Rainbow Electronics MAX782 - Manual

_______________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.
_______________________Applications
Notebook Computers
Portable Data Terminals
Communicating Computers
Pen-Entry Systems
___________________________Features
♦ 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)
♦ 5.5V to 30V Input Range
♦ Small SSOP Package
♦ Fixed Output Voltages Available:
3.3 (standard)
3.45 (High-Speed Pentium™)
3.6 (PowerPC™)
______________Ordering Information
MAX782
Triple-Output Power-Supply
Controller for Notebook Computers
________________________________________________________________ Maxim Integrated Products 1
36
35
34
33
32
31
30
29
28
27
26
25
24
23
1
2
3
4
5
6
7
8
9
10
11
12
13
14
SS3
CS3
FB3
DH3
LX3
BST3
LX5
DL3
V+
VL
FB5
PGND
DL5
BST5
SYNC
REF
GND
VPPB
VDD
VPPA
Q1
Q2
Q3
VH
D3
D2
D1
ON3
SSOP
TOP VIEW
MAX782
22
21
20
19
15
16
17
18 ON5
DH5
CS5
SS5
DB0
DB1
DA0
DA1
__________________Pin Configuration
MAX782
5.5V
TO
30V
VPP
CONTROL
ON3
ON5
SYNC
POWER
SECTION
SUSPEND POWER
LOW-BATTERY WARNING
VPP (0V/5V/12V)
µ P
MEMORY
PERIPHERALS
+3.3V
+5V
DUAL
PCMCIA
SLOTS
4
VPP (0V/5V/12V)
______Typical Application Diagram
Call toll free 1-800-998-8800 for free samples or literature.
19-0146; Rev 2; 5/94
PART TEMP. RANGE PIN-PACKAGE
MAX782CBX 0°C to +70°C 36 SSOP
MAX782RCBX 0°C to +70°C 36 SSOP
MAX782SCBX 0°C to +70°C 36 SSOP
™ Idle-Mode is a trademark of Maxim Integrated Products. Pentium is a trademark of Intel . PowerPC is a trademark of IBM.
Evaluation Kit
Information Included
Ordering Information continued on last page.
V OUT
3.3V
3.45V
3.6V