19-0146; Rev 2; 5/94
In
Kit
tion cluded
lua
Eva tion In
a
form
Triple-Output Power-Supply
Controller for Notebook Computers
___________________________Features
o
o
o
o
o
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™)
_______________General Description
The MAX782 is a system-engineered power-supply con-
troller 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 fly-
back winding controller. Other functions include dual, low-
dropout, micropower linear regulators for CMOS/RTC back-
up, 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 recti-
fication and PWM operation at heavy loads, and Idle-
Mode
TM
operation at light loads. It uses physically
small components, thanks to high operating frequen-
cies (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-tran-
sient 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 synchroniz-
able oscillator for noise-sensitive applications such as
electromagnetic pen-based systems and communicat-
ing computers. The MAX782 is a monolithic BiCMOS IC
available in fine-pitch, SSOP surface-mount packages.
MAX782
______________Ordering Information
PART
MAX782CBX
MAX782RCBX
MAX782SCBX
TEMP. RANGE
0°C to +70°C
0°C to +70°C
0°C to +70°C
PIN-PACKAGE
36 SSOP
36 SSOP
36 SSOP
V
OUT
3.3V
3.45V
3.6V
Ordering Information continued on last page.
__________________Pin Configuration
TOP VIEW
ON3
1
D1
2
D2
3
D3
4
VH
5
Q3
6
Q2
7
Q1
8
VPPA
9
VDD
10
VPPB
11
GND
12
36
SS3
35
CS3
34
FB3
33
DH3
_______________________Applications
Notebook Computers
Portable Data Terminals
Communicating Computers
Pen-Entry Systems
MAX782
32
LX3
31
BST3
30
DL3
29
V+
28
VL
27
FB5
26
PGND
25
DL5
24
BST5
23
LX5
22
DH5
21
CS5
20
SS5
19
ON5
______Typical Application Diagram
+3.3V
5.5V
TO
30V
VPP
CONTROL
ON3
ON5
SYNC
VPP (0V/5V/12V)
VPP (0V/5V/12V)
4
SUSPEND POWER
LOW-BATTERY WARNING
DUAL
PCMCIA
SLOTS
POWER
SECTION
µP
MEMORY
+5V
PERIPHERALS
REF
13
SYNC
14
DA1
15
DA0
16
DB1
17
DB0
18
MAX782
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
1
Call toll free 1-800-998-8800 for free samples or literature.
MAXIM [ MAXIM INTEGRATED PRODUCTS ]
