ETA1188

www.etasolution.com

12

Powering Minds of the Smart

OUTPUT CURRENT LIMIT CONFIGURATION

I

5000

( )

ISET

BSTOUT

ISET

V

A

R

=

×

INTERNAL SETTING BY I2C

Beside the external configuration for VOUT and ILIM, ETA1188 provide an I2C protocol to set VOUT and ILIM internally.

Once VOREG_INT[ ] is set to 1 via I2C, there is internal feedback net start run to set VOUT from 3.6V to setting level.

ETA1188 is configured as a slave at I2C address D6xH. Resister map is shown in below table.

BIT

NAME

RESET

RD/WR

FUNCTION

23

REG00: ADDRESS 00xH: INTERNAL CONFIGURATION REGISTER

7

VOREG[8]

0

RD/WR

Internal VOUT Configuration bit: 5120mV

6

VOREG[7]

0

RD/WR

Internal VOUT Configuration bit: 2560mV

5

VOREG[6]

1

RD/WR

Internal VOUT Configuration bit: 1280mV

4

VOREG[5]

0

RD/WR

Internal VOUT Configuration bit: 640mV

3

VOREG[4]

0

RD/WR

Internal VOUT Configuration bit: 320mV

2

VOREG[3]

0

RD/WR

Internal VOUT Configuration bit: 160mV

1

VOREG[2]

1

RD/WR

Internal VOUT Configuration bit: 80mV

0

VOREG[1]

1

RD/WR

Internal VOUT Configuration bit: 40mV

00

REG01: ADDRESS 01xH: INTERNAL CONFIGURATION / CONTROL REGISTER

7

VOREG[0]

0

RD/WR

Internal VOUT Configuration bit: 20mV

6

VOREG_INT

0

RD/WR

Enable internal VOREG setting:

=> 0: Use FB pin to configure VOUT regulation.

=> 1: Use VOREG[8:0] to configure VOUT regulation.

5

IOREG_INT

0

RD/WR

Enable internal IOREG setting:

=> 0: Use ISET pin to configure VOUT current limit.

=> 1: Use IOREG[:] to configure VOUT current limit.

4

IOREG[3]

0

RD/WR

Internal Current Limit Configuration bit: 500mA

3

IOREG[2]

0

RD/WR

Internal Current Limit Configuration bit: 1000mA

2

IOREG[1]

0

RD/WR

Internal Current Limit Configuration bit: 2000mA

1

SLEW<1>

0

RD/WR

VOUT Slew Rate setting

=> 00: 18mV/μs => 01: 9mV/μs

=> 10: 4.5mV/μs => 11: 2.25mV/μs

0

SLEW<0>

0

RD/WR

RECOMMENDATION of INTERNAL VOUT CONFIGURATION

ETA1188 allows to configure VOUT via I2C following setting in Register Map. It is able to configure VOUT from 3.6V to

12V. But ETA1188 always start to regulate with external FB until I2C command is sent. This requires to application

using I2C to set external FB at 5V default to avoid over voltage supply to output connected devices.

Internal configuration also burns more supply current from VIN in no load condition, so thus to avoid waste dissipation

from VIN in application, it is strong recommended to disable internal configuration when load disconnected or even in

no load condition.