MAX9171_07 Datasheet, PDF (6/12 Pages) Maxim Integrated Products – Single/Dual LVDS Line Receivers with “In-Path” Fail-Safe

Single/Dual LVDS Line Receivers with
“In-Path” Fail-Safe
MAX9171 Pin Description
PIN
SOT23 SO/TDFN
1
8
2
3
4, 5, 6
7
8
—
5
7
3, 4, 6
2
1
(TDFN only)
NAME
V_CC
GND
OUT
N.C.
IN+
IN-
EP
FUNCTION
Positive Power-Supply Input. Bypass with a 0.1µF and a 0.001µF capacitor to GND with the
smallest capacitor closest to the pin.
Ground
Receiver Output
No Connection. Not internally connected.
Noninverting Differential Receiver Input
Inverting Differential Receiver Input
Exposed Paddle. Solder to PCB ground.
MAX9172 Pin Description
PIN
SOT23 SO/TDFN
1
8
2
5
3
7
4
6
5
4
6
3
7
2
8
1
—
(TDFN only)
NAME
V_CC
GND
OUT1
OUT2
IN2-
IN2+
IN1+
IN1-
EP
FUNCTION
Positive Power-Supply Input. Bypass with a 0.1µF and a 0.001µF capacitor to GND with the
smallest capacitor closest to the pin.
Ground
Receiver Output 1
Receiver Output 2
Inverting Differential Receiver Input 2
Noninverting Differential Receiver Input 2
Noninverting Differential Receiver Input 1
Inverting Differential Receiver Input 1
Exposed Paddle. Solder to PCB ground.
Detailed Description
LVDS Inputs
The MAX9171/MAX9172 feature LVDS inputs for inter-
facing high-speed digital circuitry. The LVDS interface
standard is a signaling method intended for point-to-
point communication over controlled-impedance
media, as defined by the ANSI TIA/EIA-644 standards.
The technology uses low-voltage signals to achieve fast
transition times and minimize power dissipation and
noise immunity. The MAX9171/MAX9172 convert LVDS
Table 1. Input-Output Function Table
INPUTS
(IN_+) - (IN_-)
≥ 0mV
≤ -100mV
Open
Undriven short
Undriven parallel termination
OUTPUT
OUT_
High
Low
High
High
High
signals to LVCMOS/LVTTL signals at rates in excess of
500Mbps. These devices are capable of detecting dif-
ferential signals as low as 100mV and as high as 1.2V
within a 0 to V_CC input voltage range. Table 1 is the
input-output function table.
Fail-Safe
The MAX9171/MAX9172 fail-safe drives the receiver
output high when the differential input is:
• Open
• Undriven and shorted
• Undriven and terminated
Without fail-safe, differential noise at the input may
switch the receiver and appear as data to the receiving
system. An open input occurs when a cable and termi-
nation are disconnected. An undriven, terminated input
occurs when a cable is disconnected with the termina-
tion still connected across the receiver inputs or when
the driver of a receiver is in high impedance. An undriv-
en, shorted input can occur due to a shorted cable.
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