ZXCT1107W5-7 Diodes Inc. / Zetex, ZXCT1107W5-7 Datasheet - Page 12

• Manufacturer Part Number: ZXCT1107W5-7
• Description: Current & Power Monitors & Regulators LOW PWR HIGH-SIDE 24V 3uA MONITOR
• Manufacturer: Diodes Inc. / Zetex

Specifications of ZXCT1107W5-7

• Product Category: Current & Power Monitors & Regulators
• Rohs: yes
• Product: Current Monitors
• Supply Voltage - Max: 36 V
• Supply Voltage - Min: 2.5 V
• Input Voltage Range: 2.5 V to 36 V

Application Information
Note that in order to avoid additional error, V
value of V
R
I
R
Design Example
A current monitor is required to provide an output voltage of 2V ±6% when the load current of a 12V supply is 2A. Resistors
are available with 1% tolerance.
The sense and output resistors will contribute a total possible error of 2%, so the ZXCT11xx error must not exceed 4%. From
Table 1, the error of ZXCT1107/1109 will be 3.4% if the sense voltage is 100mV. This satisfies the total error requirement of
6%.
Equation 4 gives
Equation 5 gives
A suitable preferred value is 5.1kΩ. This gives a systematic error of +2%, which can be compensated elsewhere in the
system if desired. Figure 2 shows the resulting schematic.
ZXCT1107/1109/1110
Document number: DS35033 Rev. 3 - 2
LOADT
SENSE
GAIN
.
is chosen to give the required threshold output voltage, V
is chosen based on the threshold V
or
SENSE
. For V
R
I
R
R
R
R
OUTT
SENSE
SENSE
GAIN
GAIN
GAIN
SENSE
= 0.004 * V
=
=
=
=
= 100mV/2A = 50mΩ
V
V
. 0
. 0
I
I
OUTT
LOADT
SENSET
OUTT
004
004
= 100mV, this margin can be reduced to 1.0V.
Figure 2. Example Circuit using ZXCT1107/ZXCT1109
V
2
OUTT
*
*
(cont.)
SENSET
V
0
ZXCT1107
ZXCT1109
SENSET
1 .
= 5kΩ
V
or
GND
SUPPLY
SENSET
SUPPLY
of sense voltage selected as above, for the chosen threshold load current,
S+
must be at least 1.5V greater than V
OUT
www.diodes.com
50mΩ
LOW POWER HIGH-SIDE CURRENT MONITORS
12 of 16
5k1
S-
OUTT
I
LOAD
. From Equation 1, the threshold output current is
OUTPUT
V
OUT
Diodes Incorporated
LOAD
A Product Line of
ZXCT1107/1109/1110
OUT
. This margin depends on the
Equation 4
Equation 1a
Equation 5
© Diodes Incorporated
JULY 2011