8187
LOW-DROPOUT, 3.3 V REGULATOR
— HIGH EFFICIENCY
Designed specifically to meet the requirement for extended opera-
tion of battery-powered equipment such as cordless and cellular
telephones, the A8187SLT voltage regulator offers the reduced dropout
voltage and quiescent current essential for maximum battery life.
Applicable also to palmtop computers and personal data assistants, the
device delivers a regulated, continuous 3.3 V output at up to 75 mA
under normal operating conditions, or to 150 mA (transient) under
worst-case conditions.
A PMOS pass element provides a typical dropout voltage of only
85 mV at 60 mA of load current. The low dropout voltage permits
deeper battery discharge before output regulation is lost. Furthermore,
quiescent current does not increase 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.
This device is supplied in a small-outline plastic transistor package
(SOT-89/TO-243AA) for surface-mount applications. The A8187SLT is
rated for operation over a temperature range of -20°C to +85°C. A
similar device with an ENABLE input for control over sequential power
up, standby, or power down is the A8186SLU.
Data Sheet
27468.16A
ABSOLUTE MAXIMUM RATINGS
Input Voltage, V
I
. . . . . . . . . . . . . .
10 V
Output Current, I
O
. . . . . . . . .
150 mA*
Operating Temperature Range,
T
A
. . . . . . . . . . . . .
-20
°
C to +85
°
C
Junction Temperature, T
J
. . .
+150
°
C
†
Storage Temperature Range,
T
S
. . . . . . . . . . . .
-40
°
C to +150
°
C
* Output current rating is limited by input voltage,
duty cycle, and ambient temperature. Under
any set of conditions, do not exceed a junction
temperature of +150°C. See next page.
T
C
U Y
D L
O N
R O
P E
D C
E N
U E
IN ER
T F
N E
O R
C R
IS O
D F
—
VR
3.3 V
1
2
3
GND
Dwg. PS-022-1
OUT
IN
FEATURES AND BENEFITS
I
I
I
I
I
I
High Efficiency Provides Extended Battery Life
85 mV Typical Dropout Voltage at I
O
= 60 mA
45
µA
Typical Quiescent Current at V
I
= 6 V
Up to 150 mA Output Current
Internal Thermal Protection
Surface-Mount Package
APPLICATIONS
I
I
I
I
Cordless and Cellular Telephones
Personal Data Assistants
Personal Communicators
Palmtop Computers
† Fault conditions that produce excessive junction
temperature will activate device thermal
shutdown circuitry. These conditions can be
tolerated but should be avoided.
Always order by complete part number:
A8187SLT
.
8187
LOW-DROPOUT,
3.3 V REGULATOR
FUNCTIONAL BLOCK DIAGRAM
IN
1
3
OUT
BIAS
DRIVE
ERROR
AMP
THERMAL
PROTECT.
BANDGAP
REF.
GND
2
TAB
Dwg. FS-012-4
MAXIMUM ALLOWABLE OUTPUT CURRENT with device mounted on 2.24" x 2.24"
(56.9 mm x 56.9 mm) solder-coated copper-clad board in still air.
Maximum Allowable Output Current in Milliamperes with V
I
= 8 V, T
J
= 150°C, Period
≤10
s*
dc (Duty Cycle)
T
A
25°C
50°C
70°C
85°C
100%
100
80
65
50
90%
115
90
70
60
80%
125
100
80
65
70%
145
115
90
75
60%
150
135
110
85
50%
150
150
130
105
40%
150
150
150
130
30%
150
150
150
150
20%
150
150
150
150
* I
O
= (T
J
- T
A
)/([V
I
- V
O
] R
θJA
• dc) = (150 - T
A
)/(4.7 • 258 • dc)
Output current rating can be increased (to 150 mA maximum) by heat sinking or reducing the input voltage. Conditions that produce excessive
junction temperature will activate device thermal shutdown circuitry. These conditions can be tolerated but should be avoided.
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
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