ISL78322
Dual 2A/1.7A Low Quiescent Current 2.25MHz High Efficiency Synchronous Buck Regulator
Key Features
- Dual 2A/1.7A High Efficiency Synchronous Buck Regulator with up to 97% Efficiency, Low Iq (40µA)
- 180° Out-of-Phase Outputs Reduce Ripple Current and EMI
- Start-up with Pre-biased Output Prevents Negative Current Flow in Output Stage
- Selectable Forced PWM Mode and PFM Mode
- External Synchronization up to 8MHz
- Negative Current Detection and Protection
- 100% Maximum Duty Cycle for Lowest Dropout
- Internal Current Mode Compensation
- Peak Current Limiting, Hiccup Mode Short Circuit Protection and Over-Temperature Protection
- Pb-free (RoHs Compliant)
- AEC-Q100 Qualified Component
Description
The ISL78322 is a high efficiency, dual synchronous step-down DC/DC regulator that can deliver up to 2A/1.7A continuous output current per channel. The channels are 180°
out-of-phase for input RMS current and EMI reduction. The supply voltage range of 2.8V to 5.5V allows for the use of a single Li+ cell, three NiMH cells or a regulated 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 ISL78322 operates at 2.25MHz switching frequency which allows 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 ISL78322 has a user configurable mode of operation-forced PWM mode and PFM/PWM mode. The forced PWM mode reduces noise and RF interference while the PFM mode provides highest efficiency by reducing switching losses at light loads. In PFM mode of operation, both channels draw a total quiescent current of only 40µA, hence enabling high light load efficiency and maximizing battery life.
The ISL78322 offers a 1ms Power-Good (PG) signal to monitor both outputs at power-up. When shutdown, ISL78322 discharges the output capacitors. Other features include internal digital soft-start, enable for power sequence, overcurrent protection, and thermal shutdown. The ISL78322 is offered in a 4mmx3mm, 12 Lead DFN package with 1mm maximum height. The complete converter occupies less than 1.8cm2 area.
The ISL78322 is qualified to AECQ100 and specified for operation over the -40°C to +105°C (grade 2) ambient temperature range.
Applications
- DC/DC POL Modules
- µC/µP, FPGA and DSP Power
- Automotive Embedded Processor Power Supply Systems
