MAX16833BAUE+T Maxim Integrated Products, MAX16833BAUE+T Datasheet - Page 19

• Manufacturer Part Number: MAX16833BAUE+T
• Description: IC HB LED DVR CURR SENSE 16TSSOP
• Manufacturer: Maxim Integrated Products

Specifications of MAX16833BAUE+T

• Topology: Flyback, Low Side, PWM, SEPIC, Step-Down (Buck), Step-Up (Boost)
• Number Of Outputs: 1
• Internal Driver: No
• Type - Primary: Automotive, General Purpose
• Type - Secondary: High Brightness LED (HBLED)
• Frequency: 100kHz ~ 1MHz
• Voltage - Supply: 5 V ~ 65 V
• Mounting Type: Surface Mount
• Package / Case: 16-TSSOP (0.173", 4.40mm Width) Exposed pad
• Operating Temperature: -40°C ~ 125°C
• Current - Output / Channel: 3A
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Voltage - Output: -
• Lead Free Status / Rohs Status: Details

at f
frequency to maintain loop stability. For optimum per-
formance, choose the components using the following
equations:
The value of C4 can be calculated as below:
where R10 is the compensation resistor in ohms, f
and f
resistor in ohms, R7 is the LED current-sense resistor in
ohms, factor 6.15 is the gain of the LED current-sense
amplifier, and GM
error amplifier in amps/volts.
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 MOSFET
power dissipation or shield it. Keep all PCB traces car-
rying switching currents as short as possible to minimize
current loops. Use ground planes for best results.
ZRHP
P2
R10
/5 and C4 is chosen to set the integrator zero
are in hertz, R4 is the inductor current-sense
=
F
C
×
C4
(1 D
______________________________________________________________________________________
COMP
−
=
MAX
Layout Recommendations
π ×
2 f
is the transconductance of the
×
) R7 6.15 GM
R10
×
ZRHP
Integrated High-Side Current Sense
25
×
×
f
ZRHP
High-Voltage HB LED Drivers with
×
R4
×
COMP
ZRHP
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:
U Use a large contiguous copper plane under the ICs’
U Isolate the power components and high-current paths
U Keep the high-current paths short, especially at the
U Connect PGND and SGND at a single point.
U Keep the power traces and load connections short. This
U Route high-speed switching nodes away from the
package. Ensure that all heat-dissipating compo-
nents have adequate cooling.
from the sensitive analog circuitry.
ground terminals. This practice is essential for stable,
jitter-free operation. Keep switching loops short such that:
a) The anode of D1 must be connected very close to
b) The cathode of D1 must be connected very close
c) C
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, feedback dividers,
and analog bypass capacitors.
the drain of the MOSFET Q1.
to C
nected directly to the ground plane.
OUT
OUT
and current-sense resistor R4 must be con-
.
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