UNITRODE UC1730, UC2730, UC3730 Technical data

UC1730

Thermal Monitor

FEATURES

∙On-Chip Temperature Transducer

∙Temperature Comparator Gives Threshold Temperature Alarm

∙Power Reference Permits Airflow Diagnostics

∙Precision 2.5V Power Reference Permits Airflow Diagnostics

∙Transducer Output is Easily Scaled for Increased Sensitivity

∙Low 2.5mA Quiescent Current

BLOCK DIAGRAM

UC1730

UC2730

UC3730

DESCRIPTION

The UC1730 family of integrated circuit devices are designed to be used in a number of thermal monitoring applications. Each IC combines a temperature transducer, precision reference, and temperature comparator allowing the device to respond with a logic output if temperatures exceed a user programmed level. The reference on these devices is capable of supplying in excess of 250mA of output current − by setting a level of power dissipation the rise in die temperature will vary with airflow past the package, allowing the IC to respond to airflow conditions

These devices come in an 8-Pin DIP, plastic or ceramic, a 5-Pin TO-220 or a PLCC-20 version. In the 8-Pin version, a PTAT (proportional to absolute temperature) output reports die temperature directly. This output is configured such that its output level can be easily scaled up with two external gain resistors. A second PTAT source is internally referenced to the temperature comparator. The other input to this comparator can then be externally programmed to set a temperature threshold. When this temperature threshold is exceeded an alarm delay output is activated. Following the activation of the delay output, a separate open collector output is turned on. The delay pin can be programmed with an external RC to provide a time separation between activation of the delay pin and the alarm pin, permitting shutdown diagnostics in applications where the open collector outputs of multiple parts are wire OR’ed together.

The 5-Pin version in the TO-220 package is well suited for monitoring heatsink temperatures. Enhanced airflow sensitivities can be obtained with this package by mounting the device to a small heatsink in the airstream. This version of the device does not include the PTAT output or the open collector alarm output.

Pin numbers shown for 8-Pin DIP, ( ) number for 5-Pin TO-220.

10/94

ABSOLUTE MAXIMUM RATINGS

Input Supply Voltage, (+VIN). . . . . . . . . . . . . . . . . . . . . . . 40V Alarm Output Voltage (8-Pin Version Only) . . . . . . . . . . . 40V Alarm Delay Voltage. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10V Alarm Threshold Set Voltage . . . . . . . . . . . . . . . . . . . . . . 10V 2.5V Reference Output Current . . . . . . . . . . . . . . . . . -400 mA Alarm Output Current (8-Pin Version Only) . . . . . . . . . . 0 mA Power Dissipation at TA = 25°C (Note 2) . . . . . . . . . 1000 mW Power Dissipation at TC = 25°C (Note 2) . . . . . . . . . 2000 mW Thermal Resistance Junction to Ambient

N, 8-Pin Plastic DIP . . . . . . . . . . . . . . . . . . . . . . . . . 110°C/W J, 8-Pin Ceramic DIP . . . . . . . . . . . . . . . . . . . . . . . . 110°C/W

UC1730

UC2730

UC3730

T, 5-Pin Plastic DIP TO-220 . . . . . . . . . . . . . . . . . . . . 65°C/W Thermal Resistance Junction to Case

N, 8-Pin Plastic DIP. . . . . . . . . . . . . . . . . . . . . . . . . . . 60°C/W J, 8-Pin Ceramic DIP. . . . . . . . . . . . . . . . . . . . . . . . . . 40°C/W T, 5-Pin Plastic TO-220 . . . . . . . . . . . . . . . . . . . . . . . . . 5°C/W Operating Junction Temperature . . . . . . . . . -55°C to +150°C Storage Temperature . . . . . . . . . . . . . . . . . . -65°C to +150°C Lead Temperature (Soldering, 10 Seconds). . . . . . . . . 300°C

Note 1: Voltages are referenced to ground. Currents are positive into, negative out of, the specified terminals.

Note 2: Consult Packaging section of Databook for thermal limitations and considerations of package.

CONNECTION DIAGRAMS

DIL-8 (TOP VIEW)

N or J Package

5-PIN TO-220 (TOP VIEW)

T Package

PLCC-20 (TOP VIEW) Q Package

PACKAGE PIN FUNCTION

FUNCTION	PIN
N/C	1-3
ALARM DELAY	4
ALARM OUTPUT	5
+VIN	6
GND	7
N/C	8-13
PTAT+	14
PTAT-	15
2.5V REFERENCE	16
2.5V REFERENCE	17
ALARM	18
THRESHOLD SET
N/C	19-20

ELECTRICAL CHARACTERISTICS: Unless otherwise stated, these specifications apply for TJ = 0°C to +100°C for the UC3730, -25°C to + 100°C for the UC2730 and -55°C to +125°C for the UC1730,

+VIN = + 5V, and PTAT– = 0V. TA = TJ.

PARAMETERS	TEST CONDITIONS	MIN	TYP	MAX	UNITS
INPUT SUPPLY
Supply Current	+VIN = 35V		2.8	4.0	mA
	+VIN = 5V		2.3	3.5	mA
REFERENCE
Output Voltage	TJ = 25°C	2.475	2.5	2.525	V
	Over Temperature	2.46		2.54	V
Load Regulation	IOUT = 0 to 250mA		8.0	25	mV
Line Regulation	+VIN = 5 to 25V		1.0	5.0	mV
TEMPERATURE COMPARATOR
Temperature Comparator Threshold	at 300°K (26.85°C), Nominally 5mV/°K,	1.475	1.50	1.525	V
	VINPUT High to Low
Temperature Error		-10		10	°C
Threshold Line Regulation	+VIN = 5 to 25V		0.005	0.02	%/V
Temperature Linearity	Note 2		2.0	5.0	°C
Threshold Hysteresis		3.0	8.0	15	mV
Input Bias Current	VINPUT at 1.5V	-0.5	-0.1		μA
Max Output Current	VOUT = 1V	1.2	3.0		mA
Output Sat Voltage	IOUT = 100μA		0.05	0.25	V

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