Datasheet

ManualsBrandsMAXIM INTEGRATED ManualsPMICsPMIC - LED driver DC-DC converter TSSOP 16 EP Surface-mount

General Description

The MAX16833/MAX16833B–MAX16833D are peak

current-mode-controlled LED drivers for boost, buck-

boost, SEPIC, flyback, and high-side buck topologies. A

dimming driver designed to drive an external p-channel

in series with the LED string provides wide-range dim-

ming control. This feature provides extremely fast PWM

current switching to the LEDs with no transient overvolt-

age or undervoltage conditions. In addition to PWM dim-

ming, the ICs

provide analog dimming using a DC input

at ICTRL. The ICs sense the LED current at the high side

of the LED string.

A single resistor from RT/SYNC to ground sets the

switching frequency from 100kHz to 1MHz, while an

external clock signal capacitively coupled to RT/SYNC

allows the ICs to synchronize to an external clock. In

the MAX16833/MAX16833C, the switching frequency

can be dithered for spread-spectrum applications. The

MAX16833B/MAX16833D instead provide a 1.64V refer-

ence voltage with a 2% tolerance.

The ICs operate over a wide 5V to 65V supply range

and include a 3A sink/source gate driver for driving

a power MOSFET in high-power LED driver applica-

tions. Additional features include a fault-indicator output

(FLT) for short or overtemperature conditions and an

overvoltage-protection sense input (OVP) for overvoltage

protection. High-side current sensing combined with a

p-channel dimming MOSFET allow the positive terminal

of the LED string to be shorted to the positive input termi-

nal or to the negative input terminal without any damage.

This is a unique feature of the ICs.

Features

S Boost, SEPIC, and Buck-Boost Single-Channel

LED Drivers

+5V to +65V Wide Input Voltage Range with a

Maximum 65V Boost Output

Integrated High-Side Current-Sense Amplifier

ICTRL Pin for Analog Dimming

Integrated High-Side pMOS Dimming MOSFET

Driver (Allows Single-Wire Connection to LEDs)

Programmable Operating Frequency (100kHz to

1MHz) with Synchronization Capability

Frequency Dithering for Spread-Spectrum

Applications (MAX16833/MAX16833C)

2% Accurate 1.64V Reference (MAX16833B/

MAX16833D)

Full-Scale, High-Side, Current-Sense Voltage of

200mV

Short-Circuit, Overvoltage, and Thermal

Protection

S Fault Indicator Output

-40NC to +125NC Operating Temperature Range

Thermally Enhanced 5mm x 4.4mm, 16-Pin TSSOP

Package with Exposed Pad

19-5187; Rev 6; 8/13

Ordering Information continued at end of data sheet.

Applications

Automotive Exterior Lighting:

High-Beam/Low-Beam/Signal/Position Lights

Daytime Running Lights (DRLs)

Fog Light and Adaptive Front Light Assemblies

Commercial, Industrial, and Architectural

Lighting

Simplified Operating Circuit

Ordering Information

+Denotes a lead(Pb)-free/RoHS-compliant package.

*EP = Exposed pad.

/V denotes an automotive qualified part.

PWMDIM

IN NDRV

OVP

ISENSE+

ISENSE-

PGND

6V TO 18V

WITH LOAD

DUMP UP

TO 70V

LED+

LED-

PWMDIM

DIMOUT

MAX16833

PART TEMP RANGE PIN-PACKAGE FUNCTIONALITY MAX DUTY CYCLE (%)

MAX16833AUE+

-40°C to +125°C

16 TSSOP-EP* Frequency Dithering 88.5

MAX16833AUE/V+

-40°C to +125°C

16 TSSOP-EP* Frequency Dithering 88.5

MAX16833/MAX16833B–MAX16833D

High-Voltage HB LED Drivers with

Integrated High-Side Current Sense

EVALUATION KIT AVAILABLE

For pricing, delivery, and ordering information, please contact Maxim Direct

at 1-888-629-4642, or visit Maxim’s website at www.maximintegrated.com.

Summary of content (22 pages)

PAGE 1
EVALUATION KIT AVAILABLE MAX16833/MAX16833B–MAX16833D High-Voltage HB LED Drivers with Integrated High-Side Current Sense General Description The MAX16833/MAX16833B–MAX16833D are peak current-mode-controlled LED drivers for boost, buckboost, SEPIC, flyback, and high-side buck topologies. A dimming driver designed to drive an external p-channel in series with the LED string provides wide-range dimming control.
PAGE 2
MAX16833/MAX16833B–MAX16833D High-Voltage HB LED Drivers with Integrated High-Side Current Sense ABSOLUTE MAXIMUM RATINGS Peak Current on NDRV......................................................... Q3A Continuous Current on NDRV........................................ Q100mA Short-Circuit Duration on VCC....................................Continuous Continuous Power Dissipation (TA = +70NC) 16-Pin TSSOP (derate 26.1mW/NC above +70NC) ......2089mW Operating Temperature Range .......................
PAGE 3
MAX16833/MAX16833B–MAX16833D High-Voltage HB LED Drivers with Integrated High-Side Current Sense ELECTRICAL CHARACTERISTICS (continued) (VIN = 12V, RRT = 12.4kI, CIN = CVCC = 1µF, CLFRAMP/CREF = 0.1µF, NDRV = COMP = DIMOUT = PWMDIM = FLT = unconnected, VOVP = VCS = VPGND = VSGND = 0V, VISENSE+ = VISENSE- = 45V, VICTRL = 1.40V, TA = TJ = -40NC to +125NC, unless otherwise noted. Typical values are at TA = +25NC.
PAGE 4
MAX16833/MAX16833B–MAX16833D High-Voltage HB LED Drivers with Integrated High-Side Current Sense ELECTRICAL CHARACTERISTICS (continued) (VIN = 12V, RRT = 12.4kI, CIN = CVCC = 1µF, CLFRAMP/CREF = 0.1µF, NDRV = COMP = DIMOUT = PWMDIM = FLT = unconnected, VOVP = VCS = VPGND = VSGND = 0V, VISENSE+ = VISENSE- = 45V, VICTRL = 1.40V, TA = TJ = -40NC to +125NC, unless otherwise noted. Typical values are at TA = +25NC.
PAGE 5
MAX16833/MAX16833B–MAX16833D High-Voltage HB LED Drivers with Integrated High-Side Current Sense ELECTRICAL CHARACTERISTICS (continued) (VIN = 12V, RRT = 12.4kI, CIN = CVCC = 1µF, CLFRAMP/CREF = 0.1µF, NDRV = COMP = DIMOUT = PWMDIM = FLT = unconnected, VOVP = VCS = VPGND = VSGND = 0V, VISENSE+ = VISENSE- = 45V, VICTRL = 1.40V, TA = TJ = -40NC to +125NC, unless otherwise noted. Typical values are at TA = +25NC.) (Note 2) PARAMETER SYMBOL OPEN-DRAIN FAULT (FLT) Output Voltage Low CONDITIONS MIN VIN = 4.
PAGE 6
MAX16833/MAX16833B–MAX16833D High-Voltage HB LED Drivers with Integrated High-Side Current Sense Typical Operating Characteristics (continued) (VIN = +12V, CVIN = CVCC = 1FF, CLFRAMP/CREF = 0.1FF, TA = +25NC, unless otherwise noted.) DIMOUT FALL TIME vs. TEMPERATURE DIMOUT RISE TIME vs. TEMPERATURE 3.5 DIMOUT FALL TIME (µs) 2.2 2.0 1.8 1.6 1.4 MAX16833 toc08 MAX16833 toc07 2.4 DIMOUT RISE TIME (µs) 4.0 3.0 2.5 2.0 1.2 CDIMOUT = 6.8nF CDIMOUT = 6.8nF 1.0 1.
PAGE 7
MAX16833/MAX16833B–MAX16833D High-Voltage HB LED Drivers with Integrated High-Side Current Sense Typical Operating Characteristics (continued) (VIN = +12V, CVIN = CVCC = 1FF, CLFRAMP/CREF = 0.1FF, TA = +25NC, unless otherwise noted.) NDRV RISE/FALL TIME vs.
PAGE 8
MAX16833/MAX16833B–MAX16833D High-Voltage HB LED Drivers with Integrated High-Side Current Sense Pin Description PIN 1 8 NAME LFRAMP (MAX16833/ MAX16833C) FUNCTION Low-Frequency Ramp Output. Connect a capacitor from LFRAMP to ground to program the ramp frequency, or connect to SGND if not used. A resistor can be connected between LFRAMP and RT/ SYNC to dither the PWM switching frequency to achieve spread spectrum. REF 1.64V Reference Output.
PAGE 9
MAX16833/MAX16833B–MAX16833D High-Voltage HB LED Drivers with Integrated High-Side Current Sense MAX16833/MAX16833C Functional Diagram IN VCC UVLO 5V REG BG VCC 7V LDO 5.7V LVSH 5V UVLO THERMAL SHUTDOWN VBG NDRV 5V TSHDN 200kI PGND RT/ SYNC RESET DOMINANT RT OSCILLATOR S Q R SLOPE COMPENSATION CS/PWM BLANKING CS MAX DUTY CYCLE 2V RAMP GENERATION PWM COMP 0.42V LFRAMP MAX16833 MAX16833C VBG ICTRL MIN OUT LPF ISENSE+ GM COMP 6.15 ISENSE- SYNC ISENSE+ 3.
PAGE 10
MAX16833/MAX16833B–MAX16833D High-Voltage HB LED Drivers with Integrated High-Side Current Sense MAX16833B/MAX16833D Functional Diagram IN VCC UVLO 5V REG BG VCC 7V LDO 5.7V LVSH 5V UVLO THERMAL SHUTDOWN VBG NDRV 5V TSHDN 200kI PGND RT/ SYNC RESET DOMINANT RT OSCILLATOR S Q R SLOPE COMPENSATION CS/PWM BLANKING CS MAX DUTY CYCLE 2V 1.64V (80µA) REFERENCE PWM COMP 0.42V REF MAX16833B MAX16833D VBG ICTRL MIN OUT LPF ISENSE+ GM COMP 6.15 ISENSE- SYNC ISENSE+ 3.
PAGE 11
MAX16833/MAX16833B–MAX16833D High-Voltage HB LED Drivers with Integrated High-Side Current Sense Detailed Description The MAX16833/MAX16833B–MAX16833D are peak current-mode-controlled LED drivers for boost, buckboost, SEPIC, flyback, and high-side buck topologies. A low-side gate driver capable of sinking and sourcing 3A can drive a power MOSFET in the 100kHz to 1MHz frequency range.
PAGE 12
MAX16833/MAX16833B–MAX16833D High-Voltage HB LED Drivers with Integrated High-Side Current Sense Analog Dimming (ICTRL) The ICs offer an analog dimming control input (ICTRL). The voltage at ICTRL sets the LED current level when VICTRL < 1.2V. The LED current can be linearly adjusted from zero with the voltage on ICTRL. For VICTRL > 1.4V, an internal reference sets the LED current. The maximum withstand voltage of this input is 5.5V.
PAGE 13
MAX16833/MAX16833B–MAX16833D High-Voltage HB LED Drivers with Integrated High-Side Current Sense SYNC C1 680pF Voltage-Reference Output (REF/MAX16833B/MAX16833D) C2 1000pF RT PIN D2 SD103AWS R2 22I GND RRT 24.9I GND Figure 1. SYNC Circuit Figure 1 shows the frequency-synchronization circuit suitable for applications where a 5V amplitude pulse with 20% to 80% duty cycle is available as the synchronization source. This circuit can be used for SYNC frequencies in the 100kHz to 1MHz range.
PAGE 14
MAX16833/MAX16833B–MAX16833D High-Voltage HB LED Drivers with Integrated High-Side Current Sense Applications Information Thermal Protection The ICs feature thermal protection. When the junction temperature exceeds +160NC, the ICs turn off the external power MOSFETs by pulling the NDRV low and DIMOUT high. External MOSFETs are enabled again after the junction temperature has cooled by 10°C. This results in a cycled output during continuous thermal-overload conditions.
PAGE 15
MAX16833/MAX16833B–MAX16833D High-Voltage HB LED Drivers with Integrated High-Side Current Sense Inductor Selection Boost Configuration In the boost converter (see the Typical Operating Circuits), the average inductor current varies with the line voltage. The maximum average current occurs at the lowest line voltage. For the boost converter, the average inductor current is equal to the input current.
PAGE 16
MAX16833/MAX16833B–MAX16833D High-Voltage HB LED Drivers with Integrated High-Side Current Sense Slope Compensation Slope compensation should be added to converters with peak current-mode control operating in continuousconduction mode with more than 50% duty cycle to avoid current-loop instability and subharmonic oscillations. The minimum amount of slope compensation that is required for stability is: VSCMIN = 0.
PAGE 17
MAX16833/MAX16833B–MAX16833D High-Voltage HB LED Drivers with Integrated High-Side Current Sense where ILED is in amperes, COUT is in farads, fSW is in hertz, and VOUTRIPPLE is in volts. The remaining 50% of allowable ripple is for the ESR of the output capacitor. Based on this, the ESR of the output capacitor is given by: V ESR COUT < OUTRIPPLE (Ω) (IL P × 2) where ILP is the peak-inductor current in amperes.
PAGE 18
MAX16833/MAX16833B–MAX16833D High-Voltage HB LED Drivers with Integrated High-Side Current Sense Boost Configuration  IL × VLED 2 × C GD × fSW   PSW =  AV G   2   The worst-case RHP zero frequency (fZRHP) is calculated as follows: Boost Configuration fZRHP =  1 1  × +   IG ON IG OFF  Buck-Boost Configuration Buck-Boost Configuration  IL × (VLED + VINMAX ) 2 × C GD × fSW   PSW =  AV G   2    1 1  × +  IG IG OFF   ON where IGON and IGOFF are the gate currents of the MOSFET Q1 i
PAGE 19
MAX16833/MAX16833B–MAX16833D High-Voltage HB LED Drivers with Integrated High-Side Current Sense The value of C4 can be calculated as below: C4 = 25 π × R10 × fZRHP where R10 is the compensation resistor in ohms, fZRHP and fP2 are in hertz, R4 is the inductor current-sense resistor in ohms, R7 is the LED current-sense resistor in ohms, factor 6.15 is the gain of the LED current-sense amplifier, and GMCOMP is the transconductance of the error amplifier in amps/volts.
PAGE 20
MAX16833/MAX16833B–MAX16833D High-Voltage HB LED Drivers with Integrated High-Side Current Sense Typical Operating Circuits L1 VIN D1 6V TO 18V WITH LOAD DUMP UP TO 70V Q1 IN C1 NDRV C2 R1 R5 R7 CS LFRAMP OVP PWMDIM ISENSE+ PWMDIM R2 ISENSE- R3 RT/SYNC DIMOUT C3 C4 MAX16833 MAX16833C R9 R8 Q2 FLT COMP VCC R4 LED+ R11 LEDR10 ICTRL SGND PGND EP BOOST HEADLAMP DRIVER LED- L1 VIN 6V TO 18V WITH LOAD DUMP UP TO 70V D1 Q1 IN NDRV C2 R1 C1 R5 R7 CS REF OVP PWMDIM PWM
PAGE 21
MAX16833/MAX16833B–MAX16833D High-Voltage HB LED Drivers with Integrated High-Side Current Sense Ordering Information (continued) TEMP RANGE PIN-PACKAGE FUNCTIONALITY MAX DUTY CYCLE (%) MAX16833BAUE+ PART -40°C to +125°C 16 TSSOP-EP* Reference Voltage Output 88.5 MAX16833BAUE/V+ -40°C to +125°C 16 TSSOP-EP* Reference Voltage Output 88.
PAGE 22
MAX16833/MAX16833B–MAX16833D High-Voltage HB LED Drivers with Integrated High-Side Current Sense Revision History REVISION NUMBER REVISION DATE DESCRIPTION PAGES CHANGED 0 6/10 Initial release 1 11/10 Added MAX16833AUE — 2 12/10 Added MAX16833C and MAX16833D 3 7/11 Added MAX16833E 4 8/12 Removed MAX16833E 1–22 5 4/13 Updated startup delay time and its description 2, 11 6 8/13 Updated Functional Diagrams and the MAX16833B/MAX16833D Typical Operating Circuit 1, 21, 22 22 1–4, 6–14,