LM334H/NOPB National Semiconductor, LM334H/NOPB Datasheet - Page 8

• Manufacturer Part Number: LM334H/NOPB
• Description: IC CURRENT SOURCE ADJ TO46-3
• Manufacturer: National Semiconductor

Specifications of LM334H/NOPB

• Function: Current Source
• Accuracy: ±3%
• Voltage - Input: 1 ~ 40 V
• Current - Output: 10mA
• Operating Temperature: 0°C ~ 70°C
• Mounting Type: Through Hole
• Package / Case: TO-46-3
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Sensing Method: -
• Other names: *LM334H; *LM334H/NOPB; LM334H

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Application Hints
If the forward voltage drop of the diode was 0.65V instead of
the estimate of 0.6V (an error of 8%), the actual set current
will be
an error of less than 5%.
If the estimate for the tempco of the diode’s forward voltage
drop was off, the tempco cancellation is still reasonably
effective. Assume the tempco of the diode is 2.6mV/˚C in-
stead of 2.5mV/˚C (an error of 4%). The tempco of the circuit
is now:
A 1mA LM134 current source with no temperature compen-
sation would have a set resistor of 68Ω and a resulting
tempco of
So even if the diode’s tempco varies as much as
its estimated value, the circuit still eliminates 98% of the
LM134’s inherent tempco.
Typical Applications
*Select R3 = V
Trim R3 to calibrate
Ground Referred Fahrenheit Thermometer
REF
/583µA. V
REF
may be any stable positive voltage ≥ 2V
(Continued)
±
4% from
00569715
8
*Output impedance of the LM134 at the “R” pin is approximately
where R
to ground. This negative resistance can be reduced by a factor of 5 or
more by inserting an equivalent resistor R
output.
Terminating Remote Sensor for Voltage Output
2
is the equivalent external resistance connected from the V
Low Output Impedance Thermometer
Low Output Impedance Thermometer
3
= (R
2
00569714
/16) in series with the
00569706
00569716
−
pin