8188 Datasheet, PDF (1/12 Pages) Allegro MicroSystems – LOW-DROPOUT REGULATORS . HIGH EFFICIENCY

8188
PRELIMINARY INFORMATION
(subject to change without notice)
July 13, 1999
LOW-DROPOUT REGULATORS
— HIGH EFFICIENCY
A8188SLT-xx
Designed specifically to meet the requirement for extended opera-
tion of battery-powered equipment such as cordless and cellular tele-
phones, the A8188S— voltage regulators offer the reduced dropout
voltage and quiescent current essential for maximum battery life.
Applicable also to palmtop computers and personal data assistants,
VR
DUCTLY ₁
2
3
PRO ^ON _Dwg.PS-022-2
D ^{E where “-xx” is the required output voltage in tenths}
INUE ^{ENC ABSOLUTE MAXIMUM RATINGS}
R _{Input Voltage, VI . . . . . . . . . . . . . . 10 V}
T ^E Peak Output Current,
N ^{F IOM . . . . . . . . . . . . . . . . . . 250 mA*}
Enable Input Voltage, V_E . . . . . . . . . V_I
O ^{E Operating Temperature Range,}
C ^{R TA .}
Junction
............
Temperature, T_J
-20°C
....
to +85°C
+150°C^†
IS ^{R Storage Temperature Range,}
T_S . . . . . . . . . . . . -40°C to +150°C
D _{FO * Output current rating is limited by input}
these devices deliver a regulated output at up to 250 mA (transient),
which is limited only by package power dissipation. Regulated output
voltages between 2.5 V and 3.3 V are trimmed at wafer probe.
A PMOS pass element provides a typical dropout voltage of only
90 mV at 60 mA of load current. The low dropout voltage permits
deeper battery discharge before output regulation is lost. Quiescent
current does not increase significantly as the dropout voltage is ap-
proached, an ideal feature in standby/resume power systems where data
integrity is crucial. Regulator accuracy and excellent temperature
characteristics are provided by a bandgap reference. The A8188SL-xx
includes ENABLE inputs to give the designer complete control over
power up, standby, or power down.
These devices are supplied, without the ENABLE function, in a
standard 3-lead SOT-89/TO-243AA small-outline plastic transistor
package (suffix ‘LT’). Dual regulators (A8188SL-xx) are provided in
an 8-lead SOIC package. All devices are rated for operation over a
temperature range of -20°C to +85°C.
FEATURES AND BENEFITS
I High Efficiency Provides Extended Battery Life
I 90 mV Typical Dropout Voltage at I_O = 60 mA
I 55 µA Typical Quiescent Current
Less Than 1 µA “Sleep” Current
I 250 mA Peak Output Current
I Improved PSRR and Transient Performance
I Internal Thermal Protection
— ^{voltage, duty cycle, and ambient tempera-}
ture. Under any set of conditions, do not
exceed a junction temperature of +150°C.
See following pages.
APPLICATIONS
I Cordless and Cellular Telephones
I Personal Data Assistants
I Personal Communicators
† Fault conditions that produce excessive
junction temperature will activate device
I Palmtop Computers
thermal shutdown circuitry. These condi-
tions can be tolerated but should be
avoided.
Always order by complete part number, e.g., A8188SLT-30 .