Features
- Three Integrated Synchronous Buck PWM Controllers
- Internal Bootstrap Diodes
- Internal Compensation
- Independent Control for each Regulator and Programmable Output Voltages; Independent Enable/Shutdown/Soft-start
- Fixed Switching Frequency: 300kHz(B), 600kHz(C)
- Adaptive Shoot-Through Protection on all Synchronous Buck Controllers
- Pre-biased Output Start-up Capability
- Out-of-Phase Switching to Reduce Input Capacitance (0°/180°/0°)
- No External Current Sense Resistor
- Uses Lower MOSFET's rDS(ON)
- Current Mode Controller with Voltage Feed-Forward
- Complete Protection
- Overcurrent, Overvoltage, Undervoltage Lockout, Over-Temperature
- Cycle-by-Cycle Current Limiting
- Wide Input Voltage Range
- Input Rail Powers VIN Pin: 5.6V to 24V
- Input Rail Powers VCC_5V Pin (VIN tied to VCC_5V, for 5V input applications): 4.5V to 5.6V
- Early Warning on Input Voltage Failure
- Integrated Reset Function
- Pb-Free (RoHS Compliant)
Description
The ISL9440B and ISL9440C are quad-output synchronous buck controllers that integrate three PWM controllers and one low drop-out linear regulator controller, which are full featured and designed to provide multi-rail power for use in products such as cable and satellite set-top boxes, VoIP gateways, cable modems, and other home connectivity products as well as a variety of industrial and general purpose applications. Each output is adjustable down to 0. 8V. The PWMs are synchronized at 180° out-of-phase thus, reducing the RMS input current and ripple voltage. The ISL9440B and ISL9440C offer programmable soft-start, independent enable inputs for ease of supply rail sequencing, and integrated UV/OV/OC/OT protections in a space conscious 5mmx5mm QFN package. An early warning function is offered to output a logic signal to warn the system to back up data when input voltage falls below a certain level. The ISL9440B and ISL9440C utilize internal loop compensation to keep minimum peripheral components for compact design and a low total solution cost. These devices are implemented with current mode control with feed-forward to cover various applications even with fixed internal compensations.
Applications
- Satellite and Cable Set-Top Boxes
- Cable Modems
- VoX Gateway Devices
- NAS/SAN Devices
- ATX Power Supply
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