MAX9153EUI+T Maxim Integrated, MAX9153EUI+T Datasheet - Page 7

• Manufacturer Part Number: MAX9153EUI+T
• Description: LVDS Interface IC 800Mbps 10-Port LVDS Repeater
• Manufacturer: Maxim Integrated

Specifications of MAX9153EUI+T

• Rohs: yes

impedance (to ground) when PWRDN = low or the
device is not powered. The outputs have a typical dif-
ferential resistance of 238Ω. The internal differential
output resistance terminates induced noise and reflec-
tions from the primary termination located at the LVDS
receiver.
The MAX9153/MAX9154 current-steering output
requires a resistive load to terminate the signal and
complete the transmission loop. Because the devices
switch the direction of current flow and not voltage lev-
els, the output voltage swing is determined by the value
of the termination resistor multiplied by the output cur-
rent. With a typical 3.8mA output current, the
MAX9153/MAX9154 produce a 380mV output voltage
when driving a transmission line terminated with a 100Ω
resistor (3.8mA x 100Ω = 380mV). Logic states are
determined by the direction of current flow through the
termination resistor.
Note: V
The fail-safe feature of the MAX9153 sets the outputs
high when the differential input is:
•
•
•
Without a fail-safe circuit, when the input is undriven,
noise at the input may switch the outputs and it may
appear to the system that data is being sent. Open or
undriven terminated input conditions can occur when a
cable is disconnected or cut, or when an LVDS driver
output is in high impedance. A shorted input can occur
because of a cable failure.
When the input is driven with signals meeting the LVDS
standard, the input common-mode voltage is less than
V
Table 1. Input/Output Function Table
CC
Undriven terminated
Open
Undriven and shorted
Undriven and terminated
Undriven short
- 0.3V and the fail-safe circuit is not activated. If
High = 450mV > V
Low = -250mV > V
ID
+50mV
-50mV
Open
= RIN+ - RIN-, V
INPUT, V
_______________________________________________________________________________________
OD
OD
ID
OD
> 250mV
> -450mV
MAX9153
MAX9154
MAX9153
MAX9153
= DO_+ - DO_-
Low-Jitter, 800Mbps, 10-Port LVDS
OUTPUTS, V
Fail-Safe
High
High
High
High
Low
OD
Repeaters with 100 Ω Drive
the input is open, undriven and shorted, or undriven
and parallel terminated, an internal resistor in the fail-
safe circuit pulls both inputs above V
ing the fail-safe circuit and forcing the outputs high
(Figure 1).
The MAX9154 is essentially the MAX9153 without the
fail-safe circuit. The MAX9154 accepts input voltages
from 0 to V
allows interfacing to LVPECL input signals while retain-
ing a good common-mode tolerance.
Figure 2. MAX9154 Input Bias Resistors
Figure 1. MAX9153 Input Fail-Safe Circuit
RIN+
RIN-
RIN+
RIN-
R
R
IN1
IN1
/2
/2
CC
V
R
CC
IN2
R
R
V
(vs. 0 to 2.4V for the MAX9153), which
CC
IN3
IN3
V
CC
RECEIVER
- 0.3V
MAX9154
RECEIVER
COMPARATOR
MAX9153
CC
- 0.3V, activat-
DO1+
DO1-
DO10+
DO10-
DO1+
DO1-
DO10+
DO10-
7