DATASHEET
1.35V/1.5V REGISTERING CLOCK DRIVER WITH PARITY TEST
AND QUAD CHIP SELECT
SSTE32882HLB
Description
This 28-bit 1:2, or 26-bit 1:2 and 4-bit 1:1, registering clock
driver with parity is designed for 1.35V and 1.5V V
DD
operation.
All inputs are 1.35V and 1.5V CMOS compatible, except the
reset (RESET) and MIRROR inputs which are LVCMOS. All
outputs are 1.35V and 1.5V CMOS edge-controlled drivers
optimized to drive single terminated 25 to 50 traces in DDR3
RDIMM applications, except the open-drain error (ERROUT)
output. The clock outputs (Yn and Yn) and control net outputs
QnCKEn, QnCSn and QnODTn are designed with a different
strength and skew to compensate for different loading and
equalize signal travel speed.
The SSTE32882HLB has two basic modes of operation
associated with the Quad Chip Select Enable (QCSEN) input.
When the QCSEN input pin is open (or pulled high), the
component has two chip select inputs, DCS0 and DCS1, and two
copies of each chip select output, QACS0, QACS1, QBCS0 and
QBCS1. This is the "QuadCS disabled" mode. When the
QCSEN input pin is pulled low, the component has four chip
select inputs DCS[3:0], and four chip select outputs, QCS[3:0].
This is the "QuadCS enabled" mode. Through the remainder of
this specification, DCS[n:0] will indicate all of the chip select
inputs, where n=1 for QuadCS disabled, and n=3 for QuadCS
enabled. QxCS[n:0] will indicate all of the chip select outputs.
The SSTE32882HLB includes a high-performance, low-jitter,
low-skew buffer that distributes a differential clock input (CK
and CK) to four differential pairs of clock outputs (Yn and Yn),
and to one differential pair of feedback clock outputs (FBOUT
and FBOUT). The clock outputs are controlled by the input
clocks (CK and CK), the feedback clocks (FBIN and FBIN), and
the analog power inputs (AV
DD
and AV
SS
). When AV
DD
is
grounded, the PLL is turned off and bypassed for test purposes.
The SSTE32882HLB operates from a differential clock (CK and
CK). Data are registered at the crossing of CK going high, and
CK going low. The data is either driven to the corresponding
device outputs if exactly one of the DCS[n:0] input signals is
driven low.
Based on the control register settings, the device can change its
output characterisitics to match different DIMM net topologies.
The timing can be changed to compensate for different flight time
of signals within the target application. By disabling unused
outputs the power consumption is reduced.
The SSTE32882HLB accepts a parity bit from the memory
controller on the parity (PAR_IN) input, compares it with the data
received on the DIMM-independent data inputs (DAn, DBAn,
DRAS, DCAS, and DWE), and indicates whether a parity error
has occurred on the open-drain ERROUT pin (active low). The
convention is even parity; i.e., valid parity is defined as an even
number of ones across the DIMM-independent data inputs
combined with the parity input bit. To calculate parity, all
DIMM-independent D-inputs must be tied to a known logic state.
The DIMM-dependent signals (DCKEn, DODTn, and DCSn) are
not included in the parity check computation.
To ensure defined outputs from the register before a stable clock
has been supplied, RESET must be held in the low state during
power-up.
The SSTE32882HLB is available in a 176-ball BGA with
0.65mm ball pitch in a 11 x 20 grid. It is also available in a
176-ball Thin-Profile Fine-Pitch BGA with 0.65mm ball pitch in
an 8x22 grid. The device pinout supports outputs on the outer two
left and right columns to support easy DIMM signal routing.
Corresponding inputs are placed in a-way that two devices can be
placed back-to-back for four Rank modules while the data inputs
share the same vias. Each input and output is located close to an
associated no ball position or on the outer two rows to allow low
cost via technology combined with the small 0.65mm ball pitch.
1.35V/1.5V REGISTERING CLOCK DRIVER WITH PARITY TEST AND QUAD CHIP SELECT
1
SSTE32882HLB
7201/14
SSTE32882HLB
1.35V/1.5V REGISTERING CLOCK DRIVER WITH PARITY TEST AND QUAD CHIP SELECT
COMMERCIAL TEMPERATURE
Features
•
•
•
•
•
•
•
•
•
•
Pinout optimizes DDR3 RDIMM PCB layout
1-to-2 Register Outputs and 1-to-4 Clock Pair Outputs support stacked DDR3 RDIMMs
Phase Lock Loop clock driver for buffering one differential clock pair (CK and CK) and distributing to four differential outputs
Supports LVCMOS switching levels on the RESET and MIRROR inputs
Checks priority on DIMM-independent data inputs
Supports dynamic 1T/3T timing transaction and output inversion feature for improved timing performance during normal operations
and MRS command pass-through
Supports CKE Power Down operation modes
Supports Quad Chip Select operation features
RESET input disables differential input recievers, resets all registers, and disables all output drivers except ERROUT and QnCKEn
Provides access to internal control words for configuring the device features and adapting in different RDIMM and system
applications
•
Latch-up performance exceeds 100mA
•
ESD > 2000V per MIL-STD883, Method 3015; ESD > 200V using machine model (c = 200pF, R = 0)
•
Available in 176 Ball Grid Array package
1.35V/1.5V REGISTERING CLOCK DRIVER WITH PARITY TEST AND QUAD CHIP SELECT
2
SSTE32882HLB
7201/14
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