October 2009 Doc ID 16567 Rev 1 1/6
6
EVAL5986
EVAL5986A
2.5 A step-down switching regulator demonstration board
based on the L5986, L5986A
Features
■ 2.5 A DC output current
■ 2.9 V to 18 V input voltage
■ Output voltage adjustable from 0.6 V to 16 V
■ 250 kHz switching frequency, programmable
up to 1 MHz
■ Internal soft-start and inhibit
■ Low dropout operation: 100% duty cycle
■ Zero-load current operation
■ Overcurrent and thermal protection
■ VFQFPN8 3 mm x 3 mm package or HSOP8
for the L5986A
Description
The EVAL5986/A demonstration board provides
the design engineer with a fully functional step-
down switching regulator with an output current of
up to 2.5 A. The board integrates
STMicroelectronics’ L5986\A step-down switching
regulator, together with all the external
components required for a typical application.
The rated voltage of the input capacitor and the
Schottky diode rectifier repetitive peak reverse
voltage are both 25 V, making the board capable
of covering the entire 2.9 V - 18 V input voltage
range of the L5986/A device.
The board features an external resistor divider
(R1 and R2) designed for an output voltage
of 1.8 V.
The output voltage can be set to a level from 0.6 V
up to the input voltage.
The compensation network on the demonstration
board allows the use of MLCC as output filter to
keep the loop stable. The inductor saturation
current and forward current of the Schottky diode
are within the current limit values.
The switching frequency on the demonstration
board is set to 500 kHz by means of the R5
resistor connected to pin Fsw.
www.st.com
