MAX17149ETE+ Maxim Integrated Products, MAX17149ETE+ Datasheet - Page 13

• Manufacturer Part Number: MAX17149ETE+
• Description: LED Drivers 6-String WLED Driver
• Manufacturer: Maxim Integrated Products

Specifications of MAX17149ETE+

• Operating Supply Voltage: 3 V to 26 V
• Maximum Supply Current: 4 mA
• Maximum Power Dissipation: 1176 mW
• Maximum Operating Temperature: + 85 C
• Mounting Style: SMD/SMT
• Package / Case: TQFN-16
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant

Figure 4. MAX17129/MAX17149 Quick-PWM Control Functional Diagram
The actual switching frequency can be approximated by:
where:
V
R
The switching frequency is adjustable by changing the
off-time at each supply turn-on cycle. As mentioned
above, it is implemented by changing the voltage level
of the FSEL pin.
High-frequency operation optimizes the regulator for the
smallest component size at the expense of efficiency
D
DSON
is the forward voltage of the output diode.
is the on-resistance of the internal MOSFET.
f
s
=
T
OFF
1
×
V
EN
OVP
Low-Cost, 6-String WLED Drivers with
V
IN
+
SOFT-START
MAX17129
MAX17149
−
V
I
D
REF
V
IN
OVP
IN
IN
−
×
I
IN
R
DSON
×
SS
REF
R
DSON
ON- /OFF-TIME
CALCULATION
COMPARATOR
FSEL
ONE-SHOT
Quick-PWM Step-Up Converter
ERROR
INT
due to increased switching losses. Low-frequency oper-
ation offers the best overall efficiency but requires larger
components and PCB area.
The devices include an internal low-dropout linear
regulator (V
UVLO threshold. The hysteresis on UVLO is approxi-
mately 100mV. When V
this linear regulator generates a 3.8V supply to power the
internal PWM controller, control logic, and MOSFET driv-
er. The V
V
can operate in a low input-voltage range from 3V to 5.5V.
CC
LX
and IN pins are connected together, the MAX17129
Input Supply Voltage Configuration and
INTEGRATOR
CURRENT
CC
SENSE
CC
voltage drops to 0V with EN low. When the
) and are disabled until V
FB
IN
is higher than 6V with EN high,
OVP
CC
exceeds the
UVLO
13