LM3560 Datasheet, PDF (15/42 Pages) Texas Instruments – LM3560 Synchronous Boost Flash Driver w/ Dual 1A High-Side Current Sources (2A Total Flash Current)

the programmed Torch current level by stepping through all
of the Torch currents at (32 µs/step) until the programmed
Torch current level is reached.
PRIVACY INDICATOR MODE
The current sources (LED1 and/or LED2) can also be used
as a privacy indicator before and after flash mode. Privacy
indicate mode is enabled by setting the Enable Register bit
[1:0] to (0, 1). Privacy mode is configured via the Privacy
Register. This allows the selection of which current source to
use as the privacy indicator (either LED1, LED2, or both),
whether or not the privacy indicate mode turns off at the end
of the flash pulse, the 3 selectable privacy blink periods
(t_BLINK), and the 8 duty cycle settings for the privacy indicator
average current.
The intensity of the LEDs in privacy indicate mode is set by
PWM’ing either the lowest Torch current level (31.25 mA per
current source) or the highest Torch current level (250 mA per
current source). Bit [2] in the Enable register selects between
these two levels. Bits [2:0] in the Privacy Register select the
8 different duty cycles of 10%, 20%, 30%, 40%, 50%, 60%,
70%, and 80%. This enables privacy mode to have a PWM'd
torch current with a wide number of values (see Table 1 ). The
privacy blink options (t_BLINK) are set via bit [7:6] of the Privacy
Register. Selectable options are 128 ms, 256 ms, 512 ms, or
always on. The blink pulse period is set to 2 x t_BLINK. Figure
3 details the timing for the Privacy Indicate Mode timing on
ILED1 or ILED2.
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FIGURE 3. Privacy Indicate Timing
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TABLE 1. Privacy Indicate (PWM'd Torch) Possible Current Settings
(The listed current is with 1 current source active)
Privacy Current
Setting
(Enable Register Bit
[2])
0 = 31.25mA peak
1 = 250mA peak
0
0
0
0
0
0
0
0
1
1
1
1
Privacy Indicate Duty
Cycle
Privacy Register Bits[2:0]
see (Table 4)
000
001
010
011
100
101
110
111
000
001
010
011
ILED1 or ILED2
(Single LED)
3.125 mA
6.25 mA
9.375 mA
12.5 mA
15.625 mA
18.75 mA
21.875 mA
25 mA
25 mA
50 mA
75 mA
100 mA
14