AN2627 Datasheet, PDF (1/19 Pages) STMicroelectronics – ST8R00 syncronous boost

AN2627
Application note
ST8R00 syncronous boost
converter with output current cut-off function
Introduction
The ST8R00 family of synchronous step-up DC-DC converters with current output cut-off
function provide up to 1 A over an input voltage range of 4 V to 6 V and an output voltage
range of 6 V to 12 V.
The high switching frequency (1.2 MHz) allows the use of tiny surface-mount components.
Along with the resistor divider to set the output voltage value, an inductor and two capacitors
are required. A low output ripple is guaranteed by the current mode PWM topology and by
the use of low ESR surface-mounted ceramic capacitors.
The device is available in two versions: burst mode (ST8R00) and continuous mode
(ST8R00W).
The ST8R00 devices are thermal protected and available in the DFN8 4x4 package.
Figure 1. Simplified schematic diagram
LX
Thermal
INH _Inhibit
Ps
Ns
PGND
OUT
Po
PWM control
FB
IN
Vref
PGND
GND
AM00001v1
December 2009
Doc ID 13913 Rev 2
1/19
www.st.com