Datasheet

®
REF200
7
100µA/200µA
45
3
In Out
Com
Mirror
S
Compliance to –V + 1.5V
+V
S
100µA100µA
S
–V
FIGURE 6. Improved Low-Voltage Compliance. FIGURE 7. 100µA Current Source—80V Compliance.
100µA
100µA
± ±
40kΩ
40kΩ
0.01µF
0.01µF
1N41481N4148
1N41481N4148
(e) Bidirectional 200µA
cascoded current source.
100µA
100µA
40kΩ
40kΩ
0.01µF
0.01µF
(d) Floating 200µA cascoded
current source.
100µA
L
o
a
d
–V
S
+V
S
(a) Compliance approximate
to Gnd. HV compliance
limited by FET breakdown.
100µA
L
o
a
d
+V
S
(b) Compliance to +V – 5V.
High
Low
100µA
–V
S
33kΩ
0.01µF
S
100µA
L
o
a
d
+V
S
(c)
–V
S
27kΩ
5.1V
1N4689
NOTES: (1) FET cascoded current sources offer improved output impedance and high frequency operation. Circuit in (b)
also provides improved PSRR.
(
2
)
For current sinks
(
Circuits
(
a
)
and
(
b
)
onl
y)
, invert circuits and use “N” channel JFETS.
FIGURE 8. FET Cascode Circuits.
101
100
99
0 1020304050607080
Applied Voltage (V)
Provides 2X Higher Compliance Voltage
SERIES-CONNECTED CURRENT SOURCES
CURRENT vs APPLIED VOLTAGE
Current (µA)
100µA
100µA
High
Low