TC652AEVUA Microchip Technology, TC652AEVUA Datasheet - Page 5

• Manufacturer Part Number: TC652AEVUA
• Description: IC TEMP SNSR/DC FAN CTRLR 8-MSOP
• Manufacturer: Microchip Technology
• Series: FanSense™r
• Type: Temperature Sensorr

Specifications of TC652AEVUA

• Function: Fan Control, Temp Monitor
• Topology: ADC, Comparator, Oscillator, Register Bank
• Sensor Type: Internal
• Sensing Temperature: 25°C, 45°C Trip Points
• Output Type: Active Low
• Output Alarm: Yes
• Output Fan: Yes
• Voltage - Supply: 2.8 V ~ 5.5 V
• Operating Temperature: -40°C ~ 125°C
• Mounting Type: Surface Mount
• Package / Case: 8-MSOP, Micro8™, 8-uMAX, 8-uSOP,
• Ic Output Type: Voltage
• Sensing Accuracy Range: ± 1°C
• Supply Current: 50µA
• Supply Voltage Range: 2.8V To 5.5V
• Sensor Case Style: MSOP
• No. Of Pins: 8
• Termination Type: SMD
• Operating Supply Voltage: 5.5 V
• Mounting Style: SMD/SMT
• Filter Terminals: SMD
• Rohs Compliant: Yes
• Temperature Sensing Range: -40°C To +125°C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant, Lead free / RoHS Compliant

3.0
The TC652/TC653 acquire and convert their junction
temperature (T
state sensor with a typical accuracy of ±1°C. The
temperature data is digitally stored in an internal
register. The register is compared with pre-defined
threshold values. The six threshold values are equally
distributed over a pre-defined range of temperatures
(See Table 3-1 and Table 3-2). The TC652/TC653
control the speed of a DC brushless fan using a
fractional speed control scheme. The output stage
requires only a 2N2222-type small-signal BJT for fans
up to 300mA. For larger current fans (up to 1 Amp) a
logic-level N-channel MOSFET may be used. In
addition to controlling the speed of the fan, the TC652/
TC653 include an on-chip over-temperature alarm
(T
temperature of the chip exceeds T
feature eliminates the need for a separate temperature
sensor for over-temperature monitoring.
In normal fan operation, a pulse-train is present at
SENSE, Pin 5. A Missing Pulse Detector monitors this
pin during fan operation (FanSense
stalled, open, or unconnected fan causes the TC652/
TC653 to trigger its Start-up Timer once. If the FAULT
persists, the FAULT output goes low, and the device is
latched in its Shutdown mode. To release the fan from
shutdown, toggle the SHDN or V
TABLE 3-1:
©
T
OVER
Temperature
T
2002 Microchip Technology Inc.
T
T
T
T
H
4
1
3
L
2
T
< = T < T
< = T < T
< = T < T
< = T < T
< = T < T
(T = T
OV
< = T <T
T < T
) that gives a low-true signal when the
< = T
DETAILED DESCRIPTION
L
J
)
OV
3
1
H
2
4
J
) information from an on-chip solid
TEMPERATURE RANGE
DEFINITION FOR TC652
(MINIMUM-SPEED MODE)
100% with Over-Temp Alert
(T
OVER
= L)
PWM Duty Cycle
DD
100%
40%
50%
60%
70%
80%
90%
pin.
™
H
by 10°C. This
technology). A
TABLE 3-2:
FIGURE 3-1:
3.1
The PWM pin is designed to drive a low cost transistor
or MOSFET as the low side power switching element in
the
complementary drive and is optimized for driving NPN
transistors or N-channel MOSFETs. Since the system
relies on PWM rather than linear power control, the
dissipation in the power switch is kept to a minimum.
Generally, very small devices (TO-92 or SOT
packages) will suffice. The frequency of the PWM is
about 15Hz. The PWM is also the time base for the
Start-up Timer (see paragraphs below). The PWM duty
cycle has a range of 40% to 100% for the TC652 and
50% to 100% for the TC653.
T
Note: The temperature regions defined by the six tempera-
ture thresholds are pre-defined in the TC650/651 by means
of trimming. Once a T
thresholds are automatically equally spaced between T
T
Temperature
T
V
T
T
T
T
H
H
DD
1
4
T
.
L
2
3
< = T < T
< = T < T
< = T < T
< = T < T
OV
(T = T
< =T < T
< =T < T
T < T
system.
< = T
Set Point and
AD Converter
Temp Sensor
Temperature
PWM Output
Trim Range
Fan Detect
L
J
)
Logic
OV
1
3
4
H
2
This
100% with Over-Temp Alert
(T
DEFINITION FOR TC653
(AUTO-SHUTDOWN MODE)
TEMPERATURE RANGE
T
OVER
TC652/TC653
OVER
L
and T
FUNCTIONAL BLOCK
DIAGRAM
output
Duty Cycle
CMPTR
= L)
Control
Logic
Oscillator
PWM Duty Cycle
H
90mV
SHDN
are programmed, the T
+
-
-
has
“OFF”
100%
50%
60%
70%
80%
90%
20k
DS21453B-page 5
an
PWM
asymmetric
FAULT
V+
-
1
L
and
- T
4