19-3495; Rev 0; 11/04
Hig h -Vo lt a g e , Lo w -P o w e r Lin e a r Re g u la t o rs fo r
No t e b o o k Co m p u t e rs
Ge n e ra l De s c rip t io n
Fe a t u re s
The MAX8718/MAX8719 are micropower, 8-pin TDFN
line a r re g ula tors tha t s up p ly a lwa ys -on, ke e p -a live
p owe r to CMOS RAM, re a l-time c loc ks (RTC), a nd
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.
♦ 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
Despite a miserly 25µA (max) no-load quiescent cur-
rent, the MAX8718/MAX8719 have good line- and load-
tra ns ie nt re s p ons e a nd e xc e lle nt AC p owe r-s up p ly
rejection. They provide a clean fixed 5V or 3.3V output
(MAX8718), or a n a d jus ta b le 1.24V to 28V outp ut
(MAX8719), even when subjected to fast supply-volt-
age changes that occur during the switchover from bat-
te ry to AC-a d a p te r inp ut p owe r. The s p a c e -s a ving
TDFN package has excellent thermal characteristics
a nd tole ra te s up to 1951mW of p owe r d is s ip a tion.
Internal foldback current limiting and thermal shutdown
protect the regulator from overload and thermal faults.
♦ Thermal-Overload Protection
♦ Delayed Power-Good Output
♦ Thermally Enhanced 8-Pin TDFN Package
Ord e rin g In fo rm a t io n
OUTPUT
VOLTAGE
In addition to the main notebook-computer application,
these devices are useful in other low-power, high-volt-
PART
TEMP RANGE PIN-PACKAGE
age applications (4V < V < 28V) such as smart batter-
ies, current control loops, telecom emergency power,
and housekeeping power for off-line supplies.
IN
8 TDFN 3mm x
3mm
MAX8718ETA -40°C to +85°C
MAX8719ETA -40°C to +85°C
3.3V/5V
8 TDFN 3mm x
3mm
Adjustable
The MAX8718/MAX8719 are available in a thermally
enhanced 3mm x 3mm, 8-lead TDFN package.
Ap p lic a t io n s
P in Co n fig u ra t io n
CMOS/RTC Backup Power
Microcontroller Power
Notebook Computers
TOP VIEW
Smart-Battery Packs
1
2
3
4
8
7
6
5
OUT
IN
GND
PDAs and Handy-Terminals
Battery-Powered Systems
I.C.
MAX8718
MAX8719
5/3 (FB)
SHDN
PGOOD
V
CC
TDFN
3mm × 3mm
() ARE FOR THE MAX8719.
________________________________________________________________ Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.