Datasheet

Maxim Integrated │ 2
www.maximintegrated.com
Evaluates: MAX14986
MAX14986 Evaluation Kit
Detailed Description of Hardware
The MAX14986 evaluation kit (EV kit) evaluates the
MAX14986 dual-channel buffer. The device is designed
to redrive Serial-Attached SCSI (SAS) or Serial ATA
(SATA) signals. The EV kit is divided into four sections:
application circuit, characterization circuit, and two
calibration traces.
The application circuit utilizes 100Ω differential controlled
impedance traces and provides two SAS connectors (J1
and J2), allowing for evaluation of the device in a SAS
environment. The characterization circuit utilizes 50Ω
single-ended, controlled-impedance traces and SMA
input/output connectors, allowing for eye diagrams, and
input/output return-loss measurements.
The lower-half of the EV kit provides two sets of calibra-
tion traces (Figure 1c), all of which are matched to the
trace lengths in the characterization circuit. These traces
provide a reference for determining the performance of
only the device when evaluated in the characterization
circuit.
Application Circuit (U1)
The application circuit provides the means for evaluating
the device in a SAS/SATA application. This section of the
EV kit provides two SAS/SATA connectors (J1 and J2),
one for connection to a SAS/SATA host (e.g., a PC) and
the other for connection to a SAS/SATA device (e.g., a
hard drive).
Power Supply (VIN)
The application circuit must be powered by +3.3V. There
are two ways to get this voltage, either the on-board LDO
(U3) or an external +3.3V power supply. When using the
on-board voltage regulator, the LDO can be powered
by the 4-pin Molex connector (H1) or by a +5V external
supply connected to the VIN and GND PCB pads. When
using the on-board LDO to supply power, there is a power
LED (D1) to indicate the presence of +3.3V at VCC.
The user can also connect directly to a +3.3V supply,
which is available on a SAS power connector. The shunt
should be removed from jumper JU11 and a wire con-
nected from the SAS power pin to pin-2 (right-most pin)
of jumper JU11 (see Table 2).
Mode Control (JU6)
The device can also be used to redrive Serial ATA (SATA)
signals. The MODE pin configures the device to operate
with SATA or SAS signals. See Table 3 for jumper JU6
functions.
Table 1. Default Shunt Positions
(JU1–JU11)
Table 2. Jumper JU11 Function
Table 3. Jumper JU6 Function
*Default position.
*Default position.
JUMPER SHUNT POSITION
JU1–JU4, JU7, JU8, JU10 2-3
JU5, JU9 1-2
JU6 2-3 (SAS)
JU11 Installed
SHUNT POSITION VCC PIN (U1) DESCRIPTION
Installed* Connected to on-board LDO output U1 powered by LDO output (+3.3V)
Not installed Connected to external supply
Powered by +3.3V from an external supply or SAS power
connector
SHUNT POSITION MODE PIN (U1) DESCRIPTION
1-2 Connected to +3.3V Signal type: SATA
2-3* Connected to GND
Signal type: SAS
Not installed Not connected