MC33680_06 Datasheet, PDF (1/14 Pages) ON Semiconductor – Dual DC−DC Regulator for Electronic Organizer

MC33680
Dual DC−DC Regulator for
Electronic Organizer
The MC33680 is a dual DC−DC regulator designed for electronic
organizer applications. Both regulators apply
Pulse−Frequency−Modulation (PFM). The main step−up regulator
output can be externally adjusted from 2.7V to 5V. An internal
synchronous rectifier is used to ensure high efficiency (achieve 87%).
The auxiliary regulator with a built−in power transistor can be
configured to produce a wide range of positive voltage (can be used
for LCD contrast voltage). This voltage can be adjusted from +5V to
+25V by an external potentiometer.
The MC33680 has been designed for battery powered hand−held
products. With the low start−up voltage from 1V and the low quiescent
current (typical 35 μA); the MC33680 is best suited to operate from 1
to 2 AA/ AAA cell. Moreover, supervisory functions such as low
battery detection, CPU Power−Good signal, and back−up battery
control, for lithium battery or supercap are also included in the chip.
FEATURES:
• Low Input Voltage, 1V up
• Low Quiescent Current in Standby Mode: 35μA typical
• PFM and Synchronous Rectification to ensure high efficiency
(87% @60mA Load)
• Adjustable Main Output: +2.7V to +5V
nominal 3.3V @ 100mA max, with 1.8V input
• Auxiliary Output Voltage: +5V to +25V
+5V @ 25mA max, with 1.8V input
+25V @ 15mA max, with 1.8V input
• Current Limit Protection
• Power−Good Signal with Programmable Delay
• Battery Low Detection
• Lithium Battery or Supercap Back−up
• 32−Pin LQFP Package
APPLICATIONS:
• Digital Organizer and Dictionary
• Dual Output Power Supply (For MPU, Logic, Memory, LCD)
• Handheld Battery Powered Device (1−2 AA/AAA cell)
http://onsemi.com
32 1
32−LEAD LQFP
FTB SUFFIX
CASE 873A
PIN CONNECTIONS &
DEVICE MARKING
VAUXSW
VAUXEMR
LIBATIN
LIBATOUT
NC
VMAINGND
VMAINSW
VMAIN
MC33680
FTB
AWLYYWW
NC
DGND
LIBATCL
LIBATON
LOWBATB
PORB
DGND
LOWBATSEN
(Top View)
ORDERING INFORMATION
Device
Package
Shipping
MC33680FTB
LQFP 1250 Tray / Drypack
MC33680FTBR2 LQFP 1800 / Tape & Reel
© Semiconductor Components Industries, LLC, 2006
1
July, 2006 − Rev. 4
Publication Order Number:
MC33680/D