WBK12A and WBK13A

Programmable Low-Pass Filter Cards

Important Notice! WaveBook/516E UsersWBK option cards for WaveBook/516E are installed at the factory per customer order.
Users are not to remove or install cards for these products as the cards are not “plug-andplay” for these devices and erroneous signal values could result. If you desire to remove
or add a card to WaveBook/516E contact the factory or your service representative.
Important Notice! WaveBook/516, /516A, /512A, and WBK10A Users
With exception of the WBK30 option, WBK option cards for WaveBook/516, /516A,/512A, and WBK10A are installed at the factory per customer order. Users are not toremove or install cards for these products [other than WBK30 series cards] as the cards
are not “plug-and-play” for these devices and erroneous signal values could result. If you
desire to remove or add a card to these products, contact the factory or your service
representative.

Description
The WBK12A and WBK13A are 8-channel programmable low-pass filter cards for use with 1-MHz
WaveBook data acquisition systems. These cards install directly into a WaveBook or WBK10A module andprovide programmable low-pass filtering over all channels. Multiple WBK12A and WBK13A cards can beinstalled in one system for up to 72 channels. All of the cards’ low-pass filters and cutoff frequencies are
configured via software.
The WBK13A card has the additional capability of sampling all channels at the same time. If more than one
WBK13A card is installed [within one system] all channels will be sampled within 100 ns of each other.
Features of the WBK12A and WBK13A include:•Anti-Alias Low-Pass Filters. Each card provides 8 input channels, arranged in two 4-channel banks;
the filter and cutoff frequency configurations are applied per bank. The cards’ filters can be configured
as either an 8-pole elliptic filter with cutoff frequencies of 400 Hz to 100 kHz, or an 8-pole linearphase filter with 400 Hz to 50 kHz cutoff frequencies.

•500 Khz Low Pass Filter. You can individually configure channels to bypass the programmable filter.
The bypass option results in a 1-pole low-pass filter at approximately 500 kHz.

•Cutoff Frequencies. The WBK12A and WBK13A provide 748 discrete cutoff frequencies that can be
determined exactly by the formula Fc = 300 kHz/N; where the integer N = 3 to 750. Alternatively, you
can configure any channel to bypass the programmable filter entirely, resulting in a 1-pole low-passfilter at about 500 kHz.

•

Programmable-Gain Amplifiers. The cards’ programmable-gain instrumentation amplifiers can besoftware selected to various gains on a per channel basis. The gains are set prior to the beginning of anacquisition sequence and cannot be changed during an acquisition.

•Simultaneous Sample-and-Hold (SSH) (WBK13 only). In addition to the filtering capability of theWBK12A, the WBK13A provides per channel SSH. Simultaneous sampling of all channels occurs at
the start of a scan sequence.
When using a WaveBook with an SSH channel enabled, the per-channel sample rates
are reduced. The rate reduction is the same as that which would occur if anotherchannel were added. The per-channel rate (with SSH enabled) is:1 MHz / (n+1), where n is the number of active channels.

Programmable Low-Pass Filter Cards

988396

WBK12A and WBK13A, pg. 1

WBK12A and WBK13A Block Diagram

Hardware Setup
Configuration
All WBK12A and WBK13A series configurations are controlled by software. There are no hardware
settings.
Installation
There is no user installation permitted. See notes on page 1.

Software Setup
Reference Notes:➣ Setup information pertaining to power, expansion control, and expansion signal
connections is contained in the System Setup and Power Options chapter of theWaveBook User’s Manual (p/n 489-0901).

➣ For detailed WaveView information, refer to the WaveView Document Module that isincluded on the data acquisition CD. The document can be accessed using the<View PDFs> button on the CD’s opening screen.

pg. 2, WBK12A and WBK13A

988396

Programmable Low-Pass Filter Cards

WBK12A and WBK13A – Specifications
Name/Function:
WBK12A, Programmable Low-Pass Filter Card
WBK13A, Programmable Low-Pass Filter Card With
SSH
Number of Channels: 8Connector: Internal to WaveBook/512A, /516, /516A,/516E, and WBK10A(two 36-pin sockets mate with 36-pin connectors)
Programmable Gain Amplifier Ranges:
×1, 2, 5, 10, 20, 50, and 100
Switched Capacitor Filter Cutoff Frequencies Range:
400 Hz to 100 kHz
Number of Cutoff Frequencies: 1024
Filter Grouping: 4 channels each in 2 programmablebanks
Low-Pass Filter: Software selectable, 8-pole
elliptic filter
Low-Pass Filter Type: Software selectable,
elliptic or linear phase

Low-Pass Filter Frequency Cutoff Range:
100 kHz, 75 kHz, 60 kHz...400 Hz,
bypass defined as Fc = 300 kHz/N where N = 3 to 750
Anti-Alias Frequencies: determined by software control
Accuracy: ±0.03% FS DC, for WaveBook/512A
For WaveBook/516 Series see the table on
page 4 of this document module.
Offset: ±1 LSB max (for WaveBook/512A)
Aperture Uncertainty: 75 ps max
Voltage Droop: 1 mV/ms max (0.01 mV/ms typ)
Maximum Signal Voltage: ±5.00 VDC (×1)
THD: -65 dB (-70 dB typ) (for WaveBook/512A)
Number of Cutoff Frequencies Simultaneously Set:
two, one for each 4-channel bank of inputs
Weight: 0.14 kg (0.3 lb)

Software Selectable Cutoff Frequencies
Octave (kHz)

Number of Cutoff
Frequencies

0.400 to 0.780
0.780 to 1.570
1.57 to 3.15
3.15 to 6.3
6.3 to 12.5
12.5 to 2525 to 50
50 to 100

512
2561286432
1685Input Voltage Ranges:
Before a scan sequence begins, the input voltage ranges can be programmed via software.
The ranges can be expanded as follows:
Unipolar:

Unipolar applies to WBK 10A only.

0 to +10 V
0 to +5 V
0 to +2 V
0 to +1 V
0 to +0.5 V
0 to +0.2 V
0 to +0.1 V
Bipolar: Bipolar applies to WaveBook/516, /516A, /516E, /512A, and WBK10A-10 to +10 V-5 to +5 V
-2 to +2 V
-1 to +1 V
-0.5 to +0.5 V-0.2 to +0.2 V-0.1 to +0.1 V-.05 to + .05 V

This range applies to WBK 10A only.

Programmable Gain Amplifier Gain Ranges: ×1, 2, 5, 10, 20, 50, 100

Programmable Low-Pass Filter Cards

988396

WBK12A and WBK13A, pg. 3

Accuracy and Noise Specifications
WaveBook/516 Series(Alone)
VoltageRange

Accuracy (Note 2)
One Year, 18-28°C

Input NoiseLSB rms
DC-500KHz(typical)

WaveBook/516 Series
with a WBK12A or a WBK13A (Note 3)
Accuracy (Note 2)
One Year, 18-28°C

Input NoiseLSB rms(typical)(Note 4)0 to +10V
0 to +5V (10A)
0 to +4V (516)
0 to +2V
0 to +1V(10A only)
0 to +.5V
0 to +.2V
0 to +.1V-10 to +10V
-5 to +5V
-2 to +2V
-1 to +1V-.5 to +.5V
(10A only)± %reading.012%
.012%

± %
range.008%
.009%

.012%
.012%

.012%
.018%

.012%
.012%
.012%
.018%
.018%

-.2 to +.2V-.1 to +.1V-.05 to +.05V(10A only)
Notes: 1.
2.
3.
4.

.008%.008%.009%
.012%
.018%

± %
range.008%
.009%

1KHz
FilterFilterBypass22± %reading
.012%
.012%

2.2
2.2

2.2
2.2

33.012%
.012%

.012%
.018%

2.2
2.2

33222
3
5.018%
.018%
.018%
.012%
.012%
.012%
.018%
.018%

.033%
.08%
.16%
.008%
.008%
.009%
.012%
.018%

2.2
2.2
2.2
2.2
2.2
2.2
2.2
2.2

612
20
2.2
2.2
3
3.3
6.018%
.018%
.018%

.033%
.08%
.16%

2.2
2.2
4

1220
40

Specifications assume differential input scan, unfilteredAccuracy specification is exclusive of noise.
Unipolar ranges are unavailable for a WaveBook/516 Series with a
WBK11A, WBK12A, or WBK13A option installed.
Unipolar mode is available with WBK10A and any option.
Maximum limit is 1.3X typical.

pg. 4, WBK12A and WBK13A

988396

Programmable Low-Pass Filter Cards

Predicting Amplitude Loss
The following equations can be used to predict the amplitude loss when passing a signal through either theanti-alias or clock suppression filter.
Definition of equation terms:
Fin is the signal to be measured.
Falias is the cutoff frequency of the anti-alias filter.
Fclock is the cutoff frequency of the clock suppression filter.
1

Err 20 . log
1
Err 20 . log
1Fin
Falias1Fin

FclockTotal error, in dB, due to both filters is :11.
Etot 20 . log
Fin
Fin
1
1Falias
FclockAs an example, with the switched capacitor filter set to 10,000 Hz. and the input frequency set to 6000 Hz.
Fin = 6000
Falias = 33554
Fclock = 14848
Total amplitude loss = sum of both errors = -2.188 dB.
1.
E1 20 log
6000
133554
E1 = 0.71446
1E2 20 . log
6000
114848E2 = 1.47396
E1 E2 = 2.18843
11.
Etot 20 . log
6000
6000
113355414848
Etot = 2.18843
Fx 1 , 2 .. 8000
Fp 33554
Fc 1484811.
E ( Fx ) 20 . log
Fx
Fx
11Fp
Fc

Programmable Low-Pass Filter Cards

988396

WBK12A and WBK13A, pg. 5

00.250.50.75

11.25

E ( Fx )

1.5

1.75

22.25

2.5

2.75

30800

1600

2400

3200

4000
Fx48005600

64007200

8000

WBK12A & WBK13A, Amplitude Loss in dB due to Anti-alias and Clock Filters
Input signal is swept from 1 to 8000 Hz
switched capacitor filter frequency = 8,000 Hz
anti-alias filter cutoff = 33.554 Hz
clock filter = 14,848 Hz

pg. 6, WBK12A and WBK13A

988396

Programmable Low-Pass Filter Cards