DS620 Digital Thermometer and Thermostat

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Figure 2. Timing Diagram

Table 1. Register Summary

Parameter

Information

Size: 2-Bytes

Note that the 3 LSbs are always “don’t cares” for writes

(i.e., they are not saved) and always read out as 0s.

EEPROM

Factory State:

TH = 15ºC (0000 0111 1000 0000) [0780h]

TL = 10ºC (0000 0101 0000 0000) [0500h]

Configuration Register

Size: 2-Bytes

SRAM and EEPROM. See Figure 4 and Table 5 for

detailed information and power-up/factory state.

Temperature Register

Size: 2-Bytes

SRAM

Power-Up State: -60ºC

(1110 0010 0000 0000) [E200h]

TEMPERATURE MEASUREMENT

The DS620 measures temperature using a bandgap-based temperature sensor. A delta-sigma, analog-to-digital

converter (ADC) converts measured temperature to a 10-, 11-, 12-, or 13-bit (user-selectable) digital value that is

calibrated in °C; for °F applications, a lookup table or conversion routine must be used. Throughout this data sheet,

the term “conversion” is used to refer to the entire temperature measurement and ADC sequence.

The DS620 can be configured to power up either automatically converting temperature or in a low-power standby

state. The preferred power-up mode can be set using the AUTOC bit in the configuration register as explained in

the Configuration Register section of this data sheet.

The DS620 can be programmed to perform continuous consecutive conversions (continuous conversion mode) or

to perform single conversions on command (one-shot mode). The conversion mode is programmed through the

1SHOT bit in the configuration register as explained in the Configuration Register section of this data sheet. In

continuous conversion mode, conversions are performed after a Start Convert command is issued (or upon power-

up if the AUTOC bit in the configuration register is set to 1) until a Stop Convert command is issued, at which time

the device goes into a low-power standby state. Continuous conversions can be restarted at any time using the

Start Convert command. In one-shot mode, the DS620 performs a single temperature conversion either at power-

up (if AUTOC = 1) or when a Start Convert command is issued (if AUTOC = 0). When the conversion is complete,