4
dc2261af
DEMO MANUAL DC2261A
current sense gain
The gain of the LT6119 current sense amplifier is set by
the ratio of R
OUT
and R
IN
resistors. In the demo circuit
this means that the gain is set by the ratio of (R
OUT
)/R4,
where R
OUT
= (R7 + R10 + R11) || R8(OPT). The default
values are R7 = 2k, R10 = 6.65k, R11 = 1.33k, and R8 is not
installed. This provides a gain of 9.98k/100. By installing
the optional resistor, R8, the gain can be reduced. The gain
error is primarily set by the precision of the resistors used:
The provided resistors are a 1% tolerance which will
dominate the gain error. To reduce system gain error, the
resistors can be replaced with 0.1% resistors.
Jumper Summary
JP1: The Logic supply jumper has two settings.
- V
+
: the comparator output is tied to the V
+
supply
- EXT: the comparator output is tied to an external
supply on the VLOGIC Turret
Optional Settings
1. To power the LT6119 from a supply separate from the
load, remove R1 and connect the power supply to the
V
+
turret.
2. There are a number of optional components that allow
the DC2193 to be tailored to a specific application:
A) To free comparator inputs INC1 and INC2 for other
use, remove R7, R10 and R11 and install R8. Con-
nect LE turret as required.
B) To add filtering to the amplifier output, install C3.
C) If driving the LE turret from an external source,
pressing the reset button, SW1 will short the signal.
A resistor can be added at R13 to help isolate the
external signal.
