MAX17061ETI+ Maxim Integrated Products, MAX17061ETI+ Datasheet - Page 14

• Manufacturer Part Number: MAX17061ETI+
• Description: IC LED DRVR WHITE BCKLGT 28-TQFN
• Manufacturer: Maxim Integrated Products
• Type: Backlight, White LEDr

Specifications of MAX17061ETI+

• Topology: PWM, Step-Up (Boost)
• Number Of Outputs: 8
• Internal Driver: Yes
• Type - Primary: Automotive, Backlight
• Type - Secondary: White LED
• Frequency: 1MHz
• Voltage - Supply: 4.5 V ~ 26 V
• Voltage - Output: 5V
• Mounting Type: Surface Mount
• Package / Case: 28-TQFN Exposed Pad
• Operating Temperature: -40°C ~ 85°C
• Current - Output / Channel: 30mA
• Internal Switch(s): Yes
• Operating Supply Voltage: 5 V
• Maximum Supply Current: 2 mA
• Maximum Power Dissipation: 1667 mW
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Efficiency: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

The MAX17061 includes power-on reset (POR) and
undervoltage lockout (UVLO) features. POR resets the
fault latch and sets all the SMBus registers to their POR
values. POR occurs when V
The controller is disabled until V
threshold of 4.25V (typ). Hysteresis on UVLO is approx-
imately 85mV.
The V
with a minimum 1µF ceramic capacitor.
At startup, the MAX17061 checks the OV pin to see if
the Schottky diode is open. If the OV voltage is lower
than 84mV (typ), the boost converter does not start.
After the OV test is done, the MAX17061 performs a
diagnostic test of the LED array. The test is divided to
two phases; each phase takes approximately 1.024ms.
In the first test phase, all FB_ inputs are quickly dis-
charged down to 5.6V (typ) and then continuously dis-
charged by 800µA (typ) current sources. If a given FB_
voltage remains higher than 5.6V (typ), the string is
considered to be shorted. Otherwise, if a given FB_
8-String White LED Driver with
SMBus for LCD Panel Applications
Figure 3. Low-Input-Voltage Application Circuit
14
______________________________________________________________________________________
CC
and V
464k
DD
4.7 F
PWM
DATA
1 F
1 F
CLK
2.8V TO 5.5V
5V SUPPLY
EXTERNAL
pins should be bypassed to GND
V
IN
0.022 F
5.1k
220pF
CC
rises above 2.8V (typ).
CC
exceeds the UVLO
0.1 F
V
V
OSC
ISET
FSET
CCV
PWMI
PWMO
SCL
SDA
GND
DD
CC
MAX17061
Startup
EP
IN
2.2 H
L1
PGND1
PGND2
LX1
LX2
FB2
FB3
FB4
FB5
FB6
FB7
FB8
FB1
OV
voltage is higher than 3V (typ), the string is considered
to be unused. Unused strings should be tied to V
the second phase, each FB_ is precharged by an inter-
nal 400µA (typ) current source. If a given FB_ voltage
remains lower than 1V (typ), the FB_ is considered to
be a short to GND and the device is disabled. After the
LED string diagnostic phases are finished, the boost
converter starts. The total startup time is less than
10ms, including 4.2ms (typ) soft-start.
The MAX17061 can be placed into shutdown by clear-
ing bit 0 of the device control register (0x01). When a
critical failure is detected, the IC also enters shutdown
mode. In shutdown mode, all functions of the IC are
turned off including the 5V linear regulator. Only a
crude linear regulator remains on, providing a 4.35V
(typ) output voltage to V
capability. The fault/status register is not reset in shut-
down. When bit 0 of the device control register (0x01)
is set to 1, the MAX17061 exits shutdown mode and
starts. The fault/status register is reset at startup.
R2
61.9k
D1
2 F
2.21M
V
CC
R1
CC
UP TO 45V
, with 1µA current-sourcing
V
OUT
Shutdown
CC
. In