MIC2875 Datasheet, PDF (12/24 Pages) Microchip Technology – 4.8A ISW, Synchronous Boost Regulator with Bi-Directional Load Disconnect

MIC2875
4.0 FUNCTIONAL DESCRIPTION
4.1 Input (IN)
The input supply provides power to the internal
MOSFETs gate drivers and control circuitry for the
boost regulator. The operating input voltage range is
from 2.5V to 5.5V. A 1 μF low-ESR ceramic input
capacitor should be connected from IN to AGND as
close to MIC2875 as possible to ensure a clean supply
voltage for the device. A minimum voltage rating of 10V
is recommended for the input capacitor.
4.2 Switch Node (SW)
The MIC2875 has internal low-side and synchronous
MOSFET switches. The switch node (SW) between the
internal MOSFET switches connects directly to one
end of the inductor and provides the current path during
switching cycles. The other end of the inductor is
connected to the input supply voltage. Due to the
high-speed switching on this pin, the switch node
should be routed away from sensitive nodes wherever
possible.
4.3 Ground Path (AGND)
The ground path (AGND) is for the internal biasing and
control circuitry. AGND should be connected to the
PCB pad for the package exposed pad. The current
loop of the analog ground should be separated from
that of the power ground (PGND). AGND should be
connected to PGND and EP at a single point.
4.4 Power Ground (PGND)
The power ground (PGND) is the ground path for the
high current in the boost switches. The current loop for
the power ground should be as short as possible and
separate from the AGND loop as applicable.
4.5 Boost Converter Output (OUT)
A low-ESR ceramic capacitor of 22 μF (for operation
with VIN ≤ 5.0V), or 66 μF (for operation with V_IN >
5.0V) should be connected from V_OUT to PGND as
close as possible to the MIC2875. A minimum voltage
rating of 10V is recommended for the output capacitor.
4.6 Enable (EN)
Enable pin of the MIC2875. A logic high on this pin
enables the MIC2875. When this pin is driven low, the
MIC2875 enters the shutdown mode. When the EN pin
is left floating, it is pulled-down internally by a built-in
2.5 MΩ resistor.
4.7 Feedback/Output Voltage Sense
(FB/OUTS)
Feedback or output voltage sense pin for the boost
converter. For the fixed voltage version, this pin should
be connected to the OUT pin. For the adjustable
version, connect a resistor divider to set the output
voltage (see “Section 5.7 “Output Voltage
Programming”” for more information).
4.8 Power Good Output (/PG)
The open-drain active-low power-good output (/PG) is
low when the output voltage is above the power-good
threshold. A pull-up resistor of 1 MΩ is recommended.
4.9 Exposed Heat Sink Pad (EP)
The exposed heat sink pad, or ePad (EP), should be
connected to AGND for best thermal performance.
DS20005549A-page 12
 2015 Microchip Technology Inc.