Rainbow Electronics MAX16820 User Manual

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

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.

PART PIN-PACKAGE PKG CODE

MAX16819ATT+T 6 TDFN–EP* T633-2 +ATB

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

TOP

MARK

TOP VIEW

CC

DRV

V

654

MAX16819
MAX16820

+

1

23

IN

CSN

TDFN

GND

DIM

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).

Input Voltage Range V

Maximum Current Regulator
Switching Frequency

Ground Current I

Supply Current I

Undervoltage Lockout UVLO

Undervoltage Lockout Hysteresis 0.5 V

SENSE COMPARATOR

Sense Voltage Threshold High V

Sense Voltage Threshold Low V

Propagation Delay to Output
High

Propagation Delay to Output Low t

Current-Sense Input Current I

Current-Sense Threshold
Hysteresis

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

IN

f

SW

GND

IN

DRV open 1.5 mA

V

< 0.6V 425 µA

DIM

VIN = V
V

DRV

V

IN

V

DRV

(VIN - V

= V

CSN

> VCC - 0.5V

= V

= V

CSN

< 0.5V

) rising from 0V until V

CSN

0.5V (MAX16820)

SNSHI

(VIN - V

) rising from 0V until V

CSN

0.5V (MAX16819)

SNSLO

t

DPDH

DPDL

CSN

CS

HYS

(VIN - V
(V

CC

(VIN - V
(V

CC

Falling edge of (VIN - V
0V to DRV high, C

Rising edge of (VIN - V

0.26V to DRV low, C

(VIN - V

MAX16819 56 70 mV

MAX16820 17 35 mV

) falling from 0.26V until V

CSN

- 0.5V) (MAX16820)

) falling from 0.26V until V

CSN

- 0.5V) (MAX16819)

) = 200mV 1 µA

CSN

4.5 28.0 V

2 MHz

, VIN rising from 4V until

DIM

, VIN falling from 6V,

DIM

) from 0.26V to

CSN

= 1nF

DRV

) from 0V to

CSN

= 1nF

DRV

DRV

DRV

<

<

DRV

DRV

195 210 225

213 230 246

>

176 190 204

>

158 170 182

4.7 5.0

4.5

82 ns

82 ns

V

mV

mV

MAX16819/MAX16820

2MHz High-Brightness LED Drivers with

High-Side Current Sense and 5000:1 Dimming

_______________________________________________________________________________________ 3

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.

GATE DRIVER

Gate Driver Source Current V

Gate Driver Sink Current V

Gate Driver Output-Voltage High V

Gate Driver Output-Voltage Low V

DIM INPUT

Maximum DIM Frequency f

DIM Input-Voltage High V

DIM Input-Voltage Low V

DIM Hysteresis DIM

DIM Turn-On Time t

DIM Turn-Off Time t

DIM Input Leakage High V

DIM Input Leakage Low V

VCC REGULATOR

Regulator Output Voltage V

Load Regulation I

Line Regulation VIN = 6V to 28V, I

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

Current Limit I

Regulator Startup Time t

PARAMETER SYMBOL CONDITIONS MIN TYP MAX UNITS

= VIN, V

OH

OL

DIM

IH

IL

HYS

DIMON

DIMOFF

CC

LIM

STRAT

CSN

= VIN - 250mV, V

CSN

I

= 10mA VCC - 0.5 V

DRV

I

= -10mA 0.5 V

DRV

V

= VIN, increase DIM until V

CSN

- 0.5V)

(V

CC

V

= VIN, decrease DIM until

CSN

< 0.5V

V

DRV

DIM rising edge to V
C

DRV

DIM falling edge to V
C

DRV

= V

DIM

= 0V -1 +1 µA

DIM

I

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

VCC

I

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

VCC

= 0.1mA to 10mA, VIN = 12V 4 Ω

VCC

VIN = 4.5V, VCC = 0V 45 mA

VIN = 4.5V, VCC = 4V 18 mA

VCC = 0 to 4.5V 350 µs

= 1nF

= 1nF

IN

DRV

VCC

= 5mA, fIN = 10kHz -35 dB

VCC

= 0.5 x V

DRV

CC

= 0.5 x V

CC

0.5 A

1A

20 kHz

>

DRV

2.8 V

0.6 V

200 mV

= 0.5 x VCC,

DRV

= 0.5 x VCC,

DRV

100 ns

100 ns

10 µA

= 10mA 11 mV