Two features of the A6986 are particularly useful to designers of systems which run on the power supplied by an automotive battery:
• Its 100% duty-cycle capability helps it to withstand cold-crank events
• It has a wide input-voltage range of 4V to 38V. The output voltage is adjustable in a range from 0.85V up to the input-voltage value.
The device has two operating modes in which regulation is optimised either for high power efficiency or for noise reduction. In Low Consumption Mode (LCM), it maximises light-load efficiency while limiting the output-voltage ripple. This is suitable for applications which are active when the vehicle is stationary.
In Low Noise Mode (LNM), the A6986 operates at a constant switching frequency, and minimises output-voltage ripple over the entire load-current range. This is helpful for noise-sensitive applications such as car audio systems. The regulator implements synchronous rectification to achieve high efficiency when controlling medium or heavy loads. An adjustable switching frequency up to a maximum of 2MHz allows for the use of small supporting components, helping the designer to reduce the size of the power system.
Pulse-by-pulse current sensing on both power elements enables effective constant-current protection.
- AEC-Q100 qualified
- 30μA quiescent current
- 8μA shut-down current
- Embedded output-voltage supervisor
- Adjustable soft-start time
- Internal current limiting
- Over-voltage protection
- Output-voltage sequencing
- Battery-powered automotive applications
- Car body applications in LCM
- Car audio and low-noise applications in LNM
The STEVAL-ISA158V1, an evaluation board for the A6986, demonstrates the device’s performance over its input-voltage range of 4V to 38V.