MAX782 Datasheet, PDF (1/32 Pages) Maxim Integrated Products – Triple-Output Power-Supply Controller for Notebook Computers

19-0146; Rev 2; 5/94
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Triple-Output Power-Supply
Controller for Notebook Computers
_______________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
______Typical Application Diagram
___________________________Features
o Dual PWM Buck Controllers (+3.3V and +5V)
o Dual PCMCIA VPP Outputs (0V/5V/12V)
o Three Precision Comparators or Level Translators
o 95% Efficiency
o 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™)
______________Ordering Information
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
Ordering Information continued on last page.
VOUT
3.3V
3.45V
3.6V
__________________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
MAX782
36 _SS3
35 CS3
34 FB3
33 DH3
32 LX3
31 BST3
30 _DL3
29 _V+
28 _VL
27 _FB5
26 _PGND
5.5V
TO
30V
VPP ⁴
CONTROL
ON3
ON5
SYNC
MAX782
+3.3V
POWER
SECTION
µP
MEMORY
+5V PERIPHERALS
SUSPEND POWER
LOW-BATTERY WARNING
VPP (0V/5V/12V)
VPP (0V/5V/12V)
DUAL
PCMCIA
SLOTS
GND 12
REF 13
SYNC 14
DA1 15
DA0 16
DB1 17
DB0 18
25 DL5
24 BST5
23 LX5
22 _DH5
21 CS5
20 SS5
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 1
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