EVAL-ADA4350RUZ-P User Guide
UG-655
One Technology Way • P.O. Box 9106 • Norwood, MA 02062-9106, U.S.A. • Tel: 781.329.4700 • Fax: 781.461.3113 • www.analog.com
Evaluating the ADA4350, a FET Input Analog Front End With ADC Driver
Offered in a 28-Lead 9.8 mm × 6.4 mm TSSOP
The evaluation board is a 6-layer printed circuit board (PCB)
designed to minimize leakage currents with its guard ring
features. It accepts SMA edge mounted connectors on the
inputs and outputs for efficient connection to test equipment or
other circuitry.
FEATURES
Enables quick breadboarding/prototyping
User defined circuit configuration
Edge mounted SMA connector provisions
Easy connection to test equipment and other circuits
Guard ring to minimize leakage currents
The evaluation board components are primarily SMT 0603 case
size, with the exception of the electrolytic bypass capacitors (C9,
C10, and C13), which are 1206 case size.
GENERAL DESCRIPTION
The EVAL-ADA4350RUZ-P evaluation board is designed to
help users evaluate the ADA4350 offered in a 28-lead, 9.8 mm ×
6.4 mm thin shrink small outline package (TSSOP). The evaluation board is a populated board that enables users to quickly
prototype the best configuration of the analog front end for
their systems. Figure 1 shows the component side of the bare
evaluation board, and Figure 2 shows the solder side of the bare
evaluation board.
Figure 10 shows the ADA4350 configured as a transimpedance
amplifier with multiple gains when a dual supply is used.
Figure 3 and Figure 4 show the signal gain/noise gain of the
board when configured as Figure 10. Figure 7 to Figure 9 show
the guard ring details. Figure 11 shows the assembly drawing
and Figure 12 shows the 6-layer stackup along with the
dimensions for each layer. The bill of materials is listed in
Table 2.
11998-001
11998-102
DIGITAL PICTURES OF THE EVALUATION BOARD
Figure 1. ADA4350 Evaluation Board Component Side
PLEASE SEE THE LAST PAGE FOR AN IMPORTANT
WARNING AND LEGAL TERMS AND CONDITIONS.
Figure 2. ADA4350 Evaluation Board Solder Side
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EVAL-ADA4350RUZ-P User Guide
TABLE OF CONTENTS
Features .............................................................................................. 1
Frequency Response .....................................................................3
General Description ......................................................................... 1
Evaluation Board Control ............................................................4
Digital Pictures of the Evaluation Board ....................................... 1
Evaluation Board Electrostatic Guarding ..................................5
Revision History ............................................................................... 2
Evaluation Board Schematic and Artwork.....................................6
Evaluation Board Hardware ............................................................ 3
Ordering Information .......................................................................8
Power Supplies .............................................................................. 3
Bill of Materials ..............................................................................8
Guard Ring Features .................................................................... 3
REVISION HISTORY
5/15—Revision 0: Initial Version
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EVAL-ADA4350RUZ-P User Guide
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EVALUATION BOARD HARDWARE
The normalized transimpedance and noise gain are shown in
Figure 3 and Figure 4 with compensation capacitors installed
and not installed.
1000k
RF = 1kΩ, CF = 15pF
RF = 3kΩ, CF = 6.8pF
RF = 10kΩ, CF = 3.3pF
RF = 30kΩ, CF = 2.2pF
RF = 100kΩ, CF = 1pF
100k
GUARD RING FEATURES
SIGNAL GAIN (dB)
The ADA4350 evaluation board employs a two layer
electrostatic guarding to minimize leakage currents from
entering the TIA node.
Five mil wide guard rings encircle the inverting and
noninverting input components on the top copper layer (see
Figure 7 and Figure 9). The guard rings connect to the internal
GND copper layer with 5 mil dia vias. Each component pad
that connects to the TIA inverting and noninverting inputs is
connected to an internal copper trace with 5 mil dia vias (see
Figure 8 and Figure 9).
10k
1k
RF =
RF =
RF =
RF =
RF =
0.1k
0.01k
0.1M
1kΩ
3kΩ
10kΩ
30kΩ
100kΩ
1M
10M
FREQUENCY (Hz)
11998-003
The ADA4350 has two supplies. The analog supply is used to
power up all the analog circuitries while the digital supply is
used to power up all the digital controls. The two supplies
have separate grounds inside the chip. Table 1 shows the
supply range of the analog and digital supply, the voltages to be
applied to the supply pins in different configurations, and their
limitations.
The five feedback resistor values are approximately ½ decade
apart. The five compensation capacitors are selected for
maximum bandwidth and maximum gain flatness.
100M
Figure 3. ADA4350 Signal Gain and Noise Gain Frequency Response
This electrostatic guarding scheme provides isolation from
leakage currents but adds a 35 pF parasitic capacitance to the
TIA inverting node.
50
RF =
RF =
RF =
RF =
RF =
40
FREQUENCY RESPONSE
30
NOISE GAIN (dB)
The ADA4350 evaluation board is configured for a simulated
photodiode input. The photodiode capacitance is represented
by C1, a 51 pF capacitor. The photodiode current is simulated
by the input voltage Vin-N and R2, a 100 kΩ resistor. IPHOTODIODE
= (Vin-N)/100 kΩ.
20
10
0
RF = 1kΩ, CF = 15pF
RF = 3kΩ, CF = 6.8pF
RF = 10kΩ, CF = 3.3pF
RF = 30kΩ, CF = 2.2pF
RF = 100kΩ, CF = 1pF
–10
The total capacitance (91 pF) seen by the TIA is the sum of the
ADA4350 input capacitances (2 pF + 3 pF), the photodiode
capacitance (51 pF), and the parasitic capacitance of the
electrostatic guarding (35 pF).
1kΩ
3kΩ
10kΩ
30kΩ
100kΩ
–20
–30
0.1M
1M
10M
FREQUENCY (Hz)
11998-004
POWER SUPPLIES
100M
Figure 4. ADA4350 Signal Gain and Noise Gain Frequency Response
Table 1. Powering Up the Analog and Digital Supplies
Supply
Analog
Digital
Supply Range (V)
3.3 to 12
3.3 to 5.5
Dual Supplies (±VS)
VCC
GND
VEE
Single Supplies (+VS)
VCC
GND
VEE
+VS
−VS
+VS
0
0
VCC to DGND
≥3 V
Rev. 0 | Page 3 of 8
0
VCC to DGND
≥3 V
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EVAL-ADA4350RUZ-P User Guide
EVALUATION BOARD CONTROL
This user guide focuses on setting up the evaluation board. For
logic tables of the different control modes and for an in depth
analysis of the circuit, refer to the ADA4350 data sheet.
Manual Mode
The evaluation board is configured for manual gain selection
using the DIP switches. The DIP switch on position represents
Logic 0. To operate manually, set the enable switch to Logic 1
(off position), and set the MODE switch to Logic 1 (off
position).
To select one gain, set all gain select switches, P0 to P4, to
Logic 0 (on position) and select a gain by setting the
corresponding gain select switch to Logic 1 (off position).
11998-005
Note that only five feedback paths (FB0 to FB4) can be accessed
in the manual mode and that selecting more than one gain
connects all the selected feedback resistors in parallel.
SPI Control (Parallel Mode)
The parallel mode works very similar to the manual mode
except that five digital control lines (P0 to P4) are used instead
of the manual switches. Set the enable switch to Logic 1 (off
position), and set the MODE switch to Logic 1 (off position).
Set the DIP switches (P0 to P4) to Logic 1 (off position), and
connect the logic output of an external microcontroller or
FPGA to the plated holes next to the P0 to P4 switches. A
Logic 1 on each digital line selects the corresponding gain.
Applying a Logic 1 to more than one line at a time connects
all the selected gains in parallel.
Figure 5. Location of the LabVIEW Control Panel Program
3.
Open the LabVIEW control panel (see Figure 6). The
control panel allows the user to open and close individual
switches in the switch matrix of the ADA4350. For
example, to select the FB0 feedback path, click the S0 and
S6 switches, then click the Write New Configuration
button.
SPI Control (Serial Mode)
1.
2.
Plug the Analog Devices, Inc., SDP-S controller board onto
the 120-pin connector on the ADA4350 evaluation board.
The SDP-S control board can be purchased from Analog
Devices.
The user can also use an individual SPI interface through
the 5-pin SPI connector on the evaluation board.
Download the LabVIEW® control panel from
http://www.analog.com/ada4350-demoinstaller. Unzip the
file, click setup.exe, and follow the installation prompts. If
the installation is successful, the ADA4350 Evaluation
icon appears under Start > Programs > Analog Devices
(see Figure 5).
11998-006
Set the MODE switch and LATCH switch to Logic 0 (on
position), and the ENABLE switch to Logic 1 (off position). Set
all other gain select switches (P1 to P4) to Logic 1 (off position),
and perform the following steps:
Figure 6. Labview Control Panel
Switches
The gain select switches (S0 to S5) have around 350 Ω series
internal resistance that appears as a resistance in series with
the TIA output, while S6 to S11 has around 150 Ω switch
resistances.
Rev. 0 | Page 4 of 8
EVAL-ADA4350RUZ-P User Guide
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EVALUATION BOARD ELECTROSTATIC GUARDING
11998-008
Note that the guard ring is employed all the way from the top
copper layer through the inner layers and into the ground layer.
11998-007
The guard ring is represented by the red enclosed area around
the inputs. The evaluation board uses the guard ring to
minimize leakage currents entering the inputs causing offsets.
Figure 8. Ground Layer Guard Ring Drawing
11998-009
Figure 7. Top Layer Guard Ring Drawing
Figure 9. Guard Ring Details
Rev. 0 | Page 5 of 8
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EVAL-ADA4350RUZ-P User Guide
EVALUATION BOARD SCHEMATIC AND ARTWORK
RF5
External amp/Filter in & outputs
CN 5 CN 6
100 kΩ
1 pF
30 kΩ
2.2 pF
10 kΩ
CF5
RF4
CF4
RF3
953 Ω
R9
R8
CF3
RF2
R7
3.3 pF CF2
3 kΩ RF1
6
RF1
7
VIN1
8
SWB_OUT
9
SWA_OUT
ADA4350
0 Ω
FB4
51 pF
C1
0 Ω
FB5
100 kΩ
FB3
R1
FB2
49.9 Ω
FB0
15 pFCF0
R2
RF
R6
RF0
FB1
1 kΩ
Simulated Photo Diode
& Inverting Input
CN1
RG
6.8 pFCF1
5
4
27
1
28
2
CN 3
R1 3
3 VOUT1
49.9 Ω
IN-N 10
C3
IN-P 11
Outputs
IC1
Non- Inverting Input
CN 4
R1 4
R3
26 VOUT2
R5
49.9 Ω
REF
VC C
Ref Des Device(Type)
ADA4350
VEE DGND VCC DVDD
TSSOP-28 14
18
15
24
R1 5
R1 7
R1 6
R1 8
CN 7
R1 1
R1 9
VCC
J1
L1
L2
Digikey 732-3852-1-ND
VD D
C9
10u F 120 6
C5
C7
C1 0
10 uF 120 6
C6
C8
R2 0
10 kΩ
C1 3
10uF 120 6
C1 1
0 Ω
C1 2
C2
0 Ω 0.1 uF
VE E
R2 1
J2
R12
10 kΩ
Digikey 723-3855-1-ND
R2 2
J3:85
R2 3
VE E
0.1 uF
Power Supply connectors
0.1 uF
CS
SDI
SDO External
CLK
LATCH
J3:84
R2 4
J3:83
R2 5
J3:82
SPI Control access
R2 6
J3:43
J3:58
J3:52
J3:46
J3:40
J3:36
J3:28
J3:23
J3:17
J3:11
J3: 6
J3: 4
J3:3
J3:6 3
J3:6 9
J3:7 5
J3:8 1
J3:8 6
J3:9 3
J3:9 8
J3:10 4
J3:10 9
J3:11 5
J3:11 7
J3:11 8
SPD Connector
Figure 10. Schematic
Rev. 0 | Page 6 of 8
VD D
VDD VD D
J3:11 6
J3:5 6
VD D
100 kΩ
R2 8
IC2
R2 7
C1 4
0.1 uF
8
7
6
5
VDD
A0
WP
A1
SCL
A2
SDA
DGND
1
2
3
4
24LC32A-I/MS
J3:7 9
J3:8 0
SPD EEPROM
R2 9
100 kΩ
11998-010
IC1
Package
VCM-IN
R1 0
VD D
Power Tabl e
C4
25
CS/P4
SDI/ P3
SDO/ P2
19 20 21 22 23
16 17
SCLK/P1
13
LATCH/P0
12
EN
R4
MOD E
0 Ω
SWB_IN
0 Ω
SWA_IN
CN2
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11998-011
EVAL-ADA4350RUZ-P User Guide
11998-012
Figure 11. Component Side Assembly Drawing
Figure 12. Layer Stackup
Rev. 0 | Page 7 of 8
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EVAL-ADA4350RUZ-P User Guide
ORDERING INFORMATION
BILL OF MATERIALS
Table 2.
Qty
1
1
1
1
3
6
10
1
7
29
1
1
1
Reference Designator
None
None
None
None
C9, C10, C13
C5 to C8, C11, C12
CF0 to CF5, C1 to C4
ADA4350
Vin_P, Vin_N, VCM-IN, Vin1, Vout1, Vout2, TIA Out
R1 to R21, RF0 to RF5, RF, RG
SDP connector
Small SDP connector
24LC32AF
Description
Analog supply connector
Digital supply connector
2-pin mode selector
5-pin gain selector
10 µF capacitor
0.1 µF capacitor
Capacitor, user defined
See the ADA4350 data sheet packaging information
SMA/SMT
Resistor, user defined
Standard 120-pin SDP connector
5-pin SPI header
SDP EEPROM
Package
3-pin 100 mil header
2-pin 100 mil header
2-pin dip switch
5-pin dip switch
1206
0603
0603
28-lead TSSOP
SMA/SMT
R0603
MSOP
ESD Caution
ESD (electrostatic discharge) sensitive device. Charged devices and circuit boards can discharge without detection. Although this product features patented or proprietary protection
circuitry, damage may occur on devices subjected to high energy ESD. Therefore, proper ESD precautions should be taken to avoid performance degradation or loss of functionality.
Legal Terms and Conditions
By using the evaluation board discussed herein (together with any tools, components documentation or support materials, the “Evaluation Board”), you are agreeing to be bound by the terms and conditions
set forth below (“Agreement”) unless you have purchased the Evaluation Board, in which case the Analog Devices Standard Terms and Conditions of Sale shall govern. Do not use the Evaluation Board until you
have read and agreed to the Agreement. Your use of the Evaluation Board shall signify your acceptance of the Agreement. This Agreement is made by and between you (“Customer”) and Analog Devices, Inc.
(“ADI”), with its principal place of business at One Technology Way, Norwood, MA 02062, USA. Subject to the terms and conditions of the Agreement, ADI hereby grants to Customer a free, limited, personal,
temporary, non-exclusive, non-sublicensable, non-transferable license to use the Evaluation Board FOR EVALUATION PURPOSES ONLY. Customer understands and agrees that the Evaluation Board is provided
for the sole and exclusive purpose referenced above, and agrees not to use the Evaluation Board for any other purpose. Furthermore, the license granted is expressly made subject to the following additional
limitations: Customer shall not (i) rent, lease, display, sell, transfer, assign, sublicense, or distribute the Evaluation Board; and (ii) permit any Third Party to access the Evaluation Board. As used herein, the term
“Third Party” includes any entity other than ADI, Customer, their employees, affiliates and in-house consultants. The Evaluation Board is NOT sold to Customer; all rights not expressly granted herein, including
ownership of the Evaluation Board, are reserved by ADI. CONFIDENTIALITY. This Agreement and the Evaluation Board shall all be considered the confidential and proprietary information of ADI. Customer may
not disclose or transfer any portion of the Evaluation Board to any other party for any reason. Upon discontinuation of use of the Evaluation Board or termination of this Agreement, Customer agrees to
promptly return the Evaluation Board to ADI. ADDITIONAL RESTRICTIONS. Customer may not disassemble, decompile or reverse engineer chips on the Evaluation Board. Customer shall inform ADI of any
occurred damages or any modifications or alterations it makes to the Evaluation Board, including but not limited to soldering or any other activity that affects the material content of the Evaluation Board.
Modifications to the Evaluation Board must comply with applicable law, including but not limited to the RoHS Directive. TERMINATION. ADI may terminate this Agreement at any time upon giving written notice
to Customer. Customer agrees to return to ADI the Evaluation Board at that time. LIMITATION OF LIABILITY. THE EVALUATION BOARD PROVIDED HEREUNDER IS PROVIDED “AS IS” AND ADI MAKES NO
WARRANTIES OR REPRESENTATIONS OF ANY KIND WITH RESPECT TO IT. ADI SPECIFICALLY DISCLAIMS ANY REPRESENTATIONS, ENDORSEMENTS, GUARANTEES, OR WARRANTIES, EXPRESS OR IMPLIED, RELATED
TO THE EVALUATION BOARD INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTY OF MERCHANTABILITY, TITLE, FITNESS FOR A PARTICULAR PURPOSE OR NONINFRINGEMENT OF INTELLECTUAL
PROPERTY RIGHTS. IN NO EVENT WILL ADI AND ITS LICENSORS BE LIABLE FOR ANY INCIDENTAL, SPECIAL, INDIRECT, OR CONSEQUENTIAL DAMAGES RESULTING FROM CUSTOMER’S POSSESSION OR USE OF
THE EVALUATION BOARD, INCLUDING BUT NOT LIMITED TO LOST PROFITS, DELAY COSTS, LABOR COSTS OR LOSS OF GOODWILL. ADI’S TOTAL LIABILITY FROM ANY AND ALL CAUSES SHALL BE LIMITED TO THE
AMOUNT OF ONE HUNDRED US DOLLARS ($100.00). EXPORT. Customer agrees that it will not directly or indirectly export the Evaluation Board to another country, and that it will comply with all applicable
United States federal laws and regulations relating to exports. GOVERNING LAW. This Agreement shall be governed by and construed in accordance with the substantive laws of the Commonwealth of
Massachusetts (excluding conflict of law rules). Any legal action regarding this Agreement will be heard in the state or federal courts having jurisdiction in Suffolk County, Massachusetts, and Customer hereby
submits to the personal jurisdiction and venue of such courts. The United Nations Convention on Contracts for the International Sale of Goods shall not apply to this Agreement and is expressly disclaimed.
©2015 Analog Devices, Inc. All rights reserved. Trademarks and
registered trademarks are the property of their respective owners.
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