Maxim MAX16820ATT, MAX16819 Datasheet

General Description

The MAX16819/MAX16820, step-down constant-current
high-brightness LED (HB LED) drivers provide a cost­effective solution for automotive interior/exterior lighting,
architectural and ambient lighting, LED bulbs such as
MR16 and other LED illumination applications.

The MAX16819/MAX16820 operate from a 4.5V to 28V
input voltage range and feature a 5V/10mA on-board
regulator. A high-side current-sense resistor adjusts the
output current and a dedicated PWM input (DIM)
enables a wide range of pulsed dimming.

The MAX16819/MAX16820 are well suited for applica­tions requiring a wide input voltage range. The high-side
current-sensing and an integrated current-setting circuit­ry minimize the number of external components while
delivering an LED current with ±5% accuracy. A hys­teretic control algorithm ensures excellent input-supply
rejection and fast response during load transients and
PWM dimming. The MAX16819 features a 30% inductor
current ripple and the MAX16820 features a 10% current
ripple. These devices operate up to 2MHz switching fre­quency, thus allowing for small component size.

The MAX16819/MAX16820 operate over the -40°C to
+125°C automotive temperature range and are avail­able in 3mm x 3mm x 0.8mm, 6-pin TDFN packages.

Applications

Architectural, Industrial, and Ambient Lighting

Automotive RCL, DRL, and Fog Lights

MR16 and Other LED Bulbs

Indicators and Emergency Lighting

Features

o High-Side Current Sense
o Dedicated Dimming Control Input
o 20kHz Maximum Dimming Efficiency
o Hysteretic Control: No Compensation
o Up to 2MHz Switching Frequency
o ±5% LED Current Accuracy
o Adjustable Constant LED Current
o 4.5V to 28V Input Voltage Range
o Over 25W Output Power
o 5V, 10mA On-Board Regulator
o -40°C to +125°C Operating Temperature Range

Note: All devices are specified over the -40°C to +125°C oper­ating temperature range.

+

Denotes lead-free package.

*

EP = Exposed paddle.

MAX16819/MAX16820

2MHz High-Brightness LED Drivers with

High-Side Current Sense and 5000:1 Dimming

________________________________________________________________

Maxim Integrated Products

1

1

+

23

654

DIM

CSN

IN

GND

DRV

V

CC

MAX16819
MAX16820

TDFN

TOP VIEW

PART PIN-PACKAGE PKG CODE

TOP

MARK

MAX16819ATT+T 6 TDFN–EP* T633-2 +ATB

MAX16820ATT+T 6 TDFN-EP* T633-2 +ATC

Pin Configuration

Ordering Information

MAX16819
MAX16820

IN

CSN

DIM

V

CC

C

IN

DRV

GND

C

VCC

V

IN

LR

SENSE

Typical Operating Circuit

19-0706; Rev 1; 3/07

For pricing, delivery, and ordering information, please contact Maxim/Dallas Direct! at
1-888-629-4642, or visit Maxim’s website at www.maxim-ic.com.

MAX16819/MAX16820

2MHz High-Brightness LED Drivers with
High-Side Current Sense and 5000:1 Dimming

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(VIN= 12V, V

DIM

= VIN, C

VCC

= 1µF, R

SENSE

= 0.5Ω, TA= TJ= -40°C to +125°C, unless otherwise noted. Typical values are at

T

A

= +25°C.) (Note 1)

Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional
operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to
absolute maximum rating conditions for extended periods may affect device reliability.

IN, CSN, DIM to GND .............................................-0.3V to +30V

V

CC

, DRV to GND ....................................................-0.3V to +6V

CSN to IN...............................................................-0.3V to +0.3V

Maximum Current into Any Pin

(except IN, V

CC

, and DRV)............................................±20mA

Continuous Power Dissipation (T

A

= +70°C)

6-Pin TDFN (derate 18.17mW/

oC*

above +70°C).......1454mW

Operating Temperature Range .........................-40°C to +125°C

Junction Temperature......................................................+150°C

Storage Temperature Range .............................-65°C to +150°C

Lead Temperature (soldering, 10s) .................................+300°C

Pin-to-Pin ESD Ratings (HB Model).....................................2.5kV

*As per JEDEC51 Standard (Single-Layer Board).

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

Input Voltage Range V

IN

4.5 28.0 V

Maximum Current Regulator
Switching Frequency

f

SW

2 MHz

Ground Current I

GND

DRV open 1.5 mA

Supply Current I

IN

V

DIM

< 0.6V 425 µA

VIN = V

CSN

= V

DIM

, VIN rising from 4V until

V

DRV

> VCC - 0.5V

4.7 5.0

Undervoltage Lockout UVLO

V

IN

= V

CSN

= V

DIM

, VIN falling from 6V,

V

DRV

< 0.5V

4.5

V

Undervoltage Lockout Hysteresis 0.5 V

SENSE COMPARATOR

(VIN - V

CSN

) rising from 0V until V

DRV

<

0.5V (MAX16820)

195 210 225

Sense Voltage Threshold High V

SNSHI

(VIN - V

CSN

) rising from 0V until V

DRV

<

0.5V (MAX16819)

213 230 246

mV

(VIN - V

CSN

) falling from 0.26V until V

DRV

>

(V

CC

- 0.5V) (MAX16820)

176 190 204

Sense Voltage Threshold Low V

SNSLO

(VIN - V

CSN

) falling from 0.26V until V

DRV

>

(V

CC

- 0.5V) (MAX16819)

158 170 182

mV

Propagation Delay to Output
High

t

DPDH

Falling edge of (VIN - V

CSN

) from 0.26V to

0V to DRV high, C

DRV

= 1nF

82 ns

Propagation Delay to Output Low t

DPDL

Rising edge of (VIN - V

CSN

) from 0V to

0.26V to DRV low, C

DRV

= 1nF

82 ns

Current-Sense Input Current I

CSN

(VIN - V

CSN

) = 200mV 1 µA

MAX16819 56 70 mV

Current-Sense Threshold
Hysteresis

CS

HYS

MAX16820 17 35 mV

MAX16819/MAX16820

2MHz High-Brightness LED Drivers with

High-Side Current Sense and 5000:1 Dimming

_______________________________________________________________________________________ 3

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

GATE DRIVER

Gate Driver Source Current V

CSN

= VIN, V

DRV

= 0.5 x V

CC

0.5 A

Gate Driver Sink Current V

CSN

= VIN - 250mV, V

DRV

= 0.5 x V

CC

1A

Gate Driver Output-Voltage High V

OH

I

DRV

= 10mA VCC - 0.5 V

Gate Driver Output-Voltage Low V

OL

I

DRV

= -10mA 0.5 V

DIM INPUT

Maximum DIM Frequency f

DIM

20 kHz

DIM Input-Voltage High V

IH

V

CSN

= VIN, increase DIM until V

DRV

>

(V

CC

- 0.5V)

2.8 V

DIM Input-Voltage Low V

IL

V

CSN

= VIN, decrease DIM until

V

DRV

< 0.5V

0.6 V

DIM Hysteresis DIM

HYS

200 mV

DIM Turn-On Time t

DIMON

DIM rising edge to V

DRV

= 0.5 x VCC,

C

DRV

= 1nF

100 ns

DIM Turn-Off Time t

DIMOFF

DIM falling edge to V

DRV

= 0.5 x VCC,

C

DRV

= 1nF

100 ns

DIM Input Leakage High V

DIM

= V

IN

10 µA

DIM Input Leakage Low V

DIM

= 0V -1 +1 µA

VCC REGULATOR

I

VCC

= 0.1mA to 10mA, VIN = 5.5V to 28V 4.5 5.5 V

Regulator Output Voltage V

CC

I

VCC

= 0.1mA to 10mA, VIN = 4.5V to 28V 4.0 5.5 V

Load Regulation I

VCC

= 0.1mA to 10mA, VIN = 12V 4 Ω

Line Regulation VIN = 6V to 28V, I

VCC

= 10mA 11 mV

Power-Supply Rejection Ratio PSRR VIN = 12V, I

VCC

= 5mA, fIN = 10kHz -35 dB

VIN = 4.5V, VCC = 0V 45 mA

Current Limit I

LIM

VIN = 4.5V, VCC = 4V 18 mA

Regulator Startup Time t

STRAT

VCC = 0 to 4.5V 350 µs

ELECTRICAL CHARACTERISTICS (continued)

(VIN= 12V, V

DIM

= VIN, C

VCC

= 1µF, R

SENSE

= 0.5Ω, TA= TJ= -40°C to +125°C, unless otherwise noted. Typical values are at

T

A

= +25°C.) (Note 1)

Note 1: All devices are 100% production tested at T

J

= +25°C and +125°C. Limits to -40°C are guaranteed by design.