Industrial Converter and Protector IC
AM460
R6 and R7:
R6 VCVREF
=
− 1 ≈ 2.6 − 1 = 1.6
R7
VBG
The following example values are produced for the resistors:
R7 = 10kΩ R6 = 16kΩ
OPERATING AM460: IMPORTANT POINTS TO NOTE
1. When using AM460 it is imperative that external capacitor C1 (a top-grade ceramic capacitor) is always
connected (cf. Figure 2). Care must be taken that the value of the capacitor, also within the temperature
range, does not exceed the range of values given in the boundary conditions on page 6. In 2-wire operation
ceramic capacitor C2 must also be used (cf. Figure 8)
2. In a 2-wire setup the power consumption of the entire system (AM460 plus all external components, in-
cluding the configuration resistors) must not exceed the sum of IOUTmin (usually 4mA).
3. All AM460 function blocks not required by the application must be connected to a defined (and allowed)
potential.
4. With operation of the voltage output the load resistance at pin VOUT must be at least 2kΩ.
5. When operating the current output a maximum load resistance of 600Ω is permitted.
6. The values of external resistors R0, R1, R2, R3, R4 and R5 must be selected within the permissible range given
in the boundary conditions on page 6.
APPLICATIONS
Typical 3-wire application with an input signal referenced to ground
Figure 7 shows a 3-wire application in which AM460 amplifies and converts a positive voltage signal refer-
enced to ground. The unused blocks (e.g. OP2) have been set to defined operating points. Alternatively, these
function groups can also be used here (e.g. to supply external components).
In this particular application, using Equations 1 and 2 output voltage VOUT is calculated as:
R
1
VOUT = GV VINP with GV = GGAIN GOP = 1+
⋅ 2.2
(14)
R2
For output current IOUT the following applies according to Equation 3:
GI
R1
R2
IOUT =VINP
⋅
+ ISET with GI = GGAIN =1+
and ISET = 0
8R0
analog microelectronics
April 2003
12/18
AME [ ANALOG MICROELECTRONICS ]
