625 specifications

All specifications are subject to change


Type Bipolar, 4-quadrant, DC current source
Current generation Linear regulation with digital setting and analog control
Current range ±60 A
Compliance voltage ±5 V maximum (nominal, both source and sink)
Maximum power 300 W
Load reactance 0 H to 100 H
Current ripple (max) 4 mA RMS at 60 A, (0.007%) into 1 mΩ load (significantly reduced into a reactive load or at lower current)
Current ripple frequencyDominated by line frequency and its harmonics
Temperature coefficient ±15 ppm of full scale/°C
Line regulation 15 ppm/6% line change
Source impedance 25 Ω
Stability (1 h) 1 mA/h (after warm-up)
Stability (24 h) 10 mA/24 h (typical, dominated by temperature coefficient and line regulation)
Isolation Output optically isolated from chassis to prevent ground loops
Parallel operation 2 units can be paralleled for ±120 A, ±5 V operation

Quench, line loss, low line voltage, high line voltage, output over voltage, output over current, over temperature, and remote inhibit (on critical error conditions, magnet discharges at 1 V nominal)

Output programming

Internal current settings

Resolution 0.1 mA (20-bit)
Settling time 600 ms for 1% step to within 0.1 mA into a resistive lead
Accuracy ±10 mA ±0.05% of setting
Operation Keyboard, computer interface
ProtectionCurrent setting limit

Internal current ramp

Ramp rate 0.1 mA/s to 99.999 A/s (compliance limited)
Update rate 27.7 increments/s
Ramp segments 5
Operation Keypad, computer interface, and trigger input
Protection Ramp rate limit

External current programming

Sensitivity6 V = 60 A
Resolution Analog
Accuracy ±10 mA ±1% of setting
Bandwidth (3 dB) 40 Hz, 2-pole, low-pass filter (10 Hz pass band, compliance limited)
Input resistance >50 kΩ
Operation Voltage program through rear panel
ConnectorShared 15-pin D-sub
LimitsInternally clamped at 6.1 V

Compliance voltage setting

Range0.1 V to 5.0 V
Resolution100 µV
Accuracy±10 mV ±1% of reading


Output current

Resolution 0.1 mA
Accuracy±1 mA ±0.05% of reading
Update rate 2.5 readings/s display, 10 readings/s interface
CompensationCompensated for lead resistance and 25 Ω source resistance

Output voltage (at supply terminals)

Resolution100 µV
Accuracy±1 mV ±0.05% of reading
Update rate2.5 readings/s display, 5 readings/s interface

Remote voltage (at magnet leads)

Resolution100 µV
Accuracy±1 mV ±0.05% of reading
Update rate 1.25 readings/s
Input resistance >50 kΩ
ConnectorShared 15-pin D-sub

Persistent switch heater output (PSHO)

Current range10 mA to 125 mA
Compliance voltage (minimum) 12 V or 21 V selectable
Heater resistance (minimum) 10 Ω
Setting resolution 1 mA
Accuracy ±1 mA
Operation On/Off with lockout delay of 5 s to 100 s
ProtectionOpen or shorted heater detection, error message if off and on output currents differ
Connector BNC

Front panel

Display type 8-line by 40-character, graphic vacuum fluorescent display module
Display readingsOutput current, calculated field (T to G), output voltage, and remote voltage sense
Display settings Output current, calculated field, compliance voltage, and ramp rate
Display annunciatorsStatus and errors
LED annunciatorsPSHO on, remote, compliance limit, fault, and ramping
Keypad type26 full travel keys
Keypad functions Direct access to common operations, menu-driven setup


IEEE-488.2 interface

FeaturesSH1, AH1, T5, L4, SR1, RL1, PP0, DC1, DT1, C0, E1
Reading rate To 10 readings/s
Software support LabVIEW™ driver
Serial interface
Electrical format RS-232C
Baud rates 9600, 19200, 38400, 57600
Reading rate To 10 readings/s
Connector9-pin D-sub

Output current monitor

Sensitivity60 A = 6 V
Accuracy±1% of full scale
Noise1 mV
Source impedence 20 Ω
ConnectorShared 15-pin D-sub

Output voltage monitor

Sensitivity1 V = 1 V
Accuracy±1% of full scale
Noise1 mV
Source impedence20 Ω
ConnectorShared 15-pin D-sub

Fault output

TypeRelay (closed on fault)
Real contact 30 VDC at 1 A
ConnectorShared 25-pin D-sub

Remote inhibit input

TypeTTL or contact closure
ConnectorShared 25-pin D-sub

Trigger input

TypeTTL or contact closure
ConnectorShared 25-pin D-sub


Ambient temperature 15 ºC to 35 ºC
Cooling Air-cooled with internal 2-speed fan
Warm-up30 min at output current setting
Line power 100, 120, 220, 240 VAC +6% -10%, single phase, 50 or 60 Hz, 850 VA
Size 483 mm W × 178 mm H × 520 mm D (19 in × 7 in × 20.5 in), rack mount (integrated rack mount ears)
Weight 27.2 kg (60 lb)
Calibration schedule 1 year