AS3695C

austriamicrosystems

www.austriamicrosystems.com

Rev 1.11 / 2010-12-08

22 - 39

4.3

Power supply

4.4

Safety features

4.4.1 Temperature shutdown

If OTturnoff = 1 the outputs of the device are turned off when the die temperature reaches 140°C. If the

die temperature goes below 130°C the outputs are turned on again.

4.4.2 xRES input

In addition to the build in power on reset circuit there is an external reset input “xRES” available. This

gives the possibility to keep the outputs turned off until all blocks of the LED-driver circuits are fully

working ( DCDC, MCU ... )

4.4.3 Register Lock/Unlock

To prevent wrong writing to registers due to noise on the serial interface a lock/unlock mechanism is

implemented.

Register 0x01, 0x02, 0x03, 0x04, 0x05, 0x06, 0x07, 0x08, 0x13 , 0x61, 0x62, 0x63 belong to Group1

and can only be written if Group1 is unlocked by the “LOCKUNLOCK”-byte (Reg: 0x36 )

Register 0x0D, 0x0E, 0x11, 0x12, 0x14, 0x15 belong to Group2 and can only be written if Group2 is

unlocked by the “LOCKUNLOCK”-byte (Reg: 0x36 )

The default value of the Groups is locked.

4.5

Reference circuit

The reference circuit generates an internal supply voltage of 2.5V for the digital logic.

RegAddr: 0x58

STATUS

Bit

Name

Description

Default

Acc

ess

7

STATnosync

Sync detector status

0...no sync fault

1...sync fault. VSYNC was missed for > 100ms

0

r

6

STATOT

Overtermperature status

0...no overtemperature

1...overtemperature

0

r

5

STATopen

Status open LED detection

0...no open LED detected

1...opdn LED detected

0

r

4

STATshort

Status short LED detection

0...no short LED detected

1...short LED detected

0

r

3

Not used

0

VDD

LDO

2.5V digital supply

V2_5

AGND

4.0V to 5.5V analog supply

POR

Temp

xRES

Toff_OverT