BQ4802LYPW - 3.3V Parallel RTC with CPU Supervisor | Texas Instruments
N.º de pieza: BQ4802LYPW ✗ Fin de vidaBQ4802LYPW Descripción general
A real-time clock is a specialized timing peripheral used by embedded processors and control systems to maintain calendar time independently of the main CPU. The BQ4802LY belongs to the parallel RTC hierarchy, combining clock-and-calendar functions with CPU-supervision features. This integration reduces the need for separate timekeeping and power-fail monitoring components while providing a defined interface for an external nonvolatile SRAM backup path.
Key features include a century-based BCD calendar, operation from a 3.3 V supply, an on-chip battery-backup switchover circuit, and nonvolatile control for external SRAM. The supply supervisor detects an out-of-tolerance condition, generates an interrupt warning, and can subsequently issue a microprocessor reset. Its less-than-500 nA backup clock current is particularly useful where maintaining accurate time during long power interruptions is more important than operating from the primary supply continuously.
Technically, the BQ4802LY combines a temperature-compensated reference and comparator with its RTC and supervisor functions. The parallel interface exposes calendar and clock data to a host processor while the supervisor provides warning and reset behavior during power transitions. Battery backup preserves RTC operation when the primary supply falls away, allowing the system to resume with valid time information and protect selected external SRAM contents through the documented nonvolatile-control mechanism.
Typical applications include fax machines, copiers, industrial control systems, point-of-sale equipment, embedded instruments, and other microprocessor-based products that require calendar time and orderly power-fail handling. Its 3.3 V operating supply is appropriate for systems designed around modern low-voltage embedded logic. Design efforts should include correct battery connection, decoupling, supervisor-reset integration, and validation of backup and recovery behavior.
In practice, the BQ4802LYPW is most useful where accurate time retention and power-fail notification matter more than a minimal RTC footprint. The 28-pin TSSOP package simplifies assembly in conventional surface-mount production, although engineers should verify every signal against the manufacturer pinout and application guidance. This page combines verified manufacturer and distributor information, parameter-gap markers, family comparisons, and practical design considerations to support component selection.
Alternativas directas para BQ4802LYPW — mismo encapsulado, compatible pin a pin. Se excluyen las piezas de otro encapsulado que requieren retrabajo de la PCB.
Variantes de esta serie
Modelos de la misma serie compatibles directamente con BQ4802LYPW (mismo factor de forma y huella) — difiere en Package, Supply Monitoring, Product Type, Supply Voltage.
BQ4802LYPWR
✅ Sustitución directaConsulte el precio
Ver hoja de datos →BQ4802LYPWG4
✅ Sustitución directaConsulte el precio
Ver hoja de datos →BQ4802LYPWRG4
✅ Sustitución directa📋 Alternativa de referencia (no en el catálogo)
BQ4802LYPW Especificaciones
| Product Type | Parallel real-time clock and calendar with CPU supervisor |
| Tensión de alimentación | 3.3 V |
| Clock Format | BCD |
| Calendar Range | Century-based calendar |
| Backup Clock Operation Current | Less than 500 nA |
| Battery Backup | On-chip battery-backup switchover circuit |
| External SRAM Support | Nonvolatile control for external SRAM |
| Supervisor Function | Interrupt warning and subsequent microprocessor reset |
| Supply Monitoring | Temperature-compensated reference and comparator circuit |
| Tipo de interfaz | Parallel |
| Encapsulado | 28-pin TSSOP (PW) |
| Package Width | 4.40 mm |
| Package Body Length | 0.173 inch |
| Temperatura de funcionamiento | 0 °C to 70 °C |
| Tipo de montaje | Surface mount |
Guía de configuración de pines de BQ4802LYPW 0.173 inch
Configuración de pines para BQ4802LYPW (encapsulado 0.173 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 BQ4802LYPW.
Consulte la hoja de datos para ver la configuración completa de patillas.
Aplicaciones típicas
BQ4802LYPW es adecuado para 6 aplicacións: Industrial Control Systems, Point-of-Sale Terminals, Copiers and Office Equipment, Fax Machines and Time-Stamped Communications, Embedded Measurement Instruments, Battery-Powered Embedded Equipment.
Industrial Control Systems
The BQ4802LYPW fits 3.3 V industrial controllers that must preserve calendar time and manage host-processor recovery during power fluctuations. Its century-based BCD clock provides a persistent time record, while the integrated supervisor can issue an interrupt warning before generating a reset. The less-than-500 nA backup current helps maintain timekeeping during extended primary-supply loss. Designers should verify the 0 °C to 70 °C specification against the enclosure temperature and connect the backup supply according to the manufacturer guidance.
Recomendado
Point-of-Sale Terminals
Point-of-sale terminals benefit from the BQ4802LYPW because transaction records and audit events often need accurate wall-clock timestamps independent of the main processor. The device’s 3.3 V supply matches compact embedded systems, and its century-based calendar supports long-term date retention. The CPU-supervisor warning gives firmware time to close records or enter a safe state before reset, while backup operation preserves time after power loss. Validation should include battery life, power-cycle behavior, reset latency, and the enclosure’s thermal range.
Recomendado
Copiers and Office Equipment
The BQ4802LYPW is appropriate for copiers and office machines that need date-stamped job records, scheduled operating behavior, and dependable reset coordination. Its parallel RTC/calendar interface suits processors capable of reading BCD time data, while the integrated voltage monitor supports orderly responses to supply disturbances. Backup current below 500 nA helps limit energy use when mains power is absent. Integration should account for the device’s 28-pin TSSOP footprint and the system’s need for either a primary-supply hold-up or a backup cell.
Recomendado
Fax Machines and Time-Stamped Communications
The BQ4802LYPW can maintain date and time for fax machines and communication equipment that stamp or schedule transmitted records. Its century-based calendar avoids the common year-2000 boundary issue, while the 3.3 V variant supports low-voltage embedded platforms. The CPU-supervisor warning and reset functions can help a controller halt or protect a transmission when the supply becomes unstable. Designers should verify interface timing, backup-cell behavior, and the exact reset sequence against the application requirements.
Recomendado
Embedded Measurement Instruments
Embedded measurement instruments can use the BQ4802LYPW when logged readings require accurate timestamps and system faults require deterministic host recovery. The parallel RTC provides time-of-day and calendar data without depending on the host operating system, and the less-than-500 nA backup current supports long intervals without primary power. The supply-monitor interrupt allows acquisition or storage-control software to respond before reset. Engineers should validate oscillator accuracy, calibration needs, thermal exposure, and synchronization behavior in the finished instrument.
Recomendado
Battery-Powered Embedded Equipment
The BQ4802LYPW is useful in battery-powered embedded equipment where calendar continuity and controlled shutdown are important. The RTC can continue operating from the backup path at less than 500 nA, allowing the system to recover with a valid date after the primary battery or supply rail is depleted. The supervisor’s warning signal can initiate data preservation before the reset event. Designers should calculate backup-cell capacity and leakage budget, and confirm whether the 0 °C to 70 °C operating range covers the product’s environmental requirements.
Recomendado
Resumen de productos recomendados
Datos de referencia de ingeniería para BQ4802LYPW — comparación, orientación de diseño e información de cumplimiento.
Guía de selección
Comparación con alternativas
| Parámetro | Este producto | BQ4802YPWR | BQ4802LYPWR | BQ4802LYPWG4 |
|---|---|---|---|---|
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | Texas Instruments |
| Package | 28-pin TSSOP (PW) | 28-pin TSSOP (PW) | 28-pin TSSOP (PW) | 28-pin TSSOP (PW) |
| Supply Voltage | 3.3 V | 5 V | 3.3 V | 3.3 V |
| RTC Interface | Parallel | Parallel | Parallel | Parallel |
| Calendar Format | Century-based BCD | Century-based BCD | Century-based BCD | Century-based BCD |
| Backup Clock Current | Less than 500 nA | Less than 500 nA | Less than 500 nA | Less than 500 nA |
| CPU Supervisor | Warning interrupt and subsequent microprocessor reset | Warning interrupt and subsequent microprocessor reset | Warning interrupt and subsequent microprocessor reset | Warning interrupt and subsequent microprocessor reset |
| External SRAM Control | Nonvolatile control for external SRAM | Nonvolatile control for external SRAM | Nonvolatile control for external SRAM | Nonvolatile control for external SRAM |
Diferenciadores clave
- Combines RTC, calendar, and CPU supervision (frente a BQ4802YPWR)
- Maintains low backup-mode consumption (frente a Discrete RTC and supervisor implementations)
- Supports century-based calendar and external SRAM retention control (frente a Basic time-only calendar devices)
Notas de diseño
Validate the backup-power architecture with the manufacturer datasheet before layout. The verified data confirms an on-chip battery-backup switchover and less-than-500 nA clock operation in backup mode, but it does not provide the normal operating current, backup-cell chemistry, or switchover thresholds. Budget the backup cell for worst-case leakage and temperature, and confirm whether the external SRAM backup arrangement requires additional pull-up or hold-up components.
Route the backup and supply paths carefully because the RTC, supervisor, and external-SRAM retention function depend on clean transitions between normal and backup operation. Keep the device and its associated decoupling components close, provide a low-impedance ground reference, and separate backup-current paths from sensitive signal routes where practical. The verified package is a 28-pin TSSOP (PW); use the manufacturer land pattern rather than a generic TSSOP footprint.
Do not substitute BQ4802YPWR for BQ4802LYPW solely because both are 28-pin TSSOP devices. The verified family information identifies BQ4802Y as the 5 V version and BQ4802LY as the 3.3 V version. Likewise, BQ4802LYPWR and BQ4802LYPWG4 appear to be ordering or sourcing variants rather than independent functional replacements. Confirm supply voltage, pin functions, suffix meaning, temperature grade, and reel configuration before approving a substitution.
Design firmware around the documented warning-to-reset sequence rather than treating power loss as an instantaneous reset. The device generates an interrupt warning and subsequently a microprocessor reset when its comparator detects an out-of-tolerance supply condition. Give the host enough time to flush records or place external SRAM into a safe state, and test the complete sequence across slow ramps, short interruptions, and worst-case load transitions.
Información de cumplimiento
The supplied manufacturer and distributor search results did not provide explicit RoHS, REACH, AEC-Q100, lead-free, halogen-free, or conflict-minerals statements. These fields remain unknown rather than being inferred.
