Model VM8DAC
Low Noise
Digital to Analog Converter
8 Channel VME Module
VM8DAC VMEbus digital to analog converter
(DAC) boards from Frequency Devices Inc. offer
eight channels of precision low distortion/low
noise, digital to analog converters that operate
with a sample clock frequency derived from a
master external clock and a programmable time
base divider. The boards are available in a single
width B-size (6U) VME form factor that conforms
to VMEbus Revision C.1 as an A32/D32 Data
Transfer Bus Slave.
VM8DAC boards provide high (24-bit) and low
(16-bit) resolution data access to on-board
DAC’s. The boards interpret the received parallel
data from the VMEbus as binary-2’s complement.
This data is serialized and transferred to any
selected DAC channel at a fixed master time
base where it is converted to analog signals at a
software programmable sampling rate. The DAC
channels may be configured to 16,384, 8,192,
4,096, or 2,048 samples per second.
Eight discrete channels with programmable
sampling that provide a 24- bit DAC stage for
each channel offers the user versatile and
convenient digital to analog conversion.
Outputs synchronized to the front panel
VM8DAC Ordering Guide
Designed for Real Time Operating Systems
(RTOS) to provide minimal pipeline delay
(less than 5 microseconds). i.e. Linux or Vx
Interrupt free operation provides glitch energy
of <5nV-sec and extremely low noise density
(ï100nV/ Hz ).
VME backplane is galvanically isolated from
the analog section to reduce system
integration problems.
To order, simply specify the part number below.
25 Locust St., Haverhill, Massachusetts 01830 • Tel: 800/252-7074, 978/374-0761 • FAX:978/521-1839
e-mail: [email protected] • Web Address:
Model VM8DAC
8 Channel Low Noise
Digital to Analog Converter
25oC and Rated Power Input
Module Size/Dimensions
1. Standard 6U VME, single slot module 9.17” X 6.3”, (233mm X 160 mm)
2. Weight
~ 1 lb.
3. Input clock connector
Lemo EPG.OB.302.HLN
4. Analog output connector
Male DB25
5. Matching output connector
Female DB25
External Clock Input
6. Configuration
Differential, TTL compatible
7. Isolation
Transformer isolated
8. Frequency
222 Hz (4.194305 MHz)
Analog Output
9. Number of channels per board
10. Analog output configuration
11. Minimum output load
500 ohm
12. Maximum output voltage
+/- 10V into 10 kΩ
13. Output amplifier 3 dB bandwidth
14. Output impedance
50 Ω per leg
15. Anti-image filter
16. Inter-channel crosstalk
< -90dB
(frequencies less than 50KHz)
DAC Specifications
17. Number of bits
24 bits
18. Binary number format
Binary 2’s complement
19. Sampling rate
16,384, 8192, 4096, 2048 samples per second
20. Bipolar zero error
±2% F.S. maximum
21. Bipolar zero error drift
± 5 ppm of FS/ °C
22. Glitch energy
< 5nV-sec
23. Output-referred noise
<100nV/ Hz (40 Hz to 8192 Hz with FS 1000 Hz sine wave)
24. Amplitude match and accuracy
± 0.1 dB
25. Harmonic spikes
<-100 dB
(referred to a full scale output signal )
26. Output settling time to 1%
< 5 microseconds
(From output clock edge)
Power Requirements
27. From the + 5V VME backplane supply
1.0 A Max.
28. From the +/- 12V VME backplane supply
1.0 A
VME Interface
29. Interface configuration
A32/D32 VME Data Transfer Bus (DTB) Slave
30. Address modifier lines decoding
Full decode (0x09, 0x0A, 0x0D, and 0x0E valid)
31. Data word size
Long word (Quad Byte) and aligned word (Double Byte)
32. Bus cycle compatibility
AO, RMW, bus cycles address pipelining
33. Addressing modes
A32 (Extended) addressing only
34. Operating Temperature range
0oC to +70oC
35. Storage Temperature range
-25oC to +85oC
36. Humidity
0-95% non-condensing
We hope the information given here will be helpful. The information is based on data and our best knowledge, and we consider the information to be true and accurate. Please read all statements, recommendations or
suggestions herein in conjunction with our conditions of sale, which apply, to all goods supplied by us. We assume no responsibility for the use of these statements, recommendations or suggestions, nor do we intend
them as a recommendation for any use, which would infringe any patent or copyright.
VM8DAC 022004
25 Locust St., Haverhill, Massachusetts 01830 • Tel: 800/252-7074, 978/374-0761 • FAX:978/521-1839
e-mail: [email protected] • Web Address: