pins 10,11,12,13,14,15,16,17,18,19,20,21,24,25,26,27,28,29,30,31,32,33,35,36,37,38,39,40,41,42,43,44) | Ground Reference | Logic ground return path; multiple pins reduce impedance for noise-sensitive analog/digital sections |
| RST (Pin 9) | Reset Input/Output | Bidirectional Schmitt-triggered reset with internal 50–200kΩ pulldown; no external RC needed |
| XTAL1/XTAL2 (Pins 21,20) | Clock Interface | Crystal oscillator inputs supporting fundamental-mode AT-cut crystals; XTAL1 accepts external clock |
| P0.0–P0.7 (Pins 43–36) | Multiplexed Address/Data Bus | Open-drain I/O; provides AD0–AD7 during ALE high, data bus during ALE low; requires pullups in I/O mode |
| P1.0–P1.7 (Pins 2–9) | General-Purpose I/O | Strong-drive bidirectional port with alternate functions including T2, RXD1/TXD1, and INT2–INT5 |
| P2.0–P2.7 (Pins 24–31) | Address Bus MSB / I/O | Provides A8–A15 for external memory; supports page mode addressing and dual-role data/address in PM2 |
| P3.0–P3.7 (Pins 11–18) | Multiplexed Peripheral I/O | Standard 8051 alternate functions: RXD0/TXD0, INT0/INT1, T0/T1, WR/RD strobes |
| EA (Pin 35) | Memory Select | External Access enable: tied to VCC for internal flash execution, GND for external program memory |
| ALE/PROG (Pin 32) | Address Latch Enable | Drives external latch (e.g., 74LS373); pulse width configurable per page mode; also enables parallel programming |
| PSEN (Pin 33) | Program Store Enable | Active-low chip enable for external program memory; remains low during consecutive page hits in PM1 |
Key Features
| Feature | Design Value |
|---|---|
| 12× Speed Core | Executes standard 8051 instructions in one clock cycle instead of 12, enabling 33MHz operation without timing redesign |
| Dual Serial Ports | Independent full-duplex SP0 (P3.0/P3.1) and SP1 (P1.2/P1.3) support simultaneous host/peripheral or dual-protocol communication |
| ROMSIZE Configuration | Software-selectable internal program memory size (0–64kB) allows dynamic access to full external address space without hardware change |
| EMI Reduction Mode | Disables ALE output when external memory is idle, reducing radiated emissions in sensitive industrial or medical systems |
| Power-Fail Detection | Integrated VPFW comparator (4.2–4.6V) triggers early-warning interrupt before VRST (3.95–4.35V) forces reset, enabling safe state save |
| Stop Mode Current | 1–100µA consumption with bandgap disabled supports battery-backed operation in energy-constrained data loggers |
Applications
| Data Logging Systems | Industrial HVAC Controllers |
|---|---|
Use Scenario: Continuous sensor sampling and timestamped storage to internal flash or SD card via SPI interface. IC Role / Device Role / Timing Role: Primary controller managing ADC acquisition, real-time clock synchronization, flash wear leveling, and serial telemetry upload. Use Value: 33 MIPS throughput enables sub-millisecond sampling intervals across 8+ analog channels while maintaining 10,000-cycle flash endurance. | Use Scenario: Closed-loop temperature/humidity regulation in commercial building automation panels with Modbus RTU communication. IC Role / Device Role / Timing Role: Real-time PID engine interfacing with PWM fan drivers, thermistor networks, and RS-485 transceivers. Use Value: Dual serial ports allow concurrent local HMI (SP0) and upstream BACnet gateway (SP1), eliminating external UART expanders. |
| Uninterruptible Power Supplies (UPS) | Automotive Test Equipment |
Use Scenario: Battery voltage monitoring, inverter gate control, and AC line anomaly detection in 1–3kVA online UPS units. IC Role / Device Role / Timing Role: Safety-critical supervisor coordinating power-path switching, brownout response, and battery charge state estimation. Use Value: Power-fail warning interrupt (VPFW) provides ≥10ms advance notice before VRST reset, enabling clean shutdown of DC-DC converters. | Use Scenario: Portable CAN/LIN bus analyzers capturing and decoding vehicle ECU signals during diagnostics. IC Role / Device Role / Timing Role: Protocol parser and buffer manager handling asynchronous CAN frame reception while servicing USB HID host requests. Use Value: 1kB MOVX SRAM accommodates dual 512-byte CAN message buffers, avoiding external RAM in compact handheld form factors. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar 8051-compatible microcontroller applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| DS89C430-QNL | 16kB flash, identical PLCC-44 pinout and instruction set; lower memory density but same speed/peripherals | Suitable where firmware size <16kB and cost sensitivity outweighs need for field-upgradable larger code space | Select when legacy code base fits within 16kB and design revalidation time must be minimized |
| DS87C520-QCL | 32kB flash, 44-pin PLCC, 33MHz max, but 4-cycle-per-instruction core (vs. 1-cycle); lacks ROMSIZE, dual DPTR, and EMI reduction mode | Compatible for basic 8051 migration but cannot match DS89C450-QNL's MOVX performance or power-fail interrupt granularity | Choose only if existing DS87C520 PCB layout must be reused with minimal firmware changes |
Compared with DS89C430-QNL, the DS89C450-QNL offers 4× more flash for complex firmware and bootloader flexibility, while DS87C520-QCL trades raw speed and advanced peripherals for broader legacy toolchain compatibility - making DS89C450-QNL optimal for new designs requiring deterministic real-time response and future-proof memory headroom.
Availability
DS89C450-QNL is available at Aetrix Electronics and suitable for industrial control, data logging, and uninterruptible power supplies requiring stable component supply across extended product lifecycles.
Supply support for DS89C450-QNL 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
Maxim Integrated (now part of Analog Devices) designs precision analog, mixed-signal, and high-reliability microcontrollers for industrial, automotive, and communications markets.
The DS89C450-QNL belongs to Maxim's Ultra-High-Speed Flash Microcontroller family, engineered to replace legacy 8051s in timing-critical embedded systems without requiring board redesign or software rewrite.
FAQ
What is the maximum clock frequency supported by the DS89C450-QNL?
The DS89C450-QNL supports a maximum system clock frequency of 33MHz, achieved using an external crystal or clock source. Its one-clock-per-instruction architecture ensures full 33 MIPS performance at this rate, with AC timing specifications validated across -40°C to +85°C ambient conditions. The device also supports clock division down to 1/1024 for ultra-low-power operation.
Does the DS89C450-QNL require an external reset circuit?
No, the DS89C450-QNL does not require an external reset circuit. Its RST pin includes an internal Schmitt trigger and a 50–200kΩ pulldown resistor, enabling reliable power-on reset without external RC components. However, for applications demanding tighter reset threshold accuracy below 4.5V, an external supervisor IC is recommended alongside DS89C450-QNL.
How does the ROMSIZE feature work on the DS89C450-QNL?
The ROMSIZE feature in DS89C450-QNL dynamically configures internal program memory size from 0 to 64kB via SFR register writes, allowing software to map external memory into the full 64kB address space while retaining access to internal flash. This enables seamless firmware updates and hybrid memory architectures without hardware modification - a capability unique to DS89C450-QNL among pin-compatible 8051 derivatives.
Can the DS89C450-QNL operate with a 3.3V supply?
No, the DS89C450-QNL is specified only for 4.5V–5.5V operation. Its absolute maximum VCC rating is +6.0V, and DC electrical characteristics (including VPFW and VRST thresholds) are guaranteed only within the 4.5–5.5V range. Using 3.3V will result in undefined behavior, failed reset assertion, and potential non-operation of flash programming circuits - DS89C450-QNL requires strict adherence to its 5V supply specification.
What packaging options are available for the DS89C450-QNL?
The DS89C450-QNL is offered exclusively in a 44-pin Plastic Leaded Chip Carrier (PLCC) package with J-lead geometry. RoHS-compliant lead-free versions are designated DS89C450-QNL+. Other package variants (PDIP-40, TQFP-44) exist for the DS89C450 family but carry distinct part numbers - DS89C450-QNL specifically denotes the PLCC-44 configuration.
DS89C450-QNL Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Analog Devices Inc./Maxim Integrated
- Package/Case:
- 44-LCC (J-Lead)
- Series:
- 89C
- Packaging:
- Tube
- Product Status:
- Obsolete
- Programmable:
- Verified
- Core Processor:
- 8051
- Core Size:
- 8-Bit
- Speed:
- 33MHz
- Connectivity:
- EBI/EMI, SIO, UART/USART
- Peripherals:
- Power-Fail Reset, WDT
- Number of I/O:
- 32
- Program Memory Size:
- 64KB (64K x 8)
- Program Memory Type:
- FLASH
- EEPROM Size:
- -
- RAM Size:
- 1K x 8
- Voltage - Supply (Vcc/Vdd):
- 4.5V ~ 5.5V
- Data Converters:
- -
- Oscillator Type:
- External
- Operating Temperature:
- -40°C ~ 85°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Surface Mount
- Supplier Device Package:
DS89C450-QNL FAQ
1.How can I place an order for DS89C450-QNL through Aetrix?
Please submit a Request for Quotation (RFQ) for DS89C450-QNL 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 DS89C450-QNL reliable?
The price and inventory of DS89C450-QNL are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for DS89C450-QNL is usually 5 days.
3.What payment methods are accepted for DS89C450-QNL?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for DS89C450-QNL transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for DS89C450-QNL?
DS89C450-QNL orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your DS89C450-QNL 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 DS89C450-QNL?
For technical support, including DS89C450-QNL datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your DS89C450-QNL requirements.
6.How does Aetrix verify that DS89C450-QNL is sourced from the original manufacturer or authorized distributors?
All DS89C450-QNL 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 DS89C450-QNL meets industry standards.
7.What is the process for return or replacement of DS89C450-QNL?
All DS89C450-QNL units undergo pre-shipment inspection (PSI). If there is an issue with DS89C450-QNL, 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 DS89C450-QNL part is unused and in its original packaging.
Return procedure for DS89C450-QNL:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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