PCA9515ADR - Dual I2C/SMBus Bus Repeater 400kHz | TI
料号： PCA9515ADR ✓ 量产中| 数量 | 单价 | 小计 |
|---|---|---|
| 1 | $1.15 | $1.15 |
| 10 | $1.04 | $10.40 |
| 100 | $0.88 | $88.00 |
| 500 | $0.72 | $360.00 |
| 1,000 | $0.58 | $580.00 |
PCA9515ADR 概述
An I2C bus repeater is an interface buffer that isolates the capacitance and noise of one segment of an I2C or SMBus from another. Within the signal-chain hierarchy (I2C repeater -> bus buffer -> interface IC -> mixed-signal semiconductor), repeaters let a single controller address far more devices or far longer PCB traces and cables than the ~400 pF bus-capacitance limit would otherwise allow, while keeping rise times compliant.
Key features include two identical bidirectional open-drain buffer channels, an active-high repeater-enable input (EN) for power-up isolation and bus segmentation, 5.5-V tolerant I2C I/O and EN for mixed-mode 3.3 V/5 V operation, and lockup-free operation that accommodates the clock-stretching and arbitration behavior of multi-master I2C systems.
Technically, the PCA9515A is fabricated in a BiCMOS process. Each buffer uses a rising-edge accelerator and direction-sensing scheme that distinguishes a master-driven LOW from a slave-driven LOW, preventing the input-to-output latch-up that plagued first-generation repeaters. Because both channels are identical, the device can be used as two independent 1-bit repeaters or as a single 2-bit bus switch-style buffer.
Typical applications include I2C bus segment isolation in servers and telecom cards, capacitive load expansion on long backplanes and cables, level-tolerant buffering between 3.3 V controllers and 5 V legacy peripherals, and SMBus systems in power-management and battery-pack designs.
A key design consideration: the buffer is unidirectional-gain per edge, so it must not be used in loops or back-to-back without careful segmentation; place it where the bus capacitance exceeds roughly 400 pF or when isolating a noisy or fault-prone slave segment.
This page adds value beyond the datasheet by synthesizing distributor pricing, verified drop-in alternatives, comparison tables, and practical layout guidance in one place.
直接替换替代料： PCA9515ADR ——相同封装，引脚兼容。需要 PCB 改动的不同封装料号已排除。
快速对比工具——选择替代料号进行并排对比：
PCA9515AD
✅ 直接替换📋 参考替代料（不在目录中）
PCA9515ADG4
✅ 直接替换📋 参考替代料（不在目录中）
PCA9515AD,118
✅ 直接替换📋 参考替代料（不在目录中）
PCA9515AT,118
✅ 直接替换📋 参考替代料（不在目录中）
PCA9515ADR 规格参数
| 功能 | Dual bidirectional I2C bus and SMBus repeater (buffer) |
| Number of Channels | 2 |
| Operating Frequency | 400 kHz (max) |
| Supply Voltage (VCC) | 2.3 V to 3.6 V |
| I/O Tolerance | 5.5 V tolerant I2C I/O and enable input |
| Logic Technology | BiCMOS |
| I/O Type | Open-drain I2C |
| Enable Input | Active-high repeater-enable (EN) |
| Lockup-Free Operation | Yes |
| Protocol Compatibility | I2C bus and SMBus |
| 封装 | 8-SOIC |
| 安装类型 | Surface Mount |
| Packaging | Tape & Reel (R suffix) |
| RoHS 状态 | Compliant |
| Rating | Catalog |
PCA9515ADR 8-soic 引脚配置指南
PCA9515ADR（8-soic 封装）的引脚配置。 引脚编号、功能和连接图在制造商数据手册中定义。请参阅该手册以了解确切的封装尺寸和焊接指南。
暂无详细引脚数据： PCA9515ADR.
请参阅 数据手册 以查看完整引脚配置。
典型应用
PCA9515ADR 适用于 6 应用s: Server and Telecom Card Bus Isolation, I2C Capacitive Load Expansion, Mixed-Voltage (3.3 V / 5 V) System Interfacing, SMBus Power-Management Systems, Industrial Sensor Bus Segmentation, Display and Peripheral Module Buses.
Server and Telecom Card Bus Isolation
In server backplanes and telecom line cards, a single I2C controller often must reach many FRUs (field-replaceable units), EEPROMs, and hot-swap controllers spread across connectors and long traces. The PCA9515ADR isolates the card segment from the backplane segment, so each connector add or removal event changes the capacitance of only one side of the buffer. Its active-high EN pin lets the host disable the card-side segment during power-up or fault conditions, preventing a stuck LOW from stalling the management bus. With 400 kHz operation and 2.3 V to 3.6 V single supply, it integrates directly into typical 3.3 V management rails, and its 5.5-V tolerant I/O tolerates legacy 5 V backplane signals.
推荐
I2C Capacitive Load Expansion
Standard I2C buses are limited to roughly 400 pF of total bus capacitance. Long cables, many slave devices, and wide PCB routing quickly exceed that limit, slowing edges and corrupting data. Placing a PCA9515ADR at the midpoint splits the bus into two segments whose capacitances are each seen and re-driven by the buffer's open-drain output stages, effectively doubling (or more, with multiple repeaters) the allowable load. The BiCMOS buffer provides active edge acceleration to restore rise times on the driven segment, keeping 400 kHz timing valid. Designers should budget propagation delay per buffer and place decoupling close to VCC; each segment still needs its own pull-up resistors sized for its capacitance.
推荐
Mixed-Voltage (3.3 V / 5 V) System Interfacing
Many industrial designs combine modern 3.3 V microcontrollers with legacy 5 V peripheral devices such as EEPROMs, RTCs, and sensors on the same I2C bus. The PCA9515ADR runs from a 2.3 V to 3.6 V supply while its open-drain I2C I/O pins and EN input tolerate 5.5 V, so the controller side and peripheral side can sit at different logic rails without additional level-shifting components. The buffer re-drives the LOW levels cleanly, avoiding the marginal LOW levels that simple resistor dividers produce. Designers should ensure each rail segment has appropriate pull-ups: approximately 4.7 kilo-ohm on a 3.3 V segment and 4.7 to 10 kilo-ohm on a 5 V segment for 100 to 400 kHz operation.
推荐
SMBus Power-Management Systems
SMBus-based power management in servers, battery packs, and chargers uses a shared two-wire management bus that is vulnerable to a single misbehaving slave pulling SDA or SCL low. The PCA9515ADR is explicitly I2C-bus and SMBus compatible and lockup-free, accommodating clock-low-extend behavior used by smart-battery devices. Placing the repeater between the host segment and the battery/fan segment contains faults and capacitance spikes from hot-insertion events. The EN pin enables the host to gate the segment during battery hot-swap, meeting SMBus power-up isolation expectations. With a catalog rating and SOIC-8 package, it suits cost-sensitive rack and charger boards operating from a 3.3 V standby rail.
推荐
Industrial Sensor Bus Segmentation
Factory-floor equipment frequently scatters temperature, pressure, and current-monitor sensors along long I2C runs through cable harnesses exposed to motor noise. A PCA9515ADR placed at the harness entry re-drives both SDA and SCL, restoring signal integrity to the sensor segment while keeping the noisy, capacitive cable side isolated from the controller. The lockup-free architecture tolerates the multi-master arbitration sometimes used between a PLC and a local service controller. Its 5.5-V tolerant I/O survives cable transients that exceed nominal 3.3 V levels within the tolerance limit. Engineers should add series ferrites and TVS diodes at the cable connector, and size segment pull-ups (typically 2.2 to 4.7 kilo-ohm) for reliable 100 to 400 kHz operation over the cable length.
推荐
Display and Peripheral Module Buses
LCD/OLED display modules, touch controllers, and camera daughterboards commonly connect over short I2C stubs where connector insertion and modular cabling add unpredictable capacitance. Using a PCA9515ADR at the module edge buffers the controller from these variations, keeping rise times within the 300 ns I2C Fast-mode specification regardless of how many modules are daisy-connected. The active-high EN allows the host to hold the module segment in reset/isolation during firmware update or initialization sequences, improving system robustness. Operating from the ubiquitous 3.3 V module rail at 2.3 V to 3.6 V, and packaged in a low-cost 8-pin SOIC, it fits high-volume consumer and commercial display assemblies with minimal BOM impact.
推荐
推荐产品汇总
工程参考数据： PCA9515ADR ——对比、设计指导和合规信息。
选型指南
与替代料对比
| 参数 | 本产品 | PCA9515AD | PCA9515ADG4 | PCA9515AD,118 | PCA9515AT,118 |
|---|---|---|---|---|---|
| Package | SOIC-8 | SOIC-8 - same | SOIC-8 - same | SOIC-8 - same | SOIC-8 - same |
| Brand | Texas Instruments | Texas Instruments | Texas Instruments | NXP Semiconductors | NXP Semiconductors |
| Channels | 2 bidirectional | 2 bidirectional | 2 bidirectional | 2 bidirectional | 2 bidirectional |
| Max Bus Speed | 400 kHz | 400 kHz | 400 kHz | 400 kHz | 400 kHz |
| Supply Voltage Range | 2.3 V to 3.6 V | 2.3 V to 3.6 V | 2.3 V to 3.6 V | 2.3 V to 3.6 V | 2.3 V to 3.6 V |
| I/O Tolerance | 5.5 V tolerant | 5.5 V tolerant | 5.5 V tolerant | 5.5 V tolerant | 5.5 V tolerant |
| Enable Pin | Yes (active-high EN) | Yes (active-high EN) | Yes (active-high EN) | Yes (active-high EN) | Yes (active-high EN) |
| Lockup-Free Operation | Yes | Yes | Yes | Yes | Yes |
| Packaging / Order Quantity | Tape & Reel (2500) | Tube / Tray | Tape & Reel | Tape & Reel (2500) | Tape & Reel |
关键差异点
- True TI-original sourcing with reel packaging （对比 PCA9515AD (tube))
- Dual-sourcing flexibility （对比 PCA9515AD,118 (NXP))
- Honest trade-off: no level translation （对比 TCA9517DR)
设计说明
Each bus segment needs its own pull-up resistors - the buffer does not propagate pull-up strength across segments. For 400 kHz operation, size pull-ups so the bus rise time stays within the I2C Fast-mode 300 ns limit: roughly 2.2 to 4.7 kilo-ohm to 3.3 V on a lightly loaded segment, lower values as segment capacitance grows. Place a 100 nF ceramic decoupling capacitor directly at the VCC pin with a solid ground return. Keep the EN pin from floating; drive it actively or tie to GND through a defined resistor so the segment state is deterministic at power-up.
Although the PCA9515A is lockup-free, never connect two repeaters back-to-back or in a ring: direction detection becomes ambiguous and the bus can stall. Do not use it on segments where a slave holds SDA low longer than the buffer's direction-latch timing expects (rare, but relevant with badly implemented clock stretching). Verify the 400 kHz maximum - it is not rated for Fast-mode Plus (1 MHz). For mixed-voltage systems, remember the part itself must be powered from 2.3 V to 3.6 V only; 5 V is tolerated on I/O pins, not on VCC.
Route SDA0/SCL0 and SDA1/SCL1 as short, matched pairs on the two sides of the package; avoid running them adjacent to switching-regulator nodes to prevent capacitive coupling onto the management bus. If the repeater separates a card edge from a backplane, place it within a few centimeters of the connector on the segment most prone to faults so the enable pin can isolate the noisy side. Estimated rise-time budgeting: with 100 pF segment capacitance and 4.7 kilo-ohm pull-up, RC rise time is about 0.47 us to 63 percent - reduce the pull-up to below 3 kilo-ohm to meet 300 ns Fast-mode rise at 400 kHz.
合规信息
RoHS compliance per distributor listings for the R-suffix part. Catalog rating (not automotive AEC-Q100 qualified). REACH and halogen-free status to be confirmed on TI.com product quality pages.
