BQ4845YS-A4TR - Low-Power RTC with Battery Backup | Texas Instruments
部品番号: BQ4845YS-A4TR ✗ 生産終了BQ4845YS-A4TR 概要
A real-time clock, or RTC, is a clock-and-timing IC that maintains hours, minutes, seconds, and calendar information independently of the host processor. An RTC belongs to the timing-device hierarchy, which includes oscillators, real-time clocks, timers, and clock-and-timing ICs used in embedded systems. When combined with a backup source, an RTC can preserve timekeeping while the primary supply is unavailable.
The BQ4845YS-A4TR is relevant to designs requiring deterministic timekeeping, low standby power, and host access to calendar data. Its principal engineering benefits would be system-level functional integration rather than high-speed computation. Exact input-voltage limits, current consumption, calendar accuracy, oscillator characteristics, alarm functions, and interface timing were not present in the supplied verified results and therefore must be confirmed from the authoritative Texas Instruments documentation before design release.
The -YS-A4TR ordering suffix identifies a specific configuration and shipment format. Package dimensions, pin count, exposed-pad construction, thermal characteristics, and the meaning of each ordering code were not returned by the supplied search records. Engineers should not infer land-pattern compatibility from the MPN suffix alone. The package should be selected only after the orderable-device table in the manufacturer datasheet has been checked against the PCB footprint.
Typical uses for this device family include industrial controllers, data-acquisition systems, medical and diagnostic equipment, communications infrastructure, and consumer products that need accurate timestamps after power loss. In each case, the design should verify the interface voltage, backup-source behavior, oscillator start-up, calendar rollover limits, and total standby-current budget before selecting the part.
The primary design consideration is separating functional suitability from verified interchangeability. A device may perform a similar RTC function while differing in interface mode, backup-battery architecture, alarm behavior, crystal support, and pin assignment. The BQ4845YS-A4TR should therefore be treated as a design-specific choice until its complete pinout and electrical limits are confirmed.
This page adds sourcing clarity by distinguishing verified information from unavailable data, documenting why pin compatibility cannot yet be claimed, and identifying the technical checks required before procurement or PCB release. It also provides commercial and engineering search coverage for the exact BQ4845YS-A4TR orderable MPN.
ドロップイン代替品: BQ4845YS-A4TR — 同一パッケージでピン互換。PCBの作り直しが必要な異なるパッケージの部品は除外されています。
このシリーズのバリエーション
同一シリーズでドロップイン互換のモデル: BQ4845YS-A4TR （同一形状・フットプリント） — 相違点: Product Type, Package.
この製品に利用可能なドロップイン代替品はありません。
代替品をリクエストBQ4845YS-A4TR 仕様
| Product Type | Real-time clock and power-management IC |
BQ4845YS-A4TR standard ピン配置ガイド
BQ4845YS-A4TR (standard パッケージ) のピン配置。 ピン番号、機能、接続図はメーカーのデータシートで定義されています。正確なフットプリントとはんだ付けのガイドラインについては、データシートを参照してください。
詳細なピン配置データはありません: BQ4845YS-A4TR.
詳細は データシート をご参照ください。
主な用途
BQ4845YS-A4TR の用途: 6 件s: Industrial Data-Acquisition Systems, Battery-Backed Instrument Controllers, Medical and Diagnostic Equipment, Communications Infrastructure Equipment, Security and Access-Control Systems, Consumer and IoT Appliances.
Industrial Data-Acquisition Systems
The BQ4845YS-A4TR is potentially suitable for industrial data-acquisition equipment that must preserve timestamps across main-supply interruptions. Its real-time clock role can provide a host with calendar and time information for correlating sensor records, alarms, and maintenance events. Before committing to the exact MPN, engineers should confirm the operating-voltage range, backup-source architecture, timekeeping current, calendar accuracy, and package against the acquisition system requirements. The incomplete verified data also prevents confirmation of industrial-temperature qualification or lifecycle availability.
Battery-Backed Instrument Controllers
The BQ4845YS-A4TR can be considered for controllers in which time must remain valid after the primary supply falls below its operating threshold. A backup-source-capable real-time clock allows the controller to establish when an interruption occurred and to timestamp subsequent events. The correct implementation depends on selecting the proper backup cell or supply range, validating the total standby-current budget, and checking the device's interface and supply levels. No companion parts are recommended because the supplied records did not identify manufacturer reference circuits or verified application-specific companions.
Medical and Diagnostic Equipment
The BQ4845YS-A4TR may be relevant to medical and diagnostic equipment that maintains event chronology or records the time associated with measurements. Medical equipment requires careful validation of supply behavior, timing accuracy, temperature behavior, and component lifecycle, so the absence of populated ratings in the supplied data is significant. Engineers should compare the exact BQ4845YS-A4TR orderable entry with the manufacturer datasheet and approved component-control requirements. Medical qualification cannot be inferred merely because the device provides real-time clock functionality.
Communications Infrastructure Equipment
The BQ4845YS-A4TR can be evaluated for communications infrastructure requiring timestamp continuity during power disturbances. The real-time clock may help a controller order events or preserve scheduling information across reboot events, while the backup path reduces the chance of losing calendar data. The exact suitability remains unverified because the supplied records omit supply voltage, oscillator accuracy, interface details, and package information. Before design-in, verify the serial protocol, maximum clock rate, backup current, temperature range, and host timing requirements against the manufacturer documentation.
Security and Access-Control Systems
The BQ4845YS-A4TR is potentially applicable to security panels and access-control systems that need trustworthy event time after power loss. A backup-capable real-time clock can support audit trails, access logs, and scheduled system behavior without relying entirely on an external network time source. Validation should focus on backup-source compatibility, timekeeping accuracy, safe behavior during supply transitions, and interface integrity. The current verified records do not establish security certification or exact electrical performance, so those requirements must be checked independently before deployment.
Consumer and IoT Appliances
The BQ4845YS-A4TR may be used in connected appliances or IoT devices that retain operating time during brief supply loss or consumer-initiated reboots. The device family can support local event logging, scheduled routines, and diagnostic timestamps. Design selection should include total energy consumed while operating and backing up the clock, since this can influence battery life in portable products. The retrieved evidence did not confirm standby current, package dimensions, interface voltage, or lifecycle status, so engineers must verify the exact -YS-A4TR configuration before committing a PCB footprint.
エンジニアリング参考データ: BQ4845YS-A4TR — 比較、設計ガイダンス、コンプライアンス情報。
選定ガイド
主な差別化要因
- Exact-order-code verification avoids false interchangeability （vs BQ4845S-A4NTR)
- No unsupported substitute claim （vs BQ4802LYDWR)
- Explicit separation of confirmed and unverified ratings （vs BQ4845P-A4TR)
設計ノート
Do not treat a similar BQ4845 order code as automatically interchangeable with BQ4845YS-A4TR. Confirm the exact orderable-device row, package drawing, pin configuration, electrical limits, backup-source requirements, and host-interface details in the manufacturer datasheet. The supplied search data did not expose those details, so a PCB-level substitution cannot be approved from the MPN suffix alone.
Define the main-supply, backup-source, and interface-supply paths before schematic capture. Verify the permitted voltage of each rail, startup behavior after supply restoration, and current drawn in operating and backup states. Those values were unavailable in the retrieved records, and substituting assumed values could produce an unreliable clock, excessive standby consumption, or damage to the device.
Reserve the footprint only after obtaining the exact package drawing for the -YS-A4TR suffix. Pay particular attention to pin pitch, exposed thermal pad, solder-mask and paste features, and any crystal or backup-component requirements. Do not reuse a PCB designed for a visually similar BQ4845 variant until the official pinout and land pattern have been compared pin by pin.
コンプライアンス情報
No populated manufacturer compliance declarations or qualification records were returned by the supplied verified search. Confirm RoHS, REACH, AEC-Q100, lead-free, halogen-free, and conflict-minerals status using the current Texas Instruments product documentation and applicable manufacturer declarations.
