new release specification ? andigilog, inc. 2004 www.andigilog.com july 2005 - 70a04006 s i mistor? t emperature s ensor u ltra -l ow -p ower s ilicon t hermistor ASM121 p roduct s pecification general description the ASM121 is a high-precision, 3-lead cmos silicon thermistor in an ultra-small leadless package that provides a cost-effective solution for applications requiring high- accuracy low-power temperature monitoring. the ASM121 functions in a way that is similar to a ptc thermistor. however, it is linear-calibrated, enabling application developers to directly interpret output voltage as temperature without complex compensation for non- linearity. the ASM121 output voltage ramp has a positive slope of 10mv/c that is independent of supply voltage. the ASM121 has a guaranteed room temperature (25c) accuracy of 1c. the ASM121 does not require external calibration - each device is calibrated at the factory. features ? precision calibrated to 1c at 25c ? temperature range: -30c to 125c ? extremely linear output ramp: 10mv/c ? 0 c output: 0.50v ? output ramp is calibrated to degrees celsius ? low operating current: 14 a ? operating voltage range: +2.7 v to +3.6v ? non-linearity: 0.8 c ? 1.2mm x 1.5mm qfn package applications ? mobile phones ? mobile communications terminals ? computers ? battery management ? fax machines/printers/copiers ? portable medical instruments ? hvac, power supply modules ? disk drives ? automotive control circuits pin configuration gnd v out 1 ASM121 v dd qfn-3 2 3 gnd v out 1 ASM121 v dd qfn-3 2 3 top view, contacts underneath, actual part marking below accuracy vs temperature temperature (c) accuracy (c) -3 -2 -1 0 1 2 3 upper spec limits 0 80 100 lower spec limits - - - 25 120 125 604020 -20-40 4 -4 temperature (c) accuracy (c) -3 -2 -1 0 1 2 3 upper spec limits 0 80 100 lower spec limits - - - 25 120 125 604020 -20-40 4 -4 ordering information part number package temperature range part marking how supplied ASM121q3 3-lead qfn -30 ?c to +125 ? c jm 3000 units on t&r m ? month / year code
ASM121 - 2 - ? andigilog, inc. 2004 www.andigilog.com july 2005 - 70a04006 absolute maximum ratings 1 notes: 1. absolute maximum ratings are limits beyond which operation may cause permanent damage to the device. these are stress ratings only; functional operations at or above these limits is not implied. 2. human body model: 100pf capacitor discharged through a 1.5k resistor into each pin. machine model: 200pf capacitor discharged directly into each pin. 3. these specifications ar e guaranteed only for the test conditions listed. recommended operating ratings symbol parameter min max units v dd supply voltage +2.7 +3.6 v v out output voltage 0 1.8 v t a operating temperatur e range -30 +125 c electrical characteristics 3 limits apply for - 40c t a +125c and v dd = + 3 .0v unless otherwise noted. parameter symbol conditions min typ max units accuracy 4 t a =+25c t a =-30c (t min ) t a =+125c (t max ) -1 -4 -3 0.5 1 1 +1 +4 +3 c c c non-linearity 5 0.8 c supply current - output floating i dd t a =+25c - 30c t a +125c 14 15 a output sink capability 6 i ol +2.7v < v dd < +3.6v ? 25 a output source capability 6 i oh +2.7v < v dd < +3.6v 200 a average output slope (sensor gain) a out 10 mv/c zero-degree output voltage v out0 t a =+0c 500 mv room temp output voltage v out25 t a =+25c 750 mv self heating 7 qfn-3 0.025 c notes: 4. accuracy (expressed in c) = difference between calculated output voltage and measured output voltage. calculated output voltage = 10mv/c multiplied by device?s case temperature at specifie d conditions of temperature, voltage and power supply with an offset of 500mv (see fig. 1). 5. non-linearity is defined as the dev iation of the output-voltage-versus-temperature curve from the best-fit straight line, over the device?s rated temperature range. 6. lowest output current should be targeted; higher currents result in more self-heating of the device. 7. max self heating = ja x (v dd x i dd ). assumes a capacitive load. parameter rating supply voltage +7v output voltage v dd + 0.5v continuous current, any terminal 10ma storage temperature range -60 c to +150 c human body model 4000v esd 2 machine model 400v thermal resistance - ja qfn-3 tbd lead temp 260c
ASM121 - 3 - ? andigilog, inc. 2004 www.andigilog.com july 2005 - 70a04006 25 figure 1. ASM121 output voltage vs. temperature mounting the ASM121 package provides good thermal conductivity to the surface to which it is soldered. it?s low mass allows it to respond quickly to changes in board temperature. in this case, its temperature will be within about 0.02c of the te mperature of the surface it is attached to if the ambient air temperature is almost the same as the surface temperature. if the air temperature is much higher or lower than the surface temperature, the actual te mperature of the ASM121 die will be at an intermediate temperature between the surface temperature and the air temperature. to ensure good thermal conductivity, the backside of the ASM121 die is directly attached to the gnd pin. the lands and traces to the ASM121 will, of course, be part of the printed circuit board, which is the object whose temperature is being measured. these printed circuit board lands and traces will not cause the ASM121?s temperature to deviate from the desired temperature. alternatively, the ASM121 can be mounted inside a sealed-end metal tube, and can then be dipped into a bath or screwed into a threaded hole in a tank. as with any ic, the ASM121 and accompanying wiring and circuits must be kept insulated and dry to avoid leakage and corrosion. this is especially true if the circuit may operate at cold temperatures where condensation can occur. printed-circuit coatings and varnishes such as humiseal and epoxy paint or dips can be used to ensure that moisture cannot corrode the ASM121 or its connections. 50 75 100 125 -30 0 1750 200 750 500 v out (mv) temperature (oc) 1500 temp (oc) = (v out ? 500mv) / 10mv/oc) 900 1350 300 25 75 100 125 -30 50 0 1750 200 750 500 v out (mv) temperature (oc) 1500 temp (oc) = (v out ? 500mv) / 10mv/oc) 900 1350 300
ASM121 - 4 - ? andigilog, inc. 2004 www.andigilog.com july 2005 - 70a04006 typical performance characteristics figure 2. ASM121 current vs temperature typical applications figure 3. serial output temperature to digital converter (full scale = +125 ?c) in 10k 100k fb 1.75v ref 3.9k serial data out clock enable ASM121 3.3v v temp u1 u2 u3 serial analog-to-digital converter adjustable shunt voltage reference + -50 -25 0 25 0 75 100 125 temperature (c) 5 -50 -25 0 25 0 75 100 125 temperature (c) 5 i dd (a) -25 0 25 75 100 125 50 -25 0 25 75 100 125 temperature (c) v dd =+3v v dd =+3v v dd =+3v 7 8 9 10 11 12 13 14 15 16 7 8 9 10 11 12 13 14 15 16 7 8 9 10 11 12 -50-50 13 14 15 16 50 -50 -25 0 25 0 75 100 125 5 -50 -25 0 25 0 75 100 125 temperature (c) 5 -50 -25 0 25 0 75 100 125 5 -50 -25 0 25 0 75 100 125 temperature (c) 5 i dd (a) -25 0 25 75 100 125 50 -25 0 25 75 100 125 temperature (c) v dd =+3v v dd =+3v v dd =+3v v dd =+3v v dd =+3v v dd =+3v 7 8 9 10 11 12 13 14 15 16 7 8 9 10 11 12 13 14 15 16 7 8 9 10 11 12 -50-50 13 14 15 16 50
ASM121 - 5 - ? andigilog, inc. 2004 www.andigilog.com july 2005 - 70a04006 typical applications (cont.) 3.3v wr 5k 15k in v ref 1.75v 15k + _ parallel data output intr cs rd 8 parallel output analog-to-digital converter ASM121 u1 u3 u2 figure 4. parallel output temperature to digital converter (full scale = +125 ?c) u1 r1 2.5v r3 v temp v out + ? r2 3.3 r4 3.3 0.1 f v t u2 u3 ASM121 shunt voltage reference figure 5. thermostat / fan controller
ASM121 - 6 - ? andigilog, inc. 2004 www.andigilog.com july 2005 - 70a04006 qfn-3 package dimensions and pc layout pattern note: solder mask is recommended to be 0.07mm larger than pc lands. figure 6. package outline tape and reel data figure 7. tape dimensions and part orientation ? 1.00 + 0.25 ? 1.50 + 0.10 3.50 0.05 2.00 0.05 8.00 + 0.30 - 0.10 4.00 0.10 4.00 0.10 1.35 0.10 10 max 10 max 1.75 0.10 1.02 0.10 0.254 0.013 sec - aa sec - aa sec - bb sec - bb 1.75 0.10 part orientation pin 1 dot marking qfn 3l (1.2mm x 1.5mm) top view bottom view side view 1.500 0.050 1.200 0.050 1.000 0.050 1.050 0.050 1.000 0.050 exposed pad 0.200 0.050 0.350 0.050 0.500 0.050 2-pl 0.000 0.050 0.750 0.025 1 2 3 0.203 0.025 0.200 0.050 0.250 0.050 0.350 0.050 0.2 mm + 0.10 -0.0 0.2 mm + 0.10 -0.0 0.2 mm + 0.10 -0.0 0.6 mm + 0.10 -0.0 0.5 mm + 0.10 -0.0 0.5 mm + 0.10 -0.0 ref. package outline 1.1 mm + 0.10 -0.0 pc layout pattern pin 1 dot marking qfn 3l (1.2mm x 1.5mm) top view bottom view side view 1.500 0.050 1.200 0.050 1.000 0.050 1.050 0.050 1.000 0.050 exposed pad 0.200 0.050 0.350 0.050 0.500 0.050 2-pl 0.000 0.050 0.750 0.025 1 2 3 0.203 0.025 0.200 0.050 0.250 0.050 0.350 0.050 0.2 mm + 0.10 -0.0 0.2 mm + 0.10 -0.0 0.2 mm + 0.10 -0.0 0.6 mm + 0.10 -0.0 0.5 mm + 0.10 -0.0 0.5 mm + 0.10 -0.0 ref. package outline 1.1 mm + 0.10 -0.0 pc layout pattern
ASM121 andigilog, inc. 8380 s. kyrene rd., suite 101 tempe, arizona 85284-2120 tel: (480) 940-6200 fax: (480) 940-4255 - 7 - ? andigilog, inc. 2004 www.andigilog.com july 2005 - 70a04006 data sheet classifications preliminary specification this classification is shown on the heading of each page of a specification for produc ts that are either under development(design and qualification), or in the formative plann ing stages. andigilog reserves the right to change or discontinue these products without notice. new release specification this classification is shown on the heading of the first page onl y of a specification for prod ucts that are either under the later stages of development(characte rization and qualification), or in the early weeks of release to production. andigilog reserves the right to c hange the specification and information for these products without notice. fully released specification fully released datasheets do not contain any classifica tion in the first page header. these documents contain specification on products t hat are in full production. andigilog will no t change any guaranteed limits without written notice to the customers. obsolete datasheets that were written prior to january 1, 2001 without any header classification information should be considered as obsolete and non-active specifications, or in the best case as preliminary specifications.
ASM121 andigilog, inc. 8380 s. kyrene rd., suite 101 tempe, arizona 85284-2120 tel: (480) 940-6200 fax: (480) 940-4255 - 8 - ? andigilog, inc. 2004 www.andigilog.com july 2005 - 70a04006 notes:
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