User`s guide

20
34951A 4-channel isolated
D/A converter with
waveform memory
This module has four independent, isolated
channels that output DC voltage up to ±
16 V or DC current up to ± 20 mA. The gain
and offset can be adjusted on-the-fly. Each
channel can be controlled manually, or use
the onboard memory to download a wave-
form. The 500k of memory is global and can
store up to 32 waveforms. Any waveform
can be dynamically allocated among one
or more channels and output as a point-to-
point arbitrary waveform generator at up to
200k points/sec. You can use the standard
sine, square or ramp wave shapes provided
or define your own wave shape using over
500,000 points and output to a device under
test.ThereisalsoasingleCLKthatcanbe
divided down for each channel indepen-
dently.
The calibration command connects the D/A
converters to the internal DMM to be auto-
matically calibrated. Connections to the
module can be made via standard 50-pin
Dsub cables or a detachable terminal block.
General specifications
Maximum update rate: 200 kHz point-to-point
Monotonic: to 16-bits
Isolation: >80VDC/ACpeak
(chan-to-chassis or
chan-to-chan)
Synchronization: Software commands
or external trigger
Internal/external
CLKaccuracy: 100ppm
ACaccuracy: Notspecified
DC voltage
Amplitude: ± 16 V up to 10 mA
Resolution: 16-bits=500uV
Amplitude
accuracy(DC): ±(0.05%+3.0mV)
(90 days, Tcal ± 5°C or
Cal:MOD?: ± 5°C)
Rippleandnoise: <2mVrms,20Hzto
  250kHzinto10kΩload
Settlingtime: 40uS(-fullscaleto+full
scale step, single channel,
to rated accuracy)
Outputimpedance: <1Ωwiththeload
sensed
DC current
Range: ±20mA
Resolution: 16-bit=630nA
Accuracy: ±(0.09%+5.0µV)
(90 days, Tcal ± 5°C or
Cal:MOD?: ± 5°C)
Rippleandnoise: <2uArms,20Hzto
  250kHzinto250Ω
Compliance voltage: ± 12 V
Max open circuit
voltage: < ± 22 V
Phase-locking I/O trigger characteristics
Trigger input
 Inputlevel: TTLcompatible
(3.3 V logic, 5 V tolerant)
 Slope: Risingorfalling,
selectable
 Pulsewidth: >100nS
 Inputimpedance: >10kΩ,DCcoupled
Trigger output
 Level: TTLcompatible
  into1kΩ(3.3Vlogic)
 Outputimpedance: 50Ωtypical
Clock input
 Inputlevel: TTLcompatible
(3.3 V logic, 5 V tolerant)
 Inputimpedance: >10kΩ,DC
Maximum rate: 10 MHz
Clock output
 Level: TTLcompatible
  into1kΩ(3.3Vlogic)
 Outputimpedance: 50Ωtypical
Maximum rate: 10 MHz
Accuracy: ± 100 ppm
Channel
01
16 Bits
DAC 1
16 Bits
DACx
Channel
02
16 Bits
DAC 2
Channel
03
16 Bits
DAC 3
Channel
04
Internal clock
Internal trigger
User supplied clock (bidirectional)
User supplied trigger (bidirectional)
HI voltage sense
Disconnect
Calibration bus
(ABUS 1)
Customer
system
HI
LO
LO voltage sense
Immediate
data
Calibration constant
in non-volatile memory
Waveform
memory
16 Bits
DAC 4
Figure 14. 34951A 4-channel isolated D/A converter