Ultra-low Current Consumption High Voltage LDO Regulator ICs for Automotive

ROHM has completed development of the BD3574HFP (5V/500mA output), a high-reliability LDO regulator IC ideal for use with microcontrollers and memory in automotive ECUs (Electronic Control Units) featuring high voltage resistance (50V), high output voltage accuracy (±2%), reduced ON-resistance, high ESD resistance, and a foldback type overcurrent protection circuit for heat suppression. In addition, advanced MOS technology ensures that current consumption is minimized (30µA during operation/10µA standby).
Sample shipments of BD3574HFP will begin in April 2007 (sample price), with mass production slated to start in August 2007 at a rate of 100,000 units per month.

· Main characteristics of BD3574HFP

1. Current consumption can be reduced to 30µA, facilitating energy-conserving designs for ECUs and automotive circuits.
2. The high voltage resistance (50V) provides a generous design margin, improving reliability.
3. Electrical characteristics are maintained over a broad temperature range (−40ºC to +125ºC)
4. Foldback overcurrent and temperature protection circuits are built in
5. High output voltage accuracy (±2%) makes it ideal for precision microcontrollers
6. Built-in output phase compensation circuit allows compact ceramic capacitors (0.1µF) to be used for output

Today’s automobiles are equipped with an increasing number of ECUs in order to provide a greater level of safety and comfort. Depending on the function, some ECUs carry out operations even when the ignition is not engaged, and sometimes power is continuously supplied to backup memory even when the ECU’s internal microcontroller has stopped. As more and more ECUs are utilized current consumption increases, putting a greater strain on the battery. Therefore, low current consumption ECU components are necessary, and high voltage is important in order to prevent damage during engine startup.

ROHM is currently developing twelve types of high-reliability LDO regulator ICs in addition to the BD3574HFP. The lineup will be offered in three output voltages (3.3V/5V/Variable), two packages (TO252 and HRP5), and an optional ON/OFF switch. ROHM also offers the BD393X and BD394X LDO regulator series for automotive systems featuring ultra-low current consumption.
In addition to regulators, ROHM provides watchdog timer ICs, LED drivers, motor drivers, and other LSIs ideal for automotive body applications and is continually developing high reliability automotive components that meet or exceed customer expectations.

· Glossary

• ESD tolerance:
  The amount of static electricity a device can withstand.
• Foldback overcurrent protection:
  During output shorts this circuit reduces the output current and voltage simultaneously in order to prevent damage due to excessive heat at the output transistors.
• Phase compensation:
  In amps and other amplifier circuits, output stabilization is achieved through feedback of the amp output to the input. However, if the phase of the amplifier itself exceeds 180°, oscillation will occur. A phase compensation circuit controls the phase in order to stabilize the output and prevent oscillation.

	High-reliability LDO regulator IC