Rohm Semiconductor

BD3539NUX is a termination regulator that complies with JEDEC requirements for DDR1-SDRAM, DDR2-SDRAM, and DDR3-SDRAM. This linear power supply uses a built-in N-channel MOSFET and high-speed OP-AMPS specially designed to provide excellent transient response. It has a sink/source current capability of up to 1A and has a power supply bias requirement of 3.3 V (for DDR2 and DDR3) and 5.0 V (for DDR1, DDR2, and DDR3) for driving the N-channel MOSFET. By employing an independent reference voltage input (VDDQ) and a feedback pin (VTTS), this termination regulator provides excellent output voltage accuracy and load regulation as required by JEDEC standards. Additionally, BD3539 has a reference power supply output (VREF)for DDR-SDRAM or for memory controllers. Unlike the VTT output that goes to "Hi-Z" state, the VREF output is kept unchanged when EN input is changed to "Low", making this IC suitable for DDR-SDRAM under "Self Refresh" state.

BD354XNUV ultra low-dropout linear chipset regulator operates from a very low input supply, and offers ideal performance in low input voltage to low output voltage applications. It incorporates a built-in N-MOSFET power transistor to minimize the input-to-output voltage differential to the ON resistance (RONMAX=200mO) level. By lowering the dropout voltage in this way, the regulator realizes high current output (Iomax=1.0A) with reduced conversion loss, and thereby obviates the switching regulator and its power transistor, choke coil, and rectifier diode. Thus, BD354XNUV are designed to enable significant package profile downsizing and cost reduction. An external resistor allows the entire range of output voltage configurations between 0.65 and 2.7V, while the NRCS (soft start) function enables a controlled output voltage ramp-up, which can be programmed to whatever power supply sequence is required.