AME8750 Datasheet, PDF (7/15 Pages) Asahi Kasei Microsystems – Low-Dropout 150mA / 150mA Dual CMOS Regulator

AME, Inc.
AME8750
Low-Dropout
150mA / 150mA Dual CMOS Regulator
n Detailed Description
The AME8750 is low-dropout, low quiescent-current lin-
ear regulatior designed primarily for battery-powered appli-
cations. These parts are available with preset output volt-
age ranging from 1.8V to 3.3V, and the parts can supply
loads up 150mA.
Shutdown
AME8750A
The AME8750A has a single shutdown control input(EN).
Drive EN low to shut down both outputs, reducing supply
current to 0.3µA. Connect EN to a logic-high, or IN, for nor-
mal operation.
AME8750B
The AME8750B has independent shutdown control in-
puts (EN1 and EN2). Drive EN1 low to shutdown V_OUT1. Drive
EN2 low to shut down V_OUT2. Drive both EN1 and EN2 low to
shut down the entire chip, reducing supply current to 0.3mA.
Connect both EN1 and EN2 to a logic-high, or IN, for nor-
mal operation.
Internal P-Channel Pass Transistor
The AME8750A/AME8750B feature two 1Ω P-Channel
MOSFET pass transistors. A P-Channel MOSEFT provides
several advantages over similar designs using PNP pass
transistors, including longer battery life. It requires no base
drive, which reduces quiescent current significantly. The
AME8750A/AME8750B only consume 70µA of quiescent
current whether in dropout, light-load, or heavy-load appli-
cations.
Current Limit
The AME8750A/8750B contain two independent current
limiters, one for each regulator, which monitor and control
the pass transistor’ s gate voltage, limiting the guaranteed
maximum output current to 150mA minimum. The output
can be shorted to ground for an indefinite time without dam-
aging the part.
Thermal-Overload Protection
Thermal -overload protection limits toatl power dissipa-
tion in the AME8750A/AME8750B. When the junction
trmperature exceeds T_J=150^oC, the themal sensor signals
the shutdown logic, turning off the pass transistor and al-
lowing the IC to cool.
n Application Information
Capacitor Selection and Regulator Stability
Use a 1µF capacitor on the AME8750A/ AME8750B
input and a 1µF capacitor on the outputs. Larger input
capacitor values and lower ESRs provide better
supplynoise rejection and line transient response.
PSRR and Operation from Sources Other
than Batteries
The AME8750A/AME8750B are designed to deliver
low dopout voltages and low quiescent currents in
batterypowered systems. Power-supply rejection is
54dB at low frequencies.
(See the PSRR vs. Frequency graph)
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