Rainbow Electronics DS56 User Manual

FEATURES

DS56

Dual Temperature Comparator

PRELIMINARY

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DS56S 8-Pin SOIC (150-mil)

§ 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.

PIN ASSIGNMENT

1

V

REF

V
V

GND

T2
T1

8

2

7

3

6

4

5

PIN DESCRIPTION

V

REF

V

T2

V

T1

GND - Ground
V

TEMP

T

OUT2

T

OUT1

V

DD

- Bandgap Voltage Reference
Output

- Temperature Trip Point 2

- Temperature Trip Point 1

- Temp Sensor Output Voltage

- Thermostat output for Trip
Point 2

- Thermostat output for Trip
Point 1

- Power Supply Voltage (2.7V
to 5.5V)

V
T
T
V

DD
OUT1
OUT2
TEMP

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 SYMBOL TYPE DESCRIPTION

1 V
2 V
3 V

REF

T2
T1

4 GND GND
5 V

6 T

7 T
8 V

TEMP

OUT2

OUT1

DD

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

Analog input Trip point 2 input associated with thermostat output 2.
Analog input Trip point 1 input associated with thermostat output 1.

Ground pin.

Analog output Temperature sensor output. (+6.2 T

Digital output

(open-drain)

Digital output

(open-drain)

V

DD

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

+ 395) mV.

DegC

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 kΩ.

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 V

DD

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)

* 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].

(GND-0.3V) to +7.0V

220°C for 15 seconds (IR)

RECOMMENDED DC OPERATING CONDITIONS:

(-40°C to +125°C; 2.7V ≤ VDD ≤ 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) (-40°C to +125°C; 2.7V ≤ VDD ≤ 5.5V)

PARAMETER SYMBOL CONDITION MIN TYP MAX UNITS NOTES

Supply Current I

DD

225 µA

DC ELECTRICAL CHARACTERISTICS:
Temperature Sensor (Note 3) (-40°C to +125°C; 2.7V ≤ VDD ≤ 5.5V)

PARAMETER SYMBOL CONDITION MIN TYP MAX UNITS NOTES

Trip Point
Accuracy

V

Accuracy T

TEMP

V

DC Offset T=0°C 395 mV

TEMP

Sensor Gain
Trip Point

Hysteresis

TP

ERR

ERR

?V/?T

TP

HYST

Power Supply
Regulation

V

Output

TEMP

Impedance

-40°C≤TA≤125°C ±3
0°C≤TA≤85°C

-40°C≤TA≤125°C ±3
0°C≤TA≤85°C

±2

±2

6.25 mV/°C

3.0 5.0 7.0 °C

2.7V≤VDD≤3.3V

3.0V≤VDD≤5.5V

±2.3 mV
±0.3 mV/V

1500

°C 4

°C 5

Ω

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DC ELECTRICAL CHARACTERISTICS:

DS56

Bandgap Voltage Reference V

REF

(-40°C to +125°C; 2.7V ≤ VDD ≤ 5.5V)

PARAMETER SYMBOL CONDITION MIN TYP MAX UNITS NOTES

V

Output V

REF

Power Supply
Regulation

Load Regulation

?V

?V

?V

?I

REF

REF

REF

DD

L

2.7V≤VDD≤3.3V

/

30V≤VDD≤5.5V

/

+3.0µA≤IL≤

+50µA

1.238 1.25 1.263 V
±1.45 mV

±0.2 mV/V

0.15 mV/µA

DC ELECTRICAL CHARACTERISTICS:
Trip Point Inputs VT1/V

T2

PARAMETER SYMBOL CONDITION MIN TYP MAX UNITS NOTES

Input Bias Current I
Input Range V

BIAS

TIN

(-40°C to +125°C; 2.7V ≤ VDD ≤ 5.5V)

300 nA

(V

0

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

OUT0

VDD = 5.0V 1.0 µA

I

= +50 µA 0.4 V

OUT

(-40°C to +125°C; 2.7V ≤ VDD ≤ 5.5V)

NOTES:

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

2. Solder according to IPC standards.

3. Specified for V

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

sourcing 1.0 µA (max) and V

TEMP

load current = 50 µA.

REF

, 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 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 V

TRANSFER FUNCTION Figure 4

TEMP

TBD

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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

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

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

DS56

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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