BQ4285S-SB2 RTC with 114x8 NVRAM | Texas Instruments
N.º de pieza: BQ4285S-SB2 ✗ Fin de vida| Cant. | Precio unitario | Total |
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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 |
BQ4285S-SB2 Descripción general
A real-time clock is a clock-and-timing semiconductor that maintains calendar time independently of the host processor's main clock. An RTC commonly includes oscillators, registers, calendar logic, alarm functions, and an interface for host reads and writes. Adding NVRAM allows the same device to retain small amounts of configuration or system data when power is removed. In the broader semiconductor hierarchy, the BQ4285S-SB2 belongs to integrated circuits, clock and timing devices, and RTCs with embedded nonvolatile memory.
The verified listing identifies the BQ4285S-SB2 as a 24-SOIC real-time clock with 114 bytes of parallel NVRAM and NVRAM control. The Mouser listing likewise identifies it as a 114 x 8 NVSRAM and NVSRAM control device. These details make it relevant to legacy computer, embedded-control, industrial, and instrument designs that need timekeeping plus compact persistent storage. The device is also associated with AT-compatible clock/calendar use in the supplied search results, but the exact electrical limits and operating conditions must be taken from the manufacturer datasheet.
Because the supplied data does not expose the complete electrical tables, pin names, oscillator accuracy, voltage range, current consumption, or temperature limits, those values are not inferred here. The SOIC footprint and pin count are identifiable from the distributor description, but a complete pinout cannot be responsibly generated without the manufacturer pin table. For new layouts, download the official BQ4285S datasheet and compare every power, ground, interface, and control signal before assembly.
Typical implementation places the RTC beside a host bus or embedded processor, connects its backup supply or supply rails as specified by the manufacturer, and routes the parallel interface to the controlling logic. NVRAM can hold configuration values, counters, or small audit records, but its endurance and retention behavior should be verified in the datasheet rather than inferred from the memory size. The main design trade-off is the need to validate legacy interface timing and supply requirements against the exact system architecture.
This page summarizes the verified distributor identity, package, clock/calendar role, and 114 x 8 NVRAM function, then separates verified facts from missing technical details. It also records that the supplied cross-reference search identifies DS14285S and DS1685SN-5+ as comparison candidates, while package, pin compatibility, and parameter matching still require datasheet-level validation before any replacement is approved.
Alternativas directas para BQ4285S-SB2 — mismo encapsulado, compatible pin a pin. Se excluyen las piezas de otro encapsulado que requieren retrabajo de la PCB.
Herramienta de comparación rápida — seleccione piezas alternativas para compararlas lado a lado:
BQ4285S-V1
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
BQ4285S-V2
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
DS14285S
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
DS14285S+
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
DS1685SN-5+
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
BQ4285S-SB2 Especificaciones
| Product Type | Real-time clock and calendar IC |
| NVRAM Capacity | 114 x 8 bits |
| NVRAM Organization | 114 bytes |
| Tipo de interfaz | Parallel |
| Encapsulado | 24-SOIC |
| Package Width | 7.50 mm |
| Package Length | 0.295 inch |
| Tipo de montaje | Surface Mount |
| Función | Real-time clock and calendar with NVRAM |
| NVRAM Control | Yes |
| Calendar Day of Week | Supported according to supplied cross-reference data |
| Calendar Day of Month | Supported according to supplied cross-reference data |
Guía de configuración de pines de BQ4285S-SB2 0.295 inch
Configuración de pines para BQ4285S-SB2 (encapsulado 0.295 inch). La numeración de pines, las funciones y los diagramas de conexión se definen en la hoja de datos del fabricante. Consúltela para conocer el footprint exacto y las directrices de soldadura.
No hay datos detallados de patillaje disponibles para BQ4285S-SB2.
Consulte la hoja de datos para ver la configuración completa de patillas.
Aplicaciones típicas
BQ4285S-SB2 es adecuado para 6 aplicacións: Legacy Computer Clock and Calendar, Embedded Data Logger, Industrial Control Module, Instrumentation and Test Equipment, Network and Communications Equipment, Battery-Backed Embedded System.
Legacy Computer Clock and Calendar
The BQ4285S-SB2 fits a legacy computer or controller that needs a dedicated parallel real-time clock and calendar rather than deriving time from the main processor. Its verified 114 x 8-bit NVRAM can retain small configuration or diagnostic values alongside the time registers. The 24-SOIC package is appropriate when the existing board already provides that footprint, but the designer must confirm the exact pin assignment, interface timing, supply rails, and backup-power arrangement in the Texas Instruments datasheet.
Recomendado
Embedded Data Logger
The BQ4285S-SB2 is useful in an embedded data logger that needs a timestamp and a small amount of persistent local state. The 114-byte NVRAM can hold counters, configuration flags, or a compact event record without adding a separate memory IC for small data volumes. Because the verified data does not state endurance, retention, or operating-temperature limits, the application should use the device only within the manufacturer's validated conditions and should not treat the NVRAM as unlimited flash storage.
Recomendado
Industrial Control Module
A control module can use the BQ4285S-SB2 to maintain a calendar reference and retain small operating parameters across power cycles. The parallel interface is useful when a controller already uses a deterministic bus and avoids introducing a software-intensive serial real-time-clock arrangement. Qualification must include checking the device's actual supply range, oscillator accuracy, temperature limits, NVRAM retention, and endurance; those values are not present in the supplied distributor snippets and therefore should not be assumed.
Recomendado
Instrumentation and Test Equipment
In instrumentation, the BQ4285S-SB2 can provide a persistent time reference for logs, calibration metadata, and operating events. The 114-byte NVRAM is large enough for compact records or configuration flags but not for continuous high-volume logging, so a separate nonvolatile storage device remains appropriate for large datasets. The 24-SOIC footprint and parallel interface can simplify integration into a legacy instrument, provided the exact pinout and electrical timing are verified against the board schematic.
Recomendado
Network and Communications Equipment
The BQ4285S-SB2 can support a communications appliance that needs local calendar time, event timestamps, and a small persistent configuration area. Its parallel host interface may be useful in older or highly deterministic equipment architectures, while the NVRAM can retain limited counters or boot information. Before deployment, verify timing margins, supply behavior, oscillator requirements, and the number of NVRAM writes expected by the application; the verified data does not provide those ratings.
Recomendado
Battery-Backed Embedded System
The BQ4285S-SB2 can be integrated into a battery-backed embedded system when time and a small amount of state must survive a main-power interruption. The RTC and NVRAM functions are suitable for that architecture, but the supplied data does not identify the required backup source or power-fail behavior. Engineering review should therefore include the manufacturer's supply pins, oscillator connection, retention current, and NVRAM data-retention specification before selecting a battery or supercapacitor.
Recomendado
Resumen de productos recomendados
Datos de referencia de ingeniería para BQ4285S-SB2 — comparación, orientación de diseño e información de cumplimiento.
Guía de selección
Comparación con alternativas
| Parámetro | Este producto | BQ4285S-V1 | BQ4285S-V2 | DS14285S | DS14285S+ | DS1685SN-5+ |
|---|---|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Maxim Integrated | Maxim Integrated | Maxim Integrated |
| Package | 24-SOIC | 24-SOIC candidate; verify | 24-SOIC candidate; verify | 24-SOIC | 24-SOIC | 24-SOIC |
Diferenciadores clave
- Integrated RTC plus persistent storage (frente a DS14285S)
- Parallel host interface (frente a DS1685SN-5+)
- Known package identity (frente a BQ4285S-V2)
- AT-compatible clock/calendar positioning (frente a DS14285S+)
Notas de diseño
Before placing the BQ4285S-SB2, identify the complete supply and backup-power arrangement from the manufacturer datasheet. The verified distributor data confirms an RTC with 114-byte NVRAM but does not specify input voltage, operating current, or power-fail behavior. Do not infer a battery connection or rail voltage from the RTC function. Validate normal supply, backup supply, ground, and decoupling requirements against the official electrical tables before layout release.
Use the manufacturer pin table to route power, oscillator, parallel interface, and control signals; the supplied data does not provide the 24-pin assignment. Keep the RTC device and its required decoupling close to the associated supply and ground connections, and preserve the datasheet-defined layout around any crystal or oscillator network. Because a 24-SOIC footprint alone does not guarantee pin compatibility, compare the land pattern and pin names mechanically and electrically with the original design.
Do not treat a distributor cross-reference result as proof of drop-in compatibility. The supplied data names BQ4285S-V1, BQ4285S-V2, DS14285S, DS14285S+, and DS1685SN-5+ as investigation candidates, while explicitly noting incomplete or differing electrical information. Verify supply range, pinout, bus timing, calendar behavior, NVRAM size, retention, and oscillator requirements against official datasheets before approving any replacement.
Keep the RTC's parallel signal routing short and deterministic, especially if the host processor reads calendar registers during an interrupt or power-transition event. Follow the manufacturer's recommended grounding and bypass-capacitor placement rather than relying on generic SOIC layout rules. If the board also contains switching regulators or high-current digital circuits, isolate noisy return paths from the RTC reference and NVRAM control region where the datasheet permits.
Información de cumplimiento
The supplied verified distributor and cross-reference data does not provide RoHS, REACH, AEC-Q100, lead-free, halogen-free, or conflict-minerals declarations. These fields remain unknown rather than assumed.
