TC642CUA MICROCHIP [Microchip Technology], TC642CUA Datasheet
TC642CUA
Related parts for TC642CUA
TC642CUA Summary of contents
Page 1
M PWM Fan Speed Controller with FanSense Features • Temperature Proportional Fan Speed for Acoustic Control and Longer Fan Life • Efficient PWM Fan Drive • 3.0V to 5.5V Supply Range: - Fan Voltage Independent of TC642 Supply Voltage - ...
Page 2
TC642 Functional Block Diagram MIN V SHDN GND DS21444C-page 2 + – – V OTF + OTF – SHDN + Control Logic PWM Timer Clock Generator Start-up Timer + – Missing Pulse ...
Page 3
ELECTRICAL CHARACTERISTICS Absolute Maximum Ratings* Supply Voltage ......................................................... 6V Input Voltage, Any Pin.... (GND – 0.3V Package Thermal Resistance: PDIP (R )............................................. 125°C/W JA SOIC (R ) ............................................ 155°C/W JA MSOP (R ) .......................................... 200°C/W JA Specified ...
Page 4
TC642 2.0 PIN DESCRIPTIONS The descriptions of the pins are listed in Table 2-1. TABLE 2-1: PIN FUNCTION TABLE Pin No. Symbol Description 1 V Analog Input Analog Output Analog Input MIN 4 GND ...
Page 5
DETAILED DESCRIPTION 3.1 PWM The PWM circuit consists of a ramp generator and threshold detector. The frequency of the PWM is deter- mined by the value of the capacitor connected to the C input. A frequency ...
Page 6
TC642 The second condition by which the TC642 detects a fault is when the PWM control voltage applied to V becomes greater than that needed to drive 100% duty cycle (see Section 1.0, “Electrical Characteristics”). This indicates that the fan ...
Page 7
SYSTEM BEHAVIOR The flowcharts describing the TC642’s behavioral algorithm are shown in Figure 4-1. They can be summarized as follows: 4.1 Power-Up (1) Assuming the device is not being held in shutdown mode (V > V )… MIN REL ...
Page 8
TC642 Power-Up Power-on Reset FAULT = 1 Yes Shutdown V < V MIN SHDN OUT No V MIN Yes Fire Start-up Timer (1 SEC) Fire Start-up Yes Fan Fault Timer YES Detected? (1 SEC) Yes Fan Pulse ...
Page 9
TYPICAL APPLICATIONS Designing with the TC642 involves the following: (1) The temp sensor network must be configured to deliver 1.25V to 2.65V on V for 0% to 100% of the IN temperature range to be regulated. (2) The minimum ...
Page 10
TC642 DIV 100 NTC Thermistor 100 k @ 25˚ 23 FIGURE 5-2: Temperature Sensing Circuit. Generally, the thermistor shown in Figure 5 non- linear device ...
Page 11
We can further specify R and R by the condition that 1 2 the divider voltage is equal to our desired V yields the following equation: EQUATION MIN ...
Page 12
TC642 Table 5-1 lists recommended values for R on the nominal operating current of the fan. Note that the current draw specified by the fan manufacturer may be a worst-case rating for near-stall conditions and may not be the fan’s ...
Page 13
Some applications require the fan to be powered from the negative 12V supply to keep motor noise out of the positive voltage power supplies shown in Figure 5-8, zener diode D offsets the -12V power sup- 1 ply ...
Page 14
TC642 TABLE 5-2: TRANSISTORS AND MOSFETS FOR Q Max. V Device Package MMBT2222A SOT-23 MPS2222A TO-92 MPS6602 TO-92 SI2302 SOT-23 MGSF1N02E SOT-23 SI4410 SO-8 SI2308 SOT-23 Note 1: A series gate resistor may be used in order to control the ...
Page 15
Power Supply Routing and Bypassing Noise present on the V and V inputs may cause IN MIN erroneous operation of the FAULT output result, these inputs should be bypassed with a 0.01 F capacitor mounted as close ...
Page 16
TC642 5.8 TC642 as a Microcontroller Peripheral In a system containing a microcontroller or other host intelligence, the TC642 can be effectively managed as a CPU peripheral. Routine fan control functions can be performed by the TC642 without processor intervention. ...
Page 17
PACKAGING INFORMATION 6.1 Package Marking Information 8-Lead PDIP (300 mil) XXXXXXXX NNN YYWW 8-Lead SOIC (150 mil) XXXXXXXX YYWW NNN 8-Lead MSOP XXXXXX YWWNNN Legend: XX...X Customer specific information* YY Year code (last 2 digits of calendar year) WW ...
Page 18
TC642 8-Lead Plastic Dual In-line (P) – 300 mil (PDIP Dimension Limits Number of Pins Pitch Top to Seating Plane Molded Package Thickness Base to Seating Plane Shoulder to Shoulder Width Molded Package Width Overall Length ...
Page 19
Plastic Small Outline (SN) – Narrow, 150 mil (SOIC 45× c Dimension Limits Number of Pins Pitch Overall Height Molded Package Thickness Standoff § Overall Width Molded Package Width Overall Length Chamfer Distance Foot ...
Page 20
TC642 8-Lead Plastic Micro Small Outline Package (MS) (MSOP (F) Dimension Limits Number of Pins Pitch Overall Height Molded Package Thickness Standoff § Overall Width Molded Package Width Overall Length Foot Length Footprint (Reference) ...
Page 21
Taping Form Component Taping Orientation for 8-Pin SOIC (Narrow) Devices PIN 1 Carrier Tape, Number of Components Per Reel and Reel Size Package Carrier Width (W) 8-Pin SOIC (N) Component Taping Orientation for 8-Pin MSOP Devices PIN 1 Carrier ...
Page 22
TC642 NOTES: DS21444C-page 22 2002 Microchip Technology Inc. ...
Page 23
ON-LINE SUPPORT Microchip provides on-line support on the Microchip World Wide Web site. The web site is used by Microchip as a means to make files and information easily available to customers. To view the site, the user must have ...
Page 24
TC642 READER RESPONSE It is our intention to provide you with the best documentation possible to ensure successful use of your Microchip prod- uct. If you wish to provide your comments on organization, clarity, subject matter, and ways in which ...
Page 25
PRODUCT IDENTIFICATION SYSTEM To order or obtain information, e.g., on pricing or delivery, refer to the factory or the listed sales office. PART NO. X /XX Device Temperature Package Range Device: TC642: PWM Fan Speed Controller w/ Fault Detection Temperature ...
Page 26
TC642 NOTES: DS21444C-page 26 2002 Microchip Technology Inc. ...
Page 27
Information contained in this publication regarding device applications and the like is intended through suggestion only and may be superseded by updates your responsibility to ensure that your application meets with your specifications. No representation or warranty is ...
Page 28
M W ORLDWIDE AMERICAS Corporate Office 2355 West Chandler Blvd. Chandler, AZ 85224-6199 Tel: 480-792-7200 Fax: 480-792-7277 Technical Support: 480-792-7627 Web Address: http://www.microchip.com Rocky Mountain 2355 West Chandler Blvd. Chandler, AZ 85224-6199 Tel: 480-792-7966 Fax: 480-792-4338 Atlanta 500 Sugar Mill ...