MAX8858 Datasheet, PDF (1/2 Pages) Maxim Integrated Products – Highly Efficient, All-Internal MOSFET, 6-Channel PMIC for 2AA Digital Camera Systems

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.
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.
Applications
DSCs and DVCs
PDAs and Portable Media Players
Typical Operating Circuit
INPUT
0.9V TO 5.5V
PVBST
ONSU
SU STEP-UP
MAIN STEP-UP
ONM/SEQ ^{SD STEP-DOWN}
ONSD/EN1 SDZ STEP-DOWN
ONZ/EN2
VSU 5V
VMAIN 3.3V
VSD 1.8V
VSDZ 2.5V
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
Ordering Information
PART
MAX8858ETJ+
TEMP RANGE
-40°C to +85°C
PIN-PACKAGE
32 Thin QFN-EP*
+Denotes a lead-free package.
*EP = Exposed pad.
Pin Configuration
TOP VIEW
24 23 22 21 20 19 18 17
LXSU 25
16 LXBST
LXSU 26
15 SWBST
PVSU 27
14 PVBST
PVSD 28
LXSD 29
MAX8858
13 PVINV
12 OUTINV
PVM 30
LXM 31
EP = EXPOSED PAD
11 LXINV
10 PVZ
LXM 32
9 LXZ
[phone]
MAX8858
ONBST
ONINV
CCDBST
CCDINV
VCCDBST +15V
VCCDINV -7.5V
THIN QFN-EP
5mm x 5mm
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.