Renesas Electronics Corporation

The ISL6410, ISL6410A are synchronous current-mode PWM regulators designed to provide a total DC/DC solution for microcontrollers, microprocessors, CPLDs, FPGAs, core processors/BBP/MAC, and ASICs. The ISL6410 should be selected for applications using 3.3V ±10% as an input voltage and the ISL6410A in applications requiring 5.0V ±10%. These synchronous current mode PWM regulators have integrated N- and P-Channel power MOSFETs and provide pre-set pin programmable outputs. Synchronous rectification with internal MOSFETs is used to achieve higher efficiency and a reduced external component count. The operating frequency of 750kHz typical allows the use of small inductor and capacitor values. The device can be synchronized to an external clock signal in the range of 500kHz to 1MHz. A power good signal PG is generated when the output voltage falls outside the regulation limits. Other features include overcurrent protection and thermal overload shutdown. The ISL6410, ISL6410A are available in an MSOP 10 lead package.

The ISL6420B simplifies the implementation of a complete control and protection scheme for a high-performance DC/DC buck converter. It is designed to drive N-Channel MOSFETs in a synchronous rectified buck topology. The ISL6420B integrates control, output adjustment, monitoring and protection functions into a single package. Additionally, the IC features an external reference voltage tracking mode for externally referenced buck converter applications and DDR termination supplies, as well as a voltage margining mode for system testing in networking DC/DC converter applications. The ISL6420B provides simple, single feedback loop, voltage mode control with fast transient response. The output voltage of the converter can be precisely regulated to as low as 0.6V. The operating frequency is fully adjustable from 100kHz to 1.4MHz. High frequency operation offers cost and space savings. The error amplifier features a 15MHz gain-bandwidth product and 6V/µs slew rate that enables high converter bandwidth for fast transient response. The PWM duty cycle ranges from 0% to 100% in transient conditions. Selecting the capacitor value from the ENSS pin to ground sets a fully adjustable PWM soft-start. Pulling the ENSS pin LOW disables the controller. The ISL6420B monitors the output voltage and generates a PGOOD (power good) signal when soft-start sequence is complete and the output is within regulation. A built-in overvoltage protection circuit prevents the output voltage from going above typically 115% of the set point. Protection from overcurrent conditions is provided by monitoring the rDS(ON)of the upper MOSFET to inhibit the PWM operation appropriately. This approach simplifies the implementation and improves efficiency by eliminating the need for a current sensing resistor.

The ISL6422B is a highly integrated voltage regulator and interface IC, specifically designed for supplying power and control signals from advanced satellite set-top box (STB) modules to the low noise blocks (LNBs) of two antenna ports. The device is consists of two independent current-mode boost PWMs and two low-noise linear regulators along with the circuitry required for 22kHz tone generation, modulation and I2C device interface. The device makes the total LNB supply design simple, efficient and compact with low external component count. Two independent current-mode boost converters provide the linear regulators with input voltages that are set to the final output voltages, plus typically 0. 8V to insure minimum power dissipation across each linear regulator. This maintains constant voltage drops across each linear pass element while permitting adequate voltage range for tone injection. The final regulated output voltages are available at two output terminals to support simultaneous operation of two antenna ports for dual tuners. The outputs for each PWM can be controlled in two ways, full control from I2C using the VTOP1, VTOP2 and VBOT1, VBOT2 bits or set the I2C to the lower range ie 13V/14V and switch to higher range ie 18V/19V with the SELVTOP1, SELVTOP2 pins. All the functions on this IC are controlled via the I2C bus by writing 8 bits words onto the System Registers (SR). The same register can be read back, and four bits per output will report the diagnostic status. Separate enable commands sent on the I2C bus provide independent standby mode control for each PWM and linear combination, disabling the output into shutdown mode. Each output channel is capable of providing 750mA of continuous current. The overcurrent limit can be digitally programmed. The External modulation input EXTM1, EXTM2 can accept a modulated DiSEqC command and transfer it symmetrically to the output. Alternatively the EXTM1, EXTM2 pins can be used to modulate the continuous internal tone. The FLT pin serves as an interrupt for the processor when any condition turns OFF the LNB controller (Over- Temperature, Overcurrent, Disable). The nature of the fault can be read of the I2C registers.

The ISL6423B is a highly integrated voltage regulator and interface IC, specifically designed for supplying power and control signals from advanced satellite set-top box (STB) modules to the low noise blocks (LNBs) of singe antenna ports. The device consists of a current-mode boost PWM and a low-noise linear regulator along with the circuitry required for 22kHz tone generation, modulation and I2C device interface. The device makes the total LNB supply design simple, efficient and compact with low external component count. The current-mode boost converters provides the linear regulator with input voltage that is set to the final output voltages, plus typically 0.8V to insure minimum power dissipation across each linear regulator. This maintains constant voltage drop across the linear pass element while permitting adequate voltage range for tone injection. The final regulated output voltage is available at output terminals to support the operation of an antenna port for single tuners. The outputs for each PWM can be controlled in two ways, full control from I2C using the VTOP and VBOT bits or set the I2C to the lower range i.e., 13V/14V, and switch to higher range i.e., 18V/19V, with the SELVTOP pin. All the functions on this IC are controlled via the I2C bus by writing 8 bits words onto the System Registers (SR). The same register can be read back, and five I2C bits will report the diagnostic status. Separate enable command sent on the I2C bus provides for standby mode control for the PWM and linear combination, disabling the output and forcing a shutdown mode. The output channel is capable of providing 750mA of continuous current. The overcurrent limit can be digitally programmed to four levels. The External modulation input EXTM can accept a modulated Diseqc command and transfer it symmetrically to the output. Alternatively the EXTM pin can be used to modulate the continuos internal tone. The FLT pin serves as an interrupt for the processor when any condition turns OFF the LNB controller (Over Temperature, Overcurrent, Disabled). The nature of the Disable can be read of the I2C registers.

The ISL6439 makes easy work out of implementing a complete control and protection scheme for a DC/DC step-down converter. Designed to drive N-Channel MOSFETs in a synchronous buck topology, the ISL6439 integrates the control, output adjustment, monitoring and protection functions into a single package. The ISL6439 provides simple, single feedback loop, voltage-mode control with fast transient response. The output voltage can be precisely regulated to as low as 0. 8V, with a maximum tolerance of ±1. 5% over temperature and line voltage variations. A fixed frequency oscillator reduces design complexity, while balancing typical application cost and efficiency. The error amplifier features a 15MHz gain-bandwidth product and 6V/µs slew rate which enables high converter bandwidth for fast transient performance. The resulting PWM duty cycles range from 0% to 100%. Protection from overcurrent conditions is provided by monitoring the rDS(ON)of the upper MOSFET to inhibit PWM operation appropriately. This approach simplifies the implementation and improves efficiency by eliminating the need for a current sense resistor.