LTC2990



2990f

applicaTions inForMaTion

Figure 8. LTC2990 Serial Bus Repeated Read Byte Protocol

S

A

A S

W#

ADDRESS

COMMAND

A

0

0

1 0

DATA

b7:b0

0

10011a1:a0

ADDRESS

10011a1:a0

XXXXXb3:b0

1

2990 F07

P

A#

R

Figure 7. LTC2990 Serial Bus Read Byte Protocol

S

A

A S

W#

ADDRESS

COMMAND

A

0

0

1 0

A

0

DATA

b7:b0

0

10011a1:a0

ADDRESS

10011a1:a0

XXXXXb3:b0

1

2990 F08

P

A#

DATA

b7:b0

R

Table 2. LTC2990 Register Address and Contents

REGISTER NAME

READ/WRITE

DESCRIPTION

00h

STATUS

R

Indicates BUSY State, Conversion Status

01h

CONTROL

R/W

Controls Mode, Single/Repeat, Celsius/Kelvin

02h

TRIGGER**

R/W

Triggers an Conversion

03h

N/A

Unused Address

04h

R

Internal Temperature MSB

05h

R

Internal Temperature LSB

06h

V1 (MSB)

R

V1, V1 – V2 or TR1 MSB

07h

V1 (LSB)

R

V1, V1 – V2 or TR1 LSB

08h

V2 (MSB)

R

V2, V1 – V2 or TR1 MSB

09h

V2 (LSB)

R

V2, V1 – V2 or TR1 LSB

0Ah

V3 (MSB)

R

V3, V3 – V4 or TR2 MSB

0Bh

V3 (LSB)

R

V3, V3 – V4 or TR2 LSB

0Ch

V4 (MSB)

R

V4, V3 – V4 or TR2 MSB

0Dh

V4 (LSB)

R

V4, V3 – V4 or TR2 LSB

0Eh

R

0Fh

R

*Register Address MSBs b7-b4 are ignored.

**Writing any value triggers a conversion. Data Returned reading this register address is the Status register.

ADR1

ADR0

98h

1001 100X*

0

0

9Ah

1001 101X*

0

1

9Ch

1001 110X*

1

0

9Eh

1001 111X*

1

1

*X = R/W Bit

S

A

A DATA

W#

ADDRESS

COMMAND

A

0

0 b7:b0

DATA

b7:b0

0

10011a1:a0

XXXXXb3:b0

0

0

2990 F06

P

A

Figure 6. LTC2990 Serial Bus Repeated Write Byte Protocol