MIC22705_11 Datasheet, PDF (2/29 Pages) Micrel Semiconductor – 1MHz, 7A Integrated Switch High-Efficiency Synchronous Buck Regulator

Micrel, Inc.
MIC22705
Ordering Information
Part Number
MIC22705YML
Voltage
Adjustable
Junction Temperature Range
–40°C to +125°C
Package
24-Pin 4mm x 4mm MLF^®
Note:
MLF is a GREEN RoHs-compliant package. Lead finish is NiPdAu. Mold component is Halogen free.
Lead Finish
Pb-Free
Pin Configuration
24-Pin 4mm × 4mm MLF^® (ML)
Pin Description
Pin Number
Pin Name
1, 6, 13, 18
PVIN
2
EN/DLY
3
NC
4
RC
5
PG
14
FB
Description
Power Supply Voltage (Input): The PVIN pins are the input supply to the internal P-Channel
Power MOSFET. A 22µF ceramic is recommended for bypassing at each PVIN pin. The SVIN
pin must be connected to a PVIN pin.
Enable/Delay (Input): This pin is internally fed with a 1µA current source from SVIN. A delayed
turn on is implemented by adding a capacitor to this pin. The delay is proportional to the
capacitor value. The internal circuits are held off until EN/DLY reaches the enable threshold of
1.24V. This pin is pulled low when the input voltage is lower than the UVLO threshold.
No Connect: Leave this pin open. Do not connect to ground or route other signals through this
pin.
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 RC pin
capacitor. This feature can be used for tracking capability as well as soft start.
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.
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.
March 2011
2
M9999-033111-A