Dual-Phase Boosts Step-Up Efficiency

Linear Technology Corp. recently introduced the LTC3124 two-phase, 3-MHz current-mode synchronous boost DC/DC converter. It features output disconnect and inrush current limiting. Dual-phase operation has the benefit of reducing peak inductor and capacitor ripple currents. This allows equivalent performance to be achieved in the power supply design with smaller valued inductors and capacitors.

Source: Linear Technology

Source: Linear Technology

The LTC3124 incorporates low resistance MOSFETs with an RDS(ON) of 130mΩ (N-channel) and 200mΩ (P-channel) to deliver efficiencies as high as 95%. The output disconnect feature allows the output to be completely discharged at shutdown and reduces switch-on inrush. An input pin can be used to configure the LTC3124 for continuous frequency mode to give low-noise operation. Additional features include external synchronization, output overvoltage protection, and robust short-circuit protection.

LTC3124′s main features:

  •  VIN Range: 1.8 V to 5.5 V, 500 mV after start-up
  •  Adjustable output voltage: 2.5 V to 15 V
  •  1.5-A Output current for VIN = 5 V and VOUT = 12 V
  •   Dual-phase control reduces output voltage ripple
  •  Output disconnects from input when shut down
  •  Synchronous rectification: up to 95% efficiency
  •  Inrush current limit
  •  Up to 3-MHz programmable switching frequency synchronizable to external clock
  •  Selectable Burst Mode operation: 25-µA IQ
  •  Output Overvoltage Protection
  •  Internal soft-start
  •  < 1 µA IQ in shutdown

The LTC3124EDHC and LTC3124EFE are both available from stock in 16-lead 3 mm x 5 mm DFN and thermally enhanced TSSOP packages, respectively. One-thousand-piece pricing starts at $3.26 each.

[via Elektor]

Configurable Regulator

LinearThe LTM4644 quad output step-down µModule (micromodule) regulator is configurable as a single (16-A), dual (12-A, 4-A, or 8-A, 8-A), triple (8-A, 4-A, 4-A), or quad (4-A each) output regulator. This flexibility enables system designers to rely on one simple and compact µModule regulator for the various voltage and load current requirements of FPGAs, ASICs, and microprocessors as well as other board circuitry. The LTM4644 is ideal for communications, data storage, industrial, transportation, and medical system applications.

The LTM4644 regulator includes DC/DC controllers, power switches, inductors and compensation components. Only eight external ceramic capacitors (1206 or smaller case sizes) and four feedback resistors (0603 case size) are required to regulate four independently adjustable outputs from 0.6 to 5.5 V. Separate input pins enable the four channels to be powered from a common supply rail or different rails from 4 to 14 V.

At an ambient temperature of 55°C, the LTM4644 delivers up to 13 A at 1.5 V from a 12-V input or up to 14 A with 200-LFM airflow. The four channels operate at 90° out-of-phase to minimize input ripple whether at the 1-MHz default switching frequency or synchronized to an external clock between 700 kHz and 1.3 MHz. With the addition of an external bias supply above 4 V, the LTM4644 can regulate from an input supply voltage as low as 2.375 V. The regulator also includes output overvoltage and overcurrent fault protection.

The LTM4644 costs $22.85 each in 1,000-unit quantities.

Linear Technology Corp.
www.linear.com