BQ4802YPW - Parallel RTC with CPU Supervisor | Texas Instruments
MPN: BQ4802YPW ✗ End of Life| Qty | Unit Price | Extended |
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| 1 | $0 | $0.00 |
| 10 | $0 | $0.00 |
| 100 | $0 | $0.00 |
| 500 | $0 | $0.00 |
| 1,000 | $0 | $0.00 |
BQ4802YPW Overview
A real-time clock is a clock-and-timing IC that maintains time independently of the system processor. The BQ4802YPW belongs to the RTC, clock/calendar, timekeeping, and clock-and-timing hierarchy. Its century-based calendar and external SRAM backup-control capability make it useful in systems that require retained system time or controlled preservation of processor memory during power transitions. The integrated CPU supervisor adds another layer of power-management functionality around a clock peripheral.
The main verified features are Y2K-compliant calendar operation, parallel timekeeping, a CPU supervisor, external nonvolatile SRAM control, 5 V VCC operation as identified in the available technical description, and a 28-pin TSSOP package. These features distinguish it from basic RTC devices that provide only seconds, minutes, hours, and date registers. The TSSOP package is intended for compact surface-mount PCB designs, while the parallel interface simplifies connection to compatible microprocessor or embedded-controller buses.
The BQ4802YPW is positioned for embedded systems, industrial controllers, data-acquisition equipment, test and measurement systems, and other microprocessor-based products where accurate timekeeping and supervised power transitions are useful. A system designer should verify the exact bus timing, reset behavior, SRAM-control requirements, and electrical limits in the manufacturer datasheet before finalizing a design. The provided search data confirms the product identity and broad functionality but does not provide a complete manufacturer datasheet specification set.
The key design consideration is validating the relationship between the RTC, CPU supervisor, and external SRAM backup circuitry. If the system uses battery-backed SRAM, power sequencing and supply rails must be checked against the device's required operating conditions. As with any compact mixed-signal timing IC, PCB layout should preserve clean supply paths and follow the manufacturer's recommended decoupling and pin-routing guidance.
This page consolidates verified distributor identification, product classification, package information, and practical sourcing guidance. It also separates confirmed facts from missing electrical details so engineers can make an informed preliminary selection without assuming unverified ratings, prices, or lifecycle claims.
Drop-in alternatives for BQ4802YPW — same package, pin-to-pin compatible. Different-package parts requiring PCB rework are excluded.
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BQ4802YPWR
✅ Drop-In📋 Reference alternative (not in catalog)
BQ4802YPW Specifications
| Product Type | Y2K-compliant parallel real-time clock |
| Time-of-Day Clock | Integrated |
| Calendar | Century-based |
| CPU Supervisor | Integrated |
| External Nonvolatile SRAM Control | Integrated |
| Supply Voltage | 5 V VCC |
| Interface Type | Parallel |
| Package | 28-pin TSSOP |
| Package Width | 4.40 mm |
| Nominal Package Length | 0.173 in |
| Mounting Type | Surface mount |
| Clock/Calendar Category | Real-time clock (RTC) IC |
| Y2K Compliance | Y2K-compliant |
| Battery-Backed SRAM Interface | External nonvolatile SRAM control |
BQ4802YPW 0.173 in Pin Configuration Guide
Pin configuration for BQ4802YPW (0.173 in package). Pin numbering, functions, and connection diagrams are defined in the manufacturer datasheet. Refer to it for the exact footprint and soldering guidelines.
No detailed pinout data available for BQ4802YPW.
Refer to the datasheet for full pin configuration.
Typical Applications
BQ4802YPW is suitable for 6 applications: Industrial embedded controller timekeeping, Data acquisition and test equipment, Battery-backed data retention, Communication gateway scheduling, Programmable controller reset management, Instrumentation and service-record timestamping.
Industrial embedded controller timekeeping
The BQ4802YPW fits an embedded controller that must maintain time across processor resets or power transitions. Its verified feature set combines a time-of-day clock, century-based calendar, and CPU supervisor in one parallel RTC peripheral, while the 28-pin TSSOP package supports compact surface-mount layouts. The device can provide an independent time reference for event logging, scheduled maintenance records, and communication timestamps. The external nonvolatile SRAM-control feature may be useful when the controller must preserve selected data during a controlled power event. Because the supplied data does not include the operating-temperature range, supply limits, or supervisor timing values, engineers should verify those details in the manufacturer datasheet before using the part in a harsh industrial enclosure.
Recommended
Data acquisition and test equipment
The BQ4802YPW is appropriate for measurement systems where each data record needs a trusted date and time. The century-based calendar and Y2K-compliant timekeeping functions provide a more complete timestamp than a simple seconds-only peripheral, while the CPU supervisor can assist with processor monitoring. In a data logger, the RTC can operate alongside the acquisition controller and external memory, and the SRAM-control function can support retention logic during controlled power transitions. The verified distributor information does not specify oscillator accuracy, temperature stability, or supply-current limits, so those parameters must be obtained from the manufacturer documentation before defining the measurement system's time-tolerance budget.
Recommended
Battery-backed data retention
The BQ4802YPW's external nonvolatile SRAM control makes it relevant to systems that retain operational information during a power interruption. A controller can use the RTC to determine elapsed time across an outage and use the supervisor functions to detect or manage a controlled reset. The design must carefully coordinate the RTC supply, processor rails, external SRAM, and backup battery so that ordinary power cycling does not create unintended write or leakage paths. The available data confirms the functional block and 5 V VCC identification, but it does not provide backup-current figures, battery chemistry requirements, or power-fail thresholds. Those details must be taken directly from the BQ4802Y datasheet before schematic sign-off.
Recommended
Communication gateway scheduling
The BQ4802YPW can support communication gateways that need stable timestamps for logs, retries, and scheduled network activity. Its parallel interface and independent timekeeping are useful when the main processor is busy with packet processing or firmware updates. The CPU supervisor can complement a watchdog or reset strategy, while the calendar supports long-duration timestamp interpretation rather than a two-digit year convention. In a gateway design, the RTC should be placed on a stable supply domain and its bus signals should be checked against the host controller's voltage and timing requirements. The supplied data does not identify a standard bus protocol or logic levels, so interface compatibility must be confirmed from the full manufacturer documentation.
Recommended
Programmable controller reset management
The BQ4802YPW is useful in microprocessor systems that need an independent supervisory path alongside the clock peripheral. A controller can use the supervisor portion to monitor its operating state while the RTC preserves time and calendar information. This combination can simplify the partition of timing and supervisory functions compared with using unrelated discrete components, provided the host firmware and hardware reset architecture are designed together. The available evidence confirms the CPU-supervisor block but not its exact reset polarity, delay, or threshold behavior. Consequently, engineers should not infer watchdog or power-on-reset timing from the product summary and should verify the complete timing specification in the official datasheet.
Recommended
Instrumentation and service-record timestamping
The BQ4802YPW can be incorporated into instruments that record calibration, service, or operating events with a long-lived timestamp. Its century-based calendar and Y2K compliance help avoid ambiguity when records remain stored for many years, and the parallel interface can be connected to a suitable embedded processor or control logic. External nonvolatile SRAM control may assist systems that must retain diagnostic data across a controlled interruption. Before selecting the device for laboratory or field instrumentation, verify accuracy, drift, temperature behavior, and battery-life requirements. Those parameters are not present in the supplied distributor snippets, so the manufacturer datasheet remains the controlling source for timekeeping performance.
Recommended
Recommended Products Summary
Engineering reference data for BQ4802YPW — comparison, design guidance, and compliance information.
Selection Guide
Comparison with Alternatives
| Parameter | This Product | BQ4802YPWR |
|---|---|---|
| Brand | Texas Instruments | Texas Instruments |
Key Differentiators
- Combines RTC and supervisory functions (vs BQ4802YPWR)
- External nonvolatile SRAM control (vs BQ4802YPWR)
- Compact 28-pin TSSOP implementation (vs BQ4802YPWR)
Design Notes
The verified description identifies a 5 V VCC supply, but it does not provide the permitted supply range, absolute maximum ratings, or power-fail thresholds. Confirm those values in the official BQ4802Y datasheet before connecting the RTC, processor, and backup-SRAM rails. Check every external component and pull-up for voltage compatibility, and prevent uncontrolled current paths between backup and active supplies.
Use the official 28-pin TSSOP mechanical drawing and land pattern rather than estimating pad dimensions from a generic TSSOP footprint. Place required bypass capacitors close to the supply pins, keep the RTC supply route short, and route external SRAM-control traces away from switching nodes. Confirm pin numbering and exposed thermal or thermal-pad details against the exact ordering suffix.
Do not treat BQ4802YPW and BQ4802YPWR as interchangeable solely because both identifiers appear in search results. The supplied data does not establish a definitive drop-in relationship, package-suffix equivalence, or full electrical identity. Review the manufacturer ordering table, pinout, lifecycle status, and absolute maximum ratings before approving either part for production.
The RTC, CPU supervisor, and external SRAM-control functions can create timing and power-transition dependencies that are sensitive to board-level routing. Keep sensitive clock and supervisor nets away from noisy power converters, maintain defined return paths, and validate startup, reset, and backup behavior using the manufacturer's recommended test conditions. The supplied data does not include a reference design, so these checks remain necessary rather than optional.
Compliance Information
The supplied verified data does not state RoHS, REACH, AEC-Q100, lead-free, halogen-free, or conflict-minerals status. Confirm these claims against the current Texas Instruments product documentation and applicable distributor declarations.
