LTC3562

13

3562fa

Table 1. Write Word Protocol Used by the LTC3562

171181811

S

Slave Address

WR

A

*Sub-Address

A

Data Byte

A

P**

S = Start Condition, WR = Write Bit = 0, A = Acknowledge, P = Stop Condition

* The sub-address uses only the first four most significant bits, A7, A6, A5, and A4, for sub-addressing. The two least significant bits, A1 and A0, are

used to program the regulator operating mode.

**Stop can be delayed until all of the data registers have been written.

Table 2. Sub-Address and Data Byte Mapping

SUB-ADDRESS BYTE

DATA BYTE

A7

A6

A5

A4

A3

A2

A1

A0

B7

B6

B5

B4

B3

B2

B1

B0

PROGRAM

R600A

PROGRAM

R400A

PROGRAM

R600B

PROGRAM

R400B

NOT USED

REGULATOR

OPERATING

MODE

(SEE TABLE 3)

ENABLE

REGULATOR

DAC CODE

(See Tables 4, 5 and 6)

Figure 3. Bit Assignments

Figure 4. Timing Parameters

OPERATION

ACK

12

3

ADDRESS

WR

4

5

6

7

8

9

12345678

9

123456789

11

0

0

1

0

1

0

1

1

001010

A7

A6

A5

A4

A3

A2

A1

A0

A7

A6

A5

A4

A3

A2

A1

A0

B7

B6

B5

B4

B3

B2

B1

B0

76543210

ACK

STOP

START

SDA

SCL

ACK

SUB-ADDRESS

DATA BYTE

3562 F03

SDA

SCL

3562 F04

START

CONDITION

REPEATED START

CONDITION

STOP

CONDITION

START

CONDITION