3.5V–36V, 2.2MHz, Synchronous Dual Buck Controller with 20μA Quiescent Current

The MAX17232/MAX17233 offers dual synchronous step-down DC-DC controllers with integrated MOSFETs. They operates over a 3.5V to 36V input voltage range with 42V input transient protection, and can operate in dropout condition by running at 95% duty cycle. The controllers can generate fixed output voltages of 3.3V/5V, along with the capability to program the output voltage between 1V to 10V.

These devices use a current-mode-control architecture.The devices can be operated in pulse-width modulation (PWM) or pulse-frequency modulation (PFM) control schemes. PWM operation provides constant frequency operation at all loads, and is useful in applications sensitive to switching frequency. PFM operation disables negative inductor current and additionally skips pulses at light loads for high efficiency. The low-resistance, on-chip MOSFETs ensure high efficiency at full load and simplify the layout.

The devices are available in a 28-pin TQFN-EP package with exposed pad, and are specified for operation over -40°C to +85°C.

Applications

* Distributed Supply Regulation * General-Purpose Point-of-Load * Wall Transformer Regulation

* Eliminates External Components and Reduces Total Cost

* No Schottky-Synchronous Operation for High Efficiency and Reduced Cost

* Simple External RC Compensation for Stable Operation at Any Output Voltage

* All-Ceramic Capacitor Solution: Ultra-Compact Layout

* 180° Out-of-Phase Operation Reduces Output Ripple and Enables Cascaded Power Supplies

* Reduces Number of DC-DC Controllers to Stock

* Fixed Output Voltage with ±1% Accuracy (5V/3.3V)or Externally Resistor Adjustable (1V to 10V)

* 220kHz to 2.2MHz Adjustable Frequency with External Synchronization

* Frequency Synchronization Input

* Reduces Power Dissipation

* 92% Peak Efficiency

* 8μA (typ) in Shutdown

* 20μA (typ) Quiescent Current in PFM Mode

* Operates Reliably

* 42V Input Voltage Transient Protection

* Cycle-by-Cycle Current Limit, Thermal Shutdown

* Supply Overvoltage and Undervoltage Lockout

* Power-OK Monitor

* Reduced EMI Emission with Spread-Spectrum Control

* 50ns (typ) Minimum On-Time Guarantees PWM Operation at Low Duty Cycle at 2.2MHz