MAX9271GTJ+T Maxim Integrated, MAX9271GTJ+T Datasheet - Page 33

• Manufacturer Part Number: MAX9271GTJ+T
• Description: Serializers & Deserializers - Serdes 1.5Gbps 16Bit Coax/STP serializer
• Manufacturer: Maxim Integrated
• Type: Serializerr

Specifications of MAX9271GTJ+T

• Rohs: yes
• Data Rate: 1.5 Gbit/s
• Input Type: CMOS/LVCMOS
• Output Type: CML
• Number Of Inputs: 16
• Number Of Outputs: 1
• Operating Supply Voltage: 1.7 V to 3.6 V
• Operating Temperature Range: - 40 C to + 105 C
• Package / Case: TQFN-32
• Maximum Operating Temperature: + 105 C
• Minimum Operating Temperature: - 40 C
• Mounting Style: SMD/SMT

Table 8. Modulation Coefficients and
Maximum SDIV Settings
When CRC is enabled, the serializer adds 6 bits of CRC
to the input data. This reduces the available bits in the
input data word by 6, compared to the non-CRC case
(see
able for input data instead of 22 bits when BWS = 0, and
24 bits instead of 30 bits when BWS = 1.
The CRC generator polynomial is x
the ITU-T G704 telecommunication standard).
The parity bit is still added when CRC is enabled,
because it is used for word-boundary detection. When
CRC is enabled, each data word is scrambled and then
the 6-bit CRC and 1-bit parity are added before the
8b/10b encoding.
At the deserializer, the CRC code is recalculated. If the
recalculated CRC code does not match the received
CRC code, an error is flagged. This CRC error is reported
to the error counter.
Hamming code is a simple and effective error-correction
code to detect and/or correct errors. The MAX9271 seri-
alizer (when used with the MAX9272 GMSL deserializer)
uses a single-error correction, double-error detection per
pixel hamming-code scheme.
Maxim Integrated
BWS
1
0
Table 2
SETTING (%)
SPECTRUM
SPREAD-
for details). For example, 16 bits are avail-
0.5
1.5
0.5
1.5
1
3
4
2
1
3
4
2
Cyclic Redundancy Check (CRC)
MODULATION
COEFFICIENT
(dec)
104
104
152
152
204
204
112
112
152
152
80
80
16-Bit GMSL Serializer with Coax or
6
+ x + 1 (as used in
Hamming Code
SDIV UPPER
LIMIT (dec)
40
63
27
54
15
30
52
63
37
63
21
42
The serializer uses data interleaving for burst error toler-
ance. Burst errors up to 11 consecutive bits on the serial
link are corrected, and burst errors up to 31 consecutive
bits are detected.
Hamming code adds overhead similar to CRC. See
for details regarding the available input word size.
HS/VS encoding by a GMSL serializer allows horizontal
and vertical synchronization signals to be transmitted
while conserving pixel data bandwidth. With HS/VS
encoding enabled, 10-bit pixel data with a clock up to
100MHz can be transmitted using one video pixel of
data per HS/VS transition, versus 8-bit data with a clock
up to 100MHz without HS/VS encoding. The deserializer
performs HS/VS decoding, tracks the period of the HS/
VS signals, and uses voting to filter HS/VS bit errors.
When using HS/VS encoding, use a minimum HS/VS low-
pulse duration of two PCLKIN cycles when DBL = 0 on
the MAX9271/MAX9273. When DBL = 1, use a minimum
low-pulse duration of five PCLKIN cycles and a minimum
high-pulse duration of two PCLKIN cycles. When using
hamming code with HS/VS encoding, do not send more
than two transitions every 16 PCLKIN cycles.
When the serializer uses double-input mode (DBL = 1)
the active duration, plus the blanking duration of HS or
VS signals, should be an even number of PCLKIN cycles.
If HS/VS tracking is used without HS/VS encoding, use
DIN0 for HSYNC and DIN1 for VSYNC. In this case, if
DBL values on the serializer and the deserializer are dif-
ferent, set the deserializer’s UNEQDBL register bit to 1.
If the serializer and deserializer have unequal DBL set-
tings and HVEN = 0, then HS/VS inversion should only
be used on the side that has DBL = 1. HS/VS encoding
sends packets when HSYNC or VSYNC is low, use H/V
inversion register bits if input HSYNC and VSYNC signals
use an active-low convention to send data packets dur-
ing the inactive pixel clock periods.
The driver output is programmable for two types of cable:
100I twisted pair and 50I coax (contact the factory for
serializers with 75I cable drive).
HS/VS Encoding and/or Tracking
STP Cable Drive
MAX9271
Serial Output
Table 2
33