TC623CEOA Microchip Technology, TC623CEOA Datasheet - Page 4

• Manufacturer Part Number: TC623CEOA
• Description: IC,TEMPERATURE SENSOR,SOP,8PIN,PLASTIC
• Manufacturer: Microchip Technology

Specifications of TC623CEOA

• Rohs Compliant: YES
• Sensing Temperature: -40°C ~ 85°C
• Output Type: Active High
• Voltage - Supply: 2.7 V ~ 4.5 V
• Accuracy: ±1°C
• Package / Case: 8-SOIC (0.154", 3.90mm Width)
• Temperature Threshold: Programmable
• Full Temp Accuracy: 3 C
• Supply Voltage (max): 4.5 V
• Supply Voltage (min): 2.7 V
• Description/function: 3 V, Dual Trip Point Temperature Sensor
• Maximum Operating Temperature: + 85 C
• Minimum Operating Temperature: - 40 C
• Supply Current: 250 uA
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

TC623
3.0
3.1
The TC623 has a positive temperature coefficient
(Silicon) temperature sensor and dual threshold detec-
tor. Temperature set point programming is accom-
plished with external resistors from the HIGH SET and
LOW SET inputs to V
LIMIT outputs remain inactive (low) as long as the
measured temperature is below set point values. As
temperature increases, the LOW LIMIT is driven high
when temperature equals the LOW LIMIT set point
(±3°C). If temperature continues to climb, the HIGH
LIMIT output is driven high when temperature equals
the HIGH LIMIT set point (±3°C).
Figure 3-1 shows the relationship between the sense
resistance values and trip point temperature.
FIGURE 3-1:
DS21441C-page 4
250
200
150
100
50
-55
DETAILED DESCRIPTION
TC623 Operation
-35
-15
5
TEMPERATURE (°C)
CC
TC623 SENSE
RESISTORS VS. TRIP
TEMPERATURE
. The HIGH LIMIT and LOW
25
45
65
85
105
125
The CONTROL output is driven high when the HIGH
LIMIT output goes high and is RESET low when the
LOW LIMIT output goes low. This output provides the
logic for simple ON/OFF fan control. Figure 3-2 shows
overall TC623 operation.
FIGURE 3-2:
To prevent output “chattering” when measured temper-
ature is at (or near) the trip point values, the LOW SET
and HIGH SET inputs each have a built-in hysteresis of
-2°C max. As a result, the HIGH LIMIT and LOW LIMIT
outputs remain active until the measured temperature
falls a maximum of 2°C below the programmed HIGH
SET and LOW SET thresholds as shown in Figure 3-3.
The programmed setting threshold of Figure 3-3 is user
programmed temperature trip points of either the LOW
SET or HIGH SET inputs. The LOW LIMIT or HIGH
LIMIT output is driven active when temperature equals
the set point value (to within 3°C). The output remains
active until the temperature falls an additional 2°C
below the set point due to hysteresis.
FIGURE 3-3:
High Limit or Low Limit Ouput
Control Output (Cool Option)
Programmed Setpoint
High Limit Output
Low Limit Output
-2°C Hysteresis
High Set Point
Low Set Point
TC623 TEMPERATURE
VS. OUTPUT
HIGH SET AND LOW SET
THRESHOLDS
© 2006 Microchip Technology Inc.
Temperature