TS1100 Current-Sense Amplifier Demo Board
Page 2 Silicon Laboratories, Inc. TS1100-EVB Rev. 1.0
400 West Cesar Chavez, Austin, TX 78701
+1 (512) 416-8500 ▪ www.silabs.com
The demo board includes an on-board 0.1µF
decoupling capacitor at the V
BATT
input pin and a
47nF capacitor at the V
OUT
output pin. Depending on
the load current desired, an external resistor or active
load is to be connected to the LOAD pin.
QUICK START PROCEDURE
Required Equipment
TS1100 demo board
A DC Power Supply, an HP Model HP6624A or
equivalent
Two digital voltmeters
Load resistor or an active load (value varies
depending on I
LOAD
desired)
Table 1. Demo board test points
Table 2. Demo board test set-up per gain setting
To evaluate the TS1100 current-sense amplifier
circuit, the following steps are to be performed:
1) Before connecting the DC power supply to the
demo board, turn on the power supply, set the
DC voltage to 6V, set its short circuit current limit
to 10% higher than the maximum load current in
the application, and then turn it off.
2) Connect the DC power supply positive terminal to
the pad labeled V
BATT
and its negative terminal to
the adjacent pad labeled GND.
3) Connect a digital voltmeter to the test points
labeled TP+ and TP- to measure V
SENSE
.
4) Connect the positive terminal of a second digital
voltmeter to the test point labeled V
OUT
and the
negative terminal to the adjacent test point
labeled GND.
5) Based on the selected gain option of the current
sense amplifier, select the load resistor or an
active load according to Table 2. Connect one
end of this resistor or active load to the pad
labeled LOAD and the other end to the adjacent
pad labeled GND.
6) Turn on the power supply and observe the output
voltage at V
OUT
. The expression for the TS1100’s
output voltage is given by:
V
OUT
= I
LOAD
x 50mΩ
x R
OUT
/R1
where the TS1100’s internal R
OUT
and R1 resistor
values are listed in Table 3.
Table 3. TS1100’s Internal Gain Setting Resistors
(typical values)
7) The TS1100’s actual output voltage V
OUT
will
depend on the TS1100’s actual offset voltage
V
OS
, its gain error GE, sense resistor (R
SENSE
)
tolerance of ±1%, and the load resistor
tolerance/active load accuracy.
