Datasheet

LTC2996
6
2996f
pin FuncTions
D
+
: Diode Sense Current Source. D
+
sources the remote
diode sensing current. Connect D
+
to the anode of the re-
mote sensor device. It is recommended to connect a 470pF
bypass capacitor between D
+
and D
–
. Larger capacitors
may cause settling time errors (see Typical Performance
Characteristics). If D
+
is tied to V
CC
, the LTC2996 measures
the internal sensor temperature. Tie D
+
to V
CC
if unused.
D
–
: Diode Sense Current Sink. Connect D
–
to the cathode
of the remote sensor device. Tie D
–
to GND for single
wire remote temperature measurement (see Applications
Information) or internal temperature sensing.
Exposed Pad: Exposed pad may be left open or soldered
to GND for better thermal coupling.
GND: Device Ground
UT: Undertemperature Logic Output. Open drain logic
output that pulls to GND when V
PTAT
is below the threshold
voltage on pin VTL. When V
PTAT
rises above the threshold
voltage on pin VTL, an additional hysteresis of 20mV is
required to release UT high. UT has a weak 400kΩ pull-
up to V
CC
and may be pulled above V
CC
using an external
pull-up. Leave UT open if unused.
OT: Overtemperature Logic Output. Open drain logic output
that pulls to GND when V
PTAT
is above the threshold voltage
on pin VTH. When V
PTAT
falls below the threshold voltage
on pin VTH, an additional hysteresis of 20mV is required
to release OT high. OT has a weak 400kΩ pull-up to V
CC
and may be pulled above V
CC
using an external pull-up.
Leave OT open if unused.
V
PTAT
: Proportional to Absolute Temperature Voltage Out-
put. The voltage on this pin is proportional to the sensor’s
absolute temperature. V
PTAT
can drive up to ±200μA of
load current and up to 1000pF of capacitive load. For larger
load capacitances insert 1kΩ between V
PTAT
and the load
to ensure stability. V
PTAT
is pulled low when the supply
voltage goes below the under voltage lockout threshold.
V
REF
: Voltage Reference Output. V
REF
provides a 1.8V
reference voltage. V
REF
can drive up to ±200μA of load
current and up to 1000pF of capacitive load. For larger
load capacitances, insert 1kΩ between V
REF
and the load
to ensure stability. Leave V
REF
open if unused.
VTL: Temperature Threshold Low. When V
PTAT
is below
the voltage on VTL, UT is pulled low. Tie VTL to GND if
unused.
VTH: Temperature Threshold High. When V
PTAT
is above
the voltage on VTH, OT is pulled low. Tie VTH to V
CC
if
unused.