MAX16838B Datasheet, PDF (10/21 Pages) Maxim Integrated Products – Integrated, 2-Channel, High-Brightness LED Driver with High-Voltage Boost and SEPIC Controller

MAX16838B
Integrated, 2-Channel, High-Brightness LED Driver
with High-Voltage Boost and SEPIC Controller
Pin Description (continued)
PIN
TQFN
TSSOP
9
12
10
13
NAME
ISET
FLT
FUNCTION
LED Current-Adjust Input. Connect a resistor (R_ISET) from ISET to SGND to set the
current through each LED string (I_LED) according to the formula I_LED = 1512V/R_ISET.
Open-Drain, Active-Low Flag Output. FLT asserts when there is an open/short-LED
condition at the output or when there is a thermal shutdown event.
LED String Cathode Connection 2. OUT2 is the open-drain output of the linear current
11
14
OUT2 sink that controls the current through the LED string connected to OUT2. OUT2 sinks up
to 150mA.
12
15
LEDGND
LED Ground. LEDGND is the return path connection for the linear current sinks. Connect
SGND, LEDGND, and PGND at a single point.
LED String Cathode Connection 1. OUT1 is the open-drain output of the linear current
13
16
OUT1 sink that controls the current through the LED string connected to OUT1. OUT1 sinks up
to 150mA.
Oscillator Timing Resistor Connection. Connect a timing resistor (R_RT) from RT to SGND
14
17
RT
to program the switching frequency. Apply an AC-coupled external clock at RT to
synchronize the switching frequency with an external clock source.
15
18
COMP
Switching Converter Compensation Input. Connect an RC network from COMP to SGND
(see the Feedback Compensation section).
16
19
DIM
Digital PWM Dimming Input
Current-Sense Input. CS is the current-sense input for the switching regulator and is also
17
20
CS
connected to the source of the internal power MOSFET. Connect a sense resistor from
CS to PGND to set the switching current limit.
18
1
DRAIN Internal Switching MOSFET Drain Output
Internal Switching MOSFET Gate Input. Connect GATE to NDRV directly or through a
19
2
GATE resistor to control the rise and fall times of the gate drive. The switching MOSFET has a
typical gate charge of 3.1nC.
20
3
PGND
Power Ground. PGND is the high-switching current return path connection. Connect
SGND, LEDGND, and PGND at a single point.
Exposed Pad. EP is internally connected to SGND. Connect EP to a large-area
—
—
EP
contiguous ground plane for effective power dissipation. Connect EP to SGND.
Do not use as the only ground connection.
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