MIC22205 Datasheet, PDF (2/29 Pages) Micrel Semiconductor – 2A, Integrated, Switch, High-Efficiency

Micrel, Inc.
Ordering Information
Part Number
MIC22205YML
Voltage
Adjustable
Junction Temperature Range
–40° to +125°C
Package⁽¹⁾
12-Pin 3mm x 3mm MLF^®
Note:
1. MLF^® is a GREEN ROHS compliant package. Lead finish is NiPdAu. Mold compound is Halogen Free.
Pin Configuration
MIC22205
Lead Finish
Pb-Free
12-Pin 3mm x 3mm MLF^® (ML)
Pin Description
Pin Number
Pin Name
1
PG
2
RC
3
CF
4
SGND
5
COMP
6
FB
7
SVIN
8
PVIN
9
SW
Description
PG (output): This is an open drain output that indicates when the output voltage is below 90% of
its nominal voltage. The PG flag is asserted without delay when the enable is set low or when the
output goes below the 90% threshold.
Ramp Control: A capacitor from the RC pin-to-ground determines slew rate of output voltage
during start-up. The RC pin is internally fed with a 1µA current source. The output voltage tracks
the RC pin voltage. The slew rate is proportional by the internal 1µA source and the RC pin
capacitor. This feature can be used for tracking capability as well as soft start.
Adjustable frequency with external capacitor. Refer to Table 2.
Signal Ground: Internal signal ground for all low power circuits.
Compensation Pin (Input): The MIC22205 uses an internal compensation network containing a
fixed-frequency zero (phase lead response) and pole (phase lag response) which allows the
external compensation network to be much simplified for stability. The addition of a single
capacitor and resistor to the COMP pin will add the necessary pole and zero for voltage mode
loop stability using low-value, low-ESR ceramic capacitors.
Feedback: Input to the error amplifier. The FB pin is regulated to 0.7V. A resistor divider
connecting the feedback to the output is used to adjust the desired output voltage.
Signal Power Supply Voltage (Input): This pin is connected externally to the PVIN pin. A 2.2µF
ceramic capacitor from the SVIN pin to SGND must be placed next to the IC.
Power Supply Voltage (Input): The PVIN pins are the input supply to the internal P-Channel
Power MOSFET. A 10µF ceramic is recommended for bypassing at each PVIN pin. The SVIN
pin must be connected to a PVIN pin.
Switch (Output): This is the connection to the drain of the internal P-Channel MOSFET and drain
of the N-Channel MOSFET. This is a high-frequency, high-power connection; therefore traces
should be kept as short and as wide as practical.
August 2011
2
M9999-082511-A