MAX16816ATJ+T Maxim Integrated Products, MAX16816ATJ+T Datasheet - Page 15

• Manufacturer Part Number: MAX16816ATJ+T
• Description: IC LED DRIVR HIGH BRIGHT 32-TQFN
• Manufacturer: Maxim Integrated Products
• Type: HBLED Driverr

Specifications of MAX16816ATJ+T

• Topology: PWM, SEPIC, Step-Down (Buck), Step-Up (Boost)
• Number Of Outputs: 1
• Internal Driver: Yes
• Type - Primary: Automotive
• Type - Secondary: High Brightness LED (HBLED)
• Frequency: 125kHz ~ 500kHz
• Voltage - Supply: 5.5 V ~ 76 V
• Mounting Type: Surface Mount
• Package / Case: 32-TQFN Exposed Pad
• Operating Temperature: -40°C ~ 125°C
• Internal Switch(s): Yes
• Efficiency: 90%
• Low Level Output Current: 76 mA
• High Level Output Current: 67 mA
• Operating Supply Voltage: 5.5 V to 76 V
• Maximum Supply Current: 4.5 mA
• Maximum Power Dissipation: 2758 mW
• Maximum Operating Temperature: + 125 C
• Mounting Style: SMD/SMT
• Minimum Operating Temperature: - 40 C
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Voltage - Output: -
• Current - Output / Channel: -
• Lead Free Status / Rohs Status: Details

The MAX16816 is a current-mode PWM LED driver for
use in driving HB LEDs. An output current accuracy of
5% is achievable using two current regulation loops:
one current regulation loop controls the external switch-
ing MOSFET peak current through a sense resistor,
R
ulation loop controls the average LED string current
through the sense resistor, R
LEDs. The wide operating supply range of 5.9V/5.4V
(ON/OFF) to 76V makes the MAX16816 ideal in auto-
motive applications.
The MAX16816 provides LED binning through one pro-
grammable on-chip nonvolatile EEPROM. The LED cur-
rent can be scaled up to a factor of 1.6. This feature is
used to offset factory LED luminance variations and
allows the system to achieve overall luminance accuracy.
A programmable undervoltage lockout (UVEN) ensures
predictable operation during brownout conditions. The
UVEN input circuitry monitors the supply voltage, V
and turns the driver off when V
UVLO threshold. Connect UVEN to V
(typ) default UVLO threshold. The MAX16816 includes
a cycle-by-cycle current limit that turns off the gate
drive to the external switching MOSFET (Q
overcurrent condition and a programmable oscillator
that simplifies and optimizes the design of external
magnetics.
The MAX16816 is capable of synchronizing to an
external clock or operating in a stand-alone mode. A
single resistor, R
frequency from 125kHz to 500kHz for stand-alone
operation. To synchronize the device with an external
clock, apply a clock signal directly to the RTSYNC
input. A buffered clock output, CLKOUT, is available to
configure the MAX16816 for multichannel applications.
The external RT oscillator can be disabled by setting
EEPROM register RTOF to ‘1’.
The MAX16816 provides wide contrast pulsed dimming
(up to 1000:1) utilizing a separate dimming input. Apply
either a DC level voltage or low-frequency PWM signal
to the dimming input. DC level input results in a 200Hz
fixed dimming frequency.
The MAX16816 provides configurable on-chip non-
volatile EEPROM features including a programmable
soft-start, load current, external MOSFET gate-driver
supply voltage, blanking time, and slope compensation.
Protection features include peak current limiting, HICCUP
mode current limiting, output overvoltage protection,
short-circuit protection, and thermal shutdown. The
HICCUP current-limit circuitry reduces the power deliv-
SENSE
, from SNS+ to SNS- while the other current reg-
T
, can be used to adjust the switching
______________________________________________________________________________________
Programmable Switch-Mode LED Driver
Detailed Description
with Analog-Controlled PWM Dimming
CS
CC
, in series with the
CC
drops below the
to use the 5.7V
S
) during an
CC
,
ered to the load during severe fault conditions. A non-
latching overvoltage protection limits the voltage on the
external switching MOSFET (Q
conditions in the LED string. During continuous opera-
tion at high input voltages, the power dissipation of the
MAX16816 could exceed the maximum rating and the
internal thermal shutdown circuitry safely turns off the
MAX16816 when the device junction temperature
exceeds +165°C. When the junction temperature drops
below the hysteresis temperature, the MAX16816 auto-
matically reinitiates startup.
The MAX16816 features a dual-purpose adjustable
undervoltage lockout input and enable function
(UVEN). Connect UVEN to V
age-divider to set the undervoltage lockout (UVLO)
threshold. The device is enabled when the voltage at
UVEN exceeds the 1.244V (typ) threshold. Drive UVEN
to ground to disable the output.
Connect UVEN directly to V
(typ) UVLO threshold. Connect UVEN to V
resistive voltage-divider to select a UVLO threshold
(Figure 1). Select the desired UVLO threshold voltage,
V
equation:
where R
UVEN threshold voltage.
Figure 1. Setting the UVLO Threshold
UVLO
R
, and calculate resistor values using the following
Undervoltage Lockout/Enable (UVEN)
UV1
UV1
C
UVEN
V
=
+ R
IN
R
UV2
UV2
R
R
UV2
UV1
≤ 270kΩ. V
x
⎛
⎜
⎝
V
UVLO
Setting the UVLO Threshold
CC
V
UVEN
CC
UVEN
to select the default 5.7V
- V
MAX16816
UVEN
through a resistive volt-
S
QGND
UVEN
) under open-circuit
V
CC
is the 1.244V (typ)
⎞
⎟
⎠
CC
through a
15