ISL78228ARZ-T Datasheet, PDF (1/18 Pages) Intersil Corporation – Dual 800mA Low Quiescent Current 2.25MHz High Efficiency Synchronous Buck Regulator

Dual 800mA Low Quiescent Current 2.25MHz High
Efficiency Synchronous Buck Regulator
ISL78228
The ISL78228 is a high efficiency, dual synchronous step-down
DC/DC regulator that can deliver up to 800mA continuous
output current per channel. The supply voltage range of 2.75V
to 5.5V allows for the use of a 3.3V or 5V input. The current
mode control architecture enables very low duty cycle
operation at high frequency with fast transient response and
excellent loop stability. The ISL78228 operates above the AM
radio band as well as the 2.25MHz switching frequency,
allowing for the use of small, low cost inductors and
capacitors. Each channel is optimized for generating an output
voltage as low as 0.6V.
The ISL78228 has a user configurable mode of
operation-forced PWM mode and PFM/PWM mode. The forced
PWM mode operation reduces noise and RF interference while
the PFM mode operation provides high efficiency by reducing
switching losses at light loads. In PFM mode of operation, both
channels draw a total quiescent current of only 30µA, hence
enabling high light load efficiency in order to maximize battery
life.
The ISL78228 offers a 1ms Power-Good (PG) to monitor both
outputs at power-up. When shutdown, ISL78228 discharges
the outputs capacitor. Other features include internal digital
soft-start, enable for power sequence, overcurrent protection,
and thermal shutdown. The ISL78228 is offered in a
3mmx3mm 10 Ld DFN package with 1mm maximum height.
The complete converter occupies less than 1.8cm² area.
The ISL78228 is AEC-Q100 rated. The ISL78228 is rated for
the automotive temperature range (-40°C to +105°C).
Features
• Internal Current Mode Compensation
• 100% Maximum Duty Cycle for Lowest Dropout
• Selectable Forced PWM Mode and PFM Mode
• External Synchronization up to 4MHz
• Start-up with Pre-biased Output
• Soft-Stop Output Discharge During Disabled
• Internal Digital Soft-Start - 2ms
• Power-Good (PG) Output with 1ms Delay
• AEC-Q100 Tested
• Pb-free (RoHS Compliant)
Applications
• DC/DC POL Modules
• µC/µP, FPGA and DSP Power
• Rear Camera Systems
• Navigation Systems
• Infotainment Systems
100
90
80
2.5V_OUT-PFM
70
1.8V_OUT-PFM
2.5V_OUT-PWM
60
50
1.8V_OUT- PWM
VIN = 5V
40
0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7 0.8
OUTPUT LOAD (A)
FIGURE 1. EFFICIENCY CHARACTERISTICS CURVE
December 4, 2013
1
FN7849.2
CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures.
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