Datasheet

DS1085

9 of 21

The DIV word sets the programmable divider. These 10 bits (N0–N9) determine the value of the

programmable divider (N). The range of divisor values is from two to 1025, and is equal to the

programmed value of N plus 2 (see Table 8).

Table 8. PROGRAMMABLE DIVISOR N VALUES

BIT VALUE DIVISOR (N)

00000000 00XXXXXX 2*

00000000 01XXXXXX 3

— —

11111111 11XXXXXX 1025

*Factory Default Setting

ADDR BYTE (Address 0Dh)

MSB LSB

NAME — — — — WC A2 A1 A0

Factory

Default

X X X X 0 0 0 0

X = Don’t care.

A2, A1, A0 (Default Setting = 000)

These are the device select bits that determine the 2-wire address of the device.

WC (Default Setting = 0)

This bit determines when/if the EEPROM is written to after register contents have been changed. If

WC = 0, EEPROM is written automatically after a write register command. If WC = 1, the EEPROM is

only written when the “WRITE” command is issued. In applications where the register contents are

frequently rewritten, WC should be set to 1; otherwise, it is necessary to wait for an EEPROM write cycle

to complete (up to 10ms) between writing to the registers. Regardless of the value of the WC bit, when

the ADDR register (A2, A1, A0) is written, the current value in all registers (DAC, OFFSET, DIV, MUX,

and ADDR) are immediately written to the EEPROM.

RANGE REGISTER (Address 37h)

MSB LSB

OS5 OS4 OS3 OS2 OS1 X X X X X X X X X X X

The first five bits of the RANGE register contain the default OFFSET value. The decimal value of the

RANGE register is the value OS that is referred to in Table 6. The RANGE register is read-only.