Datasheet
8 Maxim Integrated
Integrated, 4-Channel, High-Brightness LED
Driver with High-Voltage DC-DC Controller
MAX16814
Pin Description
PIN
NAME FUNCTION
TQFN/
QFND
TSSOP
1 4 IN
Bias Supply Input. Connect a 4.75V to 40V supply to IN. Bypass IN to SGND with a ceramic
capacitor.
2 5 EN
Enable Input. Connect EN to logic-low to shut down the device. Connect EN to logic-high or IN
for normal operation. The EN logic threshold is internally set to 1.23V.
3 6 COMP
Switching Converter Compensation Input. Connect the compensation network from COMP to
SGND for current-mode control (see the Feedback Compensation section).
4 7 RT
Oscillator Timing Resistor Connection. Connect a timing resistor (R
T
) from RT to SGND to program
the switching frequency according to the formula R
T
= 7.350 x 10
9
/f
sw
(for the MAX16814A_ _
and the MAX16814U_ _) or to the formula R
T
= 7.72 x 10
9
/f
sw
(for
the
MAX16814B_ _ _). Apply
an
AC-coupled external clock at RT to synchronize the switching frequency with an external clock.
5 8
FLT
Open-Drain Fault Output. FLT asserts low when an open LED, short LED, or thermal shutdown
is detected. Connect a 10kω pullup resistor from FLT to V
CC
.
6 9 OVP
Overvoltage Threshold Adjust Input. Connect a resistor-divider from the switching converter
output to OVP and SGND. The OVP comparator reference is internally set to 1.23V.
7 10 SETI
LED Current Adjust Input. Connect a resistor (R
SETI
) from SETI to SGND to set the current
through each LED string (I
LED
) according to the formula I
LED
= 1500/R
SETI
.
8 11 RSDT
LED Short Detection Threshold Adjust Input. Connect a resistive divider from V
CC
to RSDT and
SGND to program the LED short detection threshold. Connect RSDT directly to V
CC
to disable
LED short detection. The LED short detection comparator is internally referenced to 2V.
9 12 SGND
Signal Ground. SGND is the current return path connection for the low-noise analog signals.
Connect SGND, LEDGND, and PGND at a single point.
10 13 DIM
Digital PWM Dimming Input. Apply a PWM signal to DIM for LED dimming control. Connect
DIM to V
CC
if dimming control is not used.
11 14 OUT1
LED String Cathode Connection 1. OUT1 is the open-drain output of the linear current sink that
controls the current through the LED string connected to OUT1. OUT1 sinks up to 150mA. If
unused, connect OUT1 to LEDGND.