BQ4285P-SB2 - 114x8 NVSRAM RTC Clock/Calendar | TI
N.º da peça: BQ4285P-SB2 ✓ Ativo| Qtd. | Preço unitário | Total |
|---|---|---|
| 1 | $4.19 | $4,19 |
| 10 | $4.19 | $41,90 |
| 100 | $4.19 | $419,00 |
| 500 | $4.19 | $2.095,00 |
| 1.000 | $4.19 | $4.190,00 |
BQ4285P-SB2 Visão geral
A real-time clock is a clock-and-timing integrated circuit that maintains time and calendar information independently of the system’s main processor. It is useful when a system must preserve date, time, and configuration data across power loss. The BQ4285P-SB2 extends that role by integrating 114 bytes of NVRAM and NVRAM control, allowing the same device to provide both timekeeping and retained storage.
The BQ4285P-SB2 is listed by Texas Instruments and distributors as a parallel-interface RTC clock/calendar with 114 bytes of NVRAM. Its 24-DIP package is intended for through-hole PCB assembly and provides a direct package format for designs requiring a conventional DIP footprint. The verified material also describes compatibility-oriented use in IBM AT-compatible computers and functionally compatible calendar arrangements, although exact timing, voltage, and electrical limits must be taken from the manufacturer datasheet.
Typical applications include legacy computer clock/calendar replacement, industrial control systems requiring retained configuration data, data-acquisition equipment, instrumentation, embedded systems with battery-backed timekeeping, and products that need both RTC data and a small nonvolatile parameter store. The integrated NVRAM can simplify designs by reducing the number of separate retention components, provided the host software manages the device interface correctly.
The principal design consideration is interface compatibility. Because this is a 24-pin DIP through-hole device with a parallel clock/calendar and NVRAM organization, PCB layout, signal levels, supply requirements, and software register access must be verified before substitution. Do not assume that a similarly named RTC is interchangeable without comparing the manufacturer pinout and datasheet timing specifications. The verified data supports the 114 x 8 NVRAM organization and 24-DIP package, but does not provide every electrical timing parameter in the supplied records.
This product summary synthesizes the verified distributor descriptions, manufacturer-linked datasheet result, package information, and cross-reference findings. It distinguishes documented facts from parameters that require direct confirmation from the complete Texas Instruments datasheet, helping engineers identify the correct RTC before requesting samples or placing an order.
Alternativas drop-in para BQ4285P-SB2 — mesmo encapsulamento, compatível pino a pino. Peças de encapsulamento diferente que exigem retrabalho na PCB são excluídas.
Ferramenta de comparação rápida — selecione peças alternativas para comparação lado a lado:
DS14285+
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
DS14285N
✅ Drop-In📋 Alternativa de referência (fora do catálogo)
BQ4285P-SB2 Especificações
| Product Type | Real-Time Clock (RTC) with NVRAM control |
| NVRAM Organization | 114 x 8 bits |
| Clock/Calendar Data | RTC clock/calendar |
| Interface | Parallel |
| Encapsulamento | 24-DIP, 0.600 inch, 15.24 mm |
| Tipo de montagem | Through-hole |
| Número de pinos | 24 pins |
| Manufacturer | Texas Instruments |
| Function Description | Real-Time Clock RTC with NVRAM control |
| Compatibility Reference | IBM AT-compatible computers and other applications |
| Calendar Compatibility | Day of week, day of month, month, year, and related calendar functions |
Guia de Configuração de Pinos do BQ4285P-SB2 24-dip, 0.600 inch, 15.24 mm
Configuração de pinos para BQ4285P-SB2 (pacote 24-dip, 0.600 inch, 15.24 mm). 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 BQ4285P-SB2.
Consulte a ficha técnica para a configuração completa dos pinos.
Aplicações típicas
BQ4285P-SB2 é adequado para 6 aplicaçãos: IBM AT-Compatible Clock/Calendar, Industrial Data Acquisition, Instrumentation and Test Equipment, Embedded Control with Retained Configuration, Legacy Peripheral and Bus Timing, Battery-Backed Product Controller.
IBM AT-Compatible Clock/Calendar
The BQ4285P-SB2 is a strong fit when an IBM AT-compatible system needs a parallel RTC and retained calendar data. Its documented clock/calendar function and compatibility-oriented design target legacy computer clock and calendar replacement, while the 114 x 8 NVRAM can hold configuration or status information alongside timekeeping. The 24-DIP through-hole package supports conventional PCB layouts, but designers should verify every signal, supply requirement, and software register against the manufacturer datasheet before production use.
Recomendado
Industrial Data Acquisition
The BQ4285P-SB2 can support industrial data-acquisition equipment that must record events with a real date and time and retain small configuration parameters during power loss. Its parallel RTC interface is appropriate for systems that already use a host bus or dedicated control logic, while the integrated 114 x 8 NVRAM provides a compact place for calibration or operating-status data. The design must account for through-hole assembly, signal integrity, backup-power behavior, and the exact electrical limits not supplied in the verified web excerpts.
Recomendado
Instrumentation and Test Equipment
Use the BQ4285P-SB2 in instrumentation that needs traceable event timestamps and retained setup information. The RTC supplies clock/calendar data, and the 114 x 8 NVRAM can store small operating parameters, calibration identifiers, or sequence numbers without relying only on volatile RAM. Because the device is a 24-DIP through-hole parallel-interface part, it is most practical in equipment where a legacy-style controller, backplane, or manually assembled prototype can provide compatible bus timing and pin connections.
Recomendado
Embedded Control with Retained Configuration
The BQ4285P-SB2 fits legacy embedded-control boards that need timekeeping plus nonvolatile configuration storage. Instead of separating the RTC from a small retention memory, the integrated 114 x 8 NVRAM can provide a shared device for time and limited persistent data. The implementation should use the manufacturer’s interface timing and verify backup supply behavior, NVRAM write limits, and reset-state assumptions. Its DIP format favors through-hole industrial or controller-board layouts rather than compact surface-mount designs.
Recomendado
Legacy Peripheral and Bus Timing
The parallel RTC interface and 24-DIP package make the BQ4285P-SB2 suitable for legacy peripheral boards that expose a broad bus to an RTC and calendar circuit. It can maintain time while the host is reset or unavailable and retain up to the documented 114 x 8 NVRAM organization for small persistent parameters. Board bring-up should include signal timing checks, bus contention testing, grounding review, and direct comparison with the datasheet pinout because the supplied web results do not provide individual pin functions.
Recomendado
Battery-Backed Product Controller
The BQ4285P-SB2 is potentially useful in battery-backed controller products that need date, time, and a small amount of retained data during power interruption. The RTC provides the timekeeping role and the integrated NVRAM provides persistent configuration storage, while the DIP package supports through-hole assembly in larger control boards. Before selecting it for a battery product, verify standby current, battery chemistry compatibility, oscillator accuracy, data-retention duration, and NVRAM endurance because those values are not present in the verified excerpts.
Recomendado
Resumo dos produtos recomendados
Dados de referência de engenharia para BQ4285P-SB2 — comparação, orientação de projeto e informações de conformidade.
Guia de seleção
Comparação com alternativas
| Parâmetro | Este produto | DS14285+ | DS14285N |
|---|---|---|---|
| Product Type | RTC with NVRAM control | RTC with consistent terminals and packages | RTC with consistent terminals and packages |
| Package | 24-DIP, 0.600 inch, 15.24 mm | 24-DIP | 24-DIP |
| Mounting Type | Through-hole | Through-hole | Through-hole |
| Clock/Calendar | RTC clock/calendar | Real-time clock calendar | Real-time clock calendar |
| Manufacturer | Texas Instruments | Maxim Integrated | Maxim Integrated |
Principais diferenciais
- Integrated retained storage alongside the RTC (vs DS14285+)
- Direct legacy-computer positioning (vs DS14285N)
- Documented parallel interface and DIP integration (vs DS14285N)
Notas de projeto
Treat the BQ4285P-SB2 as a through-hole 24-DIP component and preserve the verified 0.600 inch, 15.24 mm package format when laying out the PCB. Confirm the manufacturer pin numbering and pin names before routing the parallel bus; the supplied data identifies the package but does not provide the individual pin map. Keep the RTC and its associated traces away from high-current switching nodes and noisy clock sources to reduce errors in timekeeping and bus reads.
Verify the complete supply-voltage range, current consumption, and backup-power behavior from the Texas Instruments datasheet before connecting the RTC to system power or a backup battery. The verified records do not provide these values, so do not infer them from the 5 V or battery references associated with legacy RTC designs. Check power-up sequencing, ground continuity, and decoupling requirements at the device pins, then validate read and write behavior across cold-start and power-loss conditions.
The BQ4285P-SB2 uses a parallel clock/calendar interface, so host-bus timing and signal settling must be checked against the manufacturer timing specifications. Confirm address, data, enable, read/write, interrupt, and NVRAM-control behavior using the complete datasheet rather than distributor summaries. For longer traces or slower buses, use appropriate buffering and isolate noisy peripherals; the DIP package itself does not compensate for poor bus timing.
Do not substitute DS14285+ or DS14285N solely because the comparison pages show the same 24-DIP format. The verified cross-reference result states that terminals and packages are consistent, but it does not quantify supply voltage, NVRAM capacity, calendar registers, timing, or oscillator performance. Perform a pin-by-pin and register-by-register review, prototype the replacement, and confirm that IBM AT-compatible software behavior remains unchanged before approving it for production.
Informações de conformidade
The supplied verified web results do not explicitly state RoHS, REACH, AEC-Q100, lead-free, halogen-free, or conflict-minerals status for BQ4285P-SB2.
