Datasheet

ADP1660 Data Sheet
Rev. 0 | Page 12 of 28
ASSIST TO FLASH MODE
The STR_POL bit in Register 0x01 can be used to change the
default polarity of the STROBE pin from active high to active low.
Additional image sensor-specific assist to flash enable modes are
included in the device. Information about these modes is avail-
able on request from the Analog Devices, Inc., sales team.
LED2 CURRENT
0A
STROBE
I_TOR2
REG 0x0F, LED1_EN = 1
LED2_EN = 1
REG 0x01, STR_LV = 1
LED_MOD = 010
I_FL1
LED1 CURRENT
0A
I_TOR1
I_FL2
REG 0x02, FL_TIM = XXXXms
REG 0x06, I _FL1 = XX XXXXmA
REG 0x08, I_TOR1 = X XXXXmA
REG 0x09, I_FL2 = XX XXXXmA
REG 0x0B, I_TOR2 = X XXXXmA
I
2
C DATA BUS
ADP1660 SETS LED1_EN TO 0.
ADP1660 SETS LED2_EN TO 0.
ADP1660 SETS LED_MOD TO 000.
11018-015
Figure 20. Enabling Assist to Flash (Level-Sensitive) Mode
TORCH MODE
Set the assist/torch light current using the I_TORx bits. To enable
torch mode, set the LED_MOD bits to 000 (standby mode), and set
the LED1_EN and LED2_EN bits to 1 in Register 0x0F; then bring
GPIO high. Disable the LED current by bringing GPIO low or by
setting the LED1_EN and LED2_EN bits to 0. Bringing GPIO low
during torch mode automatically sets LED1_EN and LED2_EN =
0. To reenable torch mode, set LED1_EN and LED2_EN = 1 and
bring GPIO high again.
LED2 CURRENT
0A
I
2
C DATA BUS
GPIO (TORCH)
I_TOR2
LED1 CURRENT
0A
I_TOR1
REG 0x08, I_TOR1 = X XXXXmA
REG 0x0B, I_TOR2 = X XXXXmA
REG 0x0F, LED1_EN = 1
LED_MOD = 000
LED2_EN = 1
ADP1660 SETS LED1_EN TO 0.
ADP1660 SETS LED2_EN TO 0.
11018-016
Figure 21. Enabling External Torch Mode Using the GPIO Pin
TORCH TO FLASH MODE
The driver can move directly from external torch mode (using
the GPIO pin) to flash mode by bringing the STROBE pin high
before GPIO is brought low. Bringing the GPIO (torch) pin low
before STROBE goes high prevents the flash from firing.
The ADP1660 returns to standby mode after a successful flash
and sets the LED1_EN and LED2_EN bits to 0 in Register 0x0F.
LED2 CURRENT
0A
STROBE
GPIO (TORCH)
I_TOR2
REG 0x0F, LED1_EN = 1
LED2_EN = 1
REG 0x01, STR_LV = 1
LED_MOD = 000
I_FL1
LED1 CURRENT
0A
I_TOR1
I_FL2
REG 0x02, IO_CFG = 01
FL_TIM = XXXXms
REG 0x06, I _FL1 = XX XXXXmA
REG 0x08, I_TOR1 = X XXXXmA
REG 0x09, I_FL2 = XX XXXXmA
REG 0x0B, I_TOR2 = X XXXXmA
I
2
C DATA BUS
ADP1660 SETS LED1_EN TO 0.
ADP1660 SETS LED2_EN TO 0.
11018-017
Figure 22. Enabling Flash Mode from External Torch Mode
TxMASK OPERATION
When the ADP1660 is in flash mode, the TxMASK function can
reduce the battery load in response to the system enabling a power
amplifier. The device remains in flash mode, but the LED driver
output current is reduced to the programmed TxMASK current
level in less than 21 µs. The TxMASK current level is programmed
in Register 0x07 (for LED1) and in Register 0x0A (for LED2).
GPIO (TxMASK)
FL_TX = 1
LED2 CURRENT
0A
STROBE
I_TX2
REG 0x0F, LED1_EN = 1
LED2_EN = 1
REG 0x01, STR_LV = 1
LED_MOD = 011
I_FL1
LED1 CURRENT
I_TX1
0A
I_FL2
REG 0x02, IO_CFG = 10
FL_TIM = XXXXms
REG 0x06, I _FL1 = XX XXXXmA
REG 0x08, I_TOR1 = X XXXXmA
REG 0x09, I_FL2 = XX XXXXmA
REG 0x0B, I_TOR2 = X XXXXmA
I
2
C DATA BUS
ADP1660 SETS LED1_EN TO 0.
ADP1660 SETS LED2_EN TO 0.
ADP1660 SETS LED_MOD TO 000.
11018-018
Figure 23. TxMASK Operation During Flash (Level-Sensitive) Mode
After a TxMASK event occurs, a flag is set in the fault informa-
tion register (Register 0x0C, Bit 3). When the TxMASK signal
goes low again, the LED current reverts to the full flash level in
a controlled manner to avoid overshoots on the battery current.