The ISL78233, ISL78234 are highly efficient, monolithic,
synchronous step-down DC/DC converters that can deliver 3A
(ISL78233), or 4A (ISL78234) of continuous output current from
a 2.7V to 5.5V input supply. The devices use current mode control
architecture to deliver a very low duty cycle operation at high
frequency with fast transient response and excellent loop stability.
The ISL78233, ISL78234 integrate a very low ON-resistance
P-Channel (35mΩ) high-side FET and N-Channel (11mΩ)
low-side FET to maximize efficiency and minimize external
component count. The 100% duty-cycle operation allows less
than 200mV dropout voltage at 4A output current. The
operation frequency of the Pulse Width Modulator (PWM) is
adjustable from 500kHz to 4MHz. The default switching
frequency of 2MHz is set by connecting the FS pin high.
The ISL78233, ISL78234 can be configured for discontinuous
or forced continuous operation at light load. Forced continuous
operation reduces noise and RF interference, while
discontinuous mode provides higher efficiency by reducing
switching losses at light loads.
Fault protection is provided by internal hiccup mode current
limiting during short circuit and overcurrent conditions. Other
protection, such as overvoltage and over-temperature are also
integrated into the device. A power-good output voltage
monitor indicates when the output is in regulation.
The ISL78233, ISL78234 offers a 1ms Power-good (PG) timer at
power-up. When in shutdown, the ISL78233, ISL78234
discharges the output capacitor through an internal soft-stop
switch. Other features include internal fixed or adjustable
soft-start and internal/external compensation.
The ISL78233, ISL78234 is available in a 3mm x 3mm 16 Ld
Thin Quad Flat Pb-free (TQFN) package with an exposed pad for
improved thermal performance and 1mm maximum height.
The complete converter occupies less than 0.22 in2 area.
The ISL78233, ISL78234 are rated to operate across the
temperature range of -40°C to +125°C.

Features
• 2.7V to 5.5V input voltage range
• Very low ON-resistance FET’s - P-Channel 35mΩ and
N-Channel 11mΩ typical values
• High efficiency synchronous buck regulator with up to 95%
efficiency
• -1.2%/1% reference accuracy over-temperature/load/line
• Complete BOM with as few as 3 external parts
• Internal soft-start - 1ms or adjustable
• Soft-stop output discharge during disable
• Adjustable frequency from 500kHz to 4MHz - default at
2MHz
• External synchronization up to 4MHz
• Over-temperature, overcurrent, overvoltage and negative
overcurrent protection
• Shared common device pinout allows simplified output
power upgrades over time
• Tiny 3mm x 3mm TQFN package
• AEC-Q100 qualified

Applications
• DC/DC POL modules
• μC/µP, FPGA and DSP power
• Video processor/SOC power
• Li-ion battery powered devices
• Automotive infotainment power