MIC24053 Datasheet, PDF (3/30 Pages) Micrel Semiconductor – 12V, 9A High-Efficiency Buck Regulator

Micrel, Inc.
MIC24053
Pin Description (Continued)
Pin Number
22
23
24
25
26
27
28
Pin Name
CS
SGND
FB
PG
EN
VIN
VDD
Pin Function
Current Sense input. The CS pin senses current by monitoring the voltage across the low-side
MOSFET during the OFF-time. Current sensing is necessary for short circuit protection. To sense the
current accurately, connect the low-side MOSFET drain to SW using a Kelvin connection. The CS pin
is also the high-side MOSFET’s output driver return.
Signal ground. SGND must be connected directly to the ground planes. Do not route the SGND pin to
the PGND Pad on the top layer; see PCB Layout Recommendations for details.
Feedback input. Input to the transconductance amplifier of the control loop. The FB pin is regulated to
0.8V. A resistor divider connecting the feedback to the output is used to adjust the desired output
voltage.
Power Good output. Open-drain output. The PG pin is externally tied with a resistor to VDD. A high
output is asserted when VOUT > 92% of nominal.
Enable input. A logic level control of the output. The EN pin is CMOS-compatible. Logic high = enable,
logic low = shutdown. In the off state, the device’s supply current is greatly reduced (typically 5µA).
Do not leave the EN pin floating.
Power Supply Voltage input. Requires bypass capacitor to SGND.
5V Internal Linear Regulator output. VDD supply is the power MOSFET gate drive supply voltage and
the supply bus for the IC. VDD is created by internal LDO from VIN. When VIN < +5.5V, tie VDD to
PVIN pins. A 1µF ceramic capacitor from the VDD pin to SGND pins must be placed next to the IC.
November 2012
3
M9999-110712-A