BQ4850YMA-85N - 512Kx8 NVSRAM RTC | Texas Instruments
N.º da peça: BQ4850YMA-85N ✓ AtivoBQ4850YMA-85N Visão geral
A real-time clock is a specialized integrated circuit that maintains time independently of the host processor. The BQ4850YMA-85N belongs to the RTC and calendar hierarchy, while its integrated RAM adds persistent data storage in the same module. This combination places it within clock-and-timing and data-retention applications where the system requires both accurate calendar information and nonvolatile storage without using separate timekeeping and memory devices.
Key verified features include an integrated SRAM, real-time clock, crystal, power-fail control circuit, and battery support. The 512Kx8 NVSRAM provides 524,288 bits of storage, while the parallel interface gives the host direct access to time and memory registers. Operation from 4.5 V to 5.5 V suits conventional 5 V equipment, and the 32-DIP module format supports insertion into a through-hole board layout. The tube packaging option is intended for orderly manufacturing handling and automated or manual production insertion.
Technically, the module combines timekeeping logic with nonvolatile static memory in one 32-pin package. Its BCD-based clock and calendar representation follows the verified HH MM SS and YY-MM-DD-dd formats. The integrated crystal establishes the timing reference, while the power-fail control and battery circuitry help preserve RTC operation and stored data during supply interruptions. Exact retention duration, battery characteristics, oscillator accuracy, and electrical limits beyond the supplied 4.5 V to 5.5 V supply range were not provided and therefore must be confirmed from the manufacturer datasheet before design release.
Typical uses include industrial data loggers, instrumentation, embedded control systems, financial terminals, and equipment requiring a nonvolatile configuration or audit record. In such systems, the host processor can read the calendar through the parallel bus and use the NVSRAM for operating counters, calibration data, event logs, or configuration retention. Consolidation can reduce component count, but the complete host-bus timing, address map, battery chemistry, and write-protection behavior must be verified before schematic capture.
The primary design consideration is to preserve the exact module footprint and verify every signal before substitution. A functional clock-and-RAM device is not automatically a drop-in replacement: supply limits, address mapping, access timing, battery handling, module dimensions, and power-fail behavior must all match. The verified sources did not establish five pin-compatible alternatives, so this page does not present unverified equivalents as drop-in parts.
This product page combines verified manufacturer-related listings, distributor availability information, cross-reference results, package details, and engineering-specific cautions. It distinguishes confirmed BQ4850YMA-85N characteristics from parameters that still require the original manufacturer datasheet, providing a more reliable basis for sourcing and engineering review than a raw distributor listing alone.
Alternativas drop-in para BQ4850YMA-85N — mesmo encapsulamento, compatível pino a pino. Peças de encapsulamento diferente que exigem retrabalho na PCB são excluídas.
Variantes desta série
Modelos da mesma série compatíveis como drop-in com BQ4850YMA-85N (mesmo formato e footprint) — diferindo em Package Width, Product Type.
Nenhuma alternativa drop-in disponível para este produto.
Solicitar alternativasBQ4850YMA-85N Especificações
| Product Type | Real-time clock and calendar module with NVSRAM |
| RTC Time Format | HH MM SS, 24-hour format |
| RTC Date Format | YY-MM-DD-dd |
| Supply Voltage Range | 4.5 V to 5.5 V |
| Integrated Memory | 512Kx8 nonvolatile static RAM |
| Integrated Memory Capacity | 524,288 bits |
| Host Interface | Parallel |
| Encapsulamento | 32-DIP Module |
| Package Length | 15.49 mm |
| Package Width | 0.610 inch |
| Packaging | Tube |
| Integrated Functions | SRAM, real-time clock, crystal, power-fail control circuit, and battery |
| Clock Representation | BCD format |
Guia de Configuração de Pinos do BQ4850YMA-85N 0.610 inch
Configuração de pinos para BQ4850YMA-85N (pacote 0.610 inch). A numeração dos pinos, funções e diagramas de conexão estão definidos no datasheet do fabricante. Consulte-o para o footprint exato e diretrizes de soldagem.
Nenhum dado detalhado de pinagem disponível para BQ4850YMA-85N.
Consulte a ficha técnica para a configuração completa dos pinos.
Aplicações típicas
BQ4850YMA-85N é adequado para 6 aplicaçãos: Industrial Data Loggers, Precision Test and Measurement, Embedded Control Systems, Network and Communications Equipment, Financial and Transactional Terminals, Legacy Control and Repair Systems.
Industrial Data Loggers
The BQ4850YMA-85N fits industrial data loggers that need both calendar time and persistent operating records in a single 32-DIP module. Its 512Kx8 NVSRAM can hold counters, calibration values, or compact event data, while the 24-hour HH MM SS clock provides timestamps. The integrated power-fail control and battery support are valuable when data must remain available during a main-supply interruption. Because the verified data does not state temperature range, retention time, or write endurance, the application requires confirmation of those limits from the manufacturer datasheet before deployment.
Recomendado
Precision Test and Measurement
The BQ4850YMA-85N is useful in test and measurement equipment that must associate readings with a real date and time while retaining configuration data. The parallel interface supports direct host access, and the 512Kx8 NVSRAM can preserve calibration constants, instrument counters, or test sequences. Its 4.5 V to 5.5 V operating range fits conventional 5 V instrument electronics. The integrated crystal, power-fail control, and battery features help protect time and data, although oscillator accuracy and bus timing must be obtained from the original datasheet before precision requirements are accepted.
Recomendado
Embedded Control Systems
The BQ4850YMA-85N can support legacy embedded controllers that need a host-accessible calendar and nonvolatile working storage without allocating separate memory. The parallel bus provides a straightforward connection to microprocessor or programmable-logic I/O, while 512Kx8 NVSRAM offers room for configuration blocks and diagnostic counters. The 32-DIP through-hole format suits larger control boards and repairable industrial equipment. Before schematic release, verify address decoding, read/write control, signal levels, battery backup details, and timing because these electrical parameters were not included in the retrieved listing data.
Recomendado
Network and Communications Equipment
The BQ4850YMA-85N is appropriate for communications equipment requiring local event timestamps and persistent operational records across a power interruption. Its 512Kx8 NVSRAM can store diagnostic counters, configuration snapshots, or audit metadata, while the RTC supplies calendar information in a 24-hour format. The integrated power-fail control and battery circuitry make the module useful where continuity of timekeeping matters. Engineers should confirm address-map compatibility, bus timing, and package dimensions in the original datasheet before treating it as a replacement for another 32-pin clock-and-memory module.
Recomendado
Financial and Transactional Terminals
The BQ4850YMA-85N can support transactional terminals that need a real calendar and locally retained records within one module. The 512Kx8 NVSRAM provides nonvolatile storage for transaction references, operator settings, or audit data, while the 4.5 V to 5.5 V supply range supports 5 V logic systems. Its integrated battery and power-fail control can help maintain information when external power is interrupted. Deployment still requires validation of battery life, retention guarantees, environmental limits, and access timing from the manufacturer datasheet before use in a regulated or high-value transaction environment.
Recomendado
Legacy Control and Repair Systems
The BQ4850YMA-85N is particularly relevant to repair and continuation designs for legacy 5 V control equipment using a 32-DIP module footprint. The parallel interface and combined RTC/NVSRAM architecture can simplify restoration of timekeeping and retained configuration functions without redesigning the existing bus arrangement. The tube package is appropriate for orderly production use. Because the verified cross-reference evidence identifies similar but not proven pin-compatible DS1747 and DS1244Y devices, the safest approach is to preserve the original footprint and verify every pin, timing parameter, and power-control connection against the manufacturer documentation.
Recomendado
Resumo dos produtos recomendados
Dados de referência de engenharia para BQ4850YMA-85N — comparação, orientação de projeto e informações de conformidade.
Guia de seleção
Comparação com alternativas
| Parâmetro | Este produto |
|---|---|
| Brand | Texas Instruments |
| Package | 32-DIP Module |
| Product Type | RTC and calendar module with NVSRAM |
| Supply Voltage Range | 4.5 V to 5.5 V |
| Integrated Memory | 512Kx8 NVSRAM |
| Host Interface | Parallel |
| Time Format | HH MM SS, 24-hour format |
| Packaging | Tube |
Principais diferenciais
- Integrated RTC and nonvolatile storage (vs DS1747-70IND+)
- Directly documented tube-packaged configuration (vs DS1747-70)
- Power-fail and battery integration (vs DS1244Y)
Notas de projeto
Do not treat a device with similar RTC and RAM functions as a drop-in replacement merely because both have 32 pins. The verified cross-reference material describes DS1747-70, DS1747-70IND+, and DS1244Y as similar or analogous, but it does not establish identical pin mapping, access timing, battery handling, or mechanical dimensions. For the BQ4850YMA-85N, obtain the complete numbered pin table and compare it with the proposed substitute before changing a released PCB.
The BQ4850YMA-85N operates in the verified 4.5 V to 5.5 V range, so the system supply must remain inside that interval under normal and transient conditions. The part includes battery-related circuitry, but the supplied data does not identify the permitted battery chemistry, charging behavior, or backfeed limits. Those details must be established from the manufacturer datasheet before adding a backup cell or connecting the module to a separately powered host interface.
Preserve the full 32-DIP module footprint, including its documented dimensions of 0.610 inch by 15.49 mm, and verify the mechanical drawing rather than relying on a generic 32-DIP footprint. The integrated crystal and backup-battery circuitry make placement and grounding important. Review the manufacturer layout guidance for lead-clearance, bus routing, and decoupling, and avoid placing noisy switching circuitry directly beneath the module if its guidance identifies a keep-out requirement.
Route the parallel host interface with the shortest practical point-to-point paths and keep the data, address, and control signals away from high-current switching nodes. The verified data identifies a parallel interface but does not provide setup, hold, or access-time limits, so the host controller timing must be derived from the manufacturer datasheet. Add interface pull resistors only where the original reference design or device specification calls for them; random termination can alter bus behavior.
Informações de conformidade
The supplied web results do not provide verified environmental or substance-compliance declarations for this exact MPN. AEC-Q100 is not applicable because the product is an RTC module rather than an automotive-qualified device, but no automotive qualification was verified.
