19-4102; Rev 0; 5/08
ABRIDGED
Highly Efficient, All-Internal MOSFET, 6-Channel
PMIC for 2AA Digital Camera Systems
General Description
The MAX8858 PMIC provides a complete power-supply
solution for digital still cameras (DSCs) and digital video
cameras (DVCs). The MAX8858 improves performance,
component count, and board space utilization compared
to currently available solutions for two AA cell and dual-
battery designs. On-chip power MOSFETs provide up to
95% efficiency for critical power supplies. The CCD
inverter can operate directly from two AA/NiMH batteries
without the use of any additional external components.
• Step-up synchronous-rectified DC-DC converter
(SU). The MAX8858 is bootstrapped from V
VSU
.
•
•
MAIN synchronous-rectified step-up DC-DC converter
(M) with active discharge for DSP I/O supply voltage.
SDZ synchronous-rectified step-down DC-DC con-
verter (SDZ) with active discharge for DSP DDR
supply voltage.
Low-voltage (down to 1V) synchronous-rectified
step-down DC-DC converter (SD) with active dis-
charge for DSP core supply voltage.
High-voltage step-up DC-DC converter (CCDBST)
for CCD imagers or positive LCD bias supplies.
Transformerless inverting DC-DC converter (CCDINV)
with active discharge for CCD imagers or negative
LCD bias supplies.
This converter can connect
directly to two AA batteries.
Features
♦
95% Efficient Synchronous-Rectified DC-DC
Converters
♦
Up to 90% Efficient Boost-Buck Operation
♦
Up to 85% Efficient, High-Voltage DC-DC
Converters
♦
Transformerless Inverting Converter with Active
Discharge for CCD
♦
Preset Power-Up Sequencing for MAIN, SDZ, and
SD Converters
♦
Inverter Operates Directly from Two AA Batteries
♦
Internal Compensation on All Channels
♦
True Shutdown™ on All Step-Up Converters
♦
Overload Protection
♦
Startup into Short Protection
♦
Soft-Start for Controlled Inrush Current
♦
100% Duty Cycle on Step-Down Converters
♦
2MHz ±5% Switching Frequency
♦
0.1µA Shutdown Supply Current
♦
All Internal Power MOSFETs
MAX8858
•
•
•
Ordering Information
PART
MAX8858ETJ+
TEMP RANGE
-40°C to +85°C
PIN-PACKAGE
32 Thin QFN-EP*
Individual ON_ inputs provide independent on/off control
for the SU, CCDBST, and CCDINV converters, while dual-
function inputs allow independent on/off control or power-
up sequencing of the MAIN, SDZ, and SD converters.
The MAX8858 is available in a 5mm x 5mm x 0.8mm,
32-pin thin QFN package and operates over the -40°C
to +85°C extended temperature range.
+Denotes
a lead-free package.
*EP
= Exposed pad.
Pin Configuration
ONM/SEQ
FBSU
GND
REF
V
SU
TOP VIEW
DSCs and DVCs
PDAs and Portable Media Players
LXSU 25
LXSU 26
PVSU 27
INPUT
0.9V TO 5.5V
24
23
22
ONSU
21
20
19
18
FBBST
17
16
15
14
13
LXBST
SWBST
PVBST
PVINV
OUTINV
LXINV
PVZ
LXZ
Typical Operating Circuit
PVBST
ONSU
ONM/SEQ
SU STEP-UP
MAIN STEP-UP
SD STEP-DOWN
V
SU
5V
V
MAIN
3.3V
V
SD
1.8V
V
SDZ
2.5V
PVSD 28
LXSD 29
PVM 30
LXM 31
LXM 32
+
EP = EXPOSED PAD
MAX8858
ONBST
12
11
10
9
8
ONINV
Applications
ONSD/EN1 SDZ STEP-DOWN
ONZ/EN2
1
FBM
2
ONSD/EN1
3
FBSD
4
GND
5
FBZ
6
ONZ/EN2
7
FBINV
MAX8858
CCDBST
CCDINV
V
CCDBST
+15V
V
CCDINV
-7.5V
THIN QFN-EP
5mm x 5mm
ONBST
ONINV
True Shutdown is a trademark of Maxim Integrated Products, Inc.
________________________________________________________________
Maxim Integrated Products
1
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
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