ULTRA-SMALL PACKAGE PWM/PFM SWITCHING CONTROL
STEP-UP SWITCHING REGULATOR
The ME2139 series is a CMOS step-up
switching regulator which mainly consists of a
reference voltage source, an oscillation circuit,
an error amplifier, a phase compensation circuit,
a PWM/PFM switching control circuit. With an
external low-ON-resistance Nch Power MOS,
this product is applicable to applications
requiring high efficiency and high output current.
The ME2139 series switches its operation to the
PFM control circuit whose duty ratio is 15 % with
to the PWM/PFM switching control circuit under
a light load and to prevent decline in the
efficiency by IC operation current.
Low voltage operation: Start-up is guaranteed
from 0.9 V(IOUT =1 mA )
Duty ratio: Built-in PWM/PFM switching control
circuit 15 to 78 % .
External parts: coil, diode, capacitor, and
Output voltage range: 1.5V ~6.5 V
Output voltage accuracy：±2%
Soft start function: 2 mS.
MP3 players, digital audio players
Digital cameras, GPS, wireless transceiver
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