MIC2169 Micrel Semiconductor, MIC2169 Datasheet - Page 13

• Manufacturer Part Number: MIC2169
• Description: 500 KHZ PWM SYNCHRONOUS BUCK CONTROL IC
• Manufacturer: Micrel Semiconductor

Design Example
Layout and Checklist:
November 2003
MIC2169
1. Connect the current limiting (CS) resistor directly
2. Connect the VSW pin directly to the source of top
3. The feedback resistors R1 and R2 should be
4. The compensation resistor and capacitors should
5. The input bulk capacitors should be placed close to
6. The 1 F ceramic capacitor should be placed right
7. The 4.7 F to 10 F ceramic capacitor should be
8. The source of the bottom MOSFET should connect
9. Place a 0.1 F ceramic capacitor in parallel with the
to the drain of top MOSFET Q1.
MOSFET Q1 thru a 4
pose of the resistor is to filter the switch node.
placed close to the FB pin. The top side of R1
should connect directly to the output node. Run
this trace away from the switch node (junction of
Q1, Q2, and L1). The bottom side of R1 should
connect to the GND pin on the MIC2169.
be placed right next to the COMP/EN pin and the
other side should connect directly to the GND pin
on the MIC2169 rather than going to the plane.
the drain of the top MOSFET.
on the VIN pin of the MIC2169.
placed right on the VDD pin.
directly to the input capacitor GND with a thick
trace. The output capacitor and the input capacitor
should connect directly to the GND plane.
CS resistor to filter any switching noise.
to 10
resistor. The pur-
13
M9999-111803
Micrel