MAX16834ATP+ Maxim Integrated Products, MAX16834ATP+ Datasheet - Page 21

• Manufacturer Part Number: MAX16834ATP+
• Description: IC LED DRIVR HIGH BRIGHT 20-TQFN
• Manufacturer: Maxim Integrated Products
• Type: HBLED Driverr

Specifications of MAX16834ATP+

• Topology: PWM, SEPIC, Step-Down (Buck), Step-Up (Boost)
• Number Of Outputs: 1
• Internal Driver: No
• Type - Primary: Automotive, Backlight
• Type - Secondary: High Brightness LED (HBLED), RGB
• Frequency: 100kHz ~ 1MHz
• Voltage - Supply: 4.75 V ~ 28 V
• Mounting Type: Surface Mount
• Package / Case: 20-TQFN Exposed Pad
• Operating Temperature: -40°C ~ 125°C
• Internal Switch(s): Yes
• Operating Supply Voltage: 4.75 V to 28 V
• Maximum Supply Current: 10 mA
• Maximum Power Dissipation: 2051 mW
• Maximum Operating Temperature: + 125 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Voltage - Output: -
• Current - Output / Channel: -
• Efficiency: -
• Lead Free Status / Rohs Status: Lead free / RoHS Compliant

Typically, there are two sources of noise emission in a
switching power supply: high di/dt loops and high dv/dt
surfaces. For example, traces that carry the drain cur-
rent often form high di/dt loops. Similarly, the heatsink
of the MOSFET connected to the device drain presents
a dv/dt source; therefore, minimize the surface area of
the heatsink as much as is compatible with the MOS-
FET power dissipation or shield it. Keep all PCB traces
carrying switching currents as short as possible to mini-
mize current loops. Use ground planes for best results.
Careful PCB layout is critical to achieve low switching
losses and clean, stable operation. Use a multilayer
board whenever possible for better noise immunity and
power dissipation. Follow these guidelines for good
PCB layout:
1) Use a large contiguous copper plane under the
2) Isolate the power components and high-current
3) Keep the high-current paths short, especially at the
High-Power LED Driver with Integrated High-Side LED
Current Sense and PWM Dimming MOSFET Driver
MAX16834 package. Ensure that all heat-dissipat-
ing components have adequate cooling.
path from the sensitive analog circuitry.
ground terminals. This practice is essential for sta-
ble, jitter-free operation. Keep switching loops short
such that:
a) The anode of D1 must be connected very close
to the drain of the MOSFET Q1.
______________________________________________________________________________________
Layout Recommendations
4) Connect PGND and SGND to a star-point configura-
5) Keep the power traces and load connections short.
6) Route high-speed switching nodes away from the
7) To prevent discharge of the compensation capaci-
b) The cathode of D1 must be connected very
c) C
tion.
This practice is essential for high efficiency. Use
thick copper PCBs (2oz vs.1oz) to enhance full-load
efficiency.
sensitive analog areas. Use an internal PCB layer
for the PGND and SGND plane as an EMI shield to
keep radiated noise away from the device, feed-
back dividers, and analog bypass capacitors.
tors during the off-time of the dimming cycle,
ensure that the PCB area close to these compo-
nents has extremely low leakage. Discharge of
these capacitors due to leakage results in reduced
performance of the dimming circuitry.
close to C
connected directly to the ground plane.
OUT
and the current-sense resistor R8 must be
OUT
.
21