Level-Shifting Hot Swappable I²C-Bus and SMBus Bus Buffer
The PCA9512A/B is a hot swappable I²C-bus and SMBus buffer that allows I/O card insertion into a live backplane without corruption of the data and clock buses and includes two dedicated supply voltage pins to provide level shifting between 3.3 V and 5 V systems while maintaining a better noise margin for each voltage level. Either pin may be powered with supply voltages ranging from 2.7 V to 5.5 V with no constraints on which supply voltage is higher. Control circuitry prevents the backplane from being connected to the card until a stop bit or bus idle occurs on the backplane without bus contention on the card. When the connection is made, the PCA9512A/B provides bidirectional buffering, keeping the backplane and card capacitances isolated.
Both the PCA9512A and PCA9512B use identical silicon (PCN201012007F dated 13 Dec 2010), so the PCA9512B will be discontinued in the near future and is not recommended for new designs.
The PCA9512A/B rise time accelerator circuitry allows the use of weaker DC pull-up currents while still meeting rise time requirements. The PCA9512A/B incorporates a digital input pin that enables and disables the rise time accelerators on all four SDAn and SCLn pins.
During insertion, the PCA9512A/B SDAn and SCLn pins are precharged to 1 V to minimize the current required to charge the parasitic capacitance of the chip.
The incremental offset design of the PCA9510A/11A/12A/12B/13A/14A I/O drivers allows them to be connected to another PCA9510A/11A/12A/12B/13A/14A device in series or in parallel and to the I²C compliant side of static offset bus buffers, but not to the static offset side of those bus buffers.
製品詳細
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Features
System Features
- Bidirectional buffer for SDA and SCL lines increases fan-out and prevents SDA and SCL corruption during live board insertion and removal from multipoint backplane systems
- Compatible with I²C-bus Standard mode, I²C-bus Fast mode, and SMBus standards
- Built-in ΔV/Δt rise time accelerators on all SDA and SCL lines (0.6 V threshold) with ability to disable ΔV/Δt rise time accelerator through the ACC pin for lightly loaded systems, requires the bus pull-up voltage and respective supply voltage (VCC or VCC2) to be the same
- 5 V to 3.3 V level translation with optimum noise margin
- High-impedance SDAn and SCLn pins for VCC or VCC2 = 0 V
- 1 V precharge on all SDAn and SCLn pins
- Supports clock stretching and multiple controller arbitration and synchronization
- Operating power supply voltage range: 2.7 V to 5.5 V
- 0 Hz to 400 kHz clock frequency
- ESD protection exceeds 2000 V HBM per JESD22-A114 and 1000 V CDM per JESD22-C101
- Latch-up testing is done to JEDEC Standard JESD78 which exceeds 100 mA
- Packages offered: SO8, TSSOP8 (MSOP8)
部品番号： PCA9512AD, PCA9512ADP.
購入/パラメータ
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