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Renesas X5645P
- Part No.:
- X5645P
- Manufacturer:
- Renesas
- Category:
- Supervisors
- Package:
- 8-DIP (0.300", 7.62mm)
- Datasheet:
-
X5645P.pdf
- Description:
- IC SUPERVISOR 1 CHANNEL 8DIP
- Quantity:
- Payment:
- Shipping:
Inventory:2,204
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Product details
Overview
X5645P from Intersil is a CPU supervisor IC with integrated 64Kbit SPI EEPROM, providing power-on reset control, watchdog timer, low-voltage detection (VTRIP = 4.5V), and block-lock EEPROM protection in a single 8-lead PDIP package. It asserts an active-HIGH RESET signal, supports 2MHz SPI communication, operates from 4.5V to 5.5V, and delivers <50µA standby current with watchdog enabled - used in embedded microcontroller systems requiring reliable boot supervision and nonvolatile configuration storage.
For engineers reviewing the X5645P datasheet, X5645P pinout, X5645P application, or X5645P equivalent, this page details its verified reset threshold, reprogrammable VTRIP capability, 32-byte page write timing, watchdog timeout selection (200ms/600ms/1.4s), and Block Lock™ protection granularity - all confirmed for the X5645P variant per FN8135 Rev 1.00.
Technical Context
The X5645P integrates four co-located functions: power-on reset generation (active to VCC = 1V, 200ms timeout), selectable watchdog timer (three fixed timeouts controlled by nonvolatile WD0/WD1 bits), precision low-VCC supervision (factory-set 4.5V trip point, reprogrammable via VP pulse sequence), and 64Kbit SPI EEPROM with Direct Write™ cells (100k endurance, 100-year retention).
Its SPI interface complies with modes 0,0 and 1,1, uses MSB-first framing, and requires WREN/WRSR commands to enable writes; the CS/WDI pin serves dual roles - chip select and watchdog input - while WP enables in-circuit programmable ROM mode when WPEN = 1 and WP = LOW.
Key Specifications
| Parameter | Value and Actual Design Meaning |
|---|---|
| Reset Output Polarity | Active HIGH (RESET pin asserts HIGH during fault condition) |
| VTRIP Threshold | 4.5V nominal (factory-set; reprogrammable between 1.7V–5.0V using VP pulses) |
| Watchdog Timeout Options | 200ms, 600ms, or 1.4s (selected via nonvolatile WD1/WD0 bits in status register) |
| EEPROM Capacity | 64Kbit (8K × 8 organization; supports 32-byte page writes with 5ms typical cycle time) |
| Supply Voltage Range | 4.5V to 5.5V (X5645P variant; not compatible with 2.7V operation) |
| Standby Current (WDT ON) | <50µA max at VCC = 5.5V (enables long battery life in always-on monitoring applications) |
| SPI Clock Frequency | Up to 2MHz (supports fast configuration reads/writes without MCU clock dependency) |
Pinout & Package
Package: 8-lead Plastic Dual In-Line Package (PDIP), 0.300" wide, RoHS-compliant per Intersil documentation.
| Pin/Terminal | Circuit Role | Design Meaning |
|---|---|---|
| 1: CS/WDI | Chip Select / Watchdog Input | LOW enables SPI interface; HIGH-to-LOW transition resets watchdog timer - dual-function pin critical for both communication and fault recovery |
| 2: WP | Write Protect Control | When WPEN bit = 1, LOW state disables all nonvolatile status register writes - enables in-circuit ROM mode for factory programming lockout |
| 3: SO | Serial Output | Push-pull data output; shifts read data on falling edge of SCK - eliminates need for external pull-up in SPI bus |
| 4: VSS | Ground Reference | Primary return path for all internal circuits; must be connected to system ground plane for stable reset timing and EEPROM reliability |
| 5: VCC | Power Supply Input | 4.5V–5.5V only; powers reset generator, watchdog, EEPROM, and SPI logic - voltage below 4.5V invalidates VTRIP guarantee |
| 6: SI | Serial Input | Latches instruction, address, and data on rising edge of SCK - accepts WREN, WRITE, RDSR, and WRSR opcodes per Table 1 |
| 7: SCK | Serial Clock | Controls SPI timing; rising edge latches SI data, falling edge updates SO - static clock allowed to pause transfers mid-sequence |
| 8: RESET/RESET | Reset Output | Open-drain active-HIGH output; asserted when VCC < 4.5V or watchdog expires - requires external pull-down for active-LOW MCU interface |
Key Features
| Feature | Design Value |
|---|---|
| Reprogrammable VTRIP | Allows field calibration of reset threshold from 1.7V to 5.0V using VP pulses on SCK/SI - eliminates BOM variants for custom voltage margins |
| Block Lock™ Protection | Nonvolatile BL0/BL1 bits enable selective write-protection of 0%, 25%, 50%, or 100% of EEPROM array - prevents firmware corruption during field updates |
| Volatile Reset Flag | FLB bit distinguishes watchdog timeout vs. low-VCC reset - enables diagnostic logging without external hardware |
| Self-Timed EEPROM Writes | 5ms typical write cycle with automatic internal timing - removes MCU polling overhead and guarantees completion before next command |
| Power-Up Reset Validity | RESET asserted down to VCC = 1V with 200ms stabilization delay - ensures clean boot even under slow-ramp or brownout conditions |
Applications
| Industrial PLC Controller | Medical Infusion Pump |
|---|---|
Use Scenario: Monitors 5V supply rail and supervises ARM Cortex-M4 MCU during power-up and runtime. IC Role / Device Role / Timing Role: CPU supervisor generating active-HIGH reset signal and storing calibration coefficients in protected EEPROM sectors. Use Value: Prevents erratic MCU behavior during brownouts; enables field-adjustable VTRIP to accommodate aging power supplies without PCB revision. | Use Scenario: Ensures fail-safe startup and continuous watchdog supervision of safety-critical dosing algorithm. IC Role / Device Role / Timing Role: Dual-role device providing power-on reset, periodic watchdog reset, and tamper-resistant parameter storage. Use Value: FLB flag identifies root cause of reset events; Block Lock™ protects drug dosage limits from accidental overwrite during service mode. |
| Automotive Body Control Module | Smart Energy Meter |
Use Scenario: Supervises 5V domain powering CAN transceiver and microcontroller in door module. IC Role / Device Role / Timing Role: Supervisor with EEPROM storing window position memory and fault logs across ignition cycles. Use Value: 100-year data retention ensures lifetime calibration persistence; 200ms tPURST meets automotive cold-crank timing requirements. | Use Scenario: Manages secure boot and stores tariff tables, metering constants, and tamper-event history. IC Role / Device Role / Timing Role: Trusted configuration manager with reprogrammable VTRIP to adapt to varying AC-DC converter tolerances. Use Value: WPEN + WP pin combination creates hardware-enforced write lock - satisfies IEC 62056-21 security requirements for revenue-grade meters. |
Equivalent & Alternatives
The following parts are listed as comparable options for similar CPU supervisor with EEPROM applications.
| Alternative Part | Technical Difference | Application Difference | Selection Advice |
|---|---|---|---|
| MAX6900 | 5V-only operation; 32Kbit EEPROM; no VTRIP reprogramming; active-LOW reset | Lacks field-adjustable threshold and half the EEPROM capacity - suitable only for fixed-threshold designs | Select if VTRIP calibration is unnecessary and 32Kbit storage suffices |
| STM8S105K4T6C | MCU with integrated 1Kbyte EEPROM and software-configurable reset logic - no dedicated watchdog timer circuit | Requires firmware development for reset supervision; no hardware-level brownout immunity below 2.95V | Select only when full MCU control over reset behavior and minimal external BOM are prioritized over guaranteed hardware reliability |
Compared with MAX6900 and STM8S105K4T6C, the X5645P uniquely combines factory-set 4.5V VTRIP with field-reprogrammability, 64Kbit EEPROM with Block Lock™, and hardware watchdog - delivering higher integration, lower risk of firmware-induced failure, and longer-term data integrity without code maintenance.
Availability
X5645P is available at Aetrix Electronics and suitable for industrial PLC controllers, medical infusion pumps, automotive body control modules, and smart energy meters requiring stable component supply across extended temperature ranges and long production lifecycles.
Supply support for X5645P 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
Intersil Corporation (now part of Renesas Electronics) is a U.S.-based semiconductor company specializing in precision analog, power management, and interface ICs for industrial, aerospace, and communications markets.
The X5645P belongs to Intersil's CPU Supervisor with EEPROM family, designed to reduce system cost and board space by integrating reset, watchdog, voltage monitoring, and nonvolatile storage - targeting applications where firmware resilience and field-serviceable calibration are critical.
FAQ
What is the reset output polarity of the X5645P?
The X5645P features an active-HIGH RESET output (labeled RESET/RESET). It drives HIGH when VCC falls below the programmed VTRIP threshold or when the watchdog timer expires. The pin is open-drain, requiring an external pull-down resistor for compatibility with active-LOW MCU reset inputs. This polarity is fixed for the X5645P variant and differs from the active-LOW X5643.
Can the VTRIP voltage of the X5645P be changed after manufacturing?
Yes, the X5645P supports field reprogramming of its VTRIP voltage between 1.7V and 5.0V using a defined VP pulse sequence on SCK and SI pins. This allows calibration to match actual system power rail tolerances without redesigning the PCB or changing components. The procedure is documented in FN8135 Rev 1.00 Section "VCC Threshold Reset Procedure".
How does the X5645P prevent unintended EEPROM writes?
The X5645P uses three independent protections: (1) a volatile Write Enable Latch (WEL) that must be set via WREN command before each write, (2) nonvolatile Block Lock™ bits (BL0/BL1) to protect 0–100% of memory, and (3) in-circuit programmable ROM mode activated when WP = LOW and WPEN = 1 - which disables all status register writes including watchdog and lock settings.
What watchdog timeout periods are available on the X5645P?
The X5645P offers three selectable watchdog timeout periods: 200ms (WD1=1, WD0=0), 600ms (WD1=0, WD0=1), and 1.4s (WD1=0, WD0=0), configured via nonvolatile bits in the status register. The timeout is disabled when WD1=1 and WD0=1. These values are guaranteed across the industrial temperature range (-40°C to +85°C) per FN8135 Rev 1.00 Table on page 6.
Is the X5645P compatible with 2.7V supply operation?
No, the X5645P is rated exclusively for 4.5V to 5.5V operation. Its VTRIP is factory-set to 4.5V and cannot be lowered below ~2.7V via reprogramming - attempting 2.7V operation violates the recommended operating conditions and risks unreliable reset assertion. For 2.7V–5.5V systems, the X5645-2.7A variant must be used instead.
X5645P Specifications
- Product attributes
- Attribute value
- Manufacturer:
- Renesas
- Series:
- -
- Package/Case:
- 8-DIP (0.300", 7.62mm)
- Packaging:
- Tube
- Product Status:
- Obsolete
- Programmable:
- Not Verified
- Type:
- Simple Reset/Power-On Reset
- Number of Voltages Monitored:
- 1
- Voltage - Threshold:
- 4.38V
- Output:
- Open Drain or Open Collector
- Reset:
- Active High
- Reset Timeout:
- 100ms Minimum
- Operating Temperature:
- 0°C ~ 70°C (TA)
- Grade:
- -
- Qualification:
- -
- Mounting Type:
- Through Hole
- Supplier Device Package:
- 8-PDIP
X5645P FAQ
1.How can I place an order for X5645P through Aetrix?
Please submit a Request for Quotation (RFQ) for X5645P 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 X5645P reliable?
The price and inventory of X5645P are updated periodically and may fluctuate due to market conditions. Stock and pricing data are typically refreshed every 24 hours. Quotation validity for X5645P is usually 5 days.
3.What payment methods are accepted for X5645P?
We accept Wire Transfer, PayPal, Credit Card, Western Union, MoneyGram, and Escrow for X5645P transactions.
Note: Certain payment methods may incur a processing fee.
4.How is shipping managed for X5645P?
X5645P orders can be shipped via leading logistics carriers, including DHL, UPS, FedEx, TNT, or Registered Mail.
Once your X5645P 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 X5645P?
For technical support, including X5645P datasheets, pinout diagrams, or application guidance, please contact our engineering support team. They can provide detailed documentation and assistance for your X5645P requirements.
6.How does Aetrix verify that X5645P is sourced from the original manufacturer or authorized distributors?
All X5645P 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 X5645P meets industry standards.
7.What is the process for return or replacement of X5645P?
All X5645P units undergo pre-shipment inspection (PSI). If there is an issue with X5645P, 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 X5645P part is unused and in its original packaging.
Return procedure for X5645P:
1.Submit a request within 90 days.
2.Obtain a Return Material Authorization (RMA) from Aetrix.
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