AS3675 datasheet(19/81 Pages) AMSCO

19 / 81 page

www.austriamicrosystems.com/AS3675

1v3

18 - 80

AS3675

Datasheet - D e ta i l e d D e s c r i p t i o n

8.3.1

Charge Pump Mode Switching

If automatic mode switching is enabled (cp_mode_switching (see page 20) = 00 or cp_mode_switching = 01) the

charge pump monitors the current sinks, which are connected via a led to the output CPOUT. To identify these current

sources (sinks), the registers CP mode Switch1 and CP mode Switch2 (register bits curr30_on_cp (see page 21) …

curr33_on_cp, rgb1_on_cp … rgb3_on_cp, curr1_on_cp, curr2_on_cp, curr41_on_cp … curr43_on_cp and

curr6_on_cp) should be setup before starting the charge pump (cp_on (see page 20) = 1). If any of the voltage on

these current sources drops below the threshold (currlv_switch, currhv_switch), the next higher mode is selected after

the debounce time.

To avoid switching into 1:2 mode (battery current = 2 times output current), set cp_mode_switching = 01.

If the currX_on_cp=0 and the according current sink is connected to the charge pump, the current sink will be func-

tional, but there is no up switching of the charge pump, if the voltage compliance is too low for the current sink to sup-

ply the specified current.

currhv_switch

CURR1, 2, 6

minimum voltage

If the voltage drops below this threshold, the

charge pump will use the next available

mode

(1:1 -> 1:1.5 or 1:1.5 -> 1:2)

0.45

currlv_switch

CURR30-33, RGB1-

3, CURR41-3

minimum voltage

0.2

CURR30-33

0-75.6mA range

for strobe if

curr3x_strobe_high=

0.4

tdeb

CP automatic up-

switching debounce

time

cp_start_debounce=0

240

µsec

After switching on CP (cp_on set to 1), if

cp_start_debounce=1

2000

µsec

Table 14. Charge Pump Characteristics

Symbol

Parameter

Condition

Min

Typ

Max

Unit

AS3675 数据表(PDF) 19 Page - ams AG

AS3675 数据表(HTML) 19 Page - ams 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 73 74 75 76 77 78 79 80 81

数据表下载