ISL6545 and ISL6545A are 5V or 12V single-phase synchronous buck pulse-width modulation (PWM) controllers that make simple work out of implementing a complete control and protection scheme for a DC/DC step-down converter driving N-channel MOSFETs in a synchronous buck topology. Since it can work with either 5V or 12V supplies, this one IC can be used in a wide variety of applications within a system. The ISL6545 integrates the control, gate drivers, output adjustment, monitoring and protection functions into a single 8 Ld SOIC or 10 Ld DFN package. The ISL6545 provides single feedback loop, voltage-mode control with fast transient response. The output voltage can be precisely regulated to as low as 0.6V, with a maximum tolerance of ±1.0% over temperature and line voltage variations. A selectable fixed frequency oscillator (ISL6545 for 300kHz; ISL6545A for 600kHz) reduces design complexity, while balancing typical application cost and efficiency. The error amplifier features a 20MHz gain-bandwidth product and 9V/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 lower MOSFET to inhibit PWM operation appropriately. This approach simplifies the implementation and improves efficiency by eliminating the need for a current sense resistor.
The ISL6545 family are 5 V or 12 V single‑synchronous buck PWM controllers designed for DC‑DC step‑down converters that drive N‑channel MOSFETs. The devices integrate control, gate drivers, output adjustment, monitoring and protection in an 8‑lead SOIC or 10‑lead DFN package.
The document provides detailed specifications, functional block diagrams, pin descriptions, and design guidance such as soft‑start behavior, over‑current protection, and recommended external components for typical power‑supply applications.
| Operating Supply Voltage | +5 V or +12 V |
|---|---|
| Fixed Oscillator Frequency | 300 kHz (ISL6545) / 600 kHz (ISL6545A) |
| Reference Voltage Tolerance | -1.0 % to +1.0 % |
| Gain‑Bandwidth Product | 20 MHz |
| Slew Rate | 9 V/µs |
The ISL6545A uses a fixed 600 kHz oscillator.