19-0146; Rev 2; 5/94
Kit ed
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In
Triple-Output Power-Supply
Controller for Notebook Computers
_______________________Applications
Notebook Computers
Portable Data Terminals
Communicating Computers
Pen-Entry Systems
ON3
PART
TEMP. RANGE
PIN-PACKAGE
0°C to +70°C
36 SSOP
3.3V
MAX782RCBX
MAX782SCBX
0°C to +70°C
0°C to +70°C
36 SSOP
36 SSOP
3.45V
3.6V
Ordering Information continued on last page.
__________________Pin Configuration
TOP VIEW
ON3 1
36 SS3
D1 2
35 CS3
D2 3
34 FB3
D3 4
33 DH3
VH 5
Q3 6
MAX782
32 LX3
31 BST3
30 DL3
POWER
SECTION
29 V+
28 VL
27 FB5
VDD 10
26 PGND
VPPB 11
GND 12
µP
MEMORY
25 DL5
24 BST5
REF 13
SYNC 14
23 LX5
DA1 15
+5V
MAX782
22 DH5
DA0 16
21 CS5
PERIPHERALS
4
SUSPEND POWER
DB1 17
LOW-BATTERY WARNING
VPP (0V/5V/12V)
VPP (0V/5V/12V)
VOUT
MAX782CBX
VPPA 9
ON5
SYNC
______________Ordering Information
Q1 8
+3.3V
VPP
CONTROL
Dual PWM Buck Controllers (+3.3V and +5V)
Dual PCMCIA VPP Outputs (0V/5V/12V)
Three Precision Comparators or Level Translators
95% Efficiency
420µA Quiescent Current;
70µA in Standby (linear regulators alive)
o 5.5V to 30V Input Range
o Small SSOP Package
o Fixed Output Voltages Available:
3.3 (standard)
3.45 (High-Speed Pentium™)
3.6 (PowerPC™)
Q2 7
______Typical Application Diagram
5.5V
TO
30V
___________________________Features
o
o
o
o
o
DUAL
PCMCIA
SLOTS
20 SS5
DB0 18
19 ON5
SSOP
™Idle-Mode is a trademark of Maxim Integrated Products. Pentium is a trademark of Intel. PowerPC is a trademark of IBM.
________________________________________________________________ Maxim Integrated Products
Call toll free 1-800-998-8800 for free samples or literature.
1
MAX782
_______________General Description
The MAX782 is a system-engineered power-supply controller for notebook computers or similar battery-powered
equipment. It provides two high-performance step-down
(buck) pulse-width modulators (PWMs) for +3.3V and +5V,
and dual PCMCIA VPP outputs powered by an integral flyback winding controller. Other functions include dual, lowdropout, micropower linear regulators for CMOS/RTC backup, and three precision low-battery-detection comparators.
High efficiency (95% at 2A; greater than 80% at loads
from 5mA to 3A) is achieved through synchronous rectification and PWM operation at heavy loads, and IdleMode TM operation at light loads. It uses physically
small components, thanks to high operating frequencies (300kHz/200kHz) and a new current-mode PWM
architecture that allows for output filter capacitors as
small as 30µF per ampere of load. Line- and load-transient response are terrific, with a high 60kHz unity-gain
crossover frequency allowing output transients to be
corrected within four or five clock cycles. Low system
cost is achieved through a high level of integration and
the use of low-cost, external N-channel MOSFETs. The
integral flyback winding controller provides a low-cost,
+15V high-side output that regulates even in the
absence of a load on the main output.
Other features include low-noise, fixed-frequency PWM
operation at moderate to heavy loads and a synchronizable oscillator for noise-sensitive applications such as
electromagnetic pen-based systems and communicating computers. The MAX782 is a monolithic BiCMOS IC
available in fine-pitch, SSOP surface-mount packages.
