MAX16818_15 Datasheet, PDF (7/25 Pages) Maxim Integrated Products – 1.5MHz, 30A High-Efficiency, LED Driver with Rapid LED Current Pulsing

MAX16818
1.5MHz, 30A High-Efficiency, LED Driver
with Rapid LED Current Pulsing
Pin Description
PIN
NAME
1
PGND
2, 7
N.C.
3
DL
4
BST
5
LX
6
DH
8, 22, 25
SGND
9
CLKOUT
10
PGOOD
11
EN
FUNCTION
Power-Supply Ground
No Connection. Not internally connected.
Low-Side Gate-Driver Output
Boost Flying Capacitor Connection. Reservoir capacitor connection for the high-side MOSFET driver
supply. Connect a ceramic capacitor between BST and LX.
Source Connection for the High-Side MOSFET
High-Side Gate-Driver Output. Drives the gate of the high-side MOSFET.
Signal Ground. Ground connection for the internal control circuitry. Connect SGND and PGND
together at one point near the IC.
Oscillator Output. Rising edge of CLKOUT is phase-shifted from the rising edge of DH by 180°.
Power-Good Output
Output Enable. Drive high or leave unconnected for normal operation. Drive low to shut down the
power drivers. EN has an internal 15µA pullup current. Connect a capacitor from EN to SGND to
program the hiccup-mode duty cycle.
Switching-Frequency Programming and Chip-Enable Input. Connect a resistor from RT/SYNC to
12
RT/SYNC SGND to set the internal oscillator frequency. Drive RT/SYNC to synchronize the switching frequency
with external clock.
13
V_IOUT Voltage Source Output Proportional to the Inductor Current. The voltage at V_IOUT = 135 x I_LED x R_S.
14
LIM
Current-Limit Setting Input. Connect a resistor from LIM to SGND to set the hiccup current-limit
threshold. Connect a capacitor from LIM to SGND to ignore short output overcurrent pulses.
Overvoltage Protection. Connect OVI to DIFF. When OVI exceeds 12.7% above the programmed
15
OVI
output voltage, DH is latched low and DL is latched high. Toggle EN or recycle the input power to reset
the latch.
16
CLP
Current-Error Amplifier Output. Compensate the current loop by connecting an RC network to ground.
17
EAOUT Voltage-Error Amplifier Output. Connect to the external compensation network.
18
EAN
Voltage-Error Amplifier Inverting Input
19
DIFF
Differential Remote-Sense Amplifier Output. DIFF is the output of a precision unity-gain amplifier
whose inputs are SENSE+ and SENSE-.
20
CSN
Current-Sense Differential Amplifier Negative Input. The differential voltage between CSN and CSP is
amplified internally by the current-sense amplifier (gain = 34.5) to measure the inductor current.
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