AS3693B

austriami crosyst ems

www.austriamicrosystems.com

Revision 1.21 / 2011-09-30

11 - 32

7.1.1

Feedback Selection

In the AS3693B, each led – string feedback can be assigned to the specific led-supply, to minimize the power

consumption in the system. It can be chosen in between FBR, FBG and FBB.

FB R

FB G

FB B

NOFB

VC

SHORTLED

REF

OPENLED

VSL

VOL

1

2

3...16

R5

AS3693B

ANALOG REGULATION

CIRCUIT

16 REGULATORS

Feedback resistor divider

(part of DCDC converter circuit)

Voltage Feedback

input for DCDC

From main

supply

R1

R2

R3

C1

Vfb

Voltage Feedback

input for DCDC

DCDC Converter

for VDD

(Internal or externa)l

Table 7 – Feedback Selection

Addr: 05h,06h,07h,08h

Feedback Select 1-4

This register controls the Feedback of the Automatic feedback loop

Bit

Bit Name

Default

Access

Description

1:0

FB1_Select

FB5_Select

FB9_Select

FB13_Select

00

R/W

Selects the feedback of the voltage regulators

00= regulator on FBR

01= regulator on FBG

10= regulator on FBB

11= regulator not connected to FB

3:2

FB2_Select

FB6_Select

FB10_Select

FB14_Select

01

R/W

Selects the feedback of the voltage regulators

00= regulator on FBR

01= regulator on FBG

10= regulator on FBB

11= regulator not connected to FB

5:4

FB3_Select

FB7_Select

FB11_Select

FB15_Select

01

R/W

Selects the feedback of the voltage regulators

00= regulator on FBR

01= regulator on FBG

10= regulator on FBB

11= regulator not connected to FB

7:6

FB4_Select

FB8_Select

FB12_Select

FB16_Select

10

R/W

Selects the feedback of the voltage regulators

00= regulator on FBR

01= regulator on FBG

10= regulator on FBB

11= regulator not connected to FB