MAX9271GTJ/V+ Maxim Integrated, MAX9271GTJ/V+ Datasheet - Page 31

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

Specifications of MAX9271GTJ/V+

• 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

GPO on the serializer follows GPI transitions on the dese-
rializer. This GPO/GPI function can be used to transmit
signals such as frame sync in a surround-view camera
system. The GPI-to-GPO delay is 0.35ms (max). Keep
the time between GPI transitions to a minimum 0.35ms.
This includes transitions from the other deserializer in the
coax-mode splitter. Bit D4 of register 0x0E in the deserial-
izer stores the GPI input state. GPO is low after power-up.
The FC can set GPO by writing to the SET_GPO register
bit. Do not send a logic-low value on the deserializer RX/
SDA input (UART mode) longer than 100Fs in either base
or bypass mode to ensure proper GPO/GPI functionality.
The serial line driver employs current-mode logic (CML)
signaling. The driver is differential when programmed
for twisted-pair (TP). When programmed for coax, one
side of the CML driver is used. The line driver has pro-
grammable pre/deemphasis that modifies the output to
compensate for cable length. There are 13 preemphasis
settings, as shown in
levels are deemphasis levels in which the preempha-
sized swing level is the same as normal swing, but the
no-transition data (e.g., a 1 followed by a 1) is deempha-
sized. Program the preemphasis levels through register
0x06 D[3:0] of the serializer. This preemphasis function
Table 5. TP/Coax Drive Current (CMLLVL = 1000)
*Negative preemphasis levels denote deemphasis.
Maxim Integrated
(power-on default)
PREEMPHASIS
LEVEL (dB)*
10.5
14.0
-6.0
-4.1
-2.5
-1.2
1.1
2.2
3.3
4.4
6.0
8.0
0
Table
Pre/Deemphasis Driver
5. Negative preemphasis
PREEMP SETTING
16-Bit GMSL Serializer with Coax or
GPO/GPI Control
(0x06, D[3:0])
0100
0011
0010
0001
0000
1000
1001
1010
1011
1100
1101
1110
1111
(mA)
I
CML
12
13
14
15
16
16
16
16
16
15
14
13
12
compensates the high-frequency loss of the cable and
enables reliable transmission over longer link distances.
Current drive for both TP and coax modes is program-
mable. CMLLVL bits (0x06, D[7:4]) program drive current
in TP and coax modes for a single-ended voltage swing
from 100mV to 500mV.
To reduce the EMI generated by the transitions on the
serial link, the serializer output is programmable for
spread spectrum. If the deserializer driven by the serial-
izer has programmable spread spectrum, do not enable
spread for both at the same time or their interaction will
cancel benefits. The deserializer tracks the serializer’s
spread and passes the spread to the deserializer output.
The programmable spread-spectrum amplitudes are
Q0.5%, Q1%, Q1.5%, Q2%, Q3%, and Q4%
Some spread-spectrum amplitudes can only be used at
lower PCLKIN frequencies
frequency limit for the Q0.5% spread rate.
When the spread spectrum is turned on or off, the serial
link stops for several microseconds and then restarts in
order for the deserializer to lose and relock to the new
serial-data stream.
The serializer includes a sawtooth divider to control the
spread-modulation rate. Autodetection of the PCLKIN
(mA)
I
PRE
3
2
1
0
1
2
3
4
5
6
7
8
4
STP Cable Drive
SINGLE-ENDED VOLTAGE SWING
MAX (mV)
400
400
400
400
400
425
450
475
500
500
500
500
500
(Table
7). There is no PCLKIN
Spread Spectrum
MAX9271
MIN (mV)
200
250
300
350
400
375
350
325
300
250
200
150
100
(Table
6).
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