tc650 tc651 tc650/1-2 3/05/01 ?2001 microchip technology inc. ds21450a tiny integrated temperature sensor and brushless dc fan controller with over temperature alert features digital temperature sensing and multi-speed fan control built in over temperature alert (tover) temperature proportional fan speed control for acoustic noise reduction and longer fan life pulse width modulation output drive for cost and power savings solid state temperature sensing 1 o c (typical) accuracy from 25 o c to +70 o c 2.8 - 5.5v operating range tc651 includes auto fan shutdown low operating power: 50 a (typ) applications thermal protection for personal computers digital set-top boxes notebook computers data communications power supplies projectors related literature application note: 58 article: "an integrated fan speed control solu- tion can lower system costs, reduce acoustic noise and power consumption and enhance system reliability" pin configurations 8-pin msop 1 8 2 7 3 6 4 5 nc v dd pwm gnd tover nc gnd tc650 tc651 shdn typical application general description the tc650/651 are integrated temperature sensors and brushless dc fan speed controllers. the tc650/651 measure their junction temperature and control the speed of the fan based on that temperature, making them especially suited for applications in modern electronic equipment. temperature data is converted from the on-chip ther- mal sensing element and translated into a fractional fan speed from 40% to 100%. a temperature selection guide in the data sheet is used to choose the low and high tempera- ture limits to control the fan. the tc650/651 also include a single trip point over temperature alert (tover) that elimi- nates the need for additional temperature sensors. in addi- tion, the tc651 features an auto fan shutdown function for additional power savings. the tc650/651 are easy to use, and require no soft- ware overhead, and are therefore the ideal choice for implementing thermal management in a variety of systems. ordering information part operating number package temp. range tc650xxvua 8-pin msop ?40?c to +125?c tc651xxvua 8-pin msop ?40?c to +125?c notes: 1. the "x" denotes a suffix for temperature threshold settings. 2. contact factory for other temperature ranges. x (see page 5) temperature a25 b30 c35 d40 e45 f50 g55 1 8 2 7 3 6 4 5 nc v dd pwm gnd tover nc gnd gnd +5v v dd +12v tc650 tc651 shdn gnd ucontroller dc fan 500ma shdn control over temp alert
tiny integrated temperature sensor and brushless dc fan controller with over temperature alert tc650 tc651 2 tc650/1-2 03/05/01 ?2001 microchip technology inc. ds21450a storage temperature (unbiased) .......... ?5 o c to +150 o c lead temperature (soldering, 10sec duration) ............................. +300 o c * this is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operation section of this specification is not implied. exposure to absolute maximum ratings conditions for extended periods of time may affect reliability. absolute maximum ratings* input voltage (v dd to gnd) ....................................... +6v output voltage (out to gnd) ...................................... 6v voltage on any pin ............ (gnd ?0.3v) to (v dd + 0.3v) package thermal resistance ( ja ) ...................... 250 o c/w operating temperature range .............. ?0 o c to +125 o c electrical characteristics: v dd = 2.8v to 5.5v, shdn = v dd , t a = -40?c to 125?c unless otherwise specified. symbol parameter test conditions min typ max units v dd supply voltage 2.8 5.5 v i dd supply current pwm tover are open 50 90 a shdn input v ih shdn input high threshold 65 %v dd v il shdn input low threshold 15 %v dd pwm output v ol pwm output low voltage i sink = 1ma 0.3 v v oh pwm output high voltage i source = 5ma v dd ?0.5 v t r pwm rise time i oh = 5ma, 1nf from pwm to gnd 10 sec t f pwm fall time i ol = 1ma, 1nf from pwm to gnd 10 sec f out pwm frequency 10 15 hz t startup startup time v dd rises from gnd, or shdn released 32/f out sec temperature accuracy t h acc high temp accuracy note 1 t h ?3 t h t h + 3 c (t h ? l)acc temp range accuracy (t h ?t l) 20 c ?.0 +1.0 c (t h ?t l) > 20 c ?.5 +2.5 t hyst auto shutdown hysteresis tc651 only (t h ?t l )/5 c tover output v high tover output high voltage i source = 1.2ma v dd ?0.5 v v low tover output low voltage i sink = 2.5ma 0.4 v tover acc absolute accuracy at trip point t h + 10 c tover hyst trip point hysteresis 5 c notes: 1. transition from 90% to 100% duty cycle.
tc650 tc651 3 tc650/1-2 03/05/01 tiny integrated temperature sensor and brushless dc fan controller with over temperature alert ? 2001 microchip technology inc. ds21450a block diagram temp sensor duty cycle logic control ad converter oscillator temperature set point and trim range tover shdn pwm v dd v+ pin description pin no. symbol description 8-pin msop 1v dd power supply input. may be independent of fan power supply. 2 nc no connect. 3 shdn fan shutdown, active-low input. during shut down mode the chip still monitors temperature and tover is low if temperature rises above f actory setpoint. 4 gnd ground. ground return for all tc650/651 functions. 5 nc no connect. 6 tover over-temperature alert, active-low output. 7 gnd ground. 8 pwm pwm fan drive output. pulse width modulated rail-to-rail logic output. nominal frequency is 15hz.
tiny integrated temperature sensor and brushless dc fan controller with over temperature alert tc650 tc651 4 tc650/1-2 03/05/01 ?2001 microchip technology inc. ds21450a functional description the tc650/651 acquire, and convert, their junction temperature (tj) information from an on-chip solid state sensor with a typical accuracy of 1 o c (typical) . 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 1). the tc650/ 651 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 controling the speed of the fan, the tc650/651 include an on-chip over-tempera- ture alarm (tover) that gives a low-true signal when the temperature of the chip exceeds t h by 10 c. this feature eliminates the need for a separate temperature sensor for over-temperature monitoring. table 1: temperature range definition for tc650 (minimum-speed mode) temperature (t=tj) pwm duty cycle t |