1
dc936af
DEMO MANUAL DC936A
Description
LTC2609
Quad 16-Bit Rail-to-Rail
DAC with I2C Interface
Demonstration circuit 936A features the LT C
®
2609 Quad
16-bit DAC. This device establishes a new board-density
benchmark for 16-bit DACs and advances performance
standards for output drive, crosstalk and load regulation
in single supply, voltage-output multiple DACs.
DC936A has many features for evaluating the performance
of the LTC2609. Onboard 5V, 4.096V, and 2.5V precision
references are provided. The LTC2609 features separate
reference inputs for each DAC, and any of the onboard
references can be used for any of the reference inputs.
performance summary
Another feature of this board is the onboard LTC2428
20-bit ADC for monitoring DAC output voltage. The 16ppm
total error of this device is adequate for taking meaningful
measurements of various LTC2609 parameters.
Design files for this circuit board are available at
http://www.linear.com/demo
L, LT, LTC, LTM, Linear Technology and the Linear logo are registered trademarks and
QuikEval is a trademark of Linear Technology Corporation. All other trademarks are the property
of their respective owners.
Specifications are at TA = 25°C
PARAMETER CONDITION VALUE
Resolution 16 Bits
Monotonicity VCC = 5V, VREF = 4.096V 16 Bits
Differential Nonlinearity VCC = 5V, VREF = 4.096V ±1LSB
Integral Nonlinearity VCC = 5V, VREF = 4.096V ±18LSB Typical
Load Regulation VCC = VREF = 5V, Mid-Scale
IOUT = ±15mA
2LSB/mA Max
DC Crosstalk Due to Load Current Change on Any Other Channel 4µV/mA
2
dc936af
DEMO MANUAL DC936A
Figure 1. Proper Measurement Equipment Setup
Quick start proceDure
3
dc936af
DEMO MANUAL DC936A
Quick start proceDure
Connect DC936A to a DC590 USB serial controller using
the supplied 14-conductor ribbon cable. Connect DC590
to a host PC with a standard USB A/B cable. Run the
evaluation software supplied with DC590 or download it
from www.linear.com/software. The correct control panel
will be loaded automatically. Click the COLLECT button to
begin outputting codes to the DACs and reading back the
resulting output voltage for each DAC.
Complete software documentation is available from the
Help menu item, as features may be added periodically.
Figure 2. Evaluation Software
4
dc936af
DEMO MANUAL DC936A
HarDware setup
Jumpers
JP1 – REFLO Selection. Either tied to ground or supplied
externally to the REFLO turret post.
JP2 – ADC Disable. Set to ON for normal operation, with
the onboard ADC enabled. For very sensitive noise mea-
surements, the ADC may be disabled. The software will
then display a positive full-scale reading.
JP7 – VREF Select for ADC. This selects which onboard
reference is used for the LTC2428 ADC. If all DAC refer-
ences are set to the same voltage, set the ADC reference
to the same voltage. If different DAC reference voltages
are used, set the ADC reference to the highest DAC refer-
ence voltage.
JP3, JP4, JP5, JP6 – Select reference for DAC A, B, C,
and D, respectively. Onboard references are 2.5V, 4.096V,
and 5.0V. Remove jumper entirely to apply an external
reference.
JP11 – VCC select. VCC is taken either from the onboard 5V
reference or the 5V regulated supply from the controller
board. Selecting the 5V reference for VCC and VREF allows
characterization of rail to rail operation of the LTC2609.
JP8, JP9, JP10 – I2C Address Selection. These are con-
nected to the CA0, CA1, CA2 pins. The demo software uses
the global I2C address, so these pins have no effect when
used with the QuikEval™ software. They can be used in
prototyping to set the I2C address of the LTC2607 – refer
to the data sheet for the mapping of CA0, 1, 2 levels to
I2C addresses.
Analog Connections
DAC Outputs – The four DAC outputs from the LTC2609
are brought out to turrets labeled DAC A through DAC
D. These may be connected to external instruments or
other circuitry.
DAC outputs are not in alphabetical order on the circuit
board.
DAC References – The REFA, REFB, REFC, and REFD
turrets are connected directly to the reference terminals
of the onboard references. When one of the onboard
references is being used, the reference voltage may be
monitored at this point. An external reference may also
be applied to this turret after removing the associated
reference selection jumper.
REFLO – This is connected to the LTC2609 REFLO pin
and can be used to raise the zero-code output of all of
the DACs above ground potential. This is normally set to
ground, but may be raised up to 1V above ground. Refer
to the LTC2609 data sheet for details.
Ground Connections
Grounding – Separate power and signal grounds are
provided. Any large currents drawn from the DAC outputs
should be returned to the power ground turret closest to
Pin 1 on the 14-pin header. Signal ground is connected to
the exposed ground planes at the top and bottom edges
of the board, and to the two turrets labeled “GND.” Use
signal ground as the reference point for measurements
and connections to external circuits.
5
dc936af
DEMO MANUAL DC936A
experiments
The following experiments are intended to demonstrate
some of the outstanding features of the LTC2609. All can
be performed using the onboard LTC2428 to monitor
the DAC output voltage. The indicated output voltage will
typically agree with an HP3458A voltmeter to 5 digits. If
a DAC will be sinking or sourcing a significant current,
then the output voltage should be measured as close to
the DAC as possible.
Most of the data sheet specifications use a 4.096V refer-
ence, so this is the preferred reference to use for these
experiments. Using the 5 volt reference has the limitation
that VCC may be slightly lower than VREF, which may affect
the full scale error.
Using an external power supply is highly recommended for
these experiments, especially those that draw significant
current. Refer to the DC590 quick start guide for details.
Resolution
The onboard LTC2428 ADC has an input resolution of
6μV. This will easily resolve a 1LSB (76μV for VREF =
5V, 62.5μV for VREF = 4.096V) change in the LTC2609
output. Set one of the DAC channels to a voltage close to
mid-scale. Select the FINE slider on the control panel with
the mouse and use the right and left arrow keys to step
the output by single LSBs. The change should be clearly
visible in the output graph. (It may be necessary to wait
for the graph to clear if a large step has just occurred.
This can be sped up by disabling all other DAC channels
in the software by un-checking them.)
Integral Nonlinearity
A rough measurement of INL can be taken using the onboard
ADC. Measure one of the LTC2609 outputs at code 256
and 65,535 and calculate the slope and intercept using a
spreadsheet. Next, take several readings at intermediate
points. The readings should not deviate from the calcu-
lated line by more than 64LSBs, and they will typically be
within 12LSBs.
Load Regulation/DC Output Impedance
Select “Regulator” for VCC source. Set one of the outputs
to mid-scale (code 32768.) source or sink 15mA from one
of the DAC outputs by pulling it to power ground or VCC
with an appropriate value resistor. The voltage change
should be less than 2.25mV, corresponding to an output
impedance of 0.15Ω. Output impedance is typically less
than 0.030Ω. (measure DAC voltage at the output pin if
using a voltmeter.)
Zero Scale Error
Set one of the DACs to code 0. The measured output should
be less than 9mV and will typically be less than 1mV.
Offset Error
Set one of the DACs to code 256. The output voltage should
be within 1mV of the correct value, or VREF • 256/65535.
Gain Error
Set one of the DACs to code 65,535. The output voltage
should be within 0.7% of VREF, and will typically be within
0.2%.
DC Crosstalk
Set all DACs to mid-scale. Connect a 250Ω resistor from
one output to VCC or power ground (to sink or source
10mA, respectively, when the 5V reference is being used.)
A given output should not change by more than 3.5μV per
milliamp of output current in all other DACs combined.
6
dc936af
DEMO MANUAL DC936A
parts List
ITEM QTY REFERENCE PART DESCRIPTION MANUFACTURER/PART NUMBER
1 8 C1, C4, C5, C6, C8, C10, C13, C14 CAP., X7R, 0.1µF 16V,0402 TDK, C1005X7R1C104M
2 5 C2, C7, C9, C11, C12 CAP., X5R, 1.0µF 10V, 0402 TDK, C1005X5R1A105MT
3 1 C3 CAP., NPO, 100pF 50V, 0402 AVX, 04025A101MAT
4 14 E1-E14 TESTPOINT, TURRET, 0.064" MILL-MAX, 2308-2
5 6 JP1, JP2, JP8, JP9, JP10, JP11 JMP, 3 PIN 1 ROW .079CC SAMTEC TMM-103-02-L-S
6 5 JP3, JP4, JP5, JP6, JP7 HEADER, 2×3 PIN, 0.079CC SAMTEC TMM-103-02-L-D
7 11 JP1-JP11 PIN 1 AND 2 SHUNT, .079" CENTER SAMTEC 2SN-BK-G
8 1 J1 HEADER, 2×7 PIN, 0.079CC MOLEX, 87831-1420
9 3 R1, R2, R3 RES., CHIP, 4.99k, 1%, 0402 AAC, CR05-4991FM
10 2 R4, R9 RES., CHIP 10k 1/16W 5%, 0402 PANASONIC, ERJ2GEJ103X
11 3 R5, R6, R7 RES., CHIP, 7.5k, 5%, 0402 AAC, CR05-752JM
12 1 R8 RES., CHIP, 22, 5%, 0402 AAC, CR05-220JM
13 1 U1 I.C., LTC2609CGN, SSOP16GN LINEAR TECH., LTC2609CGN
14 1 U2 I.C., 24LC025, TSSOP8 MICROCHIP, 24LC025-I /ST
15 1 U3 I.C., LTC2428CG, SSOP28G LINEAR TECH., LTC2428CG
16 1 U4 I.C., LT1790ACS6-5.0, SOT23-6 LINEAR TECH., LT1790ACS6-5
17 1 U5 I.C., LT1790ACS6-4.096, SOT23-6 LINEAR TECH., LT1790ACS6-4.096
18 1 U6 I.C., LT1790ACS6-2.5, SOT23-6 LINEAR TECH., LT1790ACS6-2.5
19 1 U7 I.C., NC7WB66K8X, US8 FAIRCHILD, NC7WB66K8X
7
dc936af
DEMO MANUAL DC936A
Information furnished by Linear Technology Corporation is believed to be accurate and reliable.
However, no responsibility is assumed for its use. Linear Technology Corporation makes no representa-
tion that the interconnection of its circuits as described herein will not infringe on existing patent rights.
scHematic Diagram
5
5
4
4
3
3
2
2
1
1
D D
C C
B B
A A
ENABLE
DISABLE
GND
EXT
(NOTE 3)
I2C ADDRESS
3. U7 MULTIPLEXES THE SPI AND I2C BUSSES AND IS OR
COMPATIBILITY WITH THE DC590 CONTROLLER BOARD ONLY.
1. ALL RESISTORS ARE IN OHMS, 0402.
ALL CAPACITORS ARE IN MICROFARADS, 0402.
NOTES: UNLESS OTHERWISE SPECIFIED
2. INSTALL SHUNTS ON JP1-JP11 PIN 1 AND 2.
2.5
4.096
5.0
1
00
1
0
1
A-1
DC936A-1 * LTC2609CGN
Tuesday, October 11, 2005 1 1
QUAD 16-BIT DAC WITH I2C
KIM T.
MARK T.
A
SCHEMATIC
SIZE
DATE:
DWG NO. REV
SHEET OF
TITLE:
CONTRACT NO.
APPROVALS
DRAWN:
CHECKED:
APPROVED:
ENGINEER:
DESIGNER:
TECHNOLOGY
Fax: (408)434-0507
Milpitas, CA 95035
Phone: (408)432-1900
1630 McCarthy Blvd.
LTC Confidential-For Customer Use Only
CUSTOMER NOTICE
LINEAR TECHNOLOGY HAS MADE A BEST EFFORT TO DESIGN A
CIRCUIT THAT MEETS CUSTOMER-SUPPLIED SPECIFICATIONS;
HOWEVER, IT REMAINS THE CUSTOMER'S RESPONSIBILITY TO
VERIFY PROPER AND RELIABLE OPERATION IN THE ACTUAL
APPLICATION. COMPONENT SUBSTITUTION AND PRINTED
CIRUIT BOARD LAYOUT MAY SIGNIFICANTLY AFFECT CIRCUIT
PERFORMANCE OR RELIABILITY. CONTACT LINEAR
TECHNOLOGY APPLICATIONS ENGINEERING FOR ASSISTANCE.
THIS CIRCUIT IS PROPRIETARY TO LINEAR TECHNOLOGY AND
SUPPLIED FOR USE WITH LINEAR TECHNOLOGY PARTS.
VOUTD
VOUTB
VOUTC
VOUTA
REFC
REFD
REFB
5VREF
4.096VREF
2.5VREF
MOSI
SCK
CS
REFLO
REFA
CA1
CA0
CA2
SCK
MOSI
SCL
MISO
CS
MISO
SDA
VCC
VCC
VCC
VREF
+5VVCC
+5V
VCC
V+
VCC
VCC
VCC
4.096VREFV+
2.5VREF
5VREF
V+
V+
VREF
E1
REF LO
C3
100PF
JP9
CA1
C11
1.0UF,10V
U1
LTC2609CGN
9
10
11
13
12
16
1
2
3
4
15
5
14
6
7
8
SDA
CA1
CA0
VOUT C
REF C
VCC
GND
REF LO
REF A
VOUT A
REF D
VOUT B
VOUT D
REF B
CA2
SCL
R3
4.99K
1%
A
B
C
JP4
REFB
1
3
5 6
4
2
C9
1.0UF,10V
JP1
REF LO
C4
0.1UF
C6
0.1UF
R1
4.99K
1%
SCK
R6
7.5K
E3 REFA
C2
1.0UF,10V
U7
NC7WB66K8X
3
54
1
2
6
7
8
OE2
2AGND
1A
1B
2B
OE1
VCC
JP8
CA2
E4 VOUTB
R7
7.5K
R8
22
C14
0.1UF
E14
VREF
E5 REFB
J1
HD2X7-079-MOLEX
7
9
1
2
6
4
10
5
11
12
14
13
3
8
MOSI
EESDA
V+
5V
CS
SCK
EEVCC
MISO
EESCL
EEGND
NC
GND
GND
GND
C10
0.1UF
U6
LT1790ACS6-2.5
4 6
1
2
3 5
VIN VOUT
GND
GND
NC NC
U2
24LC025
5
8 1
2
3
4
7
6
SDA
VCC A0
A1
A2
VSS
WP
SCL
C7
1.0UF,10V
MOSI
R4
10K
C1
0.1UF
E6 VOUTC
20-BIT ADC
+
-
4-/8-CHANNEL
MUX
LTC2424/LTC2428
U3
LTC2428CG
13
12
1
5
67
8
9
10
15
4
3
2
11
14
17
18
19
20
21
22
23
24
25
26
27
28
16
CH4*
CH3
GND
ZSSET
GND MUXOUT
VCC
CH0
CH1
CH6*
ADCIN
FSSET
VCC
CH2
CH5*
CH7*
GND
CLK
CSMUX
DIN
GND
CSADC
SD0
SCK
FO
GND
GND
GND
A
B
C
JP5
REFC
1
3
5 6
4
2
E10 GND
SCL
SDA
JP2
ADC
E7 REFC
C8
0.1UF
JP11
VCC 5V REG
5V REF
U5
LT1790ACS6-4.096
4 6
1
2
3 5
VIN VOUT
GND
GND
NC NC
A
B
C
JP7
ADC REF
1
3
5 6
4
2
C12
1.0UF,10V
MISO
E8 VOUTD
E13
PWR GND
E11 GND
A
B
C
JP6
REFD
1
3
5 6
4
2
A
B
C
JP3
REFA
1
3
5 6
4
2
E2 VOUTA
U4
LT1790ACS6-5
4 6
1
2
3 5
VIN VOUT
GND
GND
NC NC
E9 REFD
E12
VCC
C13
0.1UF
C5
0.1UF
R9
10K
R2
4.99K
1%
CS
R5
7.5K
JP10
CA0
8
dc936af
DEMO MANUAL DC936A
Linear Technology Corporation
1630 McCarthy Blvd., Milpitas, CA 95035-7417
(408) 432-1900 ● FAX: (408) 434-0507 ● www.linear.com
LINEAR TECHNOLOGY CORPORATION 2013
LT 0513 • PRINTED IN USA
DEMONSTRATION BOARD IMPORTANT NOTICE
Linear Technology Corporation (LT C ) provides the enclosed product(s) under the following AS IS conditions:
This demonstration board (DEMO BOARD) kit being sold or provided by Linear Technology is intended for use for ENGINEERING DEVELOPMENT
OR EVALUATION PURPOSES ONLY and is not provided by LT C for commercial use. As such, the DEMO BOARD herein may not be complete
in terms of required design-, marketing-, and/or manufacturing-related protective considerations, including but not limited to product safety
measures typically found in finished commercial goods. As a prototype, this product does not fall within the scope of the European Union
directive on electromagnetic compatibility and therefore may or may not meet the technical requirements of the directive, or other regulations.
If this evaluation kit does not meet the specifications recited in the DEMO BOARD manual the kit may be returned within 30 days from the date
of delivery for a full refund. THE FOREGOING WARRANTY IS THE EXCLUSIVE WARRANTY MADE BY THE SELLER TO BUYER AND IS IN LIEU
OF ALL OTHER WARRANTIES, EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING ANY WARRANTY OF MERCHANTABILITY OR FITNESS
FOR ANY PARTICULAR PURPOSE. EXCEPT TO THE EXTENT OF THIS INDEMNITY, NEITHER PARTY SHALL BE LIABLE TO THE OTHER FOR
ANY INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES.
The user assumes all responsibility and liability for proper and safe handling of the goods. Further, the user releases LT C from all claims
arising from the handling or use of the goods. Due to the open construction of the product, it is the user’s responsibility to take any and all
appropriate precautions with regard to electrostatic discharge. Also be aware that the products herein may not be regulatory compliant or
agency certified (FCC, UL, CE, etc.).
No License is granted under any patent right or other intellectual property whatsoever. LT C assumes no liability for applications assistance,
customer product design, software performance, or infringement of patents or any other intellectual property rights of any kind.
LT C currently services a variety of customers for products around the world, and therefore this transaction is not exclusive.
Please read the DEMO BOARD manual prior to handling the product. Persons handling this product must have electronics training and
observe good laboratory practice standards. Common sense is encouraged.
This notice contains important safety information about temperatures and voltages. For further safety concerns, please contact a LT C applica-
tion engineer.
Mailing Address:
Linear Technology
1630 McCarthy Blvd.
Milpitas, CA 95035
Copyright © 2004, Linear Technology Corporation
