MAX16819ATT Datasheet, PDF (6/10 Pages) Maxim Integrated Products – 2MHz High-Brightness LED Drivers with High-Side Current Sense and 5000:1 Dimming

2MHz High-Brightness LED Drivers with
High-Side Current Sense and 5000:1 Dimming
Pin Description
PIN
NAME
FUNCTION
1
IN
Positive Supply Voltage Input. Bypass with a 1µF or higher value capacitor to GND.
2
CSN
Current-Sense Input
3
DIM
Logic-Level Dimming Input. Drive DIM low to turn off the current regulator. Drive DIM high to enable
the current regulator.
4
GND
Ground
5
DRV
Gate Drive Output. Connect to the gate of an external n-channel MOSFET.
6
V_CC
Voltage Regulator Output. Connect a 1µF capacitor from V_CC to GND.
EP
—
Exposed Paddle. Connect to a large-area ground plane for improved power dissipation. Do not use
as the only ground connection for the device.
Functional Diagram
IN
REGULATOR
V_CC
-
+
CS
CSN
COMPARATOR
GATE
DRIVER
DRV
BANDGAP
REF
1.23V ₊
-
UVLO
COMPARATOR
GND
DIM
DIM
BUFFER
MAX16819
MAX16820
Detailed Description
The MAX16819/MAX16820 are step-down, constant-
current, high-brightness LED (HB LED) drivers. These
devices operate from a 4.5V to 28V input voltage range
and provide up to 0.5A of source and 1A of sink drive
capability to the gate of an external MOSFET. A high-
side current-sense resistor sets the output current and
a dedicated PWM dimming input (DIM) allows for a
wide range of independent pulsed dimming.
The high-side current-sensing scheme and on-board
current-setting circuitry minimize the number of exter-
nal components while delivering LED current with a
±5% accuracy, using a 1% sense resistor. See the
Functional Diagram.
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