Low-Power Level Translating I²C-Bus/SMBus Repeater


PCA9509P Block Diagram

PCA9509P Block Diagram


Key Features

  • Bidirectional buffer isolates capacitance and allows 400 pF on port B of the device
  • Voltage level translation from port A (0.8 V to 1.5 V) to port B (2.3 V to 5.5 V)
  • No internal current source on A port to reduce current consumption for portable applications
  • Active HIGH enable input disables current mirrors to reduce standby power
  • Open-drain inputs/outputs
  • Lock-up free operation
  • Supports arbitration and clock stretching across the repeater
  • Accommodates Standard-mode and Fast-mode I²C-bus devices and multiple controllers
  • Powered-off high-impedance I²C-bus pins
  • Operating supply voltage range of 0.8 V to 1.5 V on port A, 2.3 V to 5.5 V on port B
  • All pins are 5 V tolerant with respect to ground pin
  • 0 Hz to 400 kHz clock frequency
    Remark: The maximum system operating frequency may be less than 400 kHz because of the delays added by the repeater
  • 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


部品番号: PCA9509PDP, PCA9509PGM.

Selection Recommendations

The PCA9509P should be used if an external A-port pull-up resistor is required to adjust current for noise margin considerations or to reduce operating current consumption.
Table 1. Device selection recommendation
Concern Recommended device
PCA9509 PCA9509A PCA9509P
A-port — lowest voltage 1.0 V 0.85 V 0.85 V
A-port — current source [1] yes—1 mA yes—270 μA no—external pull-up
Operating current [2] < 6.1 mA < 1.9 mA < 0.95 mA
Standby current EN = LOW < 2 mA < 22 μA max < 22 μA max
  1. The PCA9509 current mirrors do not shut down when the device is disabled allowing instant turn-on, but at the cost of the higher standby current. The PCA9509A and PCA9509P current mirrors are turned off when disabled for lowest standby power consumption, but sufficient delay (10 μs) after enable is needed before resuming operation.
  2. Operating currents do not include the current consumed by the external pull-ups on B-port or the external pull-ups on the A-port of the PCA9509P.


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