Datasheet
Enable (EN) Jumper
2-2
2.1 Enable (EN) Jumper
This jumper is used to enable the device. Connecting the EN pin to ON enables
the part. Connecting the EN pin to OFF disables the device.
2.2 Synchronization (SYNC) Jumper
This jumper is used to choose between PWM and PFM/PWM modes of
operation. Setting the jumper across PWM forces the device into the low-noise
fixed-frequency pulse width modulation (PWM) mode. Setting the jumper
across PWM/PFM enables the power save mode where the device enters a
pulse frequency modulation mode (PFM) at light to medium load currents,
which reduces quiescent current and switching frequency to a minimum to
achieve highest efficiency over the entire load current range.
Additionally an external clock between 600 kHz and 1200 kHz can be applied
to pin 2 of J2 (SYNC) in order to synchronize the converter to an external clock.
2.3 Power Good (PG)
The PG pin is an open drain output capable of sinking typically 1 mA. A pullup
resistor is required to use the PG. The pullup resistor should be placed
between the Vout and PG. The PG pin becomes active high when the output
voltage exceeds typically 98.5% of its nominal value. Leave the PG pin
unconnected when not used.
2.4 Low Battery Out (LBO)
The LBO pin is an open drain output which goes low when the voltage at the
low battery input (LBI) falls below the trip point of 1.21 V. An external pullup
resistor which is placed between LBO and Vout is required to use the LBO.