Rainbow Electronics MAX8719 - Manual

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.
Applications
CMOS/RTC Backup Power
Microcontroller Power
Notebook Computers
Smart-Battery Packs
PDAs and Handy-Terminals
Battery-Powered Systems
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
MAX8718/MAX8719
High-Voltage, Low-Power Linear Regulators for
Notebook Computers
________________________________________________________________ Maxim Integrated Products 1
TDFN
3mm × 3mm
TOP VIEW
1
2
8
7
3
4
6
5
SHDN
PGOOD V CC
OUT
I.C. GND
5/3 (FB)
IN
MAX8718
MAX8719
() ARE FOR THE MAX8719.
Pin Configuration
Ordering Information
19-3495; Rev 0; 11/04
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.
PART TEMP RANGE PIN-PACKAGE
OUTPUT
VOLTAGE
MAX8718 ETA -40 °C to +85°C
8 TDFN 3mm x
3mm
3.3V/5V
MAX8719 ETA -40 °C to +85°C
8 TDFN 3mm x
3mm
Adjustable