描述 Description

The PCA9616 is a Fast-mode Plus (Fm+) SMBus/I2C-bus buffer that extends the normalsingle-ended SMBus/I2C-bus through electrically noisy environments using a differentialSMBus/I2C-bus (dI2C) physical layer, which is transparent to the SMBus/I2C-bus protocollayer. It consists of three single-ended to differential driver channels for the SCL (serialclock), SDA (serial data), and a third channel useful for INT or other signaling.
Remark: If the third channel is not used, the INT pin (pin 7 of the TSSOP16 package)should not be left disconnected or ‘floating’ (it may generate incorrect bus signals due tosystem noise entering this high-impedance node). Tie it to VSS.
The use of differential transmission lines between identical dI2C bus buffers removeselectrical noise and common-mode offsets that are present when signal lines must passbetween different voltage domains, are bundled with hostile signals, or run adjacent toelectrical noise sources, such as high energy power supplies and electric motors.
The SMBus/I2C-bus was conceived as a simple slow speed digital link for short runs,typically on a single PCB or between adjacent PCBs with a common ground connection.Applications that extend the bus length or run long cables require careful design topreserve noise margin and reject interference.
The dI2C-bus buffers were designed to solve these problems and are ideally suited forrugged high noise environments and/or longer cable applications, allow multiple slaves,and operate at bus speeds up to 1 MHz clock rate. Cables can be extended to at leastthree meters (3 m), or longer cable runs at lower clock speeds. The dI2C-bus buffers arecompatible with existing SMBus/I2C-bus devices and can drive Standard, Fast-mode, andFast-mode Plus devices on the single-ended side.
Signal direction is automatic, and requires no external control. To prevent bus latch up,the standard SMBus/I2C-bus side of the bus buffer, the PCA9616 employs static offset,care should be taken when connecting these to other SMBus/I2C-bus buffers that may notoperate with static offset.
This device is a bridge between the normal 2-wire single-ended wired-OR SMBus/I2C-busand the 4-wire dI2C-bus.
Additional circuitry allows the PCA9616 to be used for ‘hot swap’ applications, wheresystems are always on, but require insertion or removal of modules or cards withoutdisruption to existing signals.
The PCA9616 has two supply voltages, VDD(A) and VDD(B). VDD(A), the card side supply,only serves as a reference and ranges from 0.8?V to 5.5?V. VDD(B), the line side supply,serves as the majority supply for circuitry and ranges from 3.0?V to 5.5?V.

特性 Features

? New dI2C-bus buffers offer improved resistance to system noise and ground offsetup to 1?2 of supply voltage
? Hot swap (allows insertion or removal of modules or card without disruption to busdata)
? READY signal (PCA9616 output) indicates device is ready from a cold start
? EN signal (PCA9616 input) controls PCA9616 hot swap sequence
? Bus idle detect (PCA9616 internal function) waits for a bus idle condition beforeconnection is made
? 3 channel dI2C (differential I2C-bus) to Fm+ single-ended buffer operating up to 1 MHzwith 30 mA SDA/SCL > 2.2 V, or 3 mA SDA/SCL < 2.4?V
? Compatible with I2C-bus Standard/Fast-mode and Fast-mode Plus at 1 MHz
? Active HIGH (internal pull-up resistor) Enable disables the device to high-impedancestate
? Single-ended I2C-bus on card side up to 540 pF >2.2 V and 400?pF <2.4?V
? Differential I2C-bus on cable side supporting multi-drop bus:
? Maximum cable length: 3 m (approximately 10 feet) (longer at lower frequency)
? dI2C output: 1.5 V differential output with nominal terminals
? Differential line impedance (user defined): 100 Ω nominal suggested
? Receive input sensitivity: ±200 mV
? Hysteresis: ±30 mV typical
? Input impedance: high-impedance (200 kΩ typical)
? Receive input voltage range: ?0.5 V to +5.5 V
? Lock-up free operation
? Supports arbitration and clock stretching across the dI2C-bus buffers
? Powered-off and powering-up high-impedance I2C-bus pins
? Operating supply voltage (VDD(A)) range of 0.8 V to 5.5 V with single-ended side 5.5 Vtolerant
? Differential I2C-bus operating supply voltage (VDD(B)) range of 3.0 V to 5.5 V with5.5 V tolerant. Best operation is at 5 V
? ESD protection exceeds 2000 V HBM per JESD22-A114 and 1000 V CDM perJESD22-C101
? Latch-up testing is done to JEDEC Standard JESD78 which exceeds 100 mA
? Package offering: TSSOP16

應(yīng)用 Application

帶多個電源和最高2.5 V接地偏移電勢的任何應(yīng)用
需要在電氣嘈雜環(huán)境中長期運(yùn)行I2C總線的任何應(yīng)用
在惡劣環(huán)境下監(jiān)控遠(yuǎn)程溫度/泄漏檢測器是否有返回至主機(jī)的中斷
在高度嘈雜環(huán)境下控制電源
設(shè)備機(jī)柜之間的I2C總線傳輸
商業(yè)照明和工業(yè)供暖/制冷控制