Rainbow Electronics LM61 - Manual

LM61
2.7V, SOT-23 or TO-92 Temperature Sensor
General Description
The LM61 is a precision integrated-circuit temperature sen-
sor that can sense a −30˚C to +100˚C temperature range
while operating from a single +2.7V supply. The LM61’s
output voltage is linearly proportional to Celsius (Centigrade)
temperature (+10 mV/˚C) and has a DC offset of +600 mV.
The offset allows reading negative temperatures without the
need for a negative supply. The nominal output voltage of the
LM61 ranges from +300 mV to +1600 mV for a −30˚C to
+100˚C temperature range. The LM61 is calibrated to pro-
vide accuracies of
± 2.0˚C at room temperature and ± 3˚C
over the full −25˚C to +85˚C temperature range.
The LM61’s linear output, +600 mV offset, and factory cali-
bration simplify external circuitry required in a single supply
environment where reading negative temperatures is re-
quired. Because the LM61’s quiescent current is less than
125 µA, self-heating is limited to a very low 0.2˚C in still air.
Shutdown capability for the LM61 is intrinsic because its
inherent low power consumption allows it to be powered
directly from the output of many logic gates.
Features
n Calibrated linear scale factor of +10 mV/˚C
n Rated for full −30˚ to +100˚C range
n Suitable for remote applications
n UL Recognized Component
Applications
n Cellular Phones
n Computers
n Power Supply Modules
n Battery Management
n FAX Machines
n Printers
n HVAC
n Disk Drives
n Appliances
Key Specifications
j Accuracy at 25˚C ± 2.0 or ± 3.0˚C
(max)
j Accuracy for −30˚C to +100˚C ± 4.0˚C (max)
j Accuracy for −25˚C to +85˚C ± 3.0˚C (max)
j Temperature Slope +10 mV/˚C
j Power Supply Voltage Range +2.7V to +10V
j Current Drain @ 25˚C 125 µA (max)
j Nonlinearity ± 0.8˚C (max)
j Output Impedance 800 Ω (max)
Typical Application
01289702
V
O
= (+10 mV/˚C x T ˚C) + 600 mV
Temperature (T) Typical V
O
+100˚C +1600 mV
+85˚C +1450 mV
+25˚C +850 mV
0˚C +600 mV
−25˚C +350 mV
−30˚C +300 mV
FIGURE 1. Full-Range Centigrade Temperature Sensor (−30˚C to +100˚C)
Operating from a Single Li-Ion Battery Cell
February 2004
LM61
2.7V
,
SOT
-23
or
T
O-92
T
emperature
Sensor
© 2004 National Semiconductor Corporation DS012897 www.national.com