4.0 Electrical and Mechanical Specifications
CN8223
4.2 DC Characteristics
ATM Transmitter/Receiver with UTOPIA Interface
4.2 DC Characteristics
All input and bidirectional pins have input thresholds compatible with CMOS
drive levels except those labeled as xxxHS . Leakage current for each pin is less
than 10 µA in any state. This device should be handled as an ESD-sensitive
device. Voltage on any signal pin that exceeds the power supply voltage by more
than +0.5 V can induce destructive latchup.
At V
= 0.4 V and V
= 2.4 V, all output and bidirectional pins
OL(max)
OL(min)
have drive current I = 4 mA and I = – 4 mA except for TXOUT[0] and
OL
OH
TCLKO, which are 8 mA drivers. The interrupt output pins are open drain and
require external pull-up resistors. All output and bidirectional pins (except those
labeled xxxHS ) have CMOS drive levels and can be used with CMOS or TTL
logic.
The RXCKI_HS , TXCKI_HS , and RXIN_HS inputs are differential
PECL level inputs for use in E4 and STS-3c/STM-1 modes. These inputs are
automatically selected in these modes and have input thresholds of V – 1.3 V.
dd
The PECL inputs should have V = 3.4 V and V = 4.0 V. The TXOUT_HS
IL
IH
and TCLKO_HS outputs are differential PECL outputs for use in E4 and
STS-3c/STM-1 modes. The “HS ” outputs are active at all times and should be
used (in E4 or STS-3c/STM-1 modes) in place of the TXOUT[0] and TCLKO
outputs, respectively. The “non-HS ” outputs are automatically disabled in E4 or
STS-3c/STM-1 modes to reduce switching noise injection into the IC. The
switching threshold is at 3.7 V with a V
of 3.3 V (driver off with external
OL(max)
resistor termination) and V
of 4.1 V (driver on).
OH(min)
All timing measurements in the following tables are with 20 pF loading on the
output pins.
4-2
Conexant
100046C
CONEXANT [ CONEXANT SYSTEMS, INC ]
