Allegro A8181SLB Datasheet
8181
LOW-DROPOUT,
5 V REGULATOR
NC
1
2
NC
NC NC
GROUND
GROUND
ENABLE
3
4
512
6
IN
710
IN
89
5 V
VR
16
15
14
13
11
OUT
OUT
GROUND
GROUND
NC
NC
NC
8181
LOW-DROPOUT, 5 V REGULATOR
— HIGH EFFICIENCY
Especially suited for hand-held, portable, battery-operated equipment such as cellular telephones, the A8181SLB low dropout voltage
regulator provides high efficiency for maximum battery life in a minimum package size. Equally applicable to camcorders and portable
computers, the device provides a fixed 5 V regulated continuous output
at almost 200 mA of load current under worst-case conditions. Under
normal operating conditions, output currents over 500 mA are
permitted.
A MOSFET pass element delivers high output current with an
input-output differential of less than 300 mV. For high efficiency, the
low dropout voltage allows a longer battery discharge before output
voltage regulation is lost. A low quiescent current, even during high
load conditions, makes the device ideal for standby power systems.
High regulator accuracy and excellent temperature characteristics are
provided by a bandgap reference. An enable input gives the designer
complete control over sequential power-up or emergency shutdown.
Data Sheet
27468*
Dwg. PS-018
This device is supplied in a 16-lead wide-body, small-outline
plastic power package (SOIC) for surface-mount applications. The
copper batwing provides for maximum package power dissipation in
the smallest possible construction. The A8181SLB is rated for operation over a temperature range of -20°C to +85°C.
FEATURES AND BENEFITS
ABSOLUTE MAXIMUM RATINGS
at T
= +25°C
Input Voltage, VI................................... 10 V
Output Current, I
(40% duty cycle)............................ 1 A*
(75% duty cycle)..................... 500 mA*
(continuous)............................ 370 mA*
Operating Temperature Range,
TA................................. -20°C to +85°C
Junction Temperature, T
Storage Temperature Range,
DISCONTINUED PRODUCT
TS............................... -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.
† Fault conditions that produce excessive
junction temperature will activate device thermal
shutdown circuitry. These conditions can be
tolerated but should be avoided.
A
O
.............. +150°C†
J
— FOR REFERENCE ONLY
■ High Efficiency Provides Extended Battery Life
■ Less Than 300 mV Dropout Voltage
■ Low Quiescent Current
■ >200 mA Output Current
■ LSTTL-Compatible ON/OFF Control
For Sequential Power-up or Emergency Shutdown
■ Internal Thermal Protection
■ SOIC Surface-Mount Package
Always order by complete part number: A8181SLB .
8181
12-13
4-5
7815166
LOW-DROPOUT,
5 V REGULATOR
FUNCTIONAL BLOCK DIAGRAM
IN
IN
ENABLE
ENABLE
BIAS
THERMAL
PROTECT.
DRIVE
OUT
OUT
ERROR
AMP
BANDGAP
REF.
Dwg. FS-012
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 VI = 10 V, TJ = 150°C*
dc (Duty Cycle)
T
A
25°C 370 415 465 530 620 745 930 1000 1000
50°C 295 330 370 425 495 595 745 995 1000
70°C 235 265 295 340 395 475 595 795 1000
85°C 190 215 240 275 320 385 485 645 970
*IO = (TJ - TA)/([VI - VO] R
Output current rating can be increased (to 1 A maximum) by heat sinking or reducing the input voltage. With an infinite heat sink, R
6°C/W. Conditions that produce excessive junction temperature will activate device thermal shutdown circuitry. These conditions can be tolerated
but should be avoided.
100% 90% 80% 70% 60% 50% 40% 30% 20%
• dc) = (150 - TA)/(5 • 67 • dc)
θJA
= R
-JT
=
115 Northeast Cutoff, Box 15036
Worcester, Massachusetts 01615-0036 (508) 853-5000
W
Copyright © 1992, 1995 Allegro MicroSystems, Inc.
-JA
8181
LOW-DROPOUT,
5 V REGULATOR
ELECTRICAL CHARACTERISTICS at T
+25°C (unless otherwise noted).
A
Limits
Characteristic Symbol Test Conditions Min. Typ. Max. Units
Output Voltage V
O
TA = 25°C, 5.5 V ≤ VI ≤ 10 V, 4.90 5.00 5.10 V
0 mA ≤ I
T
A
≤ 500 mA†
O
= 85°C, 5.5 V ≤ VI ≤ 10 V, 4.85 — 5.15 V
0 mA ≤ IO ≤ 500 mA*†
Output Volt. Temp. Coeff. α
Line Regulation ∆V
Load Regulation ∆V
VO
O(∆VI)
O(∆IO)
IO = 0 — ±100 — µV/°C
5.5 V ≤ VI ≤ 10 V, Output open — 10 30 mV
0 mA ≤ IO ≤ 500 mA†, VI = 6 V — 40 100 mV
Dropout Voltage VImin - VOIO = 500 mA† — — 300 mV
Quiescent Current I
(GND terminal current)
I
ENABLE Input Voltage V
Q
Q(off)
EH
V
EL
VI = 10 V, IO = 500 mA† — 87 120 µA
= 10 V, Output open — 86 120 µA
V
I
VI = 10 V, Output open, VE = 0.4 V — — 20 µA
Output ON, VI = 10 V 2.4 — — V
Output OFF, VI = 10 V — — 0.4 V
ENABLE Input Current I
Thermal Shutdown Temp. T
Thermal Resistance R
E
J
θJA
VE = VI = 10 V — — ±0.1 µA
Mounted on 2.24" x 2.24" solder-coated — 67 — °C/W
copper-clad board in still air
R
θJT
Typical values are given for circuit design information only.
* This parameter is tested to a lot sample plan only.
† Pulse test (<20 ms).
— 165 — °C
— 6.0 — °C/W
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