Summit SMB211 Synchronous DC/DC Controller

Summit Microelectronics introduced the SMB211 single-channel, synchronous DC/DC controller. The SMB211 combines high-performance power conversion and digital control in a single, space-saving device. The integration of power control functions eliminates external components and cost, improves functionality and performance, and minimizes development time. The controller is offered in a thermally-enhanced, lead-free 4mm X 4mm, 24-pad QFN. The SMB211 is ideal for printers, RAID cards, ADSL/Cable modems/routers, servers, switches/routers, digital televisions, digital set-top boxes (STB), and digital video recorders (DVRs). The SMB211 is available now in production quantities at $0.66 each for the QFN package in quantities of 10,000 units.

Summit Microelectronics SMB211 Synchronous DC/DC Controller

Summit SMB211 Synchronous DC/DC Controller Features

  • Digital Power Control via 2-wire serial interface and nonvolatile memory
  • +4.5V to +13.5 input voltage
  • More than 10A output current
  • Output voltage accuracy: ±1.0%
  • Static or dynamically programmable output voltage
    • +0.5V to +2.5V, 10mV steps
    • +1V to +5.0V, 20mV steps
  • Output current limit
  • Output voltage margining
  • Output UV/OV monitoring
  • Internal over-temperature protection
  • Forced PWM or PFM/PWM operation
  • Programmable system power control
    • Digital soft-start control
    • Power-on delay
    • Switching frequency (250/500/750/1000kHz)
    • PGOOD/RESET/SMB_ALERT output
    • Enable/disable control
    • Serial-interface slave addresses
    • Output voltage

The SMB211 integrates a synchronous DC-DC step-down (buck) converter with a useful set of digital control functions. The device’s high current drive capability allows over 10A of output, while using a wide variety of industry-standard MOSFETs. The SMB211 can operate at four different, programmable frequencies (250kHz, 500kHz, 750kHz and 1MHz) allowing optimization of efficiency and component size. Soft-start and power-on delays are also selectable to address various system requirements, especially in multi-power supply applications.

The SMB211′s output voltage accuracy is better than +/- 1 percent and supports dynamic voltage scaling as well as margin high/low control via the serial digital interface. The output voltage can be digitally set from +0.5V to +2.5V in 10mV steps, or from +1.0V to +5.0V in 20mV steps. The output voltage is monitored for both over- and under-voltage conditions, thereby increasing system reliability. A configurable logic output that can be used as a RESET, POWER GOOD or SMBAlert output signal, is also available for notifying the system of out-of-regulation conditions. The device can operate in forced-PWM for noise-sensitive applications, as well as in automatic PWM/PFM mode for maximum light-load efficiency.

The SMB211 incorporates a pulse-by-pulse current limit by monitoring the voltage drop across the upper N-FET. Various current limit thresholds as well as several over-current response modes are available for maximum design flexibility. An Enable input allows the SMB211 to enter a low-power shutdown mode (less than10uA). A standby mode, via an I2C command, is also available for reducing current consumption while keeping the serial interface active. Additionally, the SMB211 provides complete power system diagnostics by digitally flagging a variety of fault conditions (output OVLO, output UVLO, IC temperature, over-current, input UVLO and others).

The SMB211 operates directly from an input voltage of +4.5V to +13.5V, however the external FETs can be powered from a lower voltage supply, as low as 3.3V, if necessary. The rated operating temperature range is -30C to +85C. Programming is achieved via an industry-standard serial interface and configuration data is safely stored in non-volatile OTP memory.

More info: Summit Microelectronics SMB211 Synchronous DC/DC Controller (pdf)