MAXIM MAX8680

ABRIDGED
KIT
ATION
EVALU
E
L
B
AVAILA
19-0681; Rev 2; 11/07
Smallest, All-Internal MOSFET, 7-Channel
DSC PMIC in Tiny 5mm x 5mm Thin QFN
Features
The MAX8680 highly efficient complete power-supply
solution is designed for digital still cameras (DSCs) and
digital video cameras (DVCs). The device integrates
seven on-chip power MOSFET DC-DC converters with
up to 95% efficiency to power all critical power supplies
in DSC systems. Each converter also features True
Shutdown™, as well as internal compensation to minimize external component count. The seven DC-DC
converter outputs are:
• Step-up synchronous-rectified DC-DC converter
(SU). The MAX8680 is bootstrapped from VSU.
♦ 95% Efficient Synchronous-Rectified DC-DC
Converters
♦ 90% Efficient Boost-Buck Operation
♦ 85% Efficient DC-DC Converters for CCD, LCD,
WLED, and/or OLED
♦ Internal Compensation on All Channels
♦ True Shutdown on All Step-Up Converters
♦ Overload Protection
♦ Soft-Start for Controlled Startup Current
♦ Dropout Operation (100% Duty Cycle) on StepDown Converters
♦ Regulated Current Output for Up to 6 White LEDs
♦ PWM Dimming of WLED Current
♦ Adjustable LED Overvoltage Protection Up to 27V
♦ Transformerless Inverting Converter for CCD
♦ 2MHz Switching Frequency for Low-Voltage
Channels
♦ ±2.5% Switching Frequency Accuracy
♦ 1µA Shutdown Supply Current
♦ Power-On Voltage Tracking for Core and Main
Outputs
♦ All Internal Power MOSFETs
♦ SDOK Power-OK Indicator
•
MAIN synchronous-rectified step-down DC-DC converter (M) for DSP I/O supply voltage.
•
DDRZ synchronous-rectified step-down DC-DC
converter (Z) for DSP DDR supply voltage.
•
Low-voltage (down to 1V) synchronous-rectified
step-down DC-DC converter (SD) for DSP core supply voltage.
•
High-voltage, step-up DC-DC converter with current
regulation and PWM dimming control (LEDBST) for
white LEDs (WLED).
•
High-voltage step-up DC-DC converter (CCDBST)
for CCD imagers or positive LCD bias supplies.
•
Transformerless inverting DC-DC converter (CCDINV)
for CCD imagers or negative LCD bias supplies.
The MAX8680 has an independent/simultaneous
power-on sequence of the CCDBST and CCDINV converters. For a preset power-on sequence of CCDBST
before CCDINV, contact the factory.
The MAX8680 operates with 1-cell lithium-ion (Li+) battery, two-AA cell, or dual-battery designs and is available in a 5mm x 5mm, 40-pin thin QFN package. The
MAX8680 operates over the -40°C to +85°C extended
temperature range.
Typical Operating Circuit
INPUT
2.7V TO 5.5V
BATT
ONSU
ONM
Applications
DSCs and DVCs
ONSD
PDAs and Portable Media Players
ONZ
GPS Navigation Systems
SDOK
MAX8680ETL+
TEMP
RANGE
PIN-PACKAGE
-40°C to
+85°C
40 Thin QFN-EP*
5mm x 5mm x 0.8mm
+Denotes a lead-free package.
*EP= Exposed paddle.
MAIN STEP-DOWN
SD STEP-DOWN
DDRZ STEP-DOWN
VSU 5V
VMAIN 3.3V
VSD 1.8V
VDDRZ 2.5V
MAX8680
Ordering Information
PART
SU STEP-UP
PKG
CODE
ONLED
LEDBST
VLEDBST UP TO 6 WLEDs
ONBST
CCDBST
VCCDBST +15V
ONINV
CCDINV
VCCDINV -7.5V
T4055-2
Pin Configuration appears at the end of data sheet.
True Shutdown is a trademark of Maxim Integrated Products, Inc.
________________________________________________________________ Maxim Integrated Products
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.
1
MAX8680
General Description
ABRIDGED
MAX8680
Smallest, All-Internal MOSFET, 7-Channel
DSC PMIC in Tiny 5mm x 5mm Thin QFN
VBATT OR VSU
C20
0.1μF
VBATT
(2V TO 5.5V)
C1
22μF
C2
22μF
24
REF
33 BATT
C4
22μF
LXSU
FBINV
PVSU
30 PVSU
SWBST
17
R14
100kΩ
MAX8680
C16
0.1μF
SU
LXBST
FBSU
PGSU
(EP)
VSU
38
L2
4.7μH
VMAIN
(3.3V, 300mA)
C6
10μF
C17
1μF
FBBST
39 LXM
34
L3
4.7μH
VSD
(1.8V, 250mA)
C10
10μF
PVLED
SWLED
VBATT
C8
10μF
PVBST
FBM
PGM
(EP)
OVLED
5
R6
100kΩ
28
40
6
10
21
7
2
C16
1μF
VBATT
C14
1μF
R12
100kΩ
18
13
L5
4.7μH
14
VLEDBST
(16V, 30mA)
D1
C15
1μF
11, 12
R9
1.6MΩ
D4
9
D5
D6
D7
PVSD
FBLED
35
VBATT
R10
100kΩ
LXSD
C9
10μF
NOTE: ALL CONVERTERS’ POWER GROUND CONNECTIONS
ARE THROUGH THE EXPOSED PADDLE (EP).
LXLED
R11
1.4MΩ
22
PVM
C7
10μF
1
R4
100kΩ
VCCDBST
(15V, 30mA)
19, 20
PGSU
(EP)
C5
1μF
VREF
D2
PGBST
(EP)
27
R5
80kΩ
23
L6
4.7μH
R17
100Ω
26
R2
100kΩ
R13
604kΩ
LXSU
29
R1
402kΩ
R3
232kΩ
C19
4.7μF
L7
4.7μH
32
VSU
(5V, 500mA)
VCCDINV
(-7.5V, 100mA)
D3
L1
2μH
31
C3
22μF
C18
1μF
16
PVINV
15
LXINV
FBSD
PGSD
(EP)
PGLED
(EP)
EP
GND
PVZ
ONSU
ONM
8
LXZ
VBATT OR
VSU
25
ONBST
37
L4
4.7μH
VDDRZ
(2.5V, 200mA)
C12
10μF
ONINV
ONZ
FBZ
PGZ
(EP)
SDOK
C11
1μF
36
ONSD
ONLED
R15
10Ω
C13
10μF
R7
150kΩ
3
4
R8
100kΩ
R16
100kΩ
VBATT
Figure 1. MAX8680 Typical Application Circuit (for Li+ Cell Design, Connect PVZ and PVINV to BATT; for Two-AA or Dual-Battery
Design, Connect PVZ and PVINV to PVSU)
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