19-3783; Rev 1; 2/07
KIT
ATION
EVALU
BLE
AVAILA
1MHz PWM Boost Converter for 1.5A
White LED Camera Flash
General Description
Features
♦
Supports Lumileds and Other High-Power
White LEDs
♦
Independently Set Flash/Movie Currents
Flash-Mode Current Up to 1.5A
Movie-Mode Current Up to 360mA
♦
Disco Mode with Fixed 5V (Up to 1A) and 80mA
LED Current
♦
84% Efficiency (P
LED
/ P
BATT
) at 1.1A
♦
T
A
Derating Function for LED Thermal Protection
♦
Output Overvoltage Protection (OVP)
♦
Soft-Start Eliminates Inrush Current
♦
1MHz PWM Operation at All Loads
♦
Small External Components
♦
2.7V to 5.5V Input Voltage Range
♦
0.1µA Shutdown Mode
♦
14-Pin, 3mm x 3mm TDFN Package
MAX8607
The MAX8607 white LED boost converter is optimized
for camera flash/strobe applications using high-current
white LEDs. The MAX8607 integrates a 1MHz PWM
boost converter, 1.5A low-dropout (LDO) current regu-
lator, and logic control circuitry for a space-saving LED
flash design. Two logic inputs control four modes of
operation: shutdown mode reduces the quiescent cur-
rent to 0.1µA (typ), movie mode supplies up to 360mA
of LED current for continuous lighting, flash mode sup-
plies up to 1.5A of LED current for short-duration light-
ing during an exposure, and disco mode supplies +5V
(at up to 1A) to external circuits while driving the LED
with a fixed 80mA current.
The internal 1MHz boost converter features an adaptive
control scheme with an internal switching MOSFET and
synchronous rectifier to improve efficiency and mini-
mize external component count. The MAX8607 is avail-
able in a 14-pin, 3mm x 3mm TDFN package (0.8mm
max height).
Applications
Camera Flashes/Strobes
Cell Phones/Smartphones
PDAs and Digital Cameras
Ordering Information
PART*
MAX8607ETD+
PIN-PACKAGE
14 TDFN 3mm x 3mm
(T1433-1)
TOP MARK
ABA
+Indicates
lead-free package.
*The
MAX8607ETD is characterized over the -40°C to +85°C
temperature range.
Pin Configuration
TOP VIEW
INPUT
2.7V TO 5.5V
LED
2.2µH
Typical Operating Circuit
OUTPUT
LX
10µF
PGND
COMP
PGND
PGND
OUTS
OUT
LX
LX
MAX8607
OUT
OUTS
LGND
GND
10µF
UP TO 1.5A FLASH
UP TO 360mA MOVIE
14
13
12
11
10
9
8
MAX8607
+
1
COMP
2
EN1
3
EN2
4
MOV
5
FLSH
6
GND
7
LGND
MODE-
SELECT
INPUTS
EN1
EN2
FLSH
LED
MOV
TDFN
3mm x 3mm
________________________________________________________________
Maxim Integrated Products
1
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.
1MHz PWM Boost Converter for 1.5A
White LED Camera Flash
MAX8607
ABSOLUTE MAXIMUM RATINGS
OUT, OUTS, EN1, EN2 to GND ................................-0.3V to +6V
FLSH, MOV, LED, COMP, LX to GND ....-0.3V to (V
OUTS
+ 0.3V)
LGND, PGND to GND. ..........................................-0.3V to +0.3V
LX Current. ........................................................................2A
RMS
Continuous Power Dissipation (T
A
= +70°C)
14-Pin TDFN 3mm x 3mm (derate 18.2mW/°C
above +70°C)..............................................................1455mW
Operating Temperature Range ...........................-40°C to +85°C
Storage Temperature Range .............................-65°C to +150°C
Lead Temperature (soldering, 10s) .................................+300°C
Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.
ELECTRICAL CHARACTERISTICS
(V
EN1
= V
EN2
= 5V, V
OUT
= V
OUTS
= 4V, C
OUT
= 10µF, T
A
= -40°C to +85°C. Typical values are at T
A
= +25°C, unless otherwise
noted.) (Note 1)
PARAMETER
Supply Voltage
Undervoltage-Lockout
Threshold
OUT Quiescent Current, Flash or Movie Mode
OUT Quiescent Current, Shutdown Mode
CONDITIONS
IC supplied from OUTS
V
OUTS
rising, 100mV (typ) hysteresis
LX switching, I
LED
= 0mA
EN1 = EN2 = GND
T
A
= +25°C
T
A
= +85°C
5.3
3.65
4.8
T
A
= +25°C
T
A
= +85°C
Flash mode
Movie mode
Disco mode
1200
338
MIN
2.7
2.25
2.38
4
0.1
1
5.5
3.85
5.0
0.01
0.5
1500
360
80
1200
T
A
≥
0°C (Note 2)
T
A
= -40°C
-3
-6
62
±0.5
±0.5
48
80
5000
±3
200
4.4
600
600
V
COMP
= 1.5V
60
420
+3
+6
100
108
A/A
%
mV
mA
A/A
%
mV
A
mV
mV
µS
mA
5.7
3.95
5.2
1
µA
V
1
TYP
MAX
5.5
2.65
UNITS
V
V
mA
µA
Overvoltage limit, I
LED
= 0mA, V
LED
= 0V
OUT Regulation Voltage
V
LED
= 0.5V
Disco mode, I
LED
= 80mA
LED Current, Shutdown Mode
EN1 = EN2 = GND
R
MOV
= 2kΩ,
R
FLSH
= 2kΩ,
V
LED
= 0.5V
I
MOV
up to 300µA
R
MOV
= 2kΩ,
V
LED
= 0.5V
R
MOV
= 2kΩ
V
EN1
= 0V, V
EN2
= 5V
I
FLSH
up to 300µA
R
FLSH
= 2kΩ, V
LED
= 0.5V, T
A
≥
-40°C
(Note 2)
R
FLSH
= 2kΩ
Current-Source Guaranteed Sink Current
Current-Source Multiplier in MOV Mode
(I
LED
/ I
MOV)
Current-Source Accuracy in MOV Mode
MOV Current-Source Dropout Voltage
Disco Current-Source Current Setting
Current-Source Multiplier in FLSH Mode
(I
LED
/ I
FLSH)
Current-Source Accuracy in FLSH Mode
FLSH Current-Source Dropout Voltage
LX n-Channel Current Limit
MOV Regulation Voltage
FLSH Regulation Voltage
LED to COMP Transconductance
2
_______________________________________________________________________________________
1MHz PWM Boost Converter for 1.5A
White LED Camera Flash
ELECTRICAL CHARACTERISTICS (continued)
(V
EN1
= V
EN2
= 5V, V
OUT
= V
OUTS
= 4V, C
OUT
= 10µF, T
A
= -40°C to +85°C. Typical values are at T
A
= +25°C, unless otherwise
noted.) (Note 1)
PARAMETER
COMP Input Resistance to GND
LED T
A
Derating Function Threshold
LED T
A
Derating Function Slope
EN1 and EN2 Logic-High Input Voltage
EN1 and EN2 Logic-Low Input Voltage
EN1 and EN2 Logic Input Bias Current
LX n-Channel On-Resistance
LX p-Channel On-Resistance
LX Leakage
Operating Frequency
Maximum Duty Cycle
Minimum Duty Cycle
CONDITIONS
During shutdown or UVLO
Temperature when the LED current derating
function begins
T
A
= +40°C to +85°C
V
OUTS
= 2.7V to 5.5V
V
OUTS
= 2.7V to 5.5V
V
EN_
= 5.5V
I
LX
= 200mA
I
LX
= 200mA
V
LX
= 5.5V
T
A
= +25°C
T
A
= +85°C
0.8
65
T
A
= +25°C
T
A
= +85°C
0.01
0.03
50
100
0.01
0.03
1.0
75
4
8
1.2
100
200
1
1.4
0.4
1
MIN
TYP
140
+40
-1.67
MAX
250
UNITS
Ω
°C
%/°C
V
V
µA
mΩ
mΩ
µA
MHz
%
%
MAX8607
Note 1:
All devices are production tested at T
A
= +25°C. Specifications over temperature are guaranteed by design and characteri-
zation and not production tested.
Note 2:
For temperatures below the thermal derating start point.
Typical Operating Characteristics
(Circuit of Figure 2, V
IN
= V
EN1
= 3.6V, V
EN2
= 0V, T
A
= +25°C, unless otherwise noted.)
FLASH-MODE BATTERY CURRENT
vs. INPUT VOLTAGE
MAX8607toc01
MOVIE-MODE BATTERY CURRENT
vs. INPUT VOLTAGE
MAX8607toc02
BOOST CONVERTER EFFICIENCY
vs. LOAD CURRENT (DISCO MODE)
98
96
94
EFFICIENCY (%)
92
90
88
86
84
82
INCLUDES 83mA LED CURRENT
MAX8607toc03
4000
3500
BATTERY CURRENT (mA)
3000
2500
2000
1500
1000
500
0
2.7
3.1
3.5
4.7
4.3
INPUT VOLTAGE (V)
3.9
5.1
R
FLSH
= 3.01kΩ
R
FLSH
= 4.02kΩ
R
FLSH
= 8.06kΩ
R
FLSH
= 2kΩ
600
500
BATTERY CURRENT (mA)
R
MOV
= 2.00kΩ
400
300
200
R
MOV
= 6.49kΩ
100
0
100
R
MOV
= 3.57kΩ
80
2.7
3.1
3.5
4.7
4.3
INPUT VOLTAGE (V)
3.9
5.1
5.5
10
100
LOAD CURRENT (mA)
1000
5.5
_______________________________________________________________________________________
3
1MHz PWM Boost Converter for 1.5A
White LED Camera Flash
MAX8607
Typical Operating Characteristics (continued)
(Circuit of Figure 2, V
IN
= V
EN1
= 3.6V, V
EN2
= 0V, T
A
= +25°C, unless otherwise noted.)
LED CURRENT
vs. AMBIENT TEMPERATURE
MAX8607toc04
IC SUPPLY CURRENT
vs. INPUT VOLTAGE
DISCO MODE
FLASH MODE
900
800
SUPPLY CURRENT (µA)
700
600
500
400
300
200
100
0
MOVIE MODE
MAX8607toc05
400
350
300
LED CURRENT (mA)
250
200
150
100
50
0
-40
-20
60
40
AMBIENT TEMPERATURE (°C)
0
20
80
1000
2.7
3.1
3.5
4.7
4.3
INPUT VOLTAGE (V)
3.9
5.1
5.5
SWITCHING WAVEFORMS
(MOVIE MODE)
MAX8607toc06
SOFT-START RESPONSE
(STANDBY TO MOVIE-MODE TRANSITION)
MAX8607toc07
V
IN
20mV/div
V
EN1
0V 5V/div
200mA/div
V
OUT
10mV/div
I
LED
0A
I
L
100mA/div
I
IN
0A
100mA/div
V
LX
5V/div
V
OUT
0V
2V/div
400ns/div
100µs/div
SOFT-START RESPONSE
(MOVIE-MODE TO FLASH TRANSITION)
MAX8607toc08
LOAD TRANSIENT
(DISCO MODE)
MAX8607toc09
V
EN2
5V/div
I
L0AD
700mA
100mA
I
LED
200mA/div
I
IN
0A 500mA/div
0A
2V/div
V
OUT(RIPPLE)
500mV/div
V
OUT
0V
400µs/div
2ms/div
4
_______________________________________________________________________________________
1MHz PWM Boost Converter for 1.5A
White LED Camera Flash
MAX8607
Typical Operating Characteristics (continued)
(Circuit of Figure 2, V
IN
= V
EN1
= 3.6V, V
EN2
= 0V, T
A
= +25°C, unless otherwise noted.)
MOVIE-MODE LED CURRENT
vs. MOV RESISTANCE
MAX8607toc10
FLASH-MODE LED CURRENT
vs. FLSH RESISTANCE
1400
1200
LED CURRENT (mA)
1000
800
600
400
200
0
MAX8607toc11
400
350
300
LED CURRENT (mA)
250
200
150
100
50
0
1
10
R
MOV
(kΩ)
1600
100
1
10
R
FLSH
(kΩ)
100
Pin Description
PIN
1
2
3
4
5
6
7
8
9, 10
11, 12
13
14
—
NAME
COMP
EN1
EN2
MOV
FLSH
GND
LGND
LED
PGND
LX
OUT
OUTS
EP
FUNCTION
Compensation Input. Connect a 0.1µF ceramic capacitor from COMP to GND for regulator stability.
Enable Input 1. EN1 and EN2 set the operating mode (see Table 1).
Enable Input 2. EN1 and EN2 set the operating mode (see Table 1).
Movie Current Program Input. Connect a resistor from MOV to GND to set the LED current in movie mode.
R
MOV
must be greater than 2kΩ.
Flash Current Program Input. Connect a resistor from FLSH to GND to set the LED current in flash mode.
R
FLSH
must be greater than 2kΩ.
Analog Ground. Connect GND to the exposed paddle directly under the IC.
LED Current Regulator Ground. Connect LGND to the ground plane on the PC board.
LED Current Regulator. Connect LED to the cathode of the external LED. LED is high impedance during shutdown.
Power Ground. Connect PGND to the input capacitor ground. Also, connect PGND to the PC board ground plane.
Inductor Connection. Connect LX to the switched side of the inductor. LX is internally connected to the
drains of the internal MOSFETs. Both MOSFETs are off during shutdown.
Regulator Output. Connect OUT to the anode of the external LED. Bypass OUT to PGND with a 10µF or
larger ceramic capacitor. During shutdown, OUT is one body-diode drop below the input voltage.
Output Sense and IC Supply Input. Connect OUTS to OUT at the output bypass capacitor. The IC’s operating
power is supplied from OUTS.
Exposed Paddle. Connect the exposed paddle to GND directly under the IC and to a large PC board
ground plane for increased thermal performance.
_______________________________________________________________________________________
5
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