TK65010
DESIGN CONSIDERATIONS (CONT.)
The resistor divider consisting of R1/R2 can be scaled
downward by a factor scale factor (K) to utilize smaller
resistor values K x R1 and K x R2 (K < 1). By adding an
additional series resistor, which can be dependent upon
the scale factor (K) and the resistor values comprising the
divider, the VMON pin will effectively see the same voltage
source and drive impedance as illustrated in Figure 4. The
three-resistor attenuator is illustrated below in Figure 5.
VIN
K x R1
K x R2
R1 x R2
(1- K) x R1 + R2
VMON
R1 x R2
R1 + R2
+
VIN x R2
R1 + R2
VMON
FIGURE 5
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January 1999 TOKO, Inc.