ISL9440B

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
• Independently Programmable Voltage Outputs
• 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)






Application

• Satellite and Cable Set-Top Boxes
• Cable Modems
• VoX Gateway Devices
• NAS/SAN Devices
• ATX Power Supply




Pinout






Specifications

VCC_5V to GND . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to +6V
VCC_5V Output Current . . . . . . . . . . . . . . . . . . . . . . . . 100mA
VIN to GND . . . . . . . . . . . . . . . . . . . . . . . . . . . . -0.3V to +28V
BOOT/UGATE to PHASE . . . . . . . . . . . . -0.3V to VCC_5V + 0.3V
PHASE1,2,3 and ISEN1, 2,3, to GND
. . . . . . . . . . . . . . . . . . . -5V (<100ns, 10J)/-0.3V (DC) to +28V
EN/SS1,EN/SS2, EN/SS3, FB1, FB2, FB3, to GND . . . . . . -0.3V to
VCC_5V + 0.3V
LDOFB, OCSET1, OCSET2, OCSET3,
LGATE1, LGATE2, LGATE3, to GND. . . -0.3V to VCC_5V + 0.3V
PGOOD, RST, G4 to GND. . . . . . . . . . . . . . . . . . . . . -0.3V to +6V






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.