MAX8607ETD+T Maxim Integrated Products, MAX8607ETD+T Datasheet - Page 7

• Manufacturer Part Number: MAX8607ETD+T
• Description: IC LED DRIVR PHOTO FLASH 14-TDFN
• Manufacturer: Maxim Integrated Products
• Type: Photo Flash LEDr

Specifications of MAX8607ETD+T

• Topology: Linear (LDO), PWM, Step-Up (Boost)
• Number Of Outputs: 1
• Internal Driver: Yes
• Type - Primary: Flash/Torch
• Frequency: 800kHz ~ 1.2MHz
• Voltage - Supply: 2.7 V ~ 5.5 V
• Voltage - Output: 5.5V
• Mounting Type: Surface Mount
• Package / Case: 14-TDFN Exposed Pad
• Operating Temperature: -40°C ~ 85°C
• Current - Output / Channel: 360mA, 1.5A
• Internal Switch(s): Yes
• Efficiency: 84%
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Drive EN1 high and EN2 low to enable movie mode. In
this mode, the current regulator regulates the current
through the LED to 1200 times the current set by the
MOV resistor. See the Setting the Movie-Mode Current
section for details on setting the movie-mode current.
Drive EN1 and EN2 high to enable flash mode. In this
mode, the current through the LED is regulated to 5000
times the current set by the FLSH resistor. See the
Setting the Flash-Mode Current section for details on set-
ting the flash-mode current. The time duration of the flash
mode must be set using external circuitry or software.
Drive EN1 low and EN2 high to enable disco mode. In
this mode, the output of the boost converter provides a
regulated +5V at up to 1A for external circuitry, while
the LED current is regulated to 80mA. The LED current
is not adjustable in this mode.
Drive EN1 and EN2 low to place the IC into a low-
power shutdown mode. See the Shutdown section for
more details.
The output voltage of the MAX8607 is limited by internal
overvoltage-protection (OVP) circuitry, which prevents
the output from exceeding 5.7V under any conditions.
In flash and movie modes, if the output voltage nears
5.5V, the LED current is smoothly reduced through pro-
prietary means to prevent overvoltage without sudden
termination of the output current. In case of an LED with
very high forward voltage (V
more reliable and repeatable flash than would a simple
on/off comparator. In disco mode, the output is limited
by the internal 5.0V regulation.
The MAX8607 contains undervoltage-lockout (UVLO)
circuitry that disables the IC until V
2.38V. Prior to startup, V
the input voltage. This ensures a great enough input
voltage for startup.
The MAX8607 attains soft-start by charging C
with a 100µA current source. During this time, the inter-
nal MOSFET is switching at the minimum duty cycle.
Once V
until output reaches the desired regulation level. COMP
is pulled to GND with a 140Ω internal resistor during
UVLO, OVP, or shutdown. See the Typical Operating
Characteristics for an example of soft-start operation.
COMP
rises above 1V, the duty cycle increases
Mode-Select Inputs (EN1, EN2)
_______________________________________________________________________________________
OUTS
Overvoltage Protection
Undervoltage Lockout
1MHz PWM Boost Converter for 1.5A
F
is one diode drop below
), this circuit provides
OUTS
is greater than
Soft-Start
COMP
White LED Camera Flash
Drive EN1 and EN2 low to place the MAX8607 into a
low-power shutdown mode. In shutdown, supply cur-
rent is reduced to 0.1µA (typ). C
during shutdown, allowing the device to reinitiate soft-
start when it is enabled. The internal MOSFET and syn-
chronous rectifier are turned off during shutdown;
however, OUT is one body-diode drop below the input.
LED is high impedance so the external LED is off, but
any external circuitry on OUT is not disconnected and,
therefore, should include its own shutdown capability.
Typical shutdown timing characteristics are shown in
the Typical Operating Characteristics.
The MAX8607 limits the maximum LED current depend-
ing on its die temperature. Once the die temperature
reaches +40°C, the LED current decreases by 1.67%
per °C. This corresponds to approximately 0mA of LED
current at +100°C. Due to the package’s exposed pad-
dle, the die temperature is very close to the PC board
temperature. The temperature derating function allows
the LED current to be safely set higher at normal oper-
ating temperatures, thereby allowing either a brighter
flash or movie light to be used for normal ambient tem-
peratures. See the Typical Operating Characteristics
for a graph of LED Current vs. Ambient Temperature.
To set the LED current during movie mode, connect a
resistor from MOV to GND (R
to 0.6V and the current through R
LED with a gain of 1200. R
To set the LED current during flash mode, connect a
resistor from FLSH to GND (R
to 0.6V and the current through R
LED with a gain of 5000. R
Table 1. EN1 and EN2 Mode Selection
Ambient Temperature Derating Function
EN1
0
0
1
1
R
R
FLSH
MOV
Setting the Movie-Mode Current
Setting the Flash-Mode Current
Applications Information
= (0.6V x 1200) / I
= (0.6V x 5000) / I
EN2
0
1
0
1
MOV
FLSH
Shutdown
Disco Mode
Movie Mode
Flash Mode
FLSH
MOV
is calculated as:
is calculated as:
COMP
). V
). V
LED(MOV)
LED(FLSH)
FLSH
MOV
FLSH
MOV
MODE
is discharged
is mirrored to
is mirrored to
Shutdown
is regulated
is regulated
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