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UCC1926
UCC2926
UCC3926
SLUS266A - OCTOBER 1999
FEATURES
Integral Non-inductive Current Sense
Element with Internal Kelvin
Connections
20A Current Rating
Bi-directional, High Side or Low Side
Sensing
Internal Temperature Nulling Circuitry
for Current Sense Element and
Amplifier
Logic Compatible Current Direction
Status Output
Low Offset, Chopper Stabilized
Current Sense Amplifier
Uncommitted Amplifier with User
Programmable Gain
Overcurrent Indication with User
Programmable Threshold
DESCRIPTION
The UCC3926 Current Sensor IC contains a wideband, transimpedance
amplifier for converting the current through an internal, non-inductive
1.3m
shunt resistor into a proportional voltage. The sense element oper-
ates in both high-side (V
DD
referenced) and low-side (GND referenced) ap-
plications.
The UCC3926 can measure currents up to
±
20A. This transimpedance am-
plifier gain is precisely trimmed to 33.3m
to convert a 15A input into a
500mV output signal. It has a very low input offset voltage from chop-
per-stabilization. A cross-switching block rectifies the input signal by forcing
the differential output, AOP positive with respect to the other differential
output, AON. SIGN indicates the polarity of the current.
The UCC3926 programmable amplifier provides three functions. It converts
the differential transimpedance output signal into a single-ended signal. It
has a user-controlled gain stage that sets the maximum current level to the
desired voltage and it level shifts the zero current point to the desired level
as well. A comparator then compares the output of the instrumentation am-
plifier to a user-set reference voltage on OCREF, which provides an
overcurrent status bit OC.
The UCC3926 is available in the 16 pin SOIC package.
±
20A Integrated Current Sensor
BLOCK DIAGRAM
UDG-97139-1
application
INFO
available