MAX77342 Datasheet, PDF (1/50 Pages) Maxim Integrated Products – DC-DC Step-Up Converter

MAX77342
1.6A Adaptive DC-DC Step-Up Converter
with High-Side Flash Driver
General Description
The MAX77342 provides a highly efficient solution for cell
phone camera flash applications by integrating a 1.6A
PWM DC-DC step-up converter and three programmable
high-side, low-dropout LED current regulators. An I²C
interface provides flexible control of the step-up converter,
indicator, assist, torch, and flash mode selection, and
flash safety timer duration settings.
The device operates down to 2.5V, making it future proof
for new battery technologies. The step-up converter fea-
tures an internal switching MOSFET and synchronous
rectifier to improve efficiency and minimize external
component count. Three high-side, high-current regula-
tors provide support for indicator, assist, torch, and flash
modes. They can source up to 1600mA in flash mode,
100mA in torch and assist light mode, and 16mA for
indicator. The output voltage is adaptively controlled,
stepping up voltage only as high as necessary to sup-
port the required LED forward voltage in flash mode. This
approach reduces IC power dissipation by optimizing the
step-up ratio and by minimizing the losses in the current
regulator. In torch, assist light, and indicator, the current
regulators are powered directly from IN, providing the
highest system efficiency.
Additionally, the device includes a low input voltage
protection function that reduces flash current during low
battery conditions to prevent system undervoltage lockup.
Other features include shorted LED detection, overvolt-
age and thermal shutdown protection, and low-power
standby and shutdown modes. The MAX77342 is avail-
able in a 16-bump, 0.5mm pitch WLP package (2.065mm
x 2.065mm).
Simplified Block Diagram
BATTERY
2.5V TO 5.5V
LX
PGND
OUT
IN_FLED
MAX77342
IN
FLED
AGND
EN
SDA
IND
SCL
TORCH_EN
FLASH_STB
TX_MASK
Features
● 2.0V to 5.5V Operation Range
• 2.5V to 5.5V with Full Functionality
• 2.0V to 2.5V with Data Retention
● Step-Up DC-DC Converter
• 1.6A Guaranteed Output Current for V_IN ≥ 3.0V
and V_OUT ≤ 4.2V
• Adaptive Output Voltage Regulation Ensuring
Highest System Efficiency Up to 90%
• Down to 3.125% Duty Cycle
• On-Chip Power MOSFET and Synchronous Rectifier
• 1MHz/2MHz/4MHz PWM Switching Frequency
• Small 1μH Inductor
● High-Side Flash/Torch/Indicator LED Current Regulator
• I²C Programmable Flash Output Current (100mA
to 1600mA in 100mA Steps)
• I²C Programmable Torch Output Current (30mA to
100mA in 10mA Steps)
• I²C Programmable Indicator Output Current (1mA
to 16mA in 1mA Steps)
• Adaptive Regulation Voltage (150mV typ) for Flash
Mode
• Low-Dropout Voltage (100mV max) for Torch Mode
● I²C Programmable Flash Safety Timer
● Open/Short LED Detection
● Tx Mask Reducing Output Current During Tx Event
● Overvoltage Protection
● Thermal Shutdown Protection
● 1μA Shutdown Current
● 16-Bump, 0.5mm Pitch, 2.065mm x 2.065mm WLP
Applications
● Cell Phones and Smartphones
Ordering Information appears at end of data sheet.
For related parts and recommended products to use with this part, refer
to www.maximintegrated.com/MAX77342.related.
19-6754; Rev 0; 9/13