STMicroelectronics A7987
A7987 - 61 V 3A asynchronous step-down switching regulator with adjustable current limitation for automotive
The A7987 is a step-down monolithic switching regulator that can deliver up to 3 A DC. The adjustable output voltage ranges from 0.8 V to VIN. The wide input voltage range and the almost 100% duty cycle capability meet the fail-safe specifications for automotive systems. The embedded switch-over feature on the VBIAS pin maximizes efficiency at light load. The adjustable current limitation, designed to select the inductor RMS current in accordance with the nominal output current, and the high switching frequency capability make the size of the application compact. Pulse-by-pulse current sensing with digital frequency fold-back implements an effective constant current protection over the different application conditions. The peak current fold-back decreases the stress of the power components in heavy short-circuit conditions. The PGOOD open collector output can also implement the output voltage sequencing during the power-up phase. Multiple devices can be synchronized sharing the SYNCH pin to prevent beating noise for low noise requirements such as in infotainment applications.
Features
- 3 A DC output current
- 4.5 V to 61 V operating input voltage
- Adjustable fsw (250 kHz to 1.5 MHz)
- Output voltage adjustable from 0.8 V to VIN
- Synchronization
- Adjustable soft-start time
- Adjustable current limitation
- VBIAS improves efficiency at light load
- PGOOD open collector output
- Digital frequency fold-back in short-circuit
- Auto-recovery thermal shutdown
- Qualified following AEC-Q100 requirements
The STEVAL-ISA207V1 evaluation board is a step-down switching power supply based on the A7987
The STEVAL-ISA207V1 evaluation board is a step-down switching power supply based on the A7987 regulator in an HTSSOP16 package. It is designed for automotive system battery-powered applications. The output voltage can be set starting from 0.8 V. Almost low drop-out operation, due to the advanced integrated switch management, can be achieved.
The A7987 is a 61 V, 3 A step-down asynchronous switching regulator with embedded high-side power MOSFET is capable of delivering up to 3 A of current, depending on the application conditions.
The embedded switchover feature on the VBIAS pin and the light load management (pulse skipping) are included to maximize power conversion efficiency across the entire load range, and the soft-start current limit threshold and switching frequency can be adjusted according to specific application requirements.
The device includes an internal 250 kHz oscillator that can be set up to 1.5 MHz by changing an on-board resistor. Two A7987 regulators can be synchronized in a 180° out-of-phase configuration for reduced total input RMS current.
Features
- 4.5 V to 60 V input voltage
- Step-down (buck) conversion
- 3.3 V output voltage
- Up to 3 A DC output current
- 500 kHz switching frequency
- 3.5 ms programmed soft-start
- Compliant with ceramic output capacitors
- 180° out-of-phase synchronization available
- Auto recovery overcurrent and thermal protection
- RoHS and China RoHS compliant
- WEEE compliant (2012/19/UE RAEE II)
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STMicroelectronics A7987 switching regulator | Avnet Silica
