PCA9519 - 4-Ch Level Translating I2C/SMBus Repeater | NXP
N.º de pieza: PCA9519 ✓ Activo| Cant. | Precio unitario | Total |
|---|---|---|
| 1 | $0 | $0,00 |
| 10 | $0 | $0,00 |
| 100 | $0 | $0,00 |
| 500 | $0 | $0,00 |
| 1.000 | $0 | $0,00 |
PCA9519 Descripción general
An I2C-bus repeater/buffer is an interface IC that sits between a controller and a bus segment, isolating bus capacitance on each side while preserving the bidirectional, open-drain semantics of the two-wire protocol. In the power management IC and interface IC hierarchy, level-translating repeaters such as the PCA9519 belong to the I2C/SMBus buffer-and-extender family, alongside multipliers (PCA9518), hot-swap buffers, and dedicated translators (NVT2002, PCA9306).
Key features include four independent SCL/SDA channel pairs, bidirectional buffering that isolates capacitance and allows up to 400 pF on port B, and voltage level translation between a low-voltage processor side (port A, 1 V to 1.5 V) and a standard I2C/SMBus side (port B, 3.0 V to 5.5 V). Notably, the PCA9519 requires no external pull-up resistors on the lower-voltage port A, reducing BOM count and board area.
Architecturally, the PCA9519 uses rise-time accelerators on port B drivers and an open-drain detect scheme on port A, retaining all operating modes and features of the I2C-bus system - including clock stretching, arbitration, and multi-master operation - during level shifts. This allows a 1.2 V or 1.5 V microcontroller bus to directly drive standard 3.3 V or 5 V I2C peripherals without discrete MOSFET translator networks.
Typical applications include connecting low-voltage processors to standard I2C/SMBus I/O, extending bus reach and fan-out in servers, telecom line cards, and industrial control backplanes where total bus capacitance would otherwise exceed the 400 pF I2C limit.
Design consideration: because repeaters segment the bus, avoid lock-up-prone topologies by never creating a loop between port B segments and keep each segment within its capacitance budget.
This page synthesizes distributor sourcing data, drop-in alternatives, and practical design notes not found in the manufacturer datasheet.
Alternativas directas para PCA9519 — 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:
PCA9518PW
✅ Sustitución directa ⚠️ Especificaciones sin verificar📋 Alternativa de referencia (no en el catálogo)
PCA9519 Especificaciones
| Función | 4-channel level translating I2C-bus/SMBus repeater |
| Number of Channels | 4 (4 SCL/SDA pairs) |
| Port A Voltage Range | 1 V to VCC(B) 1.5 V |
| Port B Voltage Range | 3.0 V to 5.5 V |
| Port B Capacitance Drive | 400 pF |
| External Pull-ups on Port A | Not required |
| Bus Protocol | I2C-bus / SMBus |
| Direction Control | Bidirectional, automatic |
| Encapsulado | TSSOP-20 (PW) |
| Tipo de montaje | Surface Mount |
| Repeatability Features | Retains all I2C-bus operating modes during level shifts |
Guía de configuración de pines de PCA9519 tssop-20 (pw)
Configuración de pines para PCA9519 (encapsulado tssop-20 (pw)). 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 PCA9519.
Consulte la hoja de datos para ver la configuración completa de patillas.
Aplicaciones típicas
PCA9519 es adecuado para 6 aplicacións: Low-Voltage Processor to Standard I2C I/O Interface, I2C Bus Extension and Fan-Out, Server and Telecom Chassis Management (SMBus), Industrial Control Backplanes, Consumer Electronics Display and Peripheral Modules, Point-of-Sale and Handheld Device I/O.
Low-Voltage Processor to Standard I2C I/O Interface
Modern microcontrollers and SoCs increasingly run their management buses at 1.2 V or 1.5 V, while most I2C EEPROMs, RTCs, and sensors still operate at 3.3 V or 5 V. The PCA9519 bridges this gap directly: its port A connects to the 1 V to 1.5 V processor bus without external pull-ups, while port B drives the standard 3.0 V to 5.5 V peripheral bus with up to 400 pF loading. Because the repeater retains all I2C operating modes, clock stretching and multi-master arbitration work transparently. This eliminates discrete two-MOSFET-per-line translator networks and their bias resistor chains, cutting BOM count on dense boards where four separate bus pairs must be translated simultaneously.
Recomendado
I2C Bus Extension and Fan-Out
When a single I2C segment exceeds the 400 pF capacitance limit from long traces and many device inputs, the PCA9519 segments the bus: each side drives its own capacitance budget, and port B alone supports up to 400 pF per the NXP datasheet. In backplane designs, placing a repeater on each line card isolates card capacitance from the backplane trunk, so adding cards no longer degrades rise times. The four channel pairs let one device service two independent bus domains, useful for separating a chassis management bus from a payload bus. Designers should keep topologies tree-shaped - never loop port B segments back - because repeaters cannot resolve the bus lock-up that loops create in open-drain systems.
Recomendado
Server and Telecom Chassis Management (SMBus)
Server shelf management, PSU telemetry, and telecom line-card monitoring typically use SMBus at 3.3 V, while newer management controllers (BMCs) integrate 1.5 V-capable I2C masters. The PCA9519's I2C/SMBus dual specification and 3.0 V to 5.5 V port B range make it a fit for these management planes: it preserves SMBus timing behavior while translating from the low-voltage controller side. In dense shelves, multiple PCA9519 channels allow separate redundant management buses (bus A and bus B) plus two payload buses from a single 20-pin TSSOP-20 device, conserving board area. Designers should verify repeater placement does not mask ARP or PEC timeouts under worst-case loading, segmenting close to the load cluster.
Recomendado
Industrial Control Backplanes
Industrial PLC and motor-control backplanes combine long bus runs, noisy environments, and mixed logic voltages. The PCA9519 buffers the SDA/SCL lines so capacitance from remote I/O modules does not slow the processor bus edges, supporting up to 400 pF per port B segment. Its 5.5 V port B tolerance accommodates legacy 5 V industrial sensors and EEPROM blocks alongside 3.3 V modules. Because the device retains all I2C operating modes during level shifts, master arbitration between a main controller and a local service processor still functions. For electrically harsh sites, add series protection and keep each repeater segment below the capacitance limit; the buffer does not add voltage isolation, which must come from digital isolators if required.
Recomendado
Consumer Electronics Display and Peripheral Modules
Display panels, camera modules, and dock accessories often carry their own EDID EEPROMs and touch controllers on I2C at 3.3 V, while the host SoC bus may run at 1.2 V or 1.5 V. The PCA9519 provides four translated channel pairs, enough for the main EDID/DDC bus, touch bus, and two auxiliary sensor buses from one device. Its internal port A drive eliminates pull-up networks in thin, space-constrained module interconnects, and 400 pF port B drive covers cable-plus-panel capacitance for docking cables. Because repeaters segment the bus, hot-plugging one module does not capacitively load the host segment - a practical benefit for consumer dock designs where modules connect and disconnect during operation.
Recomendado
Point-of-Sale and Handheld Device I/O
Battery-powered POS terminals and handheld scanners use low-voltage application processors (1.2 V-1.5 V I2C) connected to 3.3 V peripherals such as secure elements, barcode engines, and thermal-printer controllers. The PCA9519's four channels cover secure-element, touch, printer, and expansion buses in one TSSOP-20 package, and its low-voltage port A needs no external pull-ups, which suits compact battery designs where every component counts. The 400 pF port B capacity handles flexible-cable assemblies common in hinged handheld form factors. Designers should confirm total quiescent current against battery budgets using datasheet ICC figures and consider power-gating the port B supply when the peripheral domain sleeps, since buffered segments pass no traffic when either side is unpowered.
Recomendado
Resumen de productos recomendados
Datos de referencia de ingeniería para PCA9519 — comparación, orientación de diseño e información de cumplimiento.
Guía de selección
Comparación con alternativas
| Parámetro | Este producto | PCA9518PW |
|---|---|---|
| Package | TSSOP-20 (PW) | TSSOP-20 (PW) - same footprint |
| Brand | NXP Semiconductors | NXP Semiconductors |
| Number of Channels | 4 (4 SCL/SDA pairs) | 5 (5 SCL/SDA pairs) |
| Level Translation | Yes (1 V-1.5 V to 3.0-5.5 V) | No (repeater only) |
| Bus Protocol | I2C-bus / SMBus | I2C-bus / SMBus |
Diferenciadores clave
- Integrated level translation on all four channels (frente a PCA9518PW)
- No external pull-ups required on port A (frente a Discrete MOSFET translator networks)
- 400 pF capacitance drive on port B (frente a PCA9518PW)
Notas de diseño
Never create a loop with repeaters. I2C repeaters segment the bus, and connecting port B of one PCA9519 back to port B of another in a ring causes indefinite signal reflection (lock-up), because each side sees the other's low as a request to drive low. Topologies must remain tree/star-shaped: one trunk with repeaters branching outward only. This is a documented failure mode of all I2C buffer segments, including the PCA9519 family, and is the single most common field failure when cascading repeaters.
Place a 0.1 uF ceramic decoupling capacitor directly at the VCC(B) pin with a solid ground return. Keep port A traces short since the internal drivers on the low-voltage side eliminate external pull-ups - long stubs on port A increase rise times without pull-up assistance. On port B, size pull-up resistors (typically 2.2 kOhm to 4.7 kOhm at 3.3 V) for the total segment capacitance up to 400 pF; heavily loaded segments need stronger pull-ups to meet SMBus rise-time limits. Avoid routing SDA/SCL adjacent to switching regulator nodes.
The PCA9519 operates from the port B supply domain (3.0 V to 5.5 V) while port A operates at 1 V to VCC(B) 1.5 V. Ensure the port A supply is stable and sequenced within the datasheet's specified relationship to VCC(B) before bus traffic begins; powering port A from an unsequenced rail can produce undefined output levels on the low-voltage bus. Consult the NXP datasheet for exact power-up requirements and ICC current figures to complete the power budget.
Información de cumplimiento
Compliance data was not present in the provided web data. Verify RoHS/REACH status on the official NXP product page at nxp.com/part/PCA9519PW.
