User manual
HW 1/17/05
Rev B
Page 1 of 2
6221 AC and DC Current Source 
SOURCE SPECIFICATIONS 
Settling Time
1,2 
(1% of final value) 
Range 
(+5% over 
range) 
Accuracy 
(1 Year) 
23°C±5°C 
±(%rdg. + 
amps) 
Programming 
Resolution 
Temperature 
Coefficient/°C
0°-18°C& 28°-
50°C 
Typical 
Noise 
(peak-peak)
/RMS
3,5
0.1Hz-10Hz
Typical 
Noise 
(peak-peak) 
/RMS
3,4,5
10Hz-(BW)
Output 
Response 
Bandwidth 
(BW) into 
Short 
Output 
 Resp. Fast 
 (Typical
5
) 
Output 
 Resp. Slow
 (Max) 
2nA 
0.4% + 2pA  100fA  0.02% + 200fA 400/80fA  250/50pA  10kHz 
90μs 100μs 
20nA 
0.3% + 10pA  1pA  0.02% + 200fA 4/0.8pA  250/50pA  10kHz 
90μs  100μs 
200nA 
0.3% + 100pA  10pA  0.02% + 2pA  20/4pA  2.5/0.5nA  100kHz 
30μs 100μs 
2μA 
0.1% + 1nA  100pA  0.01% + 20pA  200/40pA  25/5.0nA  1MHz 
4μs  100μs 
20μA 
0.05% + 10nA  1nA  0.005% + 200pA 2/0.4nA  500/100nA  1MHz 
2μs 100μs 
200μA 
0.05% + 100nA  10nA  0.005% + 2nA  20/4nA 
1.0/0.2μA 
1MHz 
2μs  100μs 
2mA 
0.05% + 1μA 
100nA  0.005% + 20nA 200/40nA 
5.0/1μA 
1MHz 
2μs 100μs 
20mA 
0.05% + 10μA  1μA 
0.005% + 200nA
2/0.4μA  20/4.0μA 
1MHz 
2μs  100μs 
100mA 
0.1% + 50μA 10μA  0.01% + 2μA 10/2μA 100/20μA 
1MHz 
3μs 100μs 
ADDITIONAL SOURCE SPECIFICATIONS 
OUTPUT RESISTANCE: >10
14
Ω. (2nA/20nA range) 
OUTPUT CAPACITANCE: <10pF, <100pF Filter ON. (2nA/20nA 
range) 
LOAD IMPEDANCE: Stable into 10μH typical, 100μH with Output 
Response SLOW. 
CURRENT REGULATION: Line: <0.01% of range. Load: 
<0.01% of range. 
VOLTAGE LIMIT (Compliance): Bipolar voltage limit set with 
single value. 0.1V to 105V in 0.01V programmable steps. 
Accuracy for 0.1V to 20V: 0.1% +20mV, accuracy for 20V to 
105V: 0.1% + 100mV 
MAX. OUTPUT POWER: 11W, four quadrant source or sink 
operation. 
GUARD OUTPUT: 
  Maximum Load Capacitance: 10nF. 
  Maximum Load Current: 1mA for rated accuracy. 
  Accuracy: ±1mV for output currents <2mA (excluding output lead 
voltage drop). 
PROGRAM MEMORY: (offers point-by-point control and 
triggering, e.g. Sweeps) 
  Number of Locations: 64K. 
EXTERNAL TRIGGER: TTL-compatible EXTERNAL TRIGGER 
INPUT and OUTPUT. 
  Max Trigger Rate: 1000/s. 
Source Notes 
1. Settling times are specified into a resistive load, with a maximum resistance 
equal to 2V / I
fullscale of range
. See manual for other load conditions. 
2. Settling times to 0.1% of final value are typically <2x of 1% settling times. 
3. Noise current into <100Ω. 
4. RMS Noise 10Hz-20MHz (2nA – 20mA Range) Less than 1mVrms, 5mVp-p 
(into 50Ω load). 
5. Typical values are non-warranted, apply at 23°C, represent the 50
th
 percentile, 
and are provided solely as useful information. 










