MAXIM DS56 User Manual

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DS56

www.maxim-ic.com

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.

Dual Temperature Comparato

PIN ASSIGNMENT

V

GND

DS56S 8-Pin SOIC (150-mil)

V

V

REF

1

2

T2

3

T1

4

PIN DESCRIPTION

V

- Bandgap Voltage Reference

REF

Output
VT2 - Temperature Trip Point 2
VT1 - Temperature Trip Point 1
GND - Ground
V

- Temp Sensor Output Voltage

TEMP

T

- Thermostat output for Trip

OUT2

Point 2
T

- Thermostat output for Trip

OUT1

V

8

7

6

5

T

T

V

DD

OUT1

OUT2

TEMP

Point 1
VDD - 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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DS56

ORDER INFORMATION

ORDERING
NUMBER

DS56S DS56 DS56 in 150 mil 8-pin SO
DS56S/T&R DS56 DS56 in 150 mil 8-pin SO, 2500 Piece Tape-and-Reel
DS56S+ DS56 (See Note) DS56 in Lead-Free 150 mil 8-pin SO
DS56S+T&R DS56 (See Note) DS56 in Lead-Free 150 mil 8-pin SO, 2500 Piece Tape-

DS56U DS56 DS56 in 8-pin uSOP
DS56U/T&R DS56 DS56 in 8-pin uSOP, 3000 Piece Tape-and-Reel
DS56U+ DS56 (See Note) DS56 in Lead-Free 8-pin uSOP
DS56U+T&R DS56 (See Note) DS56 in Lead-Free 8-pin uSOP, 3000 Piece Tape-and-

Note: A “+” symbol will also be marked on the package near the Pin 1 indicator.

PACKAGE
MARKING

DESCRIPTION

and-Reel

Reel

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DETAILED PIN DESCRIPTION Table 1

PIN SYMBOL TYPE DESCRIPTION

1 V

Analog output Bandgap output 1.25V (nom) voltage reference output.

REF

2 VT2 Analog input Trip point 2 input associated with thermostat output 2.
3 VT1 Analog input Trip point 1 input associated with thermostat output 1.
4 GND GND
5 V

6 T

7 T

8 VDD V

Analog output Temperature sensor output. (+6.2 T

TEMP

Digital output

OUT2

OUT1

(open-drain)

Digital output

(open-drain)

Supply Voltage 2.7V - 5.5V input power pin.

DD

Ground pin.

+ 395) mV.

DegC

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.

DS56 FUNCTIONAL BLOCK DIAGRAM Figure 1

DS56

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DS56

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

(T) = 6.2 T + 395

TEMP

The voltage associated with this transfer function is output on the V

pin, which has a typical output

TEMP

impedance of 1.5 kW.

The DS56 has two independent temperature comparators, each with its own input (or trip point) and
output. The comparison voltage (the V

transfer function) is the same for both comparators.

TEMP

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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DS56

ABSOLUTE MAXIMUM RATINGS*

Voltage on VDD (GND-0.3V) to +7.0V
Input Current at any pin 5.0 mA
Package Input Current 20 mA
Operating Temperature -40°C to +125°C
Storage Temperature -55°C to 150°C
ESD Susceptibility (Human Body Model) 1kV
Soldering Temperature (Note 2) 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 [phone].

RECOMMENDED DC OPERATING CONDITIONS:

(-40°C to +125°C; 2.7V £ V

£ 5.5V)

DD

PARAMETER SYMBOL CONDITION MIN TYP MAX UNITS NOTES

Supply Voltage VDD 2.7 5.5 V 1

DC ELECTRICAL CHARACTERISTICS:
Power Supply (Note 3) (-40°C to +125°C; 2.7V £ V

PARAMETER SYMBOL CONDITION MIN TYP MAX UNITS NOTES

Supply Current IDD 225 µA

£ 5.5V)

DD

DC ELECTRICAL CHARACTERISTICS:
Temperature Sensor (Note 3) (-40°C to +125°C; 2.7V £ V

PARAMETER SYMBOL CONDITION MIN TYP MAX UNITS NOTES

±3 Trip Point
±2
±3
±2

°C 4

°C 5

±2.3 mV
±0.3 mV/V

Accuracy

V

Accuracy T

TEMP

V

DC Offset T=0°C 395 mV

TEMP

Sensor Gain

Trip Point
Hysteresis

Power Supply
Regulation

V

Output

TEMP

Impedance

TP

ERR

ERR

∆V/∆T

TP

HYST

-40°C£TA£125°C
0°C£TA£85°C

-40°C£TA£125°C
0°C£TA£85°C

6.25 mV/°C

3.0 5.0 7.0 °C

2.7V£VDD£3.3V

3.0V£V

£5.5V

DD

1500 W

£ 5.5V)

DD

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DC ELECTRICAL CHARACTERISTICS:

DS56

Bandgap Voltage Reference V

(-40°C to +125°C; 2.7V £ VDD £ 5.5V)

REF

PARAMETER SYMBOL CONDITION MIN TYP MAX UNITS NOTES

V

Output V

REF

Power Supply
Regulation

Load Regulation

∆V

∆V

1.238 1.25 1.263 V

REF

REF

∆VDD

REF

∆IL

2.7V£VDD£3.3V

/

30V£VDD£5.5V

/

+3.0µA£IL£

+50µA

±1.45 mV

±0.2 mV/V

0.15 mV/µA

DC ELECTRICAL CHARACTERISTICS:
Trip Point Inputs V

T1/VT2

PARAMETER SYMBOL CONDITION MIN TYP MAX UNITS NOTES

Input Bias Current I

Input Range V

(-40°C to +125°C; 2.7V £ VDD £ 5.5V)

300 nA

BIAS

(V

0

TIN

DD

-1.0)

V

DC ELECTRICAL CHARACTERISTICS:
Thermostat Outputs T

OUT1/TOUT2

PARAMETER SYMBOL CONDITION MIN TYP MAX UNITS NOTES

Logic 1 Output
Leakage Current
LOGICAL 0
Output Voltage

I

V

OUT1

V

I

OUT0

(-40°C to +125°C; 2.7V £ VDD £ 5.5V)

= 5.0V 1.0 µA

DD

= +50 µA 0.4 V

OUT

NOTES:

1. All voltages are referenced to ground, unless otherwise specified.

2. Solder according to IPC standards.

3. Specified for V

sourcing 1.0 µA (max) and V

TEMP

load current = 50 µA.

REF

4. Includes error associated with internal temperature sensor, bandgap voltage V

, and comparator

REF

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 V

= 3.0V, thus taking into account sensor error, DC offset error, sensor amplifier

DD

gain variations, and amplifier nonlinearity.

TYPICAL DS56 THERMOMETER ERROR Figure 3

TBD

TYPICAL DS56 V

TRANSFER FUNCTION Figure 4

TEMP

TBD

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DS56 PHYSICAL DIMENSIONS

8-, 14-, AND 16-PIN SOIC (.150” BODY WIDTH)

DS56

PKG 8-PIN 14-PIN 16-PIN

DIM MIN MAX MIN MAX MIN MAX

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

Q

0.053

1.35

0.004

0.10

0.048

1.24

0.012

0.030

0.007

0.17

0.188

4.78

0.050 BSC

1.27 BSC

0.150

3.81

0.230

5.84

0.016

0.40
0° 8° 0° 8° 0° 8°

0.069

1.75

0.010

0.25

0.062

1.57

0.020

0.50

0.011

0.28

0.196

4.98

0.158

4.01

0.244

6.20

0.050

0.89

0.053

1.35

0.004

0.10

0.048

1.24

0.012

0.30

0.007

0.17

0.337

8.55

0.050 BSC

1.27 BSC

0.150

3.81

0.230

5.84

0.016

0.40

0.069

1.75

0.010

0.25

0.062

1.57

0.020

0.50

0.011

0.28

0.344

8.74

0.158

4.01

0.244

6.20

0.050

0.89

0.053

1.35

0.004

0.10

0.048

1.24

0.012

0.30

0.007

0.17

0.386

9.80

0.050 BSC

1.27 BSC

0.150

3.81

0.230

5.84

0.016

0.40

0.069

1.75

0.010

0.25

0.062

1.57

0.020

0.50

0.011

0.28

0.393

9.98

0.158

4.01

0.244

6.20

0.050

0.89

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