AS3689 datasheet(28/72 Pages) AMSOSRAM

28 / 72 page

AS3689

austriami crosyst ems

Datasheet, Confidential

www.austriamicrosystems.com (mlg, ptr)

Revision 1.0.2 / 20070115

26 - 70

DCDC Control 2

Addr: 22h

This register controls the Step Up DC/DC Converter and low-voltage current sinks

CURR3x.

Bit

Bit Name

Default

Access

Description

step_up_res

R/W

Gain selection for Step Up DC/DC Converter.

0 = Select 0 if Step Up DC/DC Converter is used with current

feedback (CURR1, CURR2) or if DCDC_FB is used with

current feedback only – only R1, C1 connected

1 = Select 1 if DCDC_FB is used with external resistor

divider (2 resistors).

skip_fast

R/W

Step Up DC/DC Converter output voltage at low loads, when

pulse skipping is active.

0 = Accurate output voltage, more ripple.

1 = Elevated output voltage, less ripple.

stepup_prot

R/W

Step Up DC/DC Converter protection.

0 = No overvoltage protection.

1 = Overvoltage protection on pin DCDC_FB enabled

voltage limitation =1.25V on DCDC_FB

stepup_lowcur

R/W

Step Up DC/DC Converter coil current limit.

0 = .Normal current limit

1 = Current limit reduced by approx. 33%

curr1_prot_on

R/W

0 = No overvoltage protection

1 = Pull down current on CURR1 switched on, if voltage on

CURR1 exceeds 13.75V, and step_up_on=1

curr2_prot_on

R/W

0 = No overvoltage protection

1 = Pull down current on CURR2 switched on, if voltage

exceeds on CURR2 13.75V, and step_up_on=1

curr6_prot_on

R/W

0 = No overvoltage protection

1 = Pull down current on CURR6 switched on, if voltage on

CURR6 exceeds 13.75V, and step_up_on=1

step_up_fb_auto

R/W

0 = step_up_fb select the feedback of the DCDC converter

1 = The feedback is automatically chosen within the current

sinks CURR1and CURR2 (never DCDC_FB). Only those are

used for this selection, which are enabled (currX_mode must

not be 00) and not connected to the charge pump

(currX_on_cp must be 0).

7.4.2 Current Sinks CURR30, CURR31, CURR32, CURR33

These current sinks have a preview and strobe setting. The preview and strobe can be controlled by software

(register bit) or GPIO can be programmed to enter preview mode (polarity programmable) and GPI can be

programmed to enter strobe mode (polarity programmable).

In strobe mode, a timeout timer protects the flash leds with a settable timeout of 100ms to 1600ms. This timer

has the following modes:

Flash time defined by timeout timer (Ts) independent of strobe signal (Mode 1)

Flash time limited to timeout or end of strobe pulse (Mode 2)

Flash time as timeout timer setting independent of strobe pulse length (Mode 3)

Table 12 – High Current Sinks CURR30,31,32,33 Parameters

Symbol

Parameter

Min

Typ

Max

Unit

Note

IBIT5

Current sink if Bit5 = 1

19.2

IBIT4

Current sink if Bit4 = 1

9.6

For V(CURRx) > 0.2 / 0.4V

AS3689 Datasheet(PDF) 28 Page - ams-OSRAM AG

AS3689 Datasheet(HTML) 28 Page - ams-OSRAM AG

Html Pages

1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72

Datasheet Download

Link URL