1. General description
The P82B96 is a bipolar IC that creates a non-latching, bidirectional, logic interface
between the normal I
2
C-bus and a range of other bus configurations. It can interface
I
2
C-bus logic signals to similar buses having different voltage and current levels.
For example, it can interface to the 350 µA SMBus, to 3.3 V logic devices, and to 15 V
levels and/or low-impedance lines to improve noise immunity on longer bus lengths.
It achieves this interface without any restrictions on the normal I
2
C-bus protocols or clock
speed. The IC adds minimal loading to the I
2
C-bus node, and loadings of the new bus or
remote I
2
C-bus nodes are not transmitted or transformed to the local node. Restrictions
on the number of I
2
C-bus devices in a system, or the physical separation between them,
are virtually eliminated. Transmitting SDA and SCL signals via balanced transmission
lines (twisted pairs) or with galvanic isolation (opto-coupling) is simple because separate
directional Tx and Rx signals are provided. The Tx and Rx signals may be directly
connected, without causing latching, to provide an alternative bidirectional signal line with
I
2
C-bus properties.
2. Features
n Bidirectional data transfer of I
2
C-bus signals
n Isolates capacitance allowing 400 pF on Sx/Sy side and 4000 pF on Tx/Ty side
n Tx/Ty outputs have 60 mA sink capability for driving low-impedance or high capacitive
buses
n 400 kHz operation over at least 20 meters of wire (see
AN10148
)
n Supply voltage range of 2 V to 15 V with I
2
C-bus logic levels on Sx/Sy side
independent of supply voltage
n Splits I
2
C-bus signal into pairs of forward/reverse Tx/Rx, Ty/Ry signals for interface
with opto-electrical isolators and similar devices that need unidirectional input and
output signal paths.
n Low power supply current
n ESD protection exceeds 3500 V HBM per JESD22-A114, 250 V DIP package, 400 V
SO package MM per JESD22-A115, and 1000 V CDM per JESD22-C101
n Latch-up free (bipolar process with no latching structures)
n Packages offered: DIP8, SO8 and TSSOP8
P82B96
Dual bidirectional bus buffer
Rev. 08 — 10 November 2009 Product data sheet
