DS90CR215_09 Datasheet, PDF (1/18 Pages) National Semiconductor (TI) – +3.3V Rising Edge Data Strobe LVDS 21-Bit Channel Link-66 MHz

DS90CR215/DS90CR216
June 5, 2009
+3.3V Rising Edge Data Strobe LVDS 21-Bit Channel Link -
66 MHz
General Description
The DS90CR215 transmitter converts 21 bits of CMOS/TTL
data into three LVDS (Low Voltage Differential Signaling) data
streams. A phase-locked transmit clock is transmitted in par-
allel with the data streams over a fourth LVDS link. Every
cycle of the transmit clock 21 bits of input data are sampled
and transmitted. The DS90CR216 receiver converts the
LVDS data streams back into 21 bits of CMOS/TTL data. At
a transmit clock frequency of 66 MHz, 21 bits of TTL data are
transmitted at a rate of 462 Mbps per LVDS data channel.
Using a 66 MHz clock, the data throughput is 1.386 Gbit/s
(173 Mbytes/s).
The multiplexing of the data lines provides a substantial cable
reduction. Long distance parallel single-ended buses typically
require a ground wire per active signal (and have very limited
noise rejection capability). Thus, for a 21-bit wide data and
one clock, up to 44 conductors are required. With the Channel
Link chipset as few as 9 conductors (3 data pairs, 1 clock pair
and a minimum of one ground) are needed. This provides a
80% reduction in required cable width, which provides a sys-
tem cost savings, reduces connector physical size and cost,
and reduces shielding requirements due to the cables' smaller
form factor.
The 21 CMOS/TTL inputs can support a variety of signal
combinations. For example, five 4-bit nibbles plus 1 control,
or two 9-bit (byte + parity) and 3 control.
Features
■ ^{Single +3.3V supply}
■ ^{Chipset (Tx + Rx) power consumption <250 mW (typ)}
■ ^{Power-down mode (<0.5 mW total)}
■ ^{Up to 173 Megabytes/sec bandwidth}
■ ^{Up to 1.386 Gbps data throughput}
■ ^{Narrow bus reduces cable size}
■ ^{290 mV swing LVDS devices for low EMI}
■ ^{+1V common mode range (around +1.2V)}
■ ^{PLL requires no external components}
■ ^{Low profile 48-lead TSSOP package}
■ ^{Rising edge data strobe}
■ ^{Compatible with TIA/EIA-644 LVDS standard}
■ ^{ESD Rating > 7 kV}
■ ^{Operating Temperature: −40°C to +85°C}
Block Diagrams
DS90CR215
DS90CR216
Order Number DS90CR215MTD
See NS Package Number MTD48
1290901
1290927
Order Number DS90CR216MTD
See NS Package Number MTD48
See DS90CR216AMTD with Improved AC Specifications
Recommended Alternative Device
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