ISL9440B

Triple Step-Down PWM and Single Linear Controller with Programmable Soft-Start

Product Status: Mass Production

OVERVIEW

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.

KEY 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)

PARAMETRICS

Parameters
ISL9440B
Basic Information
Production Status
Mass Production
# of Outputs
4
Input Voltage Min (V)
4.5
Input Voltage Max (V)
24
Output Voltage Min (V)
0.8
Output Voltage 1 Max (V)
24
Output Current 1 Max (A)
0.8
Switching Frequency (kHz)
300
Bias Voltage (VCC) (V)
5
Output Current 2 Max (A)
24
Output Voltage 2 Max (V)
Adj.
Output Voltage 3 Max (V)
Adj.
Linear Output
Yes
DDR Capable
No
Qualification Level
Standard
Bias Voltage Range (V)
5
Can Sample
YES
Temperature Range
-40 to +85

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