DALLAS DS56

PRELIMINARY
DS56
Dual Temperature Comparator
www.dalsemi.com
PIN ASSIGNMENT
FEATURES
§ Factory calibrated for sensitivity of +6.20
mV/°C and thermometer accuracy of ±2.0°C
over the 0°C to 85°C range and ±3°C over the
40°C to 0°C and +85°C to +125°C range
§ Measurement range of -40°C to +125°C
§ 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 ≤VDD ≤
5.5V)
§ Functionally compatible with LM56xIM
§ Applications include monitoring disk drives,
printers, office equipment, HVAC,
appliances, or any power/cost/temperaturesensitive environments.
VREF
1
8
VDD
VT2
2
7
TOUT1
VT1
3
6
TOUT2
GND
4
5
VTEMP
DS56S 8-Pin SOIC (150-mil)
PIN DESCRIPTION
VREF
VT2
VT1
GND
VTEMP
TOUT2
TOUT1
VDD
- Bandgap Voltage Reference
Output
- Temperature Trip Point 2
- Temperature Trip Point 1
- Ground
- Temp Sensor Output Voltage
- Thermostat output for Trip
Point 2
- Thermostat output for Trip
Point 1
- 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 0°C.
Both thermostat outputs have 5°C 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.
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DETAILED PIN DESCRIPTION Table 1
PIN
1
2
3
4
5
SYMBOL
VREF
VT2
VT1
GND
VTEMP
6
TOUT2
7
TOUT1
8
VDD
TYPE
Analog output
Analog input
Analog input
GND
Analog output
Digital output
(open-drain)
Digital output
(open-drain)
VDD
DESCRIPTION
Bandgap output 1.25V (nom) voltage reference output.
Trip point 2 input associated with thermostat output 2.
Trip point 1 input associated with thermostat output 1.
Ground pin.
Temperature sensor output. (+6.2 TDegC + 395) mV.
Thermostat output 2. Active low output corresponding to trip
point 2. Typical hysteresis is 5.0°C.
Thermostat output 1. Active low output corresponding to trip
point 1. Typical hysteresis is 5.0°C.
Supply Voltage 2.7V - 5.5V input power pin.
DS56 FUNCTIONAL BLOCK DIAGRAM Figure 1
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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):
VTEMP (T) = 6.2 T + 395
The voltage associated with this transfer function is output on the VTEMP pin, which has a typical output
impedance of 1.5 kΩ .
The DS56 has two independent temperature comparators, each with its own input (or trip point) and
output. The comparison voltage (the VTEMP transfer function) is the same for both comparators.
Additionally, the hysteresis for both comparators is typically 5°C (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 µA 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
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ABSOLUTE MAXIMUM RATINGS*
Voltage on VDD
Input Current at any pin
Package Input Current
Operating Temperature
Storage Temperature
ESD Susceptibility (Human Body Model)
Soldering Temperature (Note 2)
*
(GND-0.3V) to +7.0V
5.0 mA
20 mA
-40°C to +125°C
-55°C to 150°C
1kV
215°C for 60 seconds (Vapor Phase)
220°C 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:
(-40°C to +125°C; 2.7V ≤ VDD ≤ 5.5V)
PARAMETER
Supply Voltage
SYMBOL
VDD
CONDITION
DC ELECTRICAL CHARACTERISTICS:
Power Supply (Note 3)
PARAMETER
Supply Current
SYMBOL
IDD
CONDITION
DC ELECTRICAL CHARACTERISTICS:
Temperature Sensor (Note 3)
PARAMETER
Trip Point
Accuracy
VTEMP Accuracy
VTEMP DC Offset
Sensor Gain
Trip Point
Hysteresis
Power Supply
Regulation
VTEMP Output
Impedance
SYMBOL
TPERR
TERR
CONDITION
MIN
2.7
TYP
MIN
TYP
MAX
225
TYP
MAX
±3
±2
±3
±2
395
6.25
? V/? T
3.0
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NOTES
1
UNITS
µA
NOTES
(-40°C to +125°C; 2.7V ≤ VDD ≤ 5.5V)
MIN
T=0°C
2.7V≤VDD≤3.3V
3.0V≤VDD≤5.5V
UNITS
V
(-40°C to +125°C; 2.7V ≤ VDD ≤ 5.5V)
-40°C≤TA≤125°C
0°C≤TA≤85°C
-40°C≤TA≤125°C
0°C≤TA≤85°C
TPHYST
MAX
5.5
5.0
UNITS
NOTES
°C
4
°C
5
mV
mV/°C
7.0
°C
±2.3
±0.3
mV
mV/V
1500
Ω
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DS56
DC ELECTRICAL CHARACTERISTICS:
Bandgap Voltage Reference VREF
PARAMETER
VREF Output
Power Supply
Regulation
Load Regulation
SYMBOL
VREF
2.7V≤VDD≤3.3V
MAX
1.263
±1.45
UNITS
V
mV
? VDD
30V≤VDD≤5.5V
±0.2
mV/V
? VREF/
+3.0µA≤IL≤
+50µA
0.15
mV/µA
? VREF/
CONDITION
? IL
DC ELECTRICAL CHARACTERISTICS:
Trip Point Inputs VT1/VT2
PARAMETER
Input Bias Current
Input Range
SYMBOL
IBIAS
CONDITION
VTIN
MIN
1.238
TYP
1.25
SYMBOL
CONDITION
IOUT1
VOUT0
NOTES
(-40°C to +125°C; 2.7V ≤ VDD ≤ 5.5V)
MIN
TYP
0
DC ELECTRICAL CHARACTERISTICS:
Thermostat Outputs TOUT1/TOUT2
PARAMETER
Logic 1 Output
Leakage Current
LOGICAL 0
Output Voltage
(-40°C to +125°C; 2.7V ≤ VDD ≤ 5.5V)
MAX
300
(VDD
-1.0)
UNITS
nA
NOTES
V
(-40°C to +125°C; 2.7V ≤ VDD ≤ 5.5V)
MIN
TYP
MAX
UNITS
VDD = 5.0V
1.0
µA
IOUT = +50 µA
0.4
V
NOTES
NOTES:
1. All voltages are referenced to ground, unless otherwise specified.
2. Solder according to IPC standards.
3. Specified for VTEMP sourcing 1.0 µA (max) and VREF load current = 50 µA.
4. Includes error associated with internal temperature sensor, bandgap voltage VREF, and comparator
offset. External resistance tolerance and temperature coefficient not included in this spec.
5. Thermometer error (expressed in °C) is the difference between [VO(T) - 395]/6.20 and the DS56 case
temperature at VDD = 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 VTEMP TRANSFER FUNCTION Figure 4
TBD
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DS56 PHYSICAL DIMENSIONS
8-, 14-, AND 16-PIN SOIC (.150” BODY WIDTH)
PKG
DIM
A IN.
MM
A1 IN.
MM
A2 IN.
MM
b IN.
MM
C IN.
MM
D IN.
MM
e IN.
MM
E1 IN.
MM
H IN.
MM
L IN.
MM
Θ
8-PIN
MIN
MAX
0.053
0.069
1.35
1.75
0.004
0.010
0.10
0.25
0.048
0.062
1.24
1.57
0.012
0.020
0.030
0.50
0.007
0.011
0.17
0.28
0.188
0.196
4.78
4.98
0.050 BSC
1.27 BSC
0.150
0.158
3.81
4.01
0.230
0.244
5.84
6.20
0.016
0.050
0.40
0.89
0°
8°
14-PIN
MIN
MAX
0.053
0.069
1.35
1.75
0.004
0.010
0.10
0.25
0.048
0.062
1.24
1.57
0.012
0.020
0.30
0.50
0.007
0.011
0.17
0.28
0.337
0.344
8.55
8.74
0.050 BSC
1.27 BSC
0.150
0.158
3.81
4.01
0.230
0.244
5.84
6.20
0.016
0.050
0.40
0.89
0°
8°
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16-PIN
MIN
MAX
0.053
0.069
1.35
1.75
0.004
0.010
0.10
0.25
0.048
0.062
1.24
1.57
0.012
0.020
0.30
0.50
0.007
0.011
0.17
0.28
0.386
0.393
9.80
9.98
0.050 BSC
1.27 BSC
0.150
0.158
3.81
4.01
0.230
0.244
5.84
6.20
0.016
0.050
0.40
0.89
0°
8°
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