DS1620

User–defined temperature settings are stored in nonvolatile memory, so parts can be programmed prior to

insertion in a system, as well as used in standalone applications without a CPU. Temperature settings and

temperature readings are all communicated to/from the DS1620 over a simple 3–wire interface.

ORDERING INFORMATION

PART

PACKAGE MARKING

DESCRIPTION

DS1620

DS1620

8-Pin DIP (300 mil)

DS1620+

DS1620 (See Note)

Lead-Free 8-Pin DIP (300 mil)

DS1620S

DS1620

8-Pin SOIC (208 mil)

DS1620S+

DS1620 (See Note)

Lead-Free 8-Pin SOIC (208 mil)

DS1620S/T&R

DS1620

8-Pin SOIC (208 mil), 2000-Piece Tape-and-Reel

DS1620S+T&R

DS1620 (See Note)

Lead-Free 8-Pin SOIC (208 mil), 2000-Piece

Tape-and-Reel

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

DETAILED PIN DESCRIPTION Table 1

PIN

SYMBOL

DESCRIPTION

1

DQ

Data Input/Output pin for 3-wire communication port.

2

Clock input pin for 3-wire communication port. When the DS1620 is used in a

stand-alone application with no 3–wire port, this pin can be used as a convert

3

RST

Reset input pin for 3-wire communication port.

4

GND

Ground pin.

5

High/Low Combination Trigger. Goes high when temperature exceeds TH;

will reset to low when temperature falls below TL.

6

Low Temperature Trigger. Goes high when temperature falls below TL.

7

High Temperature Trigger. Goes high when temperature exceeds TH.

8

Supply Voltage. 2.7V – 5.5V input power pin.

Table 2. DS1620 REGISTER SUMMARY

REGISTER NAME

(USER ACCESS)

SIZE

MEMORY

TYPE

REGISTER CONTENTS

AND POWER-UP/POR STATE

Temperature

(Read Only)

9 Bits

SRAM

Measured Temperature (Two’s Complement)

Power-Up/POR State: -60ºC (1 1000 1000)

(Read/Write)

9 Bits

EEPROM

Upper Alarm Trip Point (Two’s Complement)

Power-Up/POR State: User-Defined.

Initial State from Factory: +15°C (0 0001 1110)

(Read/Write)

9 Bits

EEPROM

Lower Alarm Trip Point (Two’s Complement)

Power-Up/POR State: User-Defined.

Initial State from Factory: +10°C (0 0001 0100)

OPERATION-MEASURING TEMPERATURE

A block diagram of the DS1620 is shown in Figure 1.

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