MAX16818_09 Datasheet, PDF (7/25 Pages) Maxim Integrated Products – 1.5MHz, 30A High-Efficiency, LED Driver with Rapid LED Current Pulsing

1.5MHz, 30A High-Efficiency, LED Driver
with Rapid LED Current Pulsing
PIN
1
2, 7
3
4
5
6
8, 22, 25
9
10
11
12
13
14
15
16
17
18
19
20
Pin Description
NAME
PGND
N.C.
DL
BST
LX
DH
SGND
CLKOUT
PGOOD
EN
Power-Supply Ground
No Connection. Not internally connected.
Low-Side Gate Driver Output
FUNCTION
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.
RT/SYNC
V_IOUT
LIM
OVI
CLP
EAOUT
EAN
DIFF
CSN
Switching Frequency Programming and Chip-Enable Input. Connect a resistor from RT/SYNC to
SGND to set the internal oscillator frequency. Drive RT/SYNC to synchronize the switching frequency
with external clock.
Voltage Source Output Proportional to the Inductor Current. The voltage at V_IOUT = 135 x I_LED x R_S.
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
output voltage, DH is latched low and DL is latched high. Toggle EN or recycle the input power to
reset the latch.
Current-Error Amplifier Output. Compensate the current loop by connecting an RC network to ground.
Voltage-Error Amplifier Output. Connect to the external compensation network.
Voltage-Error Amplifier Inverting Input
Differential Remote-Sense Amplifier Output. DIFF is the output of a precision unity-gain amplifier
whose inputs are SENSE+ and SENSE-.
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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