ETC AN10E40

AN10E40
Preliminary Information
Field Programmable
Analog Array
The AN10E40 brings to analog what FPGAs brought to digital; extremely rapid production and prototype circuit
realization with field re-programmability. The AN10E40 consists of a 4 x 5 matrix of fully configurable switched
capacitor cells, enmeshed in a fabric of programmable interconnect resources. These programmable features are
directed by an on-chip SRAM configuration memory. The SRAM configuration memory is initialized on power up
via an on off chip serial PROM or through the AN10E40’s standard microprocessor peripheral interface.
A configuration memory image is easily constructed using the companion AnadigmDesigner software which
includes an extensive library of adjustable, proven, pre-built functions. The configurable analog blocks are often
consumed one at a time, though some of the more complex library functions may consume two or more blocks.
Specialized IO cells surround the core to bring your analog signals in and out of the array.
The AN10E40 coupled with the intuitive AnadigmDesigner software gives both digital and analog designers a
competitive advantage in designing analog circuits that can’t really be compared to any other design system in
existence. Quickly constructed, accurate, drift free, temperature compensated and programmable analog circuits
are now yours. Imagine the power of programmable with the versatility of analog.
Benefits
Extremely Rapid Analog Design – Minutes not weeks to re-spin a new design idea
In Circuit Programmable – Behavior can be changed as fast as 125 microseconds
Re-Configurable Using Conventional Logic, Serial PROMs or Microcontrollers
Extremely Stable over Voltage and Temperature
• Flexible Internal Clock and Routing Resources
No Component Aging
• No More Trimming Components
Reliable and Repeatable Performance
• No More Tuning Components
A
B
Configuration Data Shift Register
Config. Logic
CAB
CAB
CAB
CAB
CAB
CAB
Y
I
Z
X
Y
O
I
Z
X
Y
O
I
Z
X
Y
O
I
Z
X
O
Y
Z
Y
Y
O
Z
X
O
Z
Y
I
X
CAB
Z
CAB
X
CAB
Z
CAB
X
CAB
Y
I
CAB
I
O
X
CAB
I
I
Y
Z
CAB
O
O
X
CAB
X
I
Y
Z
CAB
O
O
X
CAB
O
Z
CAB
I
Y
CAB
Y
I
X
O
C
Vref
CAB
I
•
•
•
•
•
•
Z
Anadigm reserves the right to make any changes without further notice to any
products herein. Anadigm makes no warranty, representation or guarantee
regarding the suitability of its products for any particular purpose, nor does
Anadigm assume any liability arising out of the application or use of any product or
circuit, and specifically disclaims any and all liability, including with limitation
consequential or incidental damages. “Typical” parameters can and do vary in
different applications. All operating parameters, including “Typicals” must be
validated for each customer application by customer’s technical experts. Anadigm
does not convey any license under its patent rights nor the rights of others.
Anadigm products are not designed, intended, or authorized for use as
components in systems intended for surgical implant into the body, or other
applications intended to support or sustain life, or for any other application in which
the failure of the Anadigm product could create a situation where personal injury or
death may occur. Should buyer purchase or use Anadigm product for any such
unintended or unauthorized application, buyer shall indemnify and hold Anadigm
and its officers, employees, subsidiaries, affiliates, and distributors harmless
against all claims, costs, damages, and expenses, and reasonable attorney fees
arising out of, directly or indirectly, any claim of personal injury or death associated
with such unintended or unauthorized use, even if such claim alleges that Anadigm
was negligent regarding the design or manufacture of the part.
© Anadigm Ltd. 2000
© Anadigm Inc. 2000
All Rights Reserved.
AN10E40 Data Manual
i
Table of Contents
Features of AN10E40................................................................................................................................................ 1
Available IPmodule Functions................................................................................................................................... 1
How It Works............................................................................................................................................................. 1
AN10E40 Architecture............................................................................................................................................... 2
The Configurable Analog Block ................................................................................................................................ 3
A Quick Review of Switched Capacitor Circuits .................................................................................................... 3
CAB Details ........................................................................................................................................................... 4
Routing Resources.................................................................................................................................................... 4
Clock Generation ...................................................................................................................................................... 4
Voltage Reference .................................................................................................................................................... 5
Voltage Mid-Rail Generator....................................................................................................................................... 5
Analog Input Output Cell ........................................................................................................................................... 6
Sallen Key Filtering................................................................................................................................................ 6
nd
2 Order Sallen-Key Filter for Output Smoothing................................................................................................. 7
th
4 Order Sallen-Key Filter for Output Smoothing ................................................................................................. 7
nd
2 Order Sallen-Key Filter for Input Anti-Aliasing................................................................................................. 7
th
4 Order Sallen-Key Filter for Input Anti-Aliasing ................................................................................................. 8
Configuration Engine................................................................................................................................................. 9
Mode 0 – Micro Mode.......................................................................................................................................... 10
Micro Mode Configuration Sequence .............................................................................................................. 13
Micro Mode Maximum Data Transfer Rate...................................................................................................... 13
Mode 1 – Boot from ROM (BFR Mode)............................................................................................................... 14
BFR Timing.......................................................................................................................................................... 15
Configuration Clock ............................................................................................................................................. 16
Reset Sequences.................................................................................................................................................... 17
Analog Power On Reset (APOR) & Power On Reset (POR) .............................................................................. 17
Internal Reset Activity.......................................................................................................................................... 17
External Reset Assertion ..................................................................................................................................... 17
Mechanical .............................................................................................................................................................. 17
Package Details................................................................................................................................................... 17
Pin Out Description.............................................................................................................................................. 18
Package Pin Electrical Characterization ................................................................................................................. 21
Powers, Grounds and Bypassing............................................................................................................................ 21
Recommended Configuration for Power & Ground............................................................................................. 21
AVDD and AVSS ................................................................................................................................................. 21
SVDD and SVSS ................................................................................................................................................. 21
BVDD and BVSS ................................................................................................................................................. 22
ESD_VDD and ESD_VSS ................................................................................................................................... 22
CFG_VDD and CFG_VSS .................................................................................................................................. 22
OPAMVMR and CEXT ........................................................................................................................................ 22
The AN10E40 in Split Supply Systems ............................................................................................................... 22
Electrical Parameters .............................................................................................................................................. 22
Absolute Maximum Ratings................................................................................................................................. 23
Recommended Operating Conditions ................................................................................................................. 23
Digital IO .............................................................................................................................................................. 23
Voltage Mid Rail .................................................................................................................................................. 23
Vref ...................................................................................................................................................................... 23
The Analog I/O Cell ............................................................................................................................................. 24
The Analog I/O Cell Configured as a Sallen-Key Filter ....................................................................................... 25
A Programmable Inverting Gain Stage................................................................................................................ 26
A Programmable Low Pass Filter........................................................................................................................ 27
Sine Wave Oscillator ........................................................................................................................................... 28
Electrostatic Discharge Characterization ................................................................................................................ 28
A Quick Review of ESD Basics ........................................................................................................................... 28
Catastrophic Failure......................................................................................................................................... 28
Latent Defect.................................................................................................................................................... 28
ii
Basic ESD Events--What Causes Electronic Devices to Fail? ........................................................................28
Discharge to the Device ...................................................................................................................................29
Discharge from the Device...............................................................................................................................29
Field Induced Discharges ................................................................................................................................29
AN10E40 ESD Classifications .............................................................................................................................29
Standard ESD Classifications ..........................................................................................................................30
AN10E40 Data Manual
1
Features of AN10E40
•
•
•
•
•
20 Programmable Analog Cells
13 Analog IO Cells
2 Spare Op-Amps
8 Bit Programmable Internal Vref Source
4 Programmable Internal Clock Sources
•
•
•
•
•
Easy Power-On-Reset Self Boot Using Serial PROM
Microprocessor Boot Option
Intuitive Design Software
Drift Free Designs
Rapidly Configurable
•
•
•
•
•
•
•
•
Non/Inverting Comparators
1 and 2 Input Comparators
DC Reference Voltage Sources
Limiters
Schmitt Triggers
Non/Inverting Integrators
Differentiators
New IP Modules Continuously Available
Available IPmodule Functions
•
•
•
•
•
•
•
•
Gain Stages
Summing Amplifiers
Sample and Hold
Track and Hold
High, Low and Band Pass/Stop Filters
High Q, Low Q Filters
Cosine Filters
Full and Half Non/Inverting Rectifiers
How It Works
On power up, the AN10E40’s reset circuitry initializes the configuration engine. The configuration engine takes over
and first examines the state of the Mode port. The pin settings of the Mode port determine which of the boot
methods should be exercised. One popular option is to boot from an off chip Serial PROM. The configuration
engine takes care of taking data out of the Serial PROM and loading it into on-chip configuration SRAM. The whole
boot process takes just a few milliseconds. Once the configuration SRAM has been loaded, the analog circuitry is
automatically enabled and the configuration engine idled. The chip now performs the analog functions according to
the configuration bit stream just loaded.
Creating a configuration bit stream is no more complicated than using the device itself. The AnadigmDesigner
design tool provides the user an intuitive drag and drop GUI in which you simply select several of the IPmodule
functions from the extensive library, drop them onto a graphical representation of the chip, fill in some parametric
information about the IPmodule, wire up the internal and I/O connections, and hit a button to generate the bit
stream (or download it directly to the device on your bench).
The device internals are more complicated than the easy to use device may lead you to believe. The AN10E40
array is based on programmable switched capacitor op-amp cells with very flexible internal and external connection
and clocking resources. The AnadigmDesigner and the associated IPmodule library shields the user from these
complexities.
Switched capacitor circuits are remarkably stable over voltage, temperature and device aging. Using the AN10E40
for your analog circuit realization allows you to rest assured knowing that once a circuit has been designed, it will
continue perform as expected. Say goodbye to trim pots.
Another advantage of this technology is the tremendous decrease in design time. Along with the elimination of trim
pots, you’ll also be able to clear your bench of all the normal discrete R and C components. “Prototyping” is now a
drag and drop computer exercise. A simple push of a button and your design is downloaded into the AN10E40
nearly instantaneously.
The kicker to all of this is that it is infinitely re-programmable. If a single set of analog functions is not sufficient for
your system, then you can load new configuration files into the AN10E40 with only a very small interruption to the
analog signal stream. Consider how filter parameters can be changed to adapt to varying input signal conditions.
Consider how a single physical circuit can be used in all of your different system designs. Consider all the
advantages that programmable analog will bring to your designs.
2
AN10E40 Architecture
The AN10E40 is comprised of a 4x5 array of Configurable Analog Blocks (CABs), enmeshed in clocking, switching,
local and global routing resources. Nearly every element of the AN10E40 is programmable giving the user
tremendous flexibility in the sorts of processing circuits that can be realized.
A
B
Config. Logic
Configuration Data Shift Register
CAB
CAB
CAB
CAB
CAB
CAB
Y
I
Z
X
Y
O
I
Z
X
Y
O
I
Z
X
Y
O
I
Z
X
Z
Y
Y
O
Z
X
O
Z
Y
Y
I
X
CAB
Z
CAB
X
CAB
Z
CAB
X
CAB
X
I
CAB
I
O
X
CAB
I
I
Y
Z
CAB
O
O
X
CAB
O
I
Y
Z
CAB
O
O
X
CAB
I
Z
CAB
I
Y
CAB
Y
I
X
O
C
Vref
CAB
O
Y
Z
Figure 1. Block Level View of the AN10E40 array
The Configuration Logic and Shift Register work together whenever chip configuration is in process. The array of
CABs is surrounded on three sides by programmable analog input/output cells, 13 in all, with two spare
uncommitted op-amps. The lower region of the chip also contains a programmable reference voltage generator.
AN10E40 Data Manual
3
The Configurable Analog Block
The basic building block of the AN10E40 is the Configurable Analog Block. Each CAB is an op-amp surrounded by
capacitor banks, local routing resources, local switching and clocking resources, and global connection points. This
collection of hardware enables the CAB to perform many of the functions that could be achieved using an op-amp
and conventional passive components. All analog processing is accomplished with this switched capacitor circuit.
A Quick Review of Switched Capacitor Circuits
There are many excellent texts available which dive deeply into the details of sampled systems and MOS switch
capacitor circuit theory. The math gets very complex and may have kept you away from switched capacitor circuits
in the past. The good news is that the AnadigmDesigner software for Anadigm devices shields you from all the
complexities of using switched capacitor designs. Still though, it can be useful to review briefly how switched
capacitor circuits operate to eliminate the fear of the unknown.
Consider the following two circuits.
1
1
2
2
R
+
V1
-
+
V2
-
+
V1
-
+
V2
C
Conventional Circuit
Switched Capacitor Circuit
Figure 2. Switched Capacitor vs. Conventional Circuit
In the Figure 2, two circuits are shown that can both do the same job. The conventional circuit moves current
around the loop through the resistor. The amount of current of course is a function of the difference between V1
and V2 and the value of R.
The switched capacitor version of the circuit does the same job, but in a different way. With the switch in position 1,
charge moves from the V1 source to the capacitor C, when the switch is moved over to position 2, charge is then
moved from C to V2. As the switch is thrown back and forth, recognize that charge is moving over time, in other
words - current. The faster you throw the switch (and/or the bigger the capacitor is) the more current flows. Unlike
the conventional circuit, simply reprogramming the switching clock rate or the size of the capacitor allows you to
adjust the “resistance” between nodes 1 and 2.
Of course, since this is a sampled system you have to keep in mind the frequency of the signal that is being
processed by the circuit and the frequency at which it is being sampled (or switched). For signals with frequency
content constrained significantly below the sampling frequency the switched capacitor circuit works just like the
conventional circuit. In all cases, the sampling rate should be at least twice as high as the highest frequency of the
signal being processed.
4
CAB Details
The SRAM block which controls routing connections and CAB behavior is loaded during configuration time.
Configuration typically occurs at power up as an automatic process but can of course be re-initiated at any time.
The ability to re-configure the part at any time gives the user incredible flexibility in system design.
Programmable capacitor banks and local switching in both the input paths to the op-amp and a programmable
capacitor bank in the op-amp’s feedback path provide all the resources required to realize a very large number of
analog processing circuits.
Local Inputs
Local Routing Connections
Global Outputs
Local Outputs
OpAmp
Global In
Configuration Memory (SRAM)
Figure 3. Block Level View of the basic CAB
Connection between other CAB’s on the device and to the outside world are accomplished using the Local Inputs,
Local Output, and Global routing resources.
Routing Resources
The most expedient way to gain understanding of the routing resources available on the AN10E40 is to use the
associated AnadigmDesigner design software. The routing resources and your connections to them are
represented in an intuitively obvious fashion.
Local routing resources are only shown (as fly lines or rubber band lines) in the design software screen once they
are used. A CAB output may be connected to an input in any of its 8 adjacent neighbors, and additionally to the
CAB in the same row and to the right two locations.
Global routing resources allow you to move signals to disparate locations on the die. There are a total of 10
horizontal global routes and 12 vertical global routes within the array. A CAB’s output can be connected to either of
the two adjacent right or two adjacent down global routes. A CAB’s input can be driven by one of the two adjacent
right or adjacent down global routes (which one of these two routes alternates with location in the array).
Connections to the chip’s programmable reference voltage generator are only available using Global routing
resources.
Clock Generation
Recall from the discussion on switched capacitor basics that the behavior of our simple circuit was influenced by
both the value of the capacitor as well as the frequency of the clock. So it is with IPmodules placed into the CABs of
the AN10E40 array. IPmodule input clocks are all derived from the master CLOCK input pin. The maximum rated
frequency of this input is currently specified to be 20 MHz. The master clock is split into 4 pairs of non-overlapping
clocks and bussed to each of the CABs. CLOCK[3:0] are derived from the dividing the master CLOCK input down
by a factor of 1 or from 2 to 62 (in increments of two). The maximum allowable clock frequency into an IPmodule is
AN10E40 Data Manual
5
specified to be 1 MHz. You are free to drive CLOCK into the array at up to 20 MHz, then program and use
CLOCK[3:0] individually as your circuits might require.
The AN10E40 is designed such that all IPmodules along an analog signal path should use the same clock. While it
is possible to mix clocks along a signal path, it should not be done without full understanding of sampled data
systems, the effects of oversampling, undersampling and aliasing and careful consideration of possible unintended
consequences. The edges of divided clocks are synchronized only with the master clock edges, and therefor the
phase relationship of divided clocks is not guaranteed. For this reason, users are cautioned not to utilize two equal
frequency divided clocks with the exception of clocks that have a divisor of one are therefor equal to the master
clock.
Please note, the performance estimates for a placed IPmodule are based upon the known clock assignment and
divider ratios at the time of IPmodule placement. Any change in the top level chip clock settings may of course
affect your circuit behavior.
This section described the CLOCK input pin, not to be confused with the configuration clock pin CFG_CLK,
discussed below in the section Configuration Clock.
Voltage Reference
The AN10E40 provides a convenient programmable on-chip voltage reference. When your circuit requires a
comparator function against a known value, this voltage reference is easily programmed and enabled.
The value programmed into the Voltage Reference is always specified relative to signal ground. On the AN10E40,
signal ground is at VMR (see Voltage Mid-Rail Generator below).
Voltage Mid-Rail Generator
All analog signals within the array are referenced to Voltage Mid-Rail (VMR), typically 2.5 V with respect to AVSS.
The VMR signal is generated on chip, filtered with an external capacitor then routed back into the array for use by
the CABs.
Cext
10nF
Bandgap
Reference
Generator
VMR
50
To CABs
The recommended connections are:
•
10 nF between CEXT and a quiet ground node
•
VMR unloaded
•
100 nF between OPAMPVMR and a quiet ground node
OpAmpVMR
100nF
Figure 4. Filtering OpAmpVMR
The RC network provides a simple but effective low pass filter for the on-chip OpAmpVMR signal. It is not
recommended that OpAmpVMR be loaded externally with anything other than a low leakage current 100 nF
capacitor.
VMR is provided as a convenience outlet for the VMR signal. The system is designed only to drive the RC filter
network. If your system requires use of VMR, it is recommended that you first buffer it with a high impedance
amplifier. Conversely, should your system design establish a requirement for generating signal ground (VMR)
6
externally, the design software allows you to disable the on-chip VMR generator and instead drive the VMR pin
from off chip.
The Bandgap Reference Generator provides a nominal 2.5 V reference signal. Cext is a filtering cap used to quiet
any possible switching noise from getting coupled into this important reference voltage.
Analog Input Output Cell
The AN10E40 has a flexible analog IO cell that allows you to connect directly into the core’s internal circuitry, buffer
input and output signals to/from the core, and using very few external components, construct a Sallen-Key filter.
I
X
O
Y
Z
Figure 5. Analog Input Output Cell
The “I” and “O” pad designations are Input and Output; these names are relative to the IO Cell itself.
The most common configuration for use as an input is to leave the switch open and power up the buffer. Drive Y
with an external signal and connect O to an IPmodule's input. X and Z should be left unloaded.
The most common configuration for use as an output is to close the switch and power up the buffer. Drive I with an
IPmodule's output and connect an external load to Z. X and Y should be left unloaded.
Under certain circumstances it may be advantageous to leave the switch open and the buffer powered down. For
example, a single Input Output Cell can be used to simultaneously bring a pair of signals in and out of the array. I to
X is an output path from the array, and Z to O is an input path into the array. In doing so however, the external
signal driving Z will be loaded with the input impedance of the IPmodule connected to. This impedance is a function
of the IPmodule's clock speed and input capacitor size. Likewise, the user must stay alert to the external loading of
X which can affect the driving IPmodule's performance.
Another situation which might warrant such direct connections into the array is when your design's input stage will
not tolerate the non-zero offset voltage associated with an input buffer.
Sallen Key Filtering
The flexibility of the IO cell is best appreciated when considering the construction of Sallen-Key filters. Since the
array is based on switched capacitor circuits, your output signal may have unwanted switching noise present. Also,
since this is a sampled data system, some care should be taken to band limit input signals to avoid aliasing
artifacts. Sallen-Key filters are useful for filtering such frequency components out. The AN10E40 IO cells are
uniquely designed to facilitate easy construction of such filters.
The detailed derivation of the math and complete explanation of the theory of operation of these filters would be
better served by another dedicated document, however we are pleased to present the general circuit diagrams for
such filters and will instead refer you to Application Note 010. Also, there are quite a number of excellent analog
filter design tools currently on the market. The major advantage in using such a software package is that most of
them will implement the filter using standard value components, whereas the traditional cook book equation
approach often results in unrealistic component values. One good example of a filter design tool is Filter Wiz LE.
This effective and highly affordable PC based design tool is available on line from www.schematica.com.
For all such filters, as for all external ceramic capacitors in the signal path, only NPO or COG ceramic materials are
recommended (for better voltage coefficient). X7R or similar material can add noticeable distortion to the signal.
AN10E40 Data Manual
7
2nd Order Sallen-Key Filter for Output Smoothing
I
O
20
dB
X
Y
Z
2nd Order
-40dB/Decade
0
-20
-40
-60
Frequency [Hz]
nd
Figure 6. A 2
Order Sallen-Key Filter for Output Smoothing
4th Order Sallen-Key Filter for Output Smoothing
I
O
I
O
20
dB
X
Y
Z
X
Y
Z
4th Order
-80dB/Decade
0
-20
-40
-60
Frequency [Hz]
th
Figure 7. A 4 Order Sallen-Key Filter for Output Smoothing
Here, the first stage of filtering is handled by an otherwise unused IO cell. It can instead be one of the two spare opamps the AN10E40 provides. (See the Pin Out Description section for a description of pins 24, 25, 74 and 75.)
2nd Order Sallen-Key Filter for Input Anti-Aliasing
I
O
20
dB
X
Y
Z
2nd Order
-40dB/Decade
0
-20
-40
-60
Frequency [Hz]
nd
Figure 8. A 2
Order Sallen-Key Filter for Input Anti-Aliasing
8
4th Order Sallen-Key Filter for Input Anti-Aliasing
I
O
I
O
20
dB
X
Y
Z
X
Y
Z
4th Order
-80dB/Decade
0
-20
-40
-60
Frequency [Hz]
th
Figure 9. A 4 Order Sallen-Key Filter for Input Anti-Aliasing
AN10E40 Data Manual
9
Configuration Engine
The AN10E40 provides two modes of operation for loading the configuration SRAM. The simplest is Mode 1, Boot
From Serial ROM. This is the most common method of booting conventional SRAM based FPGA’s so consequently
the cost of compatible low pin count serial PROMs has been driven way down. Some designs may however want to
take advantage of the AN10E40’s on the fly reprogrammability. In this case the Micro Mode (Mode 0) may be the
appropriate configuration interface.
MODE
Pins
[2] [1]
x
0
x
1
0
x
1
x
Description
Mode 0 – Micro Mode, a conventional byte wide microprocessor interface
Mode 1 – Boot from Serial PROM (a.k.a. Boot from ROM or BFR Mode)
AN10E40 generates its own configuration clocks (using an internal oscillator). CFG_CLK is an output.
Use an external clock for configuration. CFG_CLK is the input.
Figure 10. Mode Pin Settings for Configuration Options
The configuration SRAM for the AN10E40 contains 6864 bits. Configuration files will be slightly larger to facilitate
byte alignment of data as well as address and checksum information.
The pins involved with configuration of the device are given in the following table. The F[4:0] pins change behavior
based on the setting of the MODE[2:1] pins. The signal naming convention holds that active low signals are named
with a “b” suffix.
Pins Common to Configuration Modes
Pin Name
Description
MODE[2:1]
I
Used to establish the configuration mode.
CFG_CLK
I/O If MODE[2] is high, then configuration clock input, otherwise configuration clock output.
Pins used in Micro Mode (Mode 0)
POR
I
Complete chip reset sequence begins on rising edge of POR. (Usually tied low.)
RESETb
I
Reset sequence begins on falling edge. Chip held in reset state as long as asserted low.
Configuration re-starts on release of RESETb.
F[0] CSb
I
When low, selects the AN10E40 for a data transfer transaction
F[1] RDb
I
Assert low for a Read transaction.
F[2] WRb
I
Assert low for a Write transaction.
F[3] RS
I
Register Select. RS=0 to select Function register. RS=1 to select Data/Status register.
F[4] BUSY
O Asserted high when the device is not ready to accept data, i.e. while device is resetting,
or a data shift register to configuration SRAM transfer is taking place.
DATA[7:0]
I/O Byte wide bi-directional data port
Pins used in BFR Mode (Mode 1)
POR
I
Complete chip reset sequence begins on rising edge of POR. Once complete, the
configuration sequence begins. (Usually tied low.)
RESETb
I
Reset sequence begins on falling edge. Chip held in reset state as long as asserted low.
Configuration re-starts on release of RESETb.
F[0] BFRb
I
On falling edge of BFRb, configuration sequence occurs.
F[1] ERRb
O Asserts low if a an error is detected in the configuration data stream. (Open Drain)
F[2] MEMCEb
O Asserts low to select the external memory device.
F[3] PWRUP
I
Tie to VDD.
F[4] END
O Asserts high to signify configuration has completed.
DCLK
O Data clock to serial PROM.
DATA[0]
I
Bit wide data input.
Figure 11. Configuration Pin Functions
10
Mode 0 – Micro Mode
The Micro Mode interface presents a conventional asynchronous byte wide peripheral interface. When CSb is
asserted, the DATA bus is used to write commands, read status, write and read configuration data. There are two
device configuration registers, the Function register (RS=0) and the Data/Status register (RS=1). Configuration
commands are written to the Function register. Subsequent behavior is specific to the command issued and is
documented in Figure 14.
The Data/Status register is either used to read or write configuration data or read device status. By popular
convention, RS is typically connected to the least significant bit of the processor’s address bus to map the Function
register to an even address and the Data/Status register to an odd address.
Figure 12 shows only those signals explicitly associated with Micro Mode configuration. Other signals including:
POR, OPAM_DISABLE, CEXT, OPAMP_VMR, powers, grounds and the switched capacitor CLOCK signal must
also be connected for proper operation. Please reference the Pin Out Description section for complete connection
details.
AN10E40
Microprocessor
Addr[n:0]
DECODE
MODE[2]
A[0]
WRITEb
READb
WAIT
D[7:0]
CLK
RESETb
F[0] - CSb
F[3] - RS
F[2] - WRb
F[1] - RDb
F[4] - BUSY
DATA[7:0]
CFG_CLK
RESETb
MODE[1]
CLK
RSTb
Figure 12. A conventional microprocessor interface for configuring AN10E40.
AN10E40 Data Manual
CSb
1
4
WRb
2
3
RS
5
6
DATA
7
8
BUSY
CSb
1
4
RDb
2
3
RS
9
10
DATA
7
BUSY
#
1
2
3
4
5
6
7
8
9
10
Characteristic
CSb Setup before RDb or WRb Falling Edge
RS Setup before RDb or WRb Falling Edge
RS Hold after RDb or WRb Falling Edge
Read or Write Pulse Width
DATA[7:0] Setup to Rising Edge of WRb
DATA[7:0] Hold after Rising Edge of WRb
BUSY Inactive before end of Read or Write
BUSY Active after Write
DATA[7:0] Access Time
DATA[7:0] Hold after Rising Edge of RDb
Min
10
10
10
50
20
10
50
0
20
0
Max
20
40
10
Unit
ns
ns
ns
ns
ns
ns
ns
ns
ns
ns
Figure 13. Micro Mode Write and Read Timing
Notes
11
12
DATA
[7:4]
XXXX
XXXX
DATA
[3:0]
0000
0001
XXXX
0010
XXXX
0011
XXXX
0100
XXXX
0101
XXXX
0110
1XXX
X1XX
0111
1XXX
XXXX
XXXX
XX1X
XXX1
XXXX
XXXX
DATA
[7:0]
XXXXXXX1
XXXXXX1X
XXXXX1XX
XXXX1XXX
XXX1XXXX
XX1XXXXX
X1XXXXXX
1XXXXXXX
Micro Mode Function Register Behavior
Normal Operation – No function performed.
Reset Device – Entire device configuration memory is reset. BUSY is asserted until the reset
sequence is complete.
Load Configuration – After writing this command, a complete configuration image should be
presented to the data register in 8 bit segments, starting with the configuration header block. At
any time during the loading process, a read from the data register will return status register
contents. As complete rows including Error Check Bytes (ECB) are loaded, BUSY is temporarily
asserted while row data is transferred from the internal data shift register to the currently
addressed SRAM memory row. Once this write operation is complete, BUSY is deasserted and
additional data can be written. Each time BUSY is deasserted, the status register should be
checked for incorrect ID or row configuration data errors. Once an error is detected, NO further
write accesses to the data shift register will be accepted until the device is reset, or another load
configuration command is issued.
Reset Row – Indicates that the next data written to the data register will be a device row
address. After the address is written, the contents of that configuration memory row are reset.
BUSY is asserted after the address is written and deasserted when the operation is complete.
Load Row – Indicates that the next data written to the data register will be a device row address
followed by configuration date for that row including the terminating ECB. After the ECB is
written, BUSY will be asserted during the internal write and deasserted when the write
completes. Reading the data register returns status register contents. The status register should
be checked for row configuration data errors. Once an error has been detected, NO further write
accesses to the data register will be accepted until the device is reset or a load configuration
command is issued.
Read Row – The next data written to the data register will be interpreted as a row address. After
the row address is written, BUSY is asserted while row data is copied into the data shift register.
BUSY is deasserted when the transfer is complete. Subsequent successive reads from the data
register will return row configuration data. No ECB is returned. The row data read back is the
same order as it was written, rightmost byte first.
Read Device ID – 4 subsequent reads form the data register will return the device ID. The most
significant ID byte is read first. The value of the device ID is 13 85 02 B7.
(Factory Reserved)
(Factory Reserved)
(Factory Reserved)
Internal Oscillator Disable – Normally always enabled. If internal configuration clock is
selected, oscillator can not be disabled. Writing a 0 re-enables the oscillator.
(Factory Reserved)
Analog Enable – Powers up Analog IO Cells and CAB Op-Amps.
Figure 14. Micro Mode Function Register Behavior
Micro Mode Status Register Contents
(Data[7:3] are factory reserved. Their function may change without notice.)
Incorrect Device ID detected in configuration data stream.
Row configuration data error (ECB mismatch).
Busy signal asserted. Allows software handshaking if hardware wait states are not to be used.
Asserted while last internal configuration SRAM row is being written.
Test_Count_0
End_Test
Last_Byte, asserted when last configuration byte is being written.
ID_Full, asserted when the ID has been written to the device.
Figure 15. Micro Mode Status Register Contents
AN10E40 Data Manual
13
Micro Mode Configuration Sequence
Monitor BUSY
Detect BUSY
line or read
devi ce st at us
register (RS=1).
Reset Device
Assert RESETb or write
reset command to
function register (RS=0).
No
After the reset sequence completes,
you have the option to specifically
address a single configuration row at
a time, but a more typical scenario
would be to instead write the Load
Configuration command into the
function register.
Write Load Configuration
Write load configuration
command to function
register (RS=0).
Write Data Byte
Write next configuration
data byte to the data
register (RS=1).
Stop
Error
No
BUSY?
Detect BUSY
line or read
devi ce st at us
register (RS=1).
Yes
Monitor Status
Read device
status register
(RS=1).
Last Data?
Has a complete
configuration
f i l e b e e n
written?
Yes
Finished
A
Micro
Mode
configuration
sequence typically begins with
assertion of device reset. This can be
accomplished by either asserting
RESETb or by writing the reset
command into the function register.
Enable Analog
Write 0x10 to function
register (RS=0).
At this point, the device is expecting
that a complete configuration image
will be written to the data port
(RS=1). Simplistic software might
check for device busy after every
byte write. Device busy will assert
once a long internal shift register has
been filled, and the internal
BUSY configuration engine is moving the
contents of the register into a single
row of configuration SRAM.
After the final row is loaded, reenable the bootstrap voltage and the
analog by writing 0x10 to the function
register.
It is possible to go in and uniquely
address specific rows of the
configuration SRAM. The details of
partial on-the-fly reconfiguration may
be covered in a separate application
note.
Micro Mode Maximum Data Transfer Rate
The maximum Micro Mode data transfer rate is governed by the Read and Write timing diagrams shown above.
The host processor must only write data when BUSY is inactive. BUSY is only asserted when data cannot be
accepted at the maximum rate. The host processor can either monitor the device’s BUSY output, or read the Status
Register. If processor R/W cycles are faster than the timing shown, then external circuitry must be used to insert
wait states.
14
Mode 1 – Boot from ROM (BFR Mode)
In applications where the AN10E40 should boot from a serial memory device instead of a microprocessor, connect
as shown below in Figure 16. In this stand alone configuration, the AN10E40 handles all the reset and configuration
signaling. A standard serial EEPROM holds the configuration data. (Such serial memories are widely available as
FPGA boot devices.)
Holding MODE[1] high puts the AN10E40 in BFR mode. Holding MODE[2] low instructs the AN10E40 to generate
its own configuration clocks from its on-chip ring oscillator and sets CFG_CLK to be an output.
On power up, the internal power on reset sequence begins. As it concludes, the AN10E40 examines the state of
the RESETb pin. If held low, it does nothing. When the host system releases RESETb, the self configuration
sequence begins. Both CFG_CLK and DCLK go active and MEMCEb goes low. With MEMCEb asserted, the
EEPROM presents the first data bit. With every rising DCLK edge, the AN1E40 accepts the current data bit. Also
on this rising DLCK edge, the next data bit is clocked out of the serial PROM.
AN10E40
SERIAL
EEPROM
CEb
RST/OEb
Data_Out
CLK
MODE[1]
F[0] - BFRb
F[3] - PWRUP
F[2] - MEMCEb
DATA[0]
DCLK
RESETb
CFG_CLK
RESETb
ERRb-F[1]
END-F[4]
CFG_CLK
POR
MODE[2]
Figure 16. A typical Boot From ROM connection for the AN10E40.
After this automatic power on configuration has completed, there are two options for repeating a configuration
sequence. The first is the assertion of BFRb. On a falling edge of BFRb, the AN10E40 will repeat the complete
configuration sequence. BFRb may continue to be held low for an arbitrarily long period without effecting normal
operation. The second option is the assertion of RESETb. As long as RESETb is asserted low, the AN10E40 will
hold idle in a reset condition. On the rising edge of RESETb, the AN10E40 will repeat the configuration sequence.
If there is an error detected in the configuration bit stream, ERRb will assert low and the configuration sequence will
halt. ERRb is an open drain output. If the system has more than one FPAA on board, all the ERRb signals can be
wired together to provide a single indication that some configuration error was detected.
A speed up of the configuration process is possible by supplying your own CFG_CLK. If such a speed up is
desired, tie MODE[2] high and drive CFG_CLK (it is now an input) with a clock signal up to 40 MHz. DCLK will be
1/2 the frequency of CFG_CLK, so be sure to check your EEPROM specifications to be sure that it can go that fast.
The following Configuration Clock section has more detail on the relationship between these two signals.
Figure 16 shows only those signals explicitly associated with BFR Mode configuration. Other signals including:
OPAM_DISABLE, CEXT, OPAMP_VMR, powers, grounds and the switched capacitor CLOCK signal must also be
connected for proper operation. Please reference the Pin Out Description section for complete connection details.
AN10E40 Data Manual
BFR Timing
BFRb
1
CFG_CLK
2
MEMCEb
4
5
END
3
6
ERRb
7
DCLK
8
9
D[0]
#
1
2
3
4
5
6
7
8
9
Characteristic
BFRb Pulse Width
BFRb Assertion to MEMCEb Deassertion
BFRb Assertion to END and ERRb Deassertion
BFRb Release to MEMCEb Assertion
END Assertion to MEMCEb Deassertion
Configuration Time
DCLK Period
DATA[0] Set Up Time
DATA[0] Hold Time
Min
50
Max
2
3
3
3
2
14109
14109
2
20
0
2
Figure 17. BFR Mode Timing
Unit
ns
Clk
Clk
Clk
Clk
Clk
Clk
ns
ns
Notes
15
16
Configuration Clock
CFG_CLK (in)
1
2
#
1
2
3
4
5
6
7
3
(Internal Ring Osc.)
4
5
6
Characteristic
CFG_CLK Period
CFG_CLK Low
CFG_CLK High
Ring Osc Period
Ring Osc Low
Ring Osc High
DCLK Period
(If MODE[2] = 1 then CFG_CLK is
an input. If MODE[2] = 0, then
CFG_CLK is an output running at
1 th
/8 the frequency of the internal
ring oscillator.)
7
DCLK (out)
Min
Typ
Max
Unit
50
ns
10
ns
10
ns
25
50
100
ns
10
25
50
ns
10
25
50
ns
Always twice the period of
CFG_CLK.
Figure 18. Configuration Clock Specifications
If MODE[2] is held low, a divided down version of the ring oscillator output is used as the configuration logic clock.
CFG_CLK is set to be an output and reflects this clock. If instead MODE[2] is held high, CFG_CLK becomes the
configuration logic clock input. For shortest possible configuration times, use CFG_CLK as an input.
In a minimal system, you may want to take advantage of the AN10E40’s internal ring oscillator. The operating
frequency of the ring oscillator can vary from 10MHz up to 40MHz. This variation is expected and presents no
problems for the proper operation of the configuration engine. The ring oscillator is divided by 8 before use by the
configuration engine.
AN10E40
F3, PWRUP
High_4_BFR
Sys_Rst_Low
SPROM_Clk
Configuration
Engine
MODE[1]
RST POR
CLK
RESETb
DCLK
1/2
APOR
16
0
17 Bit APOR Pulse Stretcher
EN
CLK
POR
0
Low_4_Int_Clk
Config_Clk
1
MODE[2]
CFG_CLK
Ring
Oscillator
1/8
Figure 19. Block Diagram Showing Clocks and Resets
AN10E40 Data Manual
17
Reset Sequences
There are several sub-circuits which control the AN10E40 reset sequence and subsequent re-configuration. Each
interacts with the next to ensure reliable power up and system reset behavior.
Analog Power On Reset (APOR) & Power On Reset (POR)
When coming up cold (or at the onset of a brown out condition) the APOR circuit generates a pulse. This pulse
starts a companion 17 bit counter. This counter (driven by the internal configuration clock) serves as a digital APOR
pulse stretcher to produce a much longer POR signal to the configuration engine.
The AN10E40 provides a POR input pin so that the internal POR signal may be manually asserted. In a typical
application POR is tied to system VSS. There is otherwise rarely need for such fine control.
Internal Reset Activity
When either an external reset or internal POR reset is detected, a sequence of events transpires. First of course,
the configuration engine is reset and all the analog circuitry is powered down. Next, the configuration engine
continuously cycles through the SRAM configuration memory, repeatedly zeroing out the contents. This continues
until the 17 bit POR timer rolls over.
The length of the APOR pulse is dependant on VDD ramp rate, and then the entire reset process may be paced by
the widely varying ring oscillator. As such it is not possible to know a priori the exact length of the reset sequence,
but it can be bounded as shown in the performance characteristics section.
Setting MODE[2] high, and driving CFG_CLK with a known external frequency, yields a much more deterministic
configuration time. The only uncertainty is the width of the APOR pulse, but this is typically much less than half a
clock cycle.
Once the POR timer rolls over, the state of the external RESETb pin is examined. If RESETb is asserted low then
the configuration SRAM is cleared one more time and the chip is held in the reset state; configuration is held off
until RESETb is deasserted. If RESETb is instead high as the POR timer rolls over, the configuration SRAM is
cleared on more time and the configuration sequence begins. If the chip is in BFR mode, the configuration takes
place automatically. If the chip is instead in Micro Mode, then the configuration engine waits for writes to the
function register.
External Reset Assertion
Either POR or RESETb pins can be asserted to initiate a reset. If RESETb is not asserted, then the rising edge of
POR is detected and a complete reset/configuration sequence executes. POR should be dropped before the 17 bit
counter rolls over.
If instead POR is held low, a falling edge on RESETb can be detected which will clear SRAM a single time. If
RESETb is held low, configuration is held off until RESETb is deasserted, otherwise configuration proceeds
immediately after the SRAM clear.
In BFR mode, a falling edge of the BFRb signal is detected, and it too re-initiates a configuration sequence (but no
reset sequence).
Mechanical
Package Details
The AN10E40 is currently offered in a 80 pin QFP package. This package has been characterized to have a ΘJA of
Cº
37 /W .
There are recommendations for dry pack handling of this device. If samples or production units are received without
sealed drypack then an 8 hour, 125 ºC oven bake is recommended before wave soldering. When received in
sealed drypacks, the devices should be mounted to a PCB within 48 hours of breaking the drypack seal.
18
Pin Out Description
The signal naming convention holds that active low signals are named with a “b” suffix.
Pin
1
Pin name
ARRAYCLKOUT
Type
Digital Output
2
MODE[1]
Digital Input
3
MODE[2]
Digital Input
4
CFG_CLK
Digital I/O
5
DCLK
Digital Output
6
7
8
9
10
11
12
13
14
15
16
17
18
19
DATA[0]
DATA[1]
DATA[2]
DATA[3]
DATA[4]
DATA[5]
DATA[6]
DATA[7]
F[1] (ERRb, RDb)
F[2] (MEMCEb, WRb)
F[0] (BFRb, CSb)
F[3] (PWRUP, RS)
F[4] (END, BUSY)
OPAMP_DISABLE
Digital I/O
Digital I/O
Digital I/O
Digital I/O
Digital I/O
Digital I/O
Digital I/O
Digital I/O
O.D. Out, Digital In
Digital Out, Digital In
Digital Input
Digital Input
Digital Output
Digital Input
20
RESETb
Digital Input
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
IOLDX
IOLDY
IOLDZ
IOLDZ2
IOLDY2
IOLCZ
IOLCY
IOLCX
AVDD
AVSS
SVSS
IOLBX
IOLBY
IOLBZ
IOLAZ
Analog Input
Analog Input
Analog Output
Analog Output
Analog Input
Analog Output
Analog Input
Analog Input
Power Supply
Power Supply
Power Supply
Analog Input
Analog Input
Analog Output
Analog Output
Description
Programming allows one of the 4 internal clocks
to be presented here.
Configuration mode control pin
0 = Micro Peripheral Interface Mode (Micro)
1 = Boot From Serial ROM (BFR)
Configuration mode control pin
0 = Use Internal Clock (CFG_CLK is an output,
running at 1/8 internal ring oscillator frequency.)
1 = Use External Clock (CFG_CLK is the clock
input to the configuration logic.)
Configuration logic clock
Direction controlled by MODE[2]
SPROM Configuration clock output
1/2 frequency of CFG_CLK.
Data pins used for loading configuration data
and checking status. DATA[0] is used for serial
BFR mode, and the entire byte width is used in
Micro mode.
Configuration Function pins
(BFR mode function, Micro mode function)
F[1] is an Open Drain output. In multi-FPAA
systems, all the ERRb lines can be tied together
to provide a single error indicator.
Op-Amp disable input (normally tied to Vss, not
usually utilized in systems)
Takes precedence over BFR’s PWRUP input
and Micro’s Function Register Bit Position 4
(Analog Enable)
0 = Analog circuitry enabled
1 = Analog circuitry disabled
Chip RESET
Falling edge detected to start Reset
Unbuffered Analog input
Buffered Analog input
Buffered Analog output
Uncommitted op-amp output
Uncommitted op-amp input
Buffered op-amp output
Buffered Analog input
Unbuffered Analog input
Analog VDD, 5 Volts
Analog VSS, 0 Volts
Substrate VSS, 0 Volts
Unbuffered Analog input
Buffered Analog input
Buffered analog output
Buffered op-amp output
AN10E40 Data Manual
36
37
38
39
40
41
IOLAY
IOLAX
VREFOUT
BVDD
BVSS
VMR
Analog Input
Analog Input
Analog Output
Power Supply
Power Supply
Analog Output
42
OPAMP_VMR
43
CEXT
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
IOD5Z
IOD5Y
IOD5X
IOD4Z
IOD4Y
IOD4X
ESD_VDD
ESD_VSS
IOD3Z
IOD3Y
IOD3X
IOD2Z
IOD2Y
IOD2X
IOD1Z
IOD1Y
IOD1X
IORAX
IORAY
IORAZ
IORBZ
IORBY
IORBX
CFG_VDD
SVSS
SVDD
CLOCK
Analog Output
Analog Input
Analog Input
Analog Output
Analog Input
Analog Input
Power Supply
Power Supply
Analog Output
Analog Input
Analog Input
Analog Output
Analog Input
Analog Input
Analog Output
Analog Input
Analog Input
Analog Input
Analog Input
Analog Output
Analog Output
Analog Input
Analog Input
Power Supply
Power Supply
Power Supply
Digital Input
71
72
73
74
75
76
77
78
79
80
IORCX
IORCY
IORCZ
IORDY2
IORDZ2
CFG_VSS
IORDZ
IORDY
IORDX
POR
Analog Input
Analog Input
Analog Output
Analog Input
Analog Output
Power Supply
Analog Output
Analog Input
Analog Input
Digital Input
Buffered Analog input
Unbuffered Analog input
Reference voltage
Bandgap VDD, 5 Volts
Bandgap VSS, 0 Volts
Signal ground, 2.5 Volts
Normally left floating. Can be driven by off chip
generator if the on chip VMR generator is
disabled.
Signal ground, 2.5 Volts
(usually loaded with 100nF to AVSS)
External Reference Generator Capacitor
(usually loaded with 10nF to AVSS)
Buffered op-amp output
Buffered Analog input
Unbuffered Analog input
Buffered op-amp output
Buffered Analog input
Unbuffered Analog input
ESD Structures VDD, 5 Volts
ESD Structures VSS, 0 Volts
Buffered op-amp output
Buffered Analog input
Unbuffered Analog input
Buffered Analog output
Buffered Analog input
Unbuffered Analog input
Buffered Analog output
Buffered Analog input
Unbuffered Analog input
Unbuffered Analog input
Buffered Analog input
Buffered Analog output
Buffered Analog output
Buffered Analog input
Unbuffered Analog input
Configuration (Digital) VDD ,5 Volts
Substrate VSS, 0 Volts
Substrate VDD, 5 Volts
System master clock
Used by clock generator which feeds all switch
capacitor analog circuitry.
Unbuffered Analog input
Buffered Analog Input
Buffered Analog output
Uncommitted op-amp input
Uncommitted op-amp output
Configuration (Digital) VSS, 0 Volts
Buffered Analog output
Buffered Analog input
Unbuffered Analog input
Power on Reset
Connection to VSS is typical. This input has an
active weak pull down device (capable of sinking 100
uA). If actively driving this pin, a pull up resistor may
be necessary to provide additional high state current.
19
20
80 LQFP Dimensions
DETAIL "B"
b
e
ccc
ddd
D
E
L
L1
R
R1
A
A1
A2
c
D1
E1
D2
E2
@
@1
@2
@3
(Lead width)
(Lead pitch)
(Coplanarity)
(Bent lds)
(Lead to lead width)
(Lead to lead length)
(Foot length)
(Lead length)
(Lead foot radius)
(Lead shoulder radius)
(Overall height)
(Standoff)
(Package thickness)
(Lead thickness)
(Bottom package width)
(Bottom package length)
(Top package width)
(Top package length)
(Lead flat angle)
(Lead shoulder angle)
(Top package draft angle)
(Bottom package draft angle)
0.22-0.38
0.65 Basic
Max. 0.100
Max. 0.130
16.95 - 17.45
16.95 - 17.45
0.73 - 1.03
1.60 Ref.
0.13 - 0.30
Min. 0.13
Max. 2.45
Max. 0.25
1.80 - 2.20
0.11 - 0.23
13.90 - 14.10
13.90 - 14.10
13.90 - 14.10
13.90 - 14.10
0º - 7º
Min. 0º
15º
15º
AN10E40 Data Manual
21
Package Pin Electrical Characterization
Lead Inductance
Lself [nH]
Center
Corner
4.22
5.23
Lmutual [nH]
Center
Corner
1.93
2.55
Lead Capacitance
Cself [pF]
Center
Corner
0.52
0.61
Cmutual [pF]
Center
Corner
0.18
0.26
Lead Resistance
Lead Resistance [mΩ]
Center
Corner
1.760
2.490
Lead Impedance – Z0 [Ω]
Center
Corner
90.52
92.90
Center refers to a pin to die bond wire near the center of the package (pins 10, 20, 50 and 70). Corner refers to
those bond wires near the package and die corners.
Powers, Grounds and Bypassing
In order to ensure that your design benefits from the highest possible fidelity available, there are a few signals that
you should pay special consideration to when designing the host circuit board.
Recommended Configuration for Power & Ground
The most common configuration ties the following pins together to a quiet +5 V power plane: AVDD, SVDD, BVDD
and ESD_VDD with the shortest possible connection. The following pins should be brought down to a quiet ground
plane: AVSS, SVSS, BVSS and ESD_VSS also with the shortest possible connection.
CFG_VDD and CFG_VSS can also be connected as above, but the associated digital circuitry is not as sensitive to
noise, and therefor can be connected to your system’s “noisier” power rails.
Bypassing recommendations vary with the design of your power planes, but it is usually sufficient to recommend
the use of a parallel pair of capacitors connected between each VDD pin and its associated VSS plane. These
capacitor pairs should be placed as close as possible to: AVDD, SVDD, and BVDD and connected by the shortest
path possible to the associated ground plane. The recommended capacitors are .1 uF in parallel with .01 uF. Each
of these should be low leakage and low ESR type capacitors. Polyester (Mylar) capacitors are optimal for the job,
but the generic ceramic bypass capacitors are sufficient.
Bypassing CFG_VDD to CFG_VSS can be accomplished in a manner similar to that described above, but layout is
less critical.
Bypassing ESD_VDD to ESD_VSS is not required, but can serve to optimize the performance of the ESD
protection structures in the device’s IO cells, in the unlikely event that such a current path is ever called upon.
AVDD and AVSS
AVDD and AVSS supply the op-amp and comparator circuits with +5 V and 0 V respectively. Obviously then, care
should be taken then to ensure that the quietest possible supply and ground signals are provided.
SVDD and SVSS
The wafers used in the construction of the AN10E40 are P type, so substrate ties (SVSS) should be connected to a
quiet ground potential. The N type well ties on the wafer are all connected the SVDD pin and therefor need to be
biased to a quiet positive potential. Connecting SVDD to AVDD and SVSS to AVSS is a typical configuration.
22
BVDD and BVSS
BVDD and BVSS supply all the band-gap voltage references, VMR generator and bias current generators. Here
again, the typical connection is to AVDD and AVSS.
ESD_VDD and ESD_VSS
These two signals do not normally source or sink any current to the AN10E40. In the rare event that a device pin is
electrically overstressed by an ESD or EOS event (Electrostatic Discharge or Electrical Overstress), then current is
sourced or sunk though these rails. These two should be connected to quiet supplies and here again AVDD and
AVSS are the typical connections.
CFG_VDD and CFG_VSS
The CFG_VDD and CFG_VSS rails supply all the digital configuration circuitry, the on board ring oscillator, APOR
and POR generation circuitry with +5V and 0V respectively. With the possible exception of the on board ring
oscillator, any digital supply noise produced by this circuitry would not normally effect the performance of the
analog portion, so no particular care need be taken with these supply signals from the chip’s point of view. Your
system however may have both “noisy” and “clean” power rails available. If so, CFG_Vxx may be best connected
to the “noisy” rail, leaving the “clean” supply as unpolluted as possible.
OPAMVMR and CEXT
As mentioned above in the Voltage Mid-Rail Generator section, both OPAMPVMR and CEXT should be bypassed
to a quiet ground node to ensure optimal performance. Generally, a good configuration consists of a Polyester
(Mylar) 10nF capacitor between CEXT and AVSS. A similar bypassing connection for OPAMPVMR is also
recommended. Care should be exercised in the placement of these components to minimize the signal path
between the array and the bypass capacitors.
The AN10E40 in Split Supply Systems
All analog signal processing within the AN10E40 is
referenced to its internal VMR node (Voltage Mid Rail,
normally 2.5 V above AVSS). For those applications
where a split supply (±2.5 V) is necessary, it is
possible to connect the AN10E40 as shown in Figure
20.
Here the AN10E40's internal VMR generator is
disabled (a feature available via AnadigmDesigner)
and the chip's VMR pin is instead driven externally by
the system's ground plane.
Naturally, logic circuits which interface to the AN10E40
must also be powered off the split rail as shown.
Under some circumstances, it may be more practical
to instead power the AN10E40 off a single 5 V supply
and AC coupled the ground referenced input signal.
+2.5 V
VDD
AN10E40
Boot
PROM
(or Micro)
VMR
Analog
Interface
Ground
Referenced
Analog
System
VSS
-2.5 V
Figure 20. Connecting to a Split Rail System
Electrical Parameters
Because the AN10E40 is programmable, performance characteristics are reported for representative pieces of the
device rather than for the entire device. The following graphs and numbers provide you with conservative estimates
of the sort of performance you can expect for your particular design.
AN10E40 Data Manual
23
Absolute Maximum Ratings
Min.
Supply Voltages (A,B,D,SVDD)
Analog Input Voltage
Digital Input Voltage
Storage Temperature
Typ.
-0.5 V
-0.5 V
-0.5 V
-65 C
Max.
Notes
6.5 V
1
AVDD+0.5V
DVDD+0.5V
150 C
1 - Operation with Vdd > 5.5 V may reduce device operating lifetime.
Recommended Operating Conditions
Supply Voltages (A,B,D,SVDD)
Analog Input Voltage
Standard Analog Load (small signal)
Standard Analog Load (large signal)
Standard Digital Load
Ambient Operating Temperature
Min.
Typ.
Max.
4.5 V
0.5 V
5.0 V
5.5 V
Notes
AVDD-0.5V
1 kΩ in parallel with 100 pF
10 kΩ in parallel with 100 pF
50 pF to DVSS
1k9 || 100pF
10k9 || 100pF
50 pF
-40 C
+85 C
Digital IO
Min.
Output Voltage High (Voh)
Input High Voltage (Vih)
Input Low Voltage (Vil)
Output Voltage Low (Vol)
Tri-State Leakage Current (Iozh or Iozl)
Typ.
Max.
Notes
0.8 Vdd
0.7 Vdd
0.3 Vdd
0.2 Vdd
negligible
Voltage Mid Rail
The array supplies its own internal analog ground reference known as VMR. VMR is 2.5 V above AVSS. Noise on
VMR degrades system performance so great care has been taken to provide the AN10E40 with an extremely quiet
analog reference generator.
Min.
VMR
Typ.
Max.
Notes
2.5 V
Vref
3
Vref Measured
2
1
0
-1
-2
-3
-3
-2
-1
0
Vref Programed
1
2
3
24
The Analog I/O Cell
The AN10E40 Analog I/O cells are carefully designed to provide robust drive without sacrificing bandwidth figures.
You can see from the plot below that the bandwidth of the I/O cells well exceeds the sort of signals typically
processed within the device.
Min.
Input Offset Voltage
Unity Gain
Slew Rate
-3dB Bandwidth
Input Voltage Range
-0.02 dB
Typ.
2 mV
0 dB
20 V/µs
10.8 MHz
Max.
+0.02 dB
AVSS
AVDD
0.5
AVDD- 0.5
0.5
AVDD- 0.5
0.5
AVDD- 0.5
Input Voltage Range
Output Voltage Range
Small Signal Load Defined as:
1 k9|| 100 pF
Output Voltage Range
Large Signal Load Defined as:
10 k9|| 100 pF
Notes
1 kHz, Sine, 1.0 VRMS
10 kΩ , 100 pF load
Pins IOxxZ - When used as a
direct input to the device core cells.
Pins IOxxX and IOxxY - When the
I/O cell is used as a powered input
buffer. (Input range is limited by I/O
buffer output swing limitations.)
Pins IOxxZ - When I/O cell is used
as a powered output buffer.
Pins IOxxX and IOxxY - When I/O
cell is used as a direct output from
a device core cell.
Pins IOxxZ - When I/O cell is used
as a powered output buffer.
Pins IOxxX and IOxxY - When I/O
cell is used as a direct output from
a device core cell.
AN10E40 Data Manual
25
The Analog I/O Cell Configured as a Sallen-Key Filter
The AN10E40 Analog I/O cells are especially designed to accommodate the construction of Sallen-Key topology
filters. These filters are easily constructed and are handy for input anti-aliasing or output switching noise filtering. In
this particular test, the filter was designed to roll off at 200 kHz.
Many of the measurements shown below are repeated several times with different weighting factors. CCIR IEC
468-3 Weighted and A-Weighted measurements are two standard Psophometric weightings common to audio and
communications equipment manufacture.
Min.
SNR, >500 kHz Bandwidth
SNR, 80 kHz Bandwidth
SNR, 468-3 Weighted
SNR, A Weighted
Total Harmonic Distortion (THD+N)
Typ.
85 dB
88 dB
87 dB
94 dB
0.015%
Max.
Notes
1 kHz, Sine, 1.0 Vrms
1 kHz, Sine, 1.0 Vrms
1 kHz, Sine, 1.0 Vrms
1 kHz, Sine, 1.0 Vrms
80 kHz
26
A Programmable Inverting Gain Stage
In this example, a CAB was programmed to serve as an inverting gain stage with the Gain parameter set to 2.
Notice the dead flat response throughout the band swept.
Min.
SNR, >500 kHz Bandwidth
SNR, 80 kHz Bandwidth
SNR, 468-3 Weighted
SNR, A Weighted
Total Harmonic Distortion (THD+N)
Gain Set to 0.01
Gain Set to 1.00
Gain Set to 100.0
Typ.
74 dB
76 dB
77 dB
85 dB
0.011%
+1.27%
-1.14%
-1.71%
Max.
Notes
1 kHz, Sine, 0.5 Vrms
1 kHz, Sine, 0.5 Vrms
1 kHz, Sine, 0.5Vrms
1 kHz, Sine, 0.5 Vrms
80 kHz
Gain Set Error
Gain Set Error
Gain Set Error
AN10E40 Data Manual
27
A Programmable Low Pass Filter
With a CAB programmed as a low pass (fc = 20 kHz), low Q (Q = 0.707) with a Gain of 2, the following
performance can be expected.
Min.
SNR, >500 kHz Bandwidth
SNR, 80 kHz Bandwidth
SNR, 468-3 Weighted
SNR, A Weighted
Total Harmonic Distortion (THD+N)
Gain Set to 0.01
Gain Set to 1.00
Gain Set to 100.0
fc set to 50.0 Hz, CLK at 16.13 kHz
fc set to 100.0 Hz, CLK at 16.13 kHz
fc set to 1.0 kHz, CLK at 100.0 kHz
fc set to 10.0 kHz, CLK at 250.0 kHz
Typ.
70 dB
75 dB
70 dB
78 dB
0.05%
+0.46%
-0.12%
-0.54%
+0.84%
-1.25%
+0.30%
+0.01%
Max.
Notes
1 kHz, Sine, 0.5 Vrms
1 kHz, Sine, 0.5 Vrms
1 kHz, Sine, 0.5 Vrms
1 kHz, Sine, 0.5 Vrms
80 kHz
Gain Set Error
Gain Set Error
Gain Set Error
Error in -3 db Corner Frequency
Error in -3 db Corner Frequency
Error in -3 db Corner Frequency
Error in -3 db Corner Frequency
28
Sine Wave Oscillator
The test circuit is a Sine Wave Oscillator IPmodule, programmed to generate a 1.0 V Peak, 1 kHz Sine wave. The
input clock was running at 35.714 kHz. From the plot you can see that the most significant spur at 3 kHz is nearly
60 dB down from the fundamental. Other less significant spurs are noted at 2, 5, 7 and 9 kHz.
Electrostatic Discharge Characterization
The following excerpts were copied with permission from and gratitude to: The Electrostatic Discharge Association.
An excellent tutorial on the subject of ESD and EOS can be found on their web site at http://www.esda.org/.
A Quick Review of ESD Basics
Electrostatic Discharge (ESD) damage results from handling the devices in uncontrolled surroundings or when poor
ESD control practices are used. Generally damage is classified as either a catastrophic failure or a latent defect.
Catastrophic Failure
When an electronic device is exposed to an ESD event it may no longer function. The ESD event may have caused
a metal melt, junction breakdown, or oxide failure. The device's circuitry is permanently damaged causing the
device fail.
Latent Defect
A latent defect, on the other hand, is more difficult to identify. A device that is exposed to an ESD event may be
partially degraded, yet continue to perform its intended function. However, the operating life of the device may be
reduced.
Basic ESD Events--What Causes Electronic Devices to Fail?
ESD damage is usually caused by one of three events: direct electrostatic discharge to the device; electrostatic
discharge from the device or field induced discharges.
AN10E40 Data Manual
29
Discharge to the Device
An ESD event can occur when any charged conductor (including the human body) discharges to an ESDS
(electrostatic discharge sensitive) device. The most common cause of electrostatic damage is the direct transfer of
electrostatic charge from the human body or a charged material to the electrostatic discharge sensitive (ESDS)
device. When one walks across a floor, an electrostatic charge accumulates on the body. Simple contact of a finger
to the leads of an ESDS device or assembly allows the body to discharge, possibly causing device damage. The
model used to simulate this event is the Human Body Model (HBM).
A similar discharge can occur from a charged conductive object, such as a metallic tool or fixture. The model used
to characterize this event is known as the Machine Model.
Discharge from the Device
The transfer of charge from an ESDS device is also an ESD event. The trend towards automated assembly would
seem to solve the problems of HBM ESD events. However, it has been shown that components may be more
sensitive to damage when assembled by automated equipment. A device may become charged, for example, from
sliding down the feeder. If it then contacts the insertion head or another conductive surface, a rapid discharge
occurs from the device to the metal object. This event is known as the Charged Device Model (CDM) event, and
can be more destructive than the HBM for some devices. Although the duration of the discharge is very short--often
less than one nanosecond--the peak current can reach several tens of amperes.
Field Induced Discharges
Another event that can directly or indirectly damage devices is termed Field Induction. As noted earlier, whenever
any object becomes electrostatically charged, there is an electrostatic field associated with that charge. If an ESDS
device is placed in that electrostatic field, a charge may be induced on the device. If the device is then momentarily
grounded while within the electrostatic field, a transfer of charge from the device occurs.
AN10E40 ESD Classifications
Pin Type
Digital Inputs
Digital Outputs
Digital I/0
Analog I/0
CEXT, OPAMVMR, VMR, VREF
Classifications
Class 2
Class M4
Class C6
Class 2
Class M4
Class C6
Class 2
Class M4
Class C6
Class 2
Class M4
Class C6
Class 2
Class M4
Class C6
Notes
M4 and C6 classifications are based
on estimated performance based on
extensive HBM characterization.
M4 and C6 classifications are based
on estimated performance based on
extensive HBM characterization.
M4 and C6 classifications are based
on estimated performance based on
extensive HBM characterization.
M4 and C6 classifications are based
on estimated performance based on
extensive HBM characterization.
M4 and C6 classifications are based
on estimated performance based on
extensive HBM characterization.
30
Standard ESD Classifications
ESDS Component Sensitivity Classification
Human Body Model
Class 0
Class 1A
Class 1B
Class 1C
Class 2
Class 3A
Class 3B
ESDS Component Sensitivity Classification
Machine Model
Class M1
Class M2
Class M3
Class M4
ESDS Component Sensitivity Classification
Charged Device Model
Class C1
Class C2
Class C3
Class C4
Class C5
Class C6
Class C7
ESD STM5.1-1998
<250 volts
250 volts to <500 volt
500 volts to < 1,000 volts
1000 volts to < 2,000 volts
2000 volts to < 4,000 volts
4000 volts to < 8000 volts
>= 8000 volts
ANSI/ESD-S5.2-1999
<100 volts
100 volts to <200 volts
200 volts to <400 volts
> or = 400 volts
EOS/ESD-DS5.3-1996
<125 volts
125 volts to <250 volts
250 volts to <500 volts
500 volts to <1,000 volts
1,000 volts to <1,500 volts
1,500 volts to <2,000 volts
=>2,000 volts
AN10E40 Data Manual
© Anadigm Ltd. 2000
© Anadigm Inc. 2000
All Rights Reserved.
31
AN10E40 Data Manual
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rev 1.14