1 of 6 102299 features factory calibrated for sensitivity of +6.20 mv/c and thermometer accuracy of 2.0c over the 0c to 85c range and 3c over the 40c to 0c and +85c to +125c range measurement range of -40c to +125c integrated temperature sensor and voltage reference two independent temperature setpoints with respective logic outputs with set hysteresis narrow-body so8 (150-mil) package wide power supply range (2.7v v dd 5.5v) functionally compatible with lm56xim applications include monitoring disk drives, printers, office equipment, hvac, appliances, or any power/cost/temperature- sensitive environments. pin assignment pin description v ref - bandgap voltage reference output v t2 - temperature trip point 2 v t1 - temp erature trip point 1 gnd - ground v temp - temp sensor output voltage t out2 - thermostat output for trip point 2 t out1 - thermostat output for trip point 1 v dd - power supply voltage (2.7v to 5.5v) description the DS56 dual temperature comparator has two independent open-drain thermostat outputs and respective trip point inputs. the trip points are set with external resistors that divide down the 1.25v internal bandgap voltage reference. the voltage resulting from this resistive division is compared with the voltage corresponding to the device?s junction temperature to define the thermostat output logic state. the internal temperature sensor has a typical sensitivity of +6.2mv/c and dc offset of +395 mv at 0c. both thermostat outputs have 5c of hysteresis. for applications that require temperature measurement as well as control, the temperature sensor voltage is brought out to a pin. the DS56 is packaged in a compact 150-mil, 8-pin soic. applications include disk drives, printers, office equipment, hvac, appliances, or any power/cost/temperature-sensitive environments. DS56 dual temperature comparator preliminary www.dalsemi.com 1 2 3 4 8 7 6 5 v dd t out1 t out2 v temp v ref v t2 v t1 gnd DS56s 8-pin soic (150-mil)
DS56 2 of 6 102299 detailed pin description table 1 pin symbol type description 1 v ref analog output bandgap output 1.25v (nom) voltage reference output. 2 v t2 analog input trip point 2 input associated with thermostat output 2. 3 v t1 analog input trip point 1 input associated with thermostat output 1. 4 gnd gnd ground pin. 5 v temp analog output temperature sensor output. (+6.2 t degc + 395) mv. 6 t out2 digital output (open-drain) thermostat output 2. active low output corresponding to trip point 2. typical hysteresis is 5.0c. 7 t out1 digital output (open-drain) thermostat output 1. active low output corresponding to trip point 1. typical hysteresis is 5.0c. 8 v dd v dd supply voltage 2.7v - 5.5v input power pin. DS56 functional block diagram figure 1
DS56 3 of 6 102299 overview a block diagram of the DS56 is shown in figure 1. the DS56 consists of three major components: 1. precision bandgap voltage reference 2. temperature sensor 3. thermostat comparators the DS56 incorporates an internal temperature sensor with a typical transfer function of (in mv with t expressed in c): v temp (t) = 6.2 t + 395 the voltage associated with this transfer function is output on the v temp pin, which has a typical output impedance of 1.5 k w . the DS56 has two independent temperature comparators, each with its own input (or trip point) and output. the comparison voltage (the v temp transfer function) is the same for both comparators. additionally, the hysteresis for both comparators is typically 5c (31.0 mv). the DS56 bandgap voltage reference is available on pin 1 to allow for a designer to set the trip point(s) by resistively dividing the reference voltage. one possible scenario is illustrated in figure 1. for optimum performance, the vref pin should be connected to a 50 a load. the comparator outputs are taken off-chip via open-drain fets, thus requiring external pullups. the thermostat transfer function is illustrated in figure 2. the supply range of the DS56 is 2.7v to 5.5v, allowing for applications ranging from industrial control to battery-powered portable equipment. thermostat output transfer function figure 2
DS56 4 of 6 102299 absolute maximum ratings* voltage on v dd (gnd-0.3v) to +7.0v input current at any pin 5.0 ma package input current 20 ma operating temperature -40c to +125c storage temperature -55c to 150c esd susceptibility (human body model) 1kv soldering temperature (note 2) 215c for 60 seconds (vapor phase) 220c for 15 seconds (ir) * this is a stress rating only and functional operation of the device at these or any other conditions above those indicated in the operation sections of this specification is not implied. exposure to absolute maximum rating conditions for extended periods of time may affect reliability. the dallas semiconductor DS56 is built to the highest quality standards and manufactured for long-term reliability. all dallas semiconductor devices are made using the same quality materials and manufacturing methods. however, the DS56 is not exposed to environmental stresses, such as burn-in, that some industrial applications require. for specific reliability information on this product, please contact the factory in dallas at (972) 371-4448. recommended dc operating conditions: (-40c to +125 c; 2.7v v dd 5.5v) parameter symbol condition min typ max units notes supply voltage v dd 2.7 5.5 v 1 dc electrical characteristics: power supply (note 3) (-40c to +125c; 2.7v v dd 5.5v) parameter symbol condition min typ max units notes supply current i dd 225 a dc electrical characteristics: temperature sensor (note 3) (-40c to +125c; 2.7v v dd 5.5v) parameter symbol condition min typ max units notes -40c t a 125c 3 trip point accuracy tp err 0c t a 85c 2 c 4 -40c t a 125c 3 v temp accuracy t err 0c t a 85c 2 c 5 v temp dc offset t=0c 395 mv sensor gain ? v/ ? t 6.25 mv/c trip point hysteresis tp hyst 3.0 5.0 7.0 c 2.7v v dd 3.3v 2.3 mv power supply regulation 3.0v v dd 5.5v 0.3 mv/v v temp output impedance 1500 w
DS56 5 of 6 102299 dc electrical characteristics: bandgap voltage reference v ref (-40c to +125c; 2.7v v dd 5.5v) parameter symbol condition min typ max units notes v ref output v ref 1.238 1.25 1.263 v 2.7v v dd 3.3v 1.45 mv power supply regulation ? v r ef / ? v dd 30v v dd 5.5v 0.2 mv/v load regulation ? v ref / ? i l +3.0a i l +50a 0.15 mv/a dc electrical characteristics: trip point inputs v t1 /v t2 (-40c to +125c; 2.7v v dd 5.5v) parameter symbol condition min typ max units notes input bias current i bias 300 na input range v tin 0 (v dd -1.0) v dc electrical characteristics: thermostat outputs t out1 /t out2 (-40c to +125c; 2.7v v dd 5.5v) parameter symbol condition min typ max units notes logic 1 output leakage current i out1 v dd = 5.0v 1.0 a logical 0 output voltage v out0 i out = +50 a 0.4 v notes: 1. all voltages are referenced to ground, unless otherwise specified. 2. solder according to ipc standards. 3. specified for v temp sourcing 1.0 a (max) and v ref load current = 50 a. 4. includes error associated with internal temperature sensor, bandgap voltage v ref , and comparator offset. external resistance tolerance and temperature coefficient not included in this spec. 5. thermometer error (expressed in c) is the difference between [ v o (t) - 395]/6.20 and the DS56 case temperature at v dd = 3.0v, thus taking into account sensor error, dc offset error, sensor amplifier gain variations, and amplifier nonlinearity. typical DS56 thermometer error figure 3 tbd typical DS56 v temp transfer function figure 4 tbd
DS56 6 of 6 102299 DS56 physical dimensions 8-, 14-, and 16-pin soic (.150? body width) pkg 8-pin 14-pin 16-pin dim min max min max min max a in. mm 0.053 1.35 0.069 1.75 0.053 1.35 0.069 1.75 0.053 1.35 0.069 1.75 a1 in. mm 0.004 0.10 0.010 0.25 0.004 0.10 0.010 0.25 0.004 0.10 0.010 0.25 a2 in. mm 0.048 1.24 0.062 1.57 0.048 1.24 0.062 1.57 0.048 1.24 0.062 1.57 b in. mm 0.012 0.030 0.020 0.50 0.012 0.30 0.020 0.50 0.012 0.30 0.020 0.50 c in. mm 0.007 0.17 0.011 0.28 0.007 0.17 0.011 0.28 0.007 0.17 0.011 0.28 d in. mm 0.188 4.78 0.196 4.98 0.337 8.55 0.344 8.74 0.386 9.80 0.393 9.98 e in. mm 0.050 bsc 1.27 bsc 0.050 bsc 1.27 bsc 0.050 bsc 1.27 bsc e1 in. mm 0.150 3.81 0.158 4.01 0.150 3.81 0.158 4.01 0.150 3.81 0.158 4.01 h in. mm 0.230 5.84 0.244 6.20 0.230 5.84 0.244 6.20 0.230 5.84 0.244 6.20 l in. mm 0.016 0.40 0.050 0.89 0.016 0.40 0.050 0.89 0.016 0.40 0.050 0.89 q 0 8 0 8 0 8
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