TMP01FSZ Analog Devices Inc, TMP01FSZ Datasheet - Page 11

• Manufacturer Part Number: TMP01FSZ
• Description: IC SENSOR TEMP/CONTROLLER 8SOIC
• Manufacturer: Analog Devices Inc

Specifications of TMP01FSZ

• Sensing Temperature: -55°C ~ 125°C
• Output Type: Open Collector
• Voltage - Supply: 4.5 V ~ 13.2 V
• Accuracy: ±1°C
• Package / Case: 8-SOIC (0.154", 3.90mm Width)
• Ic Output Type: Voltage
• Sensing Accuracy Range: ± 3°C
• Supply Current: 500µA
• Supply Voltage Range: 4.5V To 13.2V
• Sensor Case Style: SOIC
• No. Of Pins: 8
• Termination Type: SMD
• Temperature Sensor Function: Temp Sensor
• Package Type: SOIC N
• Operating Temperature (min): -55
• Operating Temperature (max): 150C
• Operating Temperature Classification: Military
• Filter Terminals: SMD
• Rohs Compliant: Yes
• Temperature Sensing Range: -40°C To +85°C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

SWITCHING LOADS WITH THE OPEN-COLLECTOR
OUTPUTS
In many temperature sensing and control applications, some
type of switching is required. Whether it be to turn on a heater
when the temperature goes below a minimum value or to turn
off a motor that is overheating, the open-collector outputs
OVER and UNDER can be used. For the majority of
applications, the switches used need to handle large currents on
the order of 1 A and above. Because the TMP01 is accurately
measuring temperature, the open-collector outputs should
handle less than 20 mA of current to minimize self-heating.
The OVER and UNDER outputs should not drive the equip-
ment directly. Instead, an external switching device is required
to handle the large currents. Some examples of these are relays,
power MOSFETs, thyristors, IGBTs, and Darlingtons.
Figure 17 through Figure 21 show a variety of circuits where the
TMP01 controls a switch. The main consideration in these
circuits, such as the relay in Figure 17, is the current required to
activate the switch.
R1
R2
R3
It is important to check the particular relay to ensure that the
current needed to activate the coil does not exceed the TMP01’s
recommended output current of 20 mA. This is easily deter-
mined by dividing the relay coil voltage by the specified coil
resistance. Keep in mind that the inductance of the relay creates
large voltage spikes that can damage the TMP01 output unless
protected by a commutation diode across the coil, as shown.
The relay shown has a contact rating of 10 W maximum. If
a relay capable of handling more power is desired, the larger
contacts probably require a commensurately larger coil, with
lower coil resistance and thus higher trigger current. As the
contact power handling capability increases, so does the current
needed for the coil. In some cases, an external driving transistor
should be used to remove the current load on the TMP01.
Power FETs are popular for handling a variety of high current
dc loads. Figure 18 shows the TMP01 driving a p-channel
MOSFET transistor for a simple heater circuit. When the out-
put transistor turns on, the gate of the MOSFET is pulled down
to approximately 0.6 V, turning it on. For most MOSFETs, a
gate-to-source voltage, or Vgs, on the order of −2 V to −5 V
is sufficient to turn the device on.
1
2
3
4
VREF
HYSTERESIS
GENERATOR
TEMPERATURE
COMPARATOR
SENSOR AND
REFERENCE
VOLTAGE
WINDOW
Figure 17. Reed Relay Drive
TMP01
VPTAT
8
7
6
5
OR EQUIV.
IN4001
12V
2604-12-311
COTO
MOTOR
SHUTDOWN
Rev. E | Page 11 of 20
Figure 19 shows a similar circuit for turning on an n-channel
MOSFET, except that now the gate to source voltage is positive.
For this reason, an external transistor must be used as an
inverter so that the MOSFET turns on when the UNDER
output pulls down.
R1
R2
R3
Isolated gate bipolar transistors (IGBT) combine many of the
benefits of power MOSFETs with bipolar transistors, and are
used for a variety of high power applications. Because IGBTs
have a gate similar to MOSFETs, turning on and off the devices
is relatively simple as shown in Figure 20.
The turn-on voltage for the IGBT shown (IRGBC40S) is
between 3.0 V and 5.5 V. This part has a continuous collector
current rating of 50 A and a maximum collector-to-emitter
voltage of 600 V, enabling it to work in very demanding
applications.
R1
R2
R3
R1
R2
R3
1
2
3
4
1
2
3
4
1
2
3
4
VREF
VREF
VREF
HYSTERESIS
GENERATOR
HYSTERESIS
GENERATOR
HYSTERESIS
GENERATOR
NC = NO CONNECT
NC = NO CONNECT
NC = NO CONNECT
TEMPERATURE
COMPARATOR
TEMPERATURE
COMPARATOR
TEMPERATURE
COMPARATOR
SENSOR AND
SENSOR AND
REFERENCE
SENSOR AND
REFERENCE
REFERENCE
VOLTAGE
VOLTAGE
WINDOW
WINDOW
VOLTAGE
Figure 19. Driving an N-Channel MOSFET
WINDOW
Figure 18. Driving a P-Channel MOSFET
Figure 20. Driving an IGBT
TMP01
TMP01
TMP01
VPTAT
VPTAT
VPTAT
8
7
6
5
8
7
6
5
8
7
6
5
V+
NC
NC
V+
NC
NC
V+
NC
NC
4.7kΩ
4.7kΩ
2.4kΩ (12V)
1.2kΩ (6V)
5%
2N1711
2N1711
4.7kΩ
4.7kΩ
IRFR9024
OR EQUIV.
HEATING
ELEMENT
TMP01
IRF130
MOTOR
CONTROL
IRGBC40S
HEATING
ELEMENT
+