MAX8718 Datasheet, PDF (1/10 Pages) Maxim Integrated Products – High-Voltage, Low-Power Linear Regulators for Notebook Computers

19-3495; Rev 0; 11/04
High-Voltage, Low-Power Linear Regulators for
Notebook Computers
General Description
The MAX8718/MAX8719 are micropower, 8-pin TDFN
linear regulators that supply always-on, keep-alive
power to CMOS RAM, real-time clocks (RTC), and
microcontrollers in systems with high-voltage batteries.
The circuits consist of a 100mA linear regulator and a
power-good comparator (PGOOD) with fixed-output
delay. Key features include wide input voltage range,
low-dropout voltage, and low-quiescent supply current.
Despite a miserly 25µA (max) no-load quiescent cur-
rent, the MAX8718/MAX8719 have good line- and load-
transient response and excellent AC power-supply
rejection. They provide a clean fixed 5V or 3.3V output
(MAX8718), or an adjustable 1.24V to 28V output
(MAX8719), even when subjected to fast supply-volt-
age changes that occur during the switchover from bat-
tery to AC-adapter input power. The space-saving
TDFN package has excellent thermal characteristics
and tolerates up to 1951mW of power dissipation.
Internal foldback current limiting and thermal shutdown
protect the regulator from overload and thermal faults.
In addition to the main notebook-computer application,
these devices are useful in other low-power, high-volt-
age applications (4V < V_IN < 28V) such as smart batter-
ies, current control loops, telecom emergency power,
and housekeeping power for off-line supplies.
The MAX8718/MAX8719 are available in a thermally
enhanced 3mm x 3mm, 8-lead TDFN package.
Features
♦ 4V to 28V Input Range
♦ 18µA Quiescent Supply Current
♦ <3µA Shutdown Supply Current
♦ 100mA Output Current
♦ 3.3V or 5V, Pin-Selectable Output (MAX8718)
♦ Adjustable 1.24V to 28V Output (MAX8719)
♦ ±2% Output Accuracy
♦ Thermal-Overload Protection
♦ Delayed Power-Good Output
♦ Thermally Enhanced 8-Pin TDFN Package
Ordering Information
PART
TEMP RANGE PIN-PACKAGE
OUTPUT
VOLTAGE
MAX8718ETA
-40°C to +85°C
8 TDFN 3mm x
3mm
3.3V/5V
MAX8719ETA
-40°C to +85°C
8 TDFN 3mm x
3mm
Adjustable
Applications
CMOS/RTC Backup Power
Microcontroller Power
Notebook Computers
Smart-Battery Packs
PDAs and Handy-Terminals
Battery-Powered Systems
Pin Configuration
TOP VIEW
IN 1
GND 2
5/3 (FB) 3
V_CC 4
MAX8718
MAX8719
8 OUT
7 I.C.
6 SHDN
5 PGOOD
TDFN
3mm × 3mm
() ARE FOR THE MAX8719.
________________________________________________________________ Maxim Integrated Products 1
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