MAX9163ESA Maxim Integrated, MAX9163ESA Datasheet - Page 8

• Manufacturer Part Number: MAX9163ESA
• Description: LVDS Interface IC Bus LVDS 3.3V Single Transceiver
• Manufacturer: Maxim Integrated

The MAX9163 high-speed BLVDS transceiver is
designed specifically for heavily loaded multipoint bus
applications. The MAX9163 operates from a single 3.3V
power supply, and is pin compatible with DS92LV010A.
The transceiver consists of one differential BLVDS line
driver and one LVDS receiver. The driver outputs and
receiver inputs are connected internally to minimize
bus loading. The driver and receiver can be enabled or
disabled individually or simultaneously by the use of
enable logic inputs (DE, RE).
The MAX9163 driver output uses a current-steering
configuration to generate a 9mA (typ) output current.
This current-steering approach induces less ground
bounce and no shoot-through current, enhancing noise
margin and system speed performance. The outputs
are short-circuit current limited. The MAX9163 current-
steering output requires a resistive load to terminate the
signal and complete the transmission loop. With a typi-
cal 9mA output current, the MAX9163 produces a
243mV output voltage when driving a bus terminated
with two 54Ω resistors (9mA x 27Ω = 243mV).
The MAX9163 receiver detects a differential input as
low as 100mV and translates it to a single-ended out-
put. The device features an in-path fail-safe circuit that
sets the receiver output high when the receiver inputs
are undriven and open, terminated, or shorted.
The MAX9163 has in-path fail-safe circuitry, which is
designed with a +35mV input offset voltage, a 2.5µA
current source between V
input, and a 5µA current sink between the inverting
input and ground
open, the 2.5µA current source pulls the input to about
V
Bus LVDS 3.3V Single Transceiver
8
CC
PIN
1
2
3
4
5
6
7
8
_______________________________________________________________________________________
- 0.7V and the 5µA source sink pulls the inverting
DO+/RI+ Noninverting BLVDS Driver Output/Receiver Input
DO-/RI-
NAME
ROUT
GND
V
DIN
DE
RE
CC
LVTTL/LVCMOS Driver Enable Input. The driver is enabled when DE is high. When DE is low, the driver output
is disabled and is high impedance.
LVTTL/LVCMOS Driver Input
LVTTL/LVCMOS Receiver Output
Ground
LVTTL/LVCMOS Receiver Enable Input. The receiver is enabled when RE is low. When RE is high, the receiver
output is disabled and is high impedance.
Inverting BLVDS Driver Output/Receiver Input
Power-Supply Input. Bypass V
(Figure 6). If the differential input is
Receiver In-Path Fail-Safe
Detailed Description
CC
and the noninverting
CC
to GND with 0.1µF and 0.001µF ceramic capacitors.
input to ground, which drives the receiver output high.
If the differential input is shorted or terminated with a
typical value termination resistor, the +35mV offset dri-
ves the receiver output high. If the input is terminated
and floating, the receiver output is driven high by the
+35mV offset, and the 2:1 current sink to current
source ratio (5µA:2.5µA) pulls the inputs to ground.
This can be an advantage when switching between dri-
vers on a multipoint bus. The change in common-mode
voltage on the MAX9163 is from ground to the typical
driver offset voltage of 1.2V. This is less than the
change from V
the fail-safe circuitry pulls the bus to V
The characteristic impedance of a differential PC board
trace is uniformly reduced when equal capacitive loads
are attached at equal intervals (provided that the transi-
tion time of the signal being driven on the trace is
longer than the delay between loads). This kind of load-
ing is typical of multipoint buses where cards are
attached at 1in or 0.8in intervals along the length of a
backplane. The reduction in characteristic impedance
is approximated by the following formula:
where:
Z
impedance
C
C
N = number of capacitive loads
L = trace length
Z
DF-unloaded
FUNCTION
O
L
DF loaded
= value of each capacitive load (pF)
= unloaded trace capacitance (pF/unit length)
-
=
Z
= unloaded differential characteristic
CC
DF unloaded
Effects of Capacitive Loading
to 1.2V found on some circuits where
-
x
[
Pin Description
C
O
/ (
C
CC
O
+
.
(
N x C
L
/ ))]
L