The MAX15157ATJ+ can be configured as a DDR regulator, producing an output that is exactly half the memory supply rail. The input of the power stage can be taken from the memory supply rail itself, resulting in an efficient power supply that returns the energy to the rail from which it was sourced. The MAX15157ATJ+ includes a reference buffer that provides ±5mA of drive current.
The MAX15157ATJ+ uses a unique current-mode, constant-off-time, PWM control scheme. A selectable pulse-skipping mode maintains high efficiency during light-load operation, yet still sources and sinks current on demand. The MAX15157ATJ+ can also be operated in fixed-PWM mode for low output ripple. The programmable constant-off-time architecture sets switching frequencies up to 1MHz, which allows the user to optimize performance trade-offs between efficiency, output switching noise, component size, and cost. The MAX15157ATJ+ features an adjustable soft-start to limit surge currents during startup and a low-power shutdown mode to disconnect the input from the output and reduce supply current below 1μA. The MAX15157ATJ+ is available in a 24-pin thin QFN package with an exposed backside pad.
Feature
- Dual 40mΩ Internal n-Channel MOSFETs
- Integrated Boost Switch
- +1.3V to +3.6V Input Voltage Range
- 1% VOUT Accuracy Over Line and Load
- 1MHz Maximum Switching Frequency
- DDR Termination Regulator (DDR Mode)
- Tracking Output Voltage
- Source/Sink Pulse Skipping
- ±5mA Reference Buffer
- Output Voltage (Non-DDR Mode)
- +2.5V, +1.8V, or +1.5V Pin Selectable
- +0.5V to +2.7V Adjustable
- 1.1V ±0.75% Reference Output
- Adjustable Soft-Start Inrush Current Limiting
- < 1μA (typ) Shutdown Supply Current
- < 800μA (max) Operating Supply Current
- Selectable Pulse-Skipping Operation at Light Loads
- Positive and Negative Current Limit
- Power-Good Window Comparator
- Output Short-Circuit Protection
Applications
- Active Termination Buses
- Chipset/Graphics Processor Supplies
- Notebook DDR Memory Termination
