Renesas Electronics Corporation

The ISL6442 is a high-performance, triple output controller that provides a single high-frequency power solution primarily for Broadband, DSL and Networking applications. This device integrates complete control, monitoring and protection functions for two synchronous buck PWM controllers and one linear controller. Input voltage ripple and total RMS input current is substantially reduced by synchronized 180° out-of-phase operation of the two PWMs. The two PWM buck converters provide simple voltage mode control. The output voltage of the converters can be precisely regulated to as low as 0.6V, with a maximum tolerance of ±1.5% over temperature and line variations. Programmable switching frequency up to 2.5MHz provides fast transient response and small external components. The linear controller provides a low-current output. The ISL6442 has voltage-tracking capability. Each controller has soft-start and independent enable functions combined on a single pin. A capacitor from SS/EN to ground sets the soft-start time; pulling SS/EN pin below 1V disables the controller. Both outputs can soft-start into a pre-biased load. The ISL6442 incorporates robust protection features. An adjustable overcurrent protection circuit monitors the output current by sensing the voltage drop across the upper MOSFET rDS(ON). Hiccup mode overcurrent operation protects the DC/DC converters from damage under over load and short circuit conditions. A PGOOD signal is issued when soft-start is complete and PWM outputs are within 10% of their regulated values and the linear regulator output is higher than 75% of its nominal value. Thermal shut-down circuitry turns the device off if the IC temperature exceeds +150°C.

The ISL6443A is a high-performance, triple-output controller optimized for converting wall adapter, battery or network intermediate bus DC input supplies into the system supply voltages required for a wide variety of applications. Each output is adjustable down to 0.8V. The two PWMs are synchronized at 180° out of phase, thus reducing the RMS input current and ripple voltage. The ISL6443A incorporates several protection features. An adjustable overcurrent protection circuit monitors the output current by sensing the voltage drop across the lower MOSFET. Hiccup mode overcurrent operation protects the DC/DC components from damage during output overload/short circuit conditions. Each PWM has an independent logic-level shutdown input (SD1SD1 and SD2). A single PGOOD signal is issued when soft-start is complete on both PWM controllers and their outputs are within 10% of the set point and the linear regulator output is greater than 75% of its setpoint. Thermal shutdown circuitry turns off the device if the junction temperature exceeds +150 °C.

The ISL6446A is a high-performance, triple output controller that provides a single high-frequency power solution primarily for Broadband, DSL and Networking applications. This device integrates complete control, monitoring and protection functions for two synchronous buck PWM controllers and one linear controller. Input voltage ripple and total RMS input current is substantially reduced by synchronized 180° out-of-phase operation of the two PWMs. The two PWM buck converters provide simple voltage mode control. The output voltage of the converters can be precisely regulated to as low as 0. 6V, with a maximum tolerance of ±1. 5% over-temperature and line variations. Programmable switching frequency down to 100kHz provides optimized low cost solution for ATX power supplies. It is also able to operate up to 2. 5MHz to deliver compact solutions. The linear controller provides a low-current output. Each PWM controller has soft-start and independent enable functions combined on a single pin. A capacitor from SS/EN to ground sets the soft-start time; pulling SS/EN pin below 1V disables the controller. Both outputs can soft-start into a prebiased load. The ISL6446A incorporates robust protection features. An adjustable overcurrent protection circuit monitors the output current by sensing the voltage drop across the upper MOSFET rDS(ON). Latch-off mode overcurrent operation protects the DC/DC converters from damage under overload and short-circuit conditions. A PGOOD signal is issued when soft-start is complete and PWM outputs are within 10% of their regulated values and the linear regulator output is higher than 75% of its nominal value. Thermal shutdown circuitry turns the device off if the IC temperature exceeds +150°C.

The ISL6506A and ISL6506B complement other power building blocks (voltage regulators) in ACPI-compliant designs for microprocessor and computer applications. They integrate the control of the 5VDUALand 3. 3VDUALrails into an 8 Ld EPAD SOIC package. The ISL6506A and ISL6506B's operating mode (active outputs or sleep outputs) is selectable through two digital control pins; S3 and S5. A completely integrated linear regulator generates the 3. 3VDUAL voltage plane from the ATX supply's 5VSBoutput during sleep states (S3, S4/S5). In active states (during S0 and S1/S2), the ISL6506A and ISL6506B use an external N-Channel pass MOSFET to connect the outputs directly to the 3. 3V input supplied by an ATX power supply, for minimal losses. The ISL6506A and ISL6506B power up the 5VDUALplane by switching in the ATX 5V output through an NMOS transistor in active states, or by switching in the ATX 5VSB through a PMOS (or PNP) transistor in S3 sleep state. In S4/S5 sleep states, the ISL6506B 5VDUAL output is shut down. In the ISL6506A, the 5VDUALoutput stays on during S4/S5 sleep states. The ISL6506A and ISL6506B are functionally identical, except for the sleep mode in the preceding paragraph. In addition, the ISL6506A has a 1A current limit on the internal 3. 3V LDO; the ISL6506B has a 2A current limit.

The ISL6520A makes simple work out of implementing a complete control and protection scheme for a DC/DC stepdown converter. Designed to drive N-Channel MOSFETs in a synchronous buck topology, the ISL6520A integrates the control, output adjustment, monitoring and protection functions into a single 8 Lead package. The ISL6520A 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 8V/ms 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.

The ISL6521 provides the power control and protection for four output voltages in low-voltage, high-performance applications. The IC integrates a voltage-mode PWM controller and three linear controllers, as well as monitoring and protection functions into a 16-lead SOIC package. The PWM controller is intended to regulate the low voltage supply that requires the greatest amount of current (usually the core voltage for the FPGA, ASIC, or processor) with a synchronous rectified buck converter. The linears are intended to regulate other system voltages, such as I/O (input/output) and memory circuits. Both the switching regulator and linear voltage reference provide ±2% of static regulation over line, load, and temperature ranges. All outputs are user-adjustable by means of an external resistor divider. All linear controllers can supply up to 120mA with no external pass devices. Employing bipolar NPNs for the pass transistors, the linear regulators can achieve output currents of 3A or higher with proper device selection. The ISL6521 monitors all the output voltages. The PWM controller's adjustable overcurrent function monitors the output current by using the voltage drop across the upper MOSFET's rDS(ON). The linear regulator outputs are monitored via the FB pins for undervoltage events.

The ISL6522B provides complete control and protection for a DC-DC converter optimized for high-performance microprocessor applications. It is designed to drive two N-Channel MOSFETs in a synchronous rectified buck topology. The ISL6522B integrates all of the control, output adjustment, monitoring and protection functions into a single package. The output voltage of the converter can be precisely regulated to as low as 0. 8V, with a maximum tolerance of ±1% over temperature and line voltage variations. The ISL6522B provides simple, single feedback loop, voltage-mode control with fast transient response. It includes a 200kHz free-running triangle-wave oscillator that is adjustable from below 50kHz to over 1MHz. 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 ratio ranges from 0-100%. The ISL6522B protects against overcurrent conditions by inhibiting PWM operation. The ISL6522B monitors the current by using the rDS(ON) of the upper MOSFET which eliminates the need for a current sensing resistor.