LM363 Datasheet, PDF (15/22 Pages) National Semiconductor (TI) – LM363 Precision Instrumentation Amplifier

Typical Applications
4 mA-20 mA Two Wire Current Transmitter
The LM329 reference provides excellent line regulation and gain stability When bridge is balanced
(I_OUTe4 mA) there’s no drop across R3 and R4 so that gain and offset adjustments are non-in-
teractive The LM334 configured as a zero-TC current source supplies quiescent current to circuit
R11 provides current limiting
Design Equations
 J^R2
I_OSe(I_R6aI_R7)
1a
R1
e4 mA
Gain e ^DIOUT
j
A_VXR2aR3
a
R4 10
j
mA
DV_IN R1 R3aR4
mV
when A_V e LM363 voltage gain
0 68V 68 mV
Pick I₃₃₄ e
a
j3 8 mA
R9 R10
I_MAX
eI₃₃₄
a
V_Zb2 4V
R11
e
26
mA
I_BRIDGE(MAX) j I₃₃₄-I₃₆₃-I_Z j 1 5mA
Precision Current Source (Low Output Current)
TL H 5609 – 20
R1 e R2
l l ^IOUT
e
V_IN
GR1
V_IN s 10V
TL H 5609 – 21
Precision Voltage to Current Converter (Low Input Voltage)
R1 e R2
Req e R1_ll50 kX
I_OUT
e
G V_IN
Req
e
G
1
V_IN
kX
TL H 5609 – 22
15