Renesas Electronics Corporation

The ISL8118 is a single-phase PWM controller featuring an input voltage range of +3.3V to +20V and integrated MOSFET drivers. Utilizing voltage-mode operation with input voltage feed-forward compensation, the ISL8118 maintains a constant loop gain, providing optimal transient response for applications with a wide input operating voltage range. The output voltage can be precisely regulated down to 0.591V with a system tolerance of ±1.0% over the industrial temperature range and line and load variations. A external reference input is provided to bypass the internal reference for voltage tracking or DDR memory applications. The compact 28 Ld 5mm x 5mm QFN package, integrated linear regulator as well as the external linear regulator drive option, integrated differential remote sense amplifier and integrated voltage margining with adjustable upper and lower settings decrease external component count and reduce board space requirements. Programmable soft-start with pre-biased load capability, adjustable operating frequency from 250kHz to 2MHz, sourcing and sinking overcurrent protection, overvoltage and undervoltage protection, and power-good indication with programmable delay combine to make the ISL8118 a superior choice for many power supply systems.

The ISL8121 is a two-phase buck PWM controller featuring an input voltage range of 3V to 20V and integrated MOSFET drivers. Precision voltage regulation is provided for point-of-load and other high-current applications that require efficient and compact implementation. Multiphase buck converter architecture uses interleaved timing to multiply channel ripple frequency allowing smaller filter inductors and reducing input and output ripple currents due to the ripple cancellation effect. Lower ripple results in fewer input and output capacitors. Smaller and low cost transistors can be used resulting from the higher efficiency and reduced power dissipation. The ISL8121 offers an internal 0.6V reference with a system regulation accuracy of ±0.8% (Industrial Temperature range), an optional external reference input, and user-adjustable switching frequency. Unity gain differential amplifier targeted at remote voltage sensing capability enhances the regulation. A power good signal (PGD) is issued when the output voltage is within the regulated window. An internal shunt regulator with optional external connection capability extends the operational input voltage range. For applications requiring voltage tracking or sequencing, the ISL8121 offers a host of possibilities, including coincidental, ratiometric, or offset tracking, as well as sequential startups, user adjustable for a wide range of applications. Additional features include overvoltage and overcurrent protection. Overcurrent protection can be tailored to various applications with no need for additional parts. The ISL8121 uses cost and space-saving rDS(ON)sensing for channel current balance, dynamic voltage positioning, and overcurrent protection. Channel current balancing is automatic and accurate with the integrated current-balance control system.

The ISL8126 integrates two voltage-mode PWM leading-edge modulation control with input feed-forward synchronous buck PWM controllers to control dual independent voltage regulators or a 2-phase single output regulator. It also integrates current sharing control for the power module to operate in parallel, which offers high system flexibility. The ISL8126 integrates an internal linear regulator, which generates IC’s bias voltages for applications with only one single supply rail. The internal oscillator is adjustable from 150kHz to 1. 5MHz, and is able to synchronize to an external clock signal for frequency synchronization and phase paralleling applications. Its PLL circuit can output a phase-shift-programmable clock signal for the system to be expanded to 3-, 4-, 6- and 12- phases with desired interleaving phase shift. The ISL8126’s Fault Spreading feature protects any channel from overloading/stressing due to system faults or phase failure. The undervoltage fault protection features are also designed to prevent a negative transient on the output voltage during falling down. This eliminates the Schottky diode that is used in some systems for protecting the load device from reversed output voltage damage.

The ISL8130 is a versatile controller that integrates control, output adjustment, monitoring, and protection functions into a single package for synchronous Buck, standard Boost, SEPIC, and Flyback topologies. The ISL8130 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 switching frequency is adjustable from 100kHz to 1. 4MHz. The error amplifier features a 15MHz gain-bandwidth product and 6V/μs slew rate that enables fast transient response. The PWM duty cycle ranges from 0% to 100% in transient conditions. The capacitor from the ENSS pin to ground sets soft-start slew rate. The ISL8130 monitors the output voltage and generates a power-good (PGOOD) 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. For a Buck and Buck-Boost configuration, protection from overcurrent conditions is provided by monitoring the rDS(ON)of the upper MOSFET to inhibit the PWM operation appropriately. This approach improves efficiency by eliminating the need for a current sensing resistor. For other topologies, overcurrent protection is achieved using a current sensing resistor.

The ISL81334 and ISL41334 are two-port interface ICs in which each port can be independently configured as a single RS-485, RS-422 transceiver, or as a dual (2 Tx, 2 Rx) RS-232 transceiver. With both ports set to the same mode, two RS-485, RS-422 transceivers, or four RS-232 transceivers are available. If either port is in RS-232 mode, the onboard charge pump generates RS-232 compliant ±5V Tx output levels from a single VCCsupply as low as 4.5V. Four small 0.1µF capacitors are required for the charge pump. The transceivers are RS-232 compliant, with the Rx inputs handling up to ±25V, and the Tx outputs handling ±12V. In RS-485 mode, the transceivers support both the RS-485 and RS-422 differential communication standards. The receivers feature "full fail-safe" operation, so the Rx outputs remain in a high state if the inputs are open or shorted together. The transmitters support up to three data rates, two of which are slew rate limited for problem-free communications. The charge pump disables when both ports are in RS-485 mode, thereby saving power, minimizing noise and eliminating the charge pump capacitors. Both RS-232 and RS-485 modes feature loopback and shutdown functions. Loopback internally connects the Tx outputs to the corresponding Rx input, to facilitate board level self-test implementation. The outputs remain connected to the loads during loopback, so connection problems (such as shorted connectors or cables) can be detected. Shutdown mode disables the Tx and Rx outputs, disables the charge pumps, and places the IC in a low current (µA) mode. The ISL41334 is a QFN packaged device that includes two additional user-selectable, lower speed, and edge rate options for EMI-sensitive designs, or to allow longer bus lengths. It also features a logic supply pin (VL) that sets the VOHlevel of logic outputs, and the switching points of logic inputs, to be compatible with another supply voltage in mixed voltage systems. The QFN also adds active low Rx enable pins to increase design flexibility, allowing Tx/Rx direction control, through a single signal per port, by connecting the corresponding DE and RXEN pins together. For a single port version of these devices, please see the ISL81387, ISL41387 datasheet.

The ISL81401 and ISL81401A are 4-switch synchronous buck-boost controller with peak and average current sensing and monitoring at both ends. The ISL81401 is a bidirectional device that can conduct current in both directions while the ISL81401A is an unidirectional device. The ISL81401 and ISL81401A use the proprietary buck-boost control algorithm with valley current modulation for Boost mode and peak current modulation for Buck mode control. The ISL81401 and ISL81401A have four independent control loops for input and output voltages and currents. Inherent peak current sensing at both ends and cycle-by-cycle current limit of this family of products ensures high operational reliability by providing instant current limit in fast transient conditions at either ends and in both directions. It also has two current monitoring pins at both input and output to facilitate Constant Current (CC) limit and other system management functions. CC operation down to low voltages avoids any runaway condition at over load or short-circuit conditions. In addition to multilayer overcurrent protection, it also provides full protection features such as OVP, UVP, OTP, and average and peak current limit on both input and output to ensure high reliability in both unidirectional and bidirectional operation. The IC is packaged in a space conscious 32 Ld 5mmx5mm QFN package to improve thermal dissipation and noise immunity. The unique DE/Burst mode at light-load dramatically lowers standby power consumption with consistent output ripple over different load levels.

The Intersil ISL81485 is a BiCMOS, 5V powered, single transceiver that meets both the RS-485 and RS-422 standards for balanced communication, and features a larger output voltage and higher data rate to benefit high speed applications. Unlike competitive devices, this Intersil transceiver is specified for 10% tolerance supplies (4. 5V to 5. 5V), and it delivers a much larger worst case differential output voltage (2. 0V compared to the typical 1. 5V) over the full supply range. The increased output voltage translates into longer reach, or better data integrity, at the 30Mbps data rate. This device presents a 1 unit load to the RS-485 bus, which allows up to 32 transceivers on the network. Receiver (Rx) inputs feature a fail-safe if open design, which ensures a logic high Rx output if Rx inputs are floating. Driver (Tx) outputs are short circuit protected, even for voltages exceeding the power supply voltage. Additionally, on-chip thermal shutdown circuitry disables the Tx outputs to prevent damage if power dissipation becomes excessive.