NSC ADC20D1X00 The only difference on the pin-out between Datasheet

ADC1xD1x00 Pin Compatibility
National Semiconductor
Application Note 2128
Marjorie Plisch
March 8, 2011
ADC1xD1x00 Pin
Compatibility
In order to facilitate upgrading applications from a 10-bit Gig
ADC to a 12-bit Gig ADC, the ADC10D1x00 (ADC10D1500/
ADC10D1000) is designed to be pin-compatible with the
ADC12D1x00 (ADC12D1800/1600/1000). This means that a
single board layout may be designed with both resolution
ADCs in mind for more cost efficient and time-to-market product development.
ADC10D1x00 vs. ADC12D1x00
The only difference on the pin-out between the
ADC10D1x00 and the ADC12D1x00 is that the
ADC12D1x00 has two additional data bits for each output data bank. Bits<11:2> for the ADC12D1x00 correspond to
Bits<9:0> for the ADC10D1x00. The placeholders for the two
additional bits for the ADC12D1x00 are labeled as RSV bits
on the ADC10D1x00. The RSV bits on the ADC10D1x00 correspond to the two LSB, Bits<1:0>, on the ADC12D1x00, see
Table 1.
TABLE 1. ADC1xD1x00 LSB Pins
Ball No.
ADC10D1x00 Name ADC12D1x00 Name
30153301
FIGURE 1. RSV Pin Termination
Datasheet vs. Reference Board
Y10/W10
RSV6+/-
DQd0+/-
W19/W20
RSV5+/-
DQ1+/-
W18/V17
RSV4+/-
DQ0+/-
B19/B20
RSV3+/-
DI1+/-
B18/C17
RSV2+/-
DI0+/-
For a few exceptions, National’s Reference Board does not
follow the datasheet recommendations for certain pin connections. These exceptions are listed below in Table 2. Historically, the exceptions exist because the Reference Board
was developed before silicon development was finalized. In
every case, it is correct to follow the datasheet recommendation. ‘DNC’ stands for ‘Do Not Connect’ and ‘NC’ stands for
‘Not Connected.’
C10/D10
RSV1+/-
DId1+/-
TABLE 2. Datasheet vs. RB Comparison
A10/B10
RSV0+/-
DId0+/-
V10/U10
RSV7+/-
DQd1+/-
Terminating RSV pins on the
ADC10D1x00
The RSV pins may be terminated in a way which makes one
board usable for both ADC10D1x00 and ADC12D1x00, see
Figure 1. On the ADC10D1x00, the RSV pins are high
impedance, so only the 100Ω differential termination resistor
for the LVDS driver from the ADC is necessary to be compatible with the ADC12D1x00. However, if these pins are
terminated into an FPGA and it is necessary for them to be
forced to a known voltage, then the additional 1kΩ resistors
can be added to the design; the specific value of the 1kΩ resistors may be changed based upon the requirements of the
specific FPGA. For a board which is populated with an
ADC12D1x00, the 1kΩ resistors should be left unpopulated.
Ball No.
C6
ADC1xD1x00 National Reference Board
Datasheet Name
Connection
VA
POREN (from FPGA)
C7
NC
WSS (from FPGA)
E3/F4
DNC/DNC
VTEST+/- (to header)
D1
DNC
GND
D7
DNC
VNEGI (shorted to J4/K2)
U7
DNC
VNEGQ (shorted to L2/M4)
W3
DNC
CALFAIL (to FPGA)
AN-2128
© 2011 National Semiconductor Corporation
301533
www.national.com
AN-2128
The following is an explanation of the differences:
Planning for Power Consumption
• C6 – This pin was used for an internal test function for preproduction silicon, but it is not bonded in production parts.
• C7 – This pin was used for an internal test function; it is not
bonded in production parts and may be connected to any
potential or left floating.
• E3/F4 – These pins are used for internal test functions; do
not connect them.
• D1 – This pin was used for an internal test function for preproduction silicon, but it is internally bonded in production
parts.
• D7 – On an earlier version of the silicon, J4/K2/D7 were
shorted externally. On final silicon, D7 is connected to the
other pins internally, so it is no longer necessary to do so
externally.
• U7 – On an earlier version of the silicon, L2/M4/U7 were
shorted externally. On final silicon, U7 is connected to the
other pins internally, so it is no longer necessary to do so
externally.
• W3 – This pin is used for an internal test function; do not
connect it. Despite its name, note that the CALFAIL pin does
not indicate that the execution of the calibration process has
actually failed.
In general, higher speed ADCs consume more power and the
ADC12D1x00 family consumes more power than the
ADC10D1x00. If a system will be upgraded from a 10-bit to
12-bit ADC, take care to design the power supply accordingly
with margin, so that it can supply the maximum required power. The limits for the power consumption, PC, may be found
in each datasheet.
www.national.com
2
AN-2128
Notes
3
www.national.com
ADC1xD1x00 Pin Compatibility
Notes
For more National Semiconductor product information and proven design tools, visit the following Web sites at:
www.national.com
Products
Design Support
Amplifiers
www.national.com/amplifiers
WEBENCH® Tools
www.national.com/webench
Audio
www.national.com/audio
App Notes
www.national.com/appnotes
Clock and Timing
www.national.com/timing
Reference Designs
www.national.com/refdesigns
Data Converters
www.national.com/adc
Samples
www.national.com/samples
Interface
www.national.com/interface
Eval Boards
www.national.com/evalboards
LVDS
www.national.com/lvds
Packaging
www.national.com/packaging
Power Management
www.national.com/power
Green Compliance
www.national.com/quality/green
Switching Regulators
www.national.com/switchers
Distributors
www.national.com/contacts
LDOs
www.national.com/ldo
Quality and Reliability
www.national.com/quality
LED Lighting
www.national.com/led
Feedback/Support
www.national.com/feedback
Voltage References
www.national.com/vref
Design Made Easy
www.national.com/easy
www.national.com/powerwise
Applications & Markets
www.national.com/solutions
Mil/Aero
www.national.com/milaero
PowerWise® Solutions
Serial Digital Interface (SDI) www.national.com/sdi
Temperature Sensors
www.national.com/tempsensors SolarMagic™
www.national.com/solarmagic
PLL/VCO
www.national.com/wireless
www.national.com/training
PowerWise® Design
University
THE CONTENTS OF THIS DOCUMENT ARE PROVIDED IN CONNECTION WITH NATIONAL SEMICONDUCTOR CORPORATION
(“NATIONAL”) PRODUCTS. NATIONAL MAKES NO REPRESENTATIONS OR WARRANTIES WITH RESPECT TO THE ACCURACY
OR COMPLETENESS OF THE CONTENTS OF THIS PUBLICATION AND RESERVES THE RIGHT TO MAKE CHANGES TO
SPECIFICATIONS AND PRODUCT DESCRIPTIONS AT ANY TIME WITHOUT NOTICE. NO LICENSE, WHETHER EXPRESS,
IMPLIED, ARISING BY ESTOPPEL OR OTHERWISE, TO ANY INTELLECTUAL PROPERTY RIGHTS IS GRANTED BY THIS
DOCUMENT.
TESTING AND OTHER QUALITY CONTROLS ARE USED TO THE EXTENT NATIONAL DEEMS NECESSARY TO SUPPORT
NATIONAL’S PRODUCT WARRANTY. EXCEPT WHERE MANDATED BY GOVERNMENT REQUIREMENTS, TESTING OF ALL
PARAMETERS OF EACH PRODUCT IS NOT NECESSARILY PERFORMED. NATIONAL ASSUMES NO LIABILITY FOR
APPLICATIONS ASSISTANCE OR BUYER PRODUCT DESIGN. BUYERS ARE RESPONSIBLE FOR THEIR PRODUCTS AND
APPLICATIONS USING NATIONAL COMPONENTS. PRIOR TO USING OR DISTRIBUTING ANY PRODUCTS THAT INCLUDE
NATIONAL COMPONENTS, BUYERS SHOULD PROVIDE ADEQUATE DESIGN, TESTING AND OPERATING SAFEGUARDS.
EXCEPT AS PROVIDED IN NATIONAL’S TERMS AND CONDITIONS OF SALE FOR SUCH PRODUCTS, NATIONAL ASSUMES NO
LIABILITY WHATSOEVER, AND NATIONAL DISCLAIMS ANY EXPRESS OR IMPLIED WARRANTY RELATING TO THE SALE
AND/OR USE OF NATIONAL PRODUCTS INCLUDING LIABILITY OR WARRANTIES RELATING TO FITNESS FOR A PARTICULAR
PURPOSE, MERCHANTABILITY, OR INFRINGEMENT OF ANY PATENT, COPYRIGHT OR OTHER INTELLECTUAL PROPERTY
RIGHT.
LIFE SUPPORT POLICY
NATIONAL’S PRODUCTS ARE NOT AUTHORIZED FOR USE AS CRITICAL COMPONENTS IN LIFE SUPPORT DEVICES OR
SYSTEMS WITHOUT THE EXPRESS PRIOR WRITTEN APPROVAL OF THE CHIEF EXECUTIVE OFFICER AND GENERAL
COUNSEL OF NATIONAL SEMICONDUCTOR CORPORATION. As used herein:
Life support devices or systems are devices which (a) are intended for surgical implant into the body, or (b) support or sustain life and
whose failure to perform when properly used in accordance with instructions for use provided in the labeling can be reasonably expected
to result in a significant injury to the user. A critical component is any component in a life support device or system whose failure to perform
can be reasonably expected to cause the failure of the life support device or system or to affect its safety or effectiveness.
National Semiconductor and the National Semiconductor logo are registered trademarks of National Semiconductor Corporation. All other
brand or product names may be trademarks or registered trademarks of their respective holders.
AN-2128
Copyright© 2010 National Semiconductor Corporation
For the most current product information visit us at www.national.com
National Semiconductor
Americas Technical
Support Center
Email: [email protected]
Tel: 1-800-272-9959
www.national.com
National Semiconductor Europe
Technical Support Center
Email: [email protected]
National Semiconductor Asia
Pacific Technical Support Center
Email: [email protected]
National Semiconductor Japan
Technical Support Center
Email: [email protected]
Similar pages