Versatile Automotive 60V/70V 2.2MHz Buck Controller with 7µA I and Optional Bypass Mode

The MAX25206/MAX25207/MAX25208 are automotive 2.2MHz synchronous step-down controllers with 7µA IQ. These devices operate with an input voltage supply from 3.5V to 60V (MAX25206/MAX25207) and 70V (MAX25208). They can operate in dropout condition by running at 99% (typ) duty cycle. These controllers are intended for applications with mid- to high-power requirements that operate at a wide input voltage range such as during automotive cold-crank or engine stop-start conditions. The MAX25207 has an optional bypass mode which allows 100% high-side switch on until step-down function is needed during automotive transients.

The MAX25206/MAX25207/MAX25208 step-down controllers operate at up to 2.2MHz frequency to allow small external components, reduced output ripple, and to guarantee no AM band interference. The switching frequency is resistor adjustable (220kHz to 2200kHz). SYNC input programmability enables three frequency modes for optimized performance: forced fixed-frequency operation (FPWM), skip mode with ultra-low quiescent current, and synchronization to an external clock. The IC also provides SYNCOUT output to enable two controllers to operate in parallel. The MAX25206/MAX25207/MAX25208 have a pin selectable spread-spectrum option for frequency modulation to minimize EMI.

The MAX25206/MAX25207/MAX25208 feature a PGOOD monitor and undervoltage lockout. Protection features include cycle-by-cycle current limit and thermal shutdown. These controllers are specified for operation over the -40°C to +125°C automotive temperature range.

Applications

* 24V Truck systems, Infotainment Systems, 48V systems

* Meets Stringent Automotive OEM Module Power Consumption and Performance Specifications

* 7µA Quiescent Current in Skip Mode

* Fixed 5.0V/3.3V or Adjustable 0.7V to 20V Output

* ±1.5% Output-Voltage Accuracy for 5V Fixed Setting

* Enables Crank-Ready Designs

* Wide Input Supply Range from 3.5V to 60V/70V

* EMI Reduction Features Reduce Interference with Sensitive Radio Bands without Sacrificing Wide Input Voltage Range

* 50ns (typ) Minimum On-Time Allows Skip-Free Operation for 3.3V Output from Car Battery at 2.2MHz

* Spread-Spectrum Option

* Frequency-Synchronization Input

* Resistor-Programmable Frequency Between 220kHz and 2.2MHz

* Integration and Thermally Enhanced Packages Save Board Space and Cost

* 2.2MHz Step-Down Controller

* 180° Out-of-Phase SYNCOUT Output for Synchronization

* Current-Mode Controller with Forced-Continuous and Skip Modes

* Thermally Enhanced 20-Pin Side-Wettable (SW) 4mm x 4mm TQFN-EP Package

* Protection Features Improve System Reliability

* Supply Undervoltage Lockout

* Output Overvoltage and Undervoltage Monitoring

* Overtemperature and Short-Circuit Protection

* -40°C to +125°C Grade 1 Automotive Temperature Range