BQ4847YMT RTC Module with CPU Supervisor | Texas Instruments
MPN: BQ4847YMT ✓ Hoạt độngBQ4847YMT Tóm tắt
A real-time clock, or RTC, is a clock-and-timing IC that maintains time independently of the system processor. It typically supplies calendar and alarm information, supports battery-backed operation during main-power loss, and allows embedded equipment to retain accurate timestamps after restart. The BQ4847YMT combines the RTC, clock source, backup battery, supervisor circuitry, and external-SRAM retention control in one module, reducing the number of separate timing and power components a board must accommodate.
Key features include BCD time-of-day and calendar counting from seconds through years, an integrated battery and crystal, an on-chip battery-backup switchover circuit, nonvolatile control for an external SRAM, a 130 mAh battery capacity, and ±1 minute per month clock accuracy. The CPU-supervisor function helps system firmware distinguish normal operation from reset or power-failure events, while watchdog, interrupt, reset, and battery-low warning functions support reliable embedded-control behavior.
The module uses a parallel interface rather than the serial bus found in many compact RTC packages. According to the verified distributor descriptions, it is packaged as a 28-DIP module and is categorized as a clock/calendar RTC IC. The integrated battery and crystal mean the associated crystal and primary backup-cell implementation details are contained within the module rather than requiring the same external arrangement as a conventional RTC IC.
Typical uses include industrial controllers, data-acquisition equipment, embedded instruments, access-control systems, and legacy computer hardware requiring a parallel RTC interface. Designers should preserve the module's pinout and battery behavior, account for main-supply and backup-supply sequencing, and verify reset, watchdog, and SRAM-retention requirements against the application. The supplied verified data does not specify a full electrical limit table, operating-temperature range, or lead-time figures, so those details should be confirmed in the manufacturer documentation.
Bộ thay thế dễ dàng lắp đặt cho BQ4847YMT — cùng gói, chân-to-chân tương thích. Các bộ phận yêu cầu hàn PCB bị loại trừ.
Các biến thể trong loạt này
Các mẫu cùng loạt có thể lắp đặt dễ dàng tương thích với BQ4847YMT (cùng hình factor và footprint) — khác nhau ở Interface, Mounting Type, Package, REACH Status, RoHS Status.
BQ4847-MT
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
BQ4845
✅ Drop-In📋 Tham chiếu thay thế (không có trong danh mục)
BQ4847YMT Thông số kỹ thuật
| Product Type | Real-time clock module with CPU supervisor |
| Time Representation | BCD seconds through years |
| Giao diện | Parallel clock/calendar interface |
| Integrated Functions | RTC, CPU supervisor, watchdog timer, reset, interrupts, battery-low warning |
| Battery Type | Integrated 130 mAh battery |
| Clock Accuracy | ±1 minute per month |
| Backup Control | On-chip battery-backup switchover circuit |
| External SRAM Control | Nonvolatile control for an external SRAM |
| Crystal | Integrated quartz crystal |
| Hộp | 28-DIP module |
| Package Width | 15.49 mm |
| Distributor Listing Size | 0.61 inch |
| Kiểu lắp đặt | Through-hole DIP module |
| Reset and Watchdog | CPU supervisor with watchdog and reset functions |
| Battery Warning | Battery-low warning feature |
| Interrupt Support | Interrupt features |
| Calendar Range | Seconds through years |
| Trạng thái RoHS | unknown |
| REACH Status | unknown |
| AEC-Q100 Qualification | unknown |
| Lead-Free Status | unknown |
Hướng dẫn cấu hình chân BQ4847YMT 15.49 mm
Cấu hình chân cho BQ4847YMT (15.49 mm gói). Số thứ tự chân, chức năng và sơ đồ kết nối được xác định trong tài liệu thông số kỹ thuật của nhà sản xuất. Tham khảo nó để biết footprint và hướng dẫn hàn chính xác.
Không có dữ liệu chân cụ thể sẵn có cho BQ4847YMT.
Tham khảo: tài liệu kỹ thuật cho cấu hình chân đầy đủ.
Ứng dụng tiêu biểu
BQ4847YMT phù hợp cho 6 Áp dụngs: Industrial Data Loggers, Embedded Access-Control Systems, Data-Acquisition Instruments, Legacy Computer Peripherals, Battery-Backed Embedded Control, Test and Measurement Equipment.
Industrial Data Loggers
The BQ4847YMT fits industrial data-logging equipment that must retain timestamps when the main supply fails or the controller restarts. Its ±1 minute per month clock accuracy provides a defined timing basis, while the integrated 130 mAh battery supports backup operation without adding a separate crystal and primary backup cell. The parallel clock/calendar interface can be connected to a controller with suitable GPIO or bus-interface logic. The CPU-supervisor, reset, watchdog, interrupt, and battery-low warning functions help the firmware distinguish power events and protect the logging sequence. Before layout, confirm voltage levels, reset timing, and SRAM-control requirements in the manufacturer datasheet.
Được đề xuất
Embedded Access-Control Systems
BQ4847YMT is appropriate for access-control and security equipment requiring a persistent calendar record independent of the main processor. The RTC counts seconds through years in BCD format, which supports event timestamps across long operating periods. The integrated battery and quartz crystal simplify the backup-timekeeping implementation, while the CPU supervisor and reset features provide useful system-state inputs for lockout and event-log handling. The external-SRAM retention control can support designs that need nonvolatile storage behavior, although the exact SRAM interface must be verified. Use the parallel interface and the module’s through-hole package in a layout that accounts for mechanical clearance and battery access.
Được đề xuất
Data-Acquisition Instruments
The BQ4847YMT can serve as the time base in measurement instruments where samples must be correlated with a calendar and retained across power interruptions. Its ±1 minute per month specification provides a useful accuracy reference for slow-changing process and laboratory records, and the backup battery helps preserve elapsed time during service or restart. The integrated crystal removes the need for a separate oscillator in the timer subsystem, leaving the design team to focus on bus decoding and signal-chain calibration. Watchdog and reset functions can reduce recovery time after unexpected events, while battery-low warning permits maintenance before timekeeping becomes unreliable. Verify operating temperature and supply limits against the exact manufacturer documentation.
Được đề xuất
Legacy Computer Peripherals
BQ4847YMT is suited to legacy computer and peripheral designs that require a parallel RTC/calendar interface rather than a modern serial RTC. The module combines timekeeping, crystal, backup battery, and CPU-supervisor functions in a 28-DIP package, which can simplify retrofitting compared with reconstructing all functions from discrete components. The external-SRAM backup-control feature is useful where retained data or configuration state must survive a main-power transition. Designers should verify signal timing, address or data-line mapping, and supply sequencing because the supplied data does not include a complete pinout or electrical table. Mechanical design must also account for the module’s 15.49 mm width and through-hole construction.
Được đề xuất
Battery-Backed Embedded Control
The BQ4847YMT fits embedded controllers that must know the date and time after a brownout, watchdog reset, or power cycle. Its integrated 130 mAh battery and on-chip backup switchover provide a defined backup-power concept, while the CPU supervisor and reset functions can inform the application firmware about the source of recovery. The integrated crystal makes the module a compact timing subsystem for control boards that do not need a separately calibrated clock source. Battery-low warning is useful for preventive maintenance, and the interrupt capability can flag RTC-related events. Confirm whether the external-SRAM control feature is needed and validate all backup-supply timing in the exact datasheet.
Được đề xuất
Test and Measurement Equipment
BQ4847YMT can provide timestamp continuity for test and measurement systems whose records need to remain meaningful after a mains interruption. The ±1 minute per month clock accuracy is suitable for event-level and general-purpose instrument timestamping, while the 130 mAh integrated battery supports the module’s backup function. The CPU-supervisor, watchdog, reset, and interrupt features allow a controller to distinguish deliberate shutdowns from faults and schedule recovery actions. The parallel interface may require level-compatible logic and careful signal routing, so the design should verify voltage thresholds and timing. The 28-DIP module also provides a mechanically identifiable through-hole footprint for legacy and industrial instrument platforms.
Được đề xuất
Tóm tắt các sản phẩm được đề xuất
Dữ liệu tham khảo kỹ thuật cho BQ4847YMT — so sánh, hướng dẫn thiết kế và thông tin tuân thủ.
Hướng dẫn chọn lựa
So sánh với các sản phẩm thay thế
| Tham số | Sản phẩm này | BQ4847-MT | BQ4845 |
|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments |
| RTC Function | Real-time clock with clock/calendar | Real-time clock module | Functionally equivalent RTC family part per verified material |
Bảo phân biệt quan trọng
- Integrated backup timing subsystem (vsBQ4845)
- External-SRAM retention control (vsBQ4802LY)
- Parallel clock/calendar integration (vsM41T82RM6F)
Ghi chú thiết kế
Validate main-supply, backup-supply, and external-SRAM power sequencing against the manufacturer datasheet before connecting the module. The verified feature set confirms an on-chip battery-backup switchover circuit and nonvolatile external-SRAM control, but the supplied data does not provide the required voltage thresholds or timing windows. Keep main-rail decoupling close to the board power entry and ensure that backup operation cannot backfeed or damage the SRAM or system supply.
Treat BQ4847YMT as a 28-DIP through-hole module rather than a generic 28-pin IC footprint. Confirm the mechanical drawing, pin numbering, battery clearance, and connector orientation before layout. The distributor listing identifies a 15.49 mm-wide module, so provide the specified keepout and avoid placing tall or heat-generating components that could interfere with the module body, battery area, or nearby signal routing.
Do not substitute BQ4802LY or an assumed BQ4845 variant without a complete pin-level comparison. The verified material specifically notes that BQ4802LY lacks an integrated crystal and may require an adapter board, while it does not establish BQ4845 as a direct BQ4847YMT drop-in replacement. Verify pinout, supply levels, reset behavior, battery backup, calendar access, and external-SRAM control before releasing a replacement design.
Route the parallel clock/calendar interface away from noisy switching nodes and provide a defined ground reference close to the controller interface. The supplied data confirms a parallel interface but does not specify signal timing or logic levels, so use the manufacturer timing diagram and external buffering or level translation only where the datasheet requires it. Keep the module’s crystal and backup circuitry away from high-current edges and maintain a stable return path.
Thông tin tuân thủ
The supplied verified web data does not provide compliance declarations for BQ4847YMT. RoHS, REACH, AEC-Q100, lead-free, halogen-free, and conflict-minerals status remain unknown until confirmed through the current manufacturer or authorized-distributor documentation.
