4mA
20mA
16mA
+VCC
8
750Ω(2)
12V, 200mW
3.5mA
0.5mA
B
QEXT 23.6V, 377mW
2N2222(1)
12
XTR101
QINT 18mW
Other Suitable Types
Package
Type
VPS
40V
9
E
TO-225
TO-220
TO-220
2N4922
TIP29B
TIP31B
210Ω
3.47V, 60mW
1.5mA
Quiescent
0.95V, 17mW
IOUT
52.6Ω
7
11
Short Circuit
Worst Case
RL
250Ω
10
1mA
1mA
2mA
18mA
20mA
NOTES: (1) An external transistor is used in the maufacturing test circuit for testing electrical specifications.
(2) This resistor is required for the 2N2222 with VPS > 24V to limit power dissipation.
FIGURE 2. Power Calculation of XTR101 with External Transistor.
1500
1250
1000
750
30
25
20
15
10
60
50
40
30
20
Span = ∆IO = 16mA
Without external transistor
VPS – 11.6V
20mA
RL max =
Ω
L = 600
R
Operating
Region
Ω
500
L = 1k
R
With external transistor
RL = 600Ω
250
0
5
0
10
0
RL = 1kΩ
RL = 100Ω
0
10
20
30
40
50
60
10
20
30
40
VCC (V)
Power Supply Voltage, VPS (V)
FIGURE 3. Thermal Feedback Due to Change in Output
Current.
FIGURE 4. Power Supply Operating Range.
4. The maximum input signal level (eINFS) is 1V with RS = ∞
6. Always choose RL (including line resistance) so that the
voltage between pins 7 and 8 (+VCC) remains within the
11.6V to 40V range as the output changes between the
4-20mA range (see Figure 4).
and proportionally less as RS decreases.
5. Always return the current references (pins 10 and 11) to
the output (pin 7) through an appropriate resistor. If the
references are not used for biasing or excitation, connect
them together to pin 7. Each reference must have between
0V and +(VCC – 4V) with respect to pin 7.
7. It is recommended that a reverse polarity protection diode
(D1 in Figure 1) be used. This will prevent damage to the
XTR101 caused by a momentary (e.g., transient) or long
term application of the wrong polarity of voltage between
pins 7 and 8.
®
7
XTR101
BB [ BURR-BROWN CORPORATION ]
