Rainbow Electronics MAX1585 - Manual

General Description
The MAX1584/MAX1585 provide a complete power-
supply solution for slim digital cameras. They improve
performance, component count, and size compared to
conventional multichannel controllers in 2-cell AA, 1-cell
Li+, and dual-battery designs. On-chip MOSFETs pro-
vide up to 95% efficiency for critical power supplies,
while additional channels operate with external FETs for
optimum design flexibility. This optimizes overall effi-
ciency and cost, while also reducing board space.
The MAX1584/MAX1585 include 5 high-efficiency DC-
DC conversion channels:
• Step-up DC-DC converter with on-chip FETs
• Step-down DC-DC converter with on-chip FETs
• Three PWM DC-DC controllers for CCD, LCD, LED,
or other functions
The step-down DC-DC converter can operate directly
from the battery or from the step-up output, providing
boost-buck capability with a compound efficiency of up
to 90%. Both devices include three PWM DC-DC con-
trollers: the MAX1584 includes two step-up controllers
and one step-down controller, while the MAX1585
includes one step-up controller, one inverting controller,
and one step-down controller. All DC-DC channels
operate at one fixed frequency—settable from 100kHz
to 1MHz—to optimize size, cost, and efficiency. Other
features include soft-start, power-OK outputs, and over-
load protection. The MAX1584/MAX1585 are available
in space-saving, 32-pin thin QFN packages. An evalua-
tion kit is available to expedite designs.
Applications
Digital Cameras
PDAs
Features
♦ Step-Up DC-DC Converter, 95% Efficient
♦ Step-Down DC-DC Converter
Operate from Battery for 95% Efficient
Step-Down
90% Efficient Boost-Buck with Step-Up
♦ Three Auxiliary PWM DC-DC Controllers
♦ No Transformers (MAX1585)
♦ Up to 1MHz Operating Frequency
♦ 1mA Shutdown Mode
♦ Internal Soft-Start Control
♦ Overload Protection
♦ Compact 32-Pin Thin QFN Package (5mm x 5mm)
MAX1584/MAX1585
5-Channel Slim DSC Power Supplies
________________________________________________________________ Maxim Integrated Products 1
Ordering Information
MAX1585
INPUT
0.7V TO 5.5V
ONSU
ONSD
ON1
ON2
ON3
STEP-UP SYSTEM +5V
STEP-DOWN CORE +1.8V
AUX1 LCD, CCD, LED +15V
AUX2 CCD -7.5V
AUX3 LOGIC +3.3V
Typical Operating Circuit
19-2883; Rev 0; 7/03
For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.
EVALUATION KIT
AVAILABLE
PART TEMP RANGE
PIN-
PACKAGE AUX
FUNCTIONS
MAX1584ETJ -40 °C to +85°C
32 Thin QFN
5mm x 5mm 2 step-up
1 step-down
MAX1585ETJ -40 °C to +85°C
32 Thin QFN
5mm x 5mm
1 step-up
1 step-down
1 inverting
1 CC1
2 FB1
3 PGSD
4 LXSD
5 PVSD
6 ONSD
7 CCSD
8 FBSD
9
ON1
10
ON2
11
ON3
12
ONSU
13
REF
14
FBSU
15
CCSU
16
AUX1OK
32
FB3
31
CC3
30
GND
29
DL1
28
DL3
27
DL2
26
PV
25
INDL2
24 CC2
23 FB2
22 PVSU
21 LXSU
20 PGSU
19 OSC
18 SCF
17 SDOK
MAX1584
MAX1585
THIN QFN
5mm x 5mm
Pin Configuration