Rainbow Electronics MAX16832C - Manual

General Description
The MAX16832A/MAX16832C step-down constant-cur-
rent high-brightness LED (HB LED) drivers provide a
cost-effective design solution for automotive
interior/exterior lighting, architectural and ambient light-
ing, LED bulbs, and other LED illumination applications.
The MAX16832A/MAX16832C operate from a +6.5V to
+65V input voltage range. A high-side current-sense
resistor adjusts the output current up to 700mA, and a
dedicated pulse-width modulation (PWM) input
enables pulsed LED dimming over a wide range of
brightness levels.
These devices are well suited for applications requiring
a wide input voltage range. The high-side current sens-
ing and an integrated current-setting circuitry minimize
the number of external components while delivering an
average output current with ±3% accuracy. A hysteretic
control method ensures excellent input supply rejection
and fast response during load transients and PWM dim-
ming. The MAX16832A allows 10% current ripple, and
the MAX16832C allows 30% current ripple. Both
devices operate up to a 2MHz switching frequency,
thus allowing the use of small-sized components.
The MAX16832A/MAX16832C offer an analog dimming
feature that reduces the output current by applying an
external DC voltage below the internal 2V threshold volt-
age from TEMP_I to GND. TEMP_I also sources 25µA to
a negative temperature coefficient (NTC) thermistor con-
nected between TEMP_I and GND, thus providing an
analog thermal-foldback feature that reduces the LED
current when the temperature of the LED string exceeds
a specified temperature point. Additional features
include thermal-shutdown protection.
The MAX16832A/MAX16832C operate over the -40°C to
+125°C automotive temperature range and are available
in a thermally enhanced 8-pin SO package.
Applications
Architectural, Industrial, and Ambient Lighting
Automotive RCL, DRL, and Fog Lights
Heads-Up Displays
Indicator and Emergency Lighting
MR16 and MR111 LED Lights
Features
♦ High-Efficiency Solution
♦ 6.5V to 65V Input Voltage Range
♦ On-Board 65V, 0.45Ω Power MOSFET
♦ Hysteretic Control: Up to 2MHz Switching
Frequency
♦ ±3% LED Current Accuracy
♦ 200mV Current-Sense Reference
♦ Resistor-Programmable Constant LED Current
♦ Integrated High-Side Current Sense
♦ Thermal-Foldback Protection/Linear Dimming
♦ Thermal-Shutdown Protection
♦ Available in a Thermally Enhanced 8-Pin SO
Package
♦ -40°C to +125°C Operating Temperature Range
MAX16832A/MAX16832C
2MHz, High-Brightness LED Drivers with
Integrated MOSFET and High-Side Current Sense
________________________________________________________________ Maxim Integrated Products 1
Ordering Information
LX
LX PGND
1
2
8
7
TEMP_I
DIM IN
GND
CS
3
4
6
5
MAX16832A
MAX16832C
L1
C2
ON
OFF
D1
HB LEDs
NTC*
*OPTIONAL
R SENSE
V IN
C1
Typical Application Circuit
19-4140; Rev 0; 5/08
For pricing, delivery, and ordering information, please contact Maxim Direct at 1-888-629-4642,
or visit Maxim’s website at www.maxim-ic.com.
+ Denotes a lead-free package.
* Future product—contact factory for availability.
** EP = Exposed pad.
PART TEMP RANGE PIN-PACKAGE
MAX16832AASA+ -40°C to +125°C 8 SO-EP**
MAX16832CASA+* -40°C to +125°C 8 SO-EP**
Pin Configuration appears at end of data sheet.