ADP1655 Analog Devices, ADP1655 Datasheet - Page 13

• Manufacturer Part Number: ADP1655
• Description: Dual LED Flash Driver with I2C Compatible Interface
• Manufacturer: Analog Devices

Specifications of ADP1655

• Product Description: Serial 2 WLED Flash Driver
• Led #: 2
• Led Configuration: Serial
• Topology: Inductive
• Application: Flash
• I2c Support: Yes
• Max Iout (ma): 400mA
• Brightness Control: I2C
• Peak Efficiency (%): n/a
• Switching Frequency: 2MHz
• Over Volt Protection (v): 10V
• Vin Min (v): 2.5V
• Vout (v): Current Output
• Synchronous: Yes
• Package: 12-Bump WLCSP

2-BIT LOGIC INTERFACE MODE (I2C/EN = 0)
In 2-bit logic interface mode, the two control pins, EN1 and
EN2, select whether the part is disabled or operating in assist
light mode or flash mode, as outlined in Table 6. Additionally,
the TORCH pin selects torch mode.
Figure 29 illustrates state transitions of 2-bit logic mode con-
trolled by digital inputs EN1, EN2, TORCH, and TX_MASK.
When the ADP1655 is in flash mode, the TX_MASK pin can
be used to reduce the battery load. The device remains in flash
mode, but the LED driver output current is reduced to the assist
light level.
Table 6. 2-Bit Logic Interface Mode Selection
Mode
Shutdown
Torch
Assist light
Reserved
Flash
EXTERNAL
TORCH
Figure 29. 2-Bit Logic Mode State Transitions (I2C/EN = 0)
I2C/
EN
0
0
0
0
0
EN1 = 0
EN2 = 1
TORCH = 0
TORCH = 1
EN1 = 1
EN2 = 1
EN1
0
0
0
1
1
ASSIST
LIGHT
EN2
0
0
1
0
1
EN1 = 1
EN2 = 1
EN1 = 0
TORCH
0
1
X
X
X
EN2 = 0
SHUTDOWN
EN1 = 1
EN2 = 1
FLASH
EN1 = 0
EN2 = 0
Output Current
0 mA
One LED: 80 mA
Two LEDs: 40 mA
One LED: 80 mA
Two LEDs: 40 mA
0 mA
One LED: 500 mA
Two LEDs: 320 mA
TIMEOUT
Rev. 0 | Page 13 of 24
I
The ADP1655 includes an I
control of the LED current, as well as for a readback of system
status registers. The I
0x61 in read mode.
Table 7. I
Mode
Standby
Torch
Assist light
Flash
1
2
Registers values are reset to the default values when VIN supply
falls below the undervoltage (UVLO) level.
Figure 30 illustrates the I
The subaddress content selects which of the five ADP1655
registers is written to first. The ADP1655 sends an acknowl-
edgement to the master after the 8-bit data byte has been written.
The ADP1655 increments the subaddress automatically and starts
receiving a data byte to the following register until the master
sends an I
I
from the register denoted by the subaddress and increments
the subaddress automatically, sending data from the next reg-
ister until the master sends an I
Figure 33.
State transitions between standby, assist light, flash, and
external torch modes are described in the State Transitions
section and Figure 34.
The register definitions are shown in the I
section. The lowest bit number (0) represents the least
significant bit, and the highest bit number (7) represents
the most significant bit.
2
2
Torch mode has to be enabled from Register 0x04.
The output current value depends on the register settings.
C read sequence of a single register. ADP1655 sends the data
C INTERFACE MODE (I2C/EN = 1)
2
2
C Interface Mode Selection
C stop as shown in Figure 31. Figure 32 shows the
I2C/
EN
1
1
1
1
SCL
X
X
X
X
2
C chip address is 0x60 in write mode and
2
C write sequence to a single register.
SDA
X
X
X
X
2
C-compatible serial interface for
2
C stop condition as shown in
TORCH
0
1
X
X
2
C Register Map
Output Current
0 mA
20 mA to 160 mA
20 mA to 160 mA
200 mA to 500 mA
ADP1655
1, 2
2
2