Diodes ZXCT1021 - Manual (Page 6)

ZXCT1021
Issue 9 - July 2007 6 www.zetex.com
© Zetex Semiconductors plc 2007
Application information
The ZXCT1021 has a fixed dc voltage gain of 100. No external scaling resistors are required for
the output. Output voltage is simply defined as:
V
OUT
= 10 x V
SENSE
(V)
Where V
SENSE
= V
IN
- V
LOAD
PCB trace shunt resistor for low cost solution
Figure 1 shows a PCB layout suggestion for a low cost solution where a PCB resistive trace in
replacement for a conventional shunt resistor, can be used. The resistor section is 25mm x
0.25mm giving approximately 150m
⍀ using 1 oz copper. Smaller resistances can be used if
required.
Total circuit solution: 1 component. Shows area of 150m
⍀
sense resistor compared to SOT23 package.
Practical tolerance of the PCB resistor will be around 5%
depending on manufacturing methods.
V
IN
V
OUT
GND
Figure 1 PCB layout suggestion
Load
ZXCT1021/2