Easy to Use AD4000 Series 16-/18-/20-Bit Precision SAR ADCs User Guide
UG-1042
Rev. E | Page 5 of 25
SDP-H1 CONTROLLER BOARD
The evaluation board uses a serial port interface (SPI) and is
connected to the high speed controller board for the system
demonstration platform (
SDP-H1
) controller board. The
SDP-H1
board requires power from a 12 V wall adapter. The
SDP-H1
has
a Xilinx® Spartan 6 and an
ADSP-BF527
processor with
connectivity to the PC through a USB 2.0 high speed port. The
controller boards allow the configuration and capture of data on
daughter boards from the PC via USB.
The
SDP-H1
has an FMC low pin count (LPC) connector with
full differential low voltage differential signaling (LVDS) and
singled-ended low voltage complementary metal-oxide
semiconductor (LVCMOS) support. It also has the 120-pin
connector, found on the
SDP-B
, which exposes the Blackfin®
processor peripherals. This connector provides a configurable
serial, parallel I
2
C and SPI, and general purpose input/output
(GPIO) communications lines to the attached daughter board.
SOLDER LINKS
The three solder link options on the evaluation board are
configured depending on which generic of the ADC is on the
specific evaluation board, as described in Table 3.
Table 2. Jumper Detail with Factory Default Setting
Link
Default
Function
Comment
SL1
A
+V
S
Change to B if using bench
supplies
SL2
A
−V
S
Change to B if using bench
supplies
SL5
A
+V
S
Change to B if using bench
supplies
SL6
A
−V
S
Change to B if using bench
supplies
SL7
A
VDD for
ADC
Change to B if using bench
supplies
SL8
A
−V
S
Change to B if using bench
supplies
SL9
A
+V
S
Change to B if using bench
supplies
LK2
A
VREF
Change to B if using the
ADR3450
LK5
B
SDI
Change to A if using V_DRIVE
JP1
B
FSEL (U3)
Change to A if using ground
JP2
B
ADC drivers
Change to A if using FDA
ADA4940-1
JP3
B
ADC drivers
Change to A if using FDA
ADA4940-1
JP4
B
ADC drivers
Change to A if using FDA
ADA4940-1
JP5
B
ADC drivers
Change to A if using FDA
ADA4940-1
JP7
B
V_DRIVE
Change to A if using external
3.3 V for V_DRIVE
JP8
B
STOP (U20)
Change to A if using CNV_FMC
from
SDP-H1
connector
Table 3. Jumpers Specific to 10-Lead Precision ADCs
Link Default
Configuration
Generic
SL4
A
Differential input
AD4001
,
AD4003
,
AD4020
SL4
B
Single-ended or
pseudo differential
AD4000
,
AD4002
ANALOG INPUTS
The analog inputs to the evaluation board are SMA connectors,
J6 and J10. These inputs are buffered with dedicated amplifier
circuitry (U12 and U14), as shown in Figure 27. The circuit allows
different configurations, input range scaling, filtering, addition of a
dc component, and use of different op amp and supplies. The
analog input amplifiers are set as unity-gain buffers at the factory.
The default configuration sets both U12 and U14 at midscale,
generated from a buffered reference voltage divider (VCM).
The evaluation board is factory configured to provide either a
single-ended path or a fully differential path.
For dynamic performance, a fast Fourier transform (FFT) test
can be performed by applying a very low distortion ac source.
For low frequency testing, the audio precision source (such as the
SYS-2700 series) can be used directly because the outputs on these
are isolated. Set the outputs for balanced and floating ground.
Different precision sources can be used with additional filtering.
Because the evaluation board uses the amplifiers in unity-gain,
the noninverting input has a common-mode input with a 590 Ω
resistor divider, and it must be taken into account when directly
connecting a source.
