TC670ECHTR Microchip Technology Inc., TC670ECHTR Datasheet

Page 1

... THRESHOLD 1 GND 2 CLEAR 3  2003 Microchip Technology Inc. General Description The TC670 is an integrated fan speed sensor that predicts and/or detects fan failure, preventing thermal damage to systems with cooling fans. When the fan speed falls below a user-specified level, the TC670 asserts an ALERT signal. With this design, a critical minimum fan speed is determined by the user ...

Page 2

... Section 2.0, “Typical DD PIN FUNCTION TABLE Description Analog Input Ground Terminal Digital Input Bias Supply Input Digital (Open-Drain) Output Analog Input = 3.0V to 5.5V, DD Units Conditions V µ kΩ MΩ 3. 2.5 mA SINK ms °C °C °C/W varies from DD  2003 Microchip Technology Inc. ...

Page 3

... THRESHOLD Voltage (V) FIGURE 2-3: Fan Speed vs. Threshold Voltage.  2003 Microchip Technology Inc. = 3.0V to 5.5V, CLEAR = Low. DD 160 +90°C 140 120 100 +25° -45° 0.5 5.1 5.4 5.7 6 ...

Page 4

... TC670 Note: Unless otherwise indicated, all limits are specified at +25°C, V FIGURE 2-7: CLEAR pin high to ALERT pin high Timing Diagram. DS21688C-page 4 = 3.0V to 5.5V, CLEAR = Low. DD  2003 Microchip Technology Inc. ...

Page 5

... Care should be taken to keep this pin away from switching signals, such as the fan excitation signals in order to avoid false signals on the SENSE pin.  2003 Microchip Technology Inc. TC670 3.3 Digital Input (CLEAR) The CLEAR input is used to reset or blank the ALERT output ...

Page 6

... ALERT LED 0.1 µF 4 +12V CLEAR 3 5 ALERT FAN FAN 1 THRESHOLD C SENSE 6 SENSE SENSE GND 2 Typical Application Circuit. ) through a SENSE ). The low value current sensing ) is connected between the ground is termi- SENSE  2003 Microchip Technology Inc. ...

Page 7

... A second technique is to identify the fan’s minimum speed and calibrate the threshold voltage accordingly.  2003 Microchip Technology Inc. 4.2.1 THRESHOLD CALIBRATION USING FAN’S FULL SCALE SPEED The fan should first be run at full speed. At full speed, the threshold voltage level should be adjusted until the ALERT output is asserted ...

Page 8

... Component Taping Orientation for 6-Pin SOT-23A (EIAJ SC-74) Devices Device Marking PIN 1 Carrier Tape, Number of Components Per Reel and Reel Size: Package Carrier Width (W) 6-Pin SOT-23A 8 mm DS21688C-page 8 Code DA User Direction of Feed P Pitch (P) Part Per Full Reel Reel Size 3000 7 in.  2003 Microchip Technology Inc. ...

Page 9

... Mold Draft Angle Top Mold Draft Angle Bottom *Controlling Parameter Notes: Dimensions D and E1 do not include mold flash or protrusions. Mold flash or protrusions shall not exceed .005" (0.127mm) per side. JEITA (formerly EIAJ) equivalent: SC-74A Drawing No. C04-120  2003 Microchip Technology Inc φ ...

Page 10

... TC670 NOTES: DS21688C-page 10  2003 Microchip Technology Inc. ...

Page 11

... Please specify which device, revision of silicon and Data Sheet (include Literature #) you are using. Customer Notification System Register on our web site (www.microchip.com/cn) to receive the most current information on our products.  2003 Microchip Technology Inc. TC670 Examples: a) TC670ECHTR: Predictive Fan Failure Detector, SOT-23 package. DS21688C-page11 ...

Page 12

... TC670 NOTES: DS21688C-page 12  2003 Microchip Technology Inc. ...

Page 13

... Microchip. No licenses are conveyed, implicitly or otherwise, under any intellectual property rights.  2003 Microchip Technology Inc. Trademarks The Microchip name and logo, the Microchip logo, K MPLAB, PIC, PICmicro, PICSTART, PRO MATE and PowerSmart are registered trademarks of Microchip Technology Incorporated in the U ...

Page 14

... Italy Microchip Technology SRL Via Quasimodo, 12 20025 Legnano (MI) Milan, Italy Tel: 39-0331-742611 Fax: 39-0331-466781 United Kingdom Microchip Ltd. 505 Eskdale Road Winnersh Triangle Wokingham Berkshire, England RG41 5TU Tel: 44 118 921 5869 Fax: 44-118 921-5820 02/12/03  2003 Microchip Technology Inc. ...