MAXIM MAX16801A, MAX16801B, MAX16802A, MAX16802B Technical data

General Description

The MAX16801A/B/MAX16802A/B high-brightness (HB) LED driver-control ICs contain all the circuitry required for the design of wide-input-voltage-range LED drivers for general lighting and display applications. The MAX16801 is well suited for universal input (rectified 85VAC to 265VAC) LED drivers, while the MAX16802 is intended for low-input-voltage (10.8VDC to 24VDC) LED drivers.

When the LED current needs to be tightly regulated, an additional on-board error amplifier with 1% accurate reference can be utilized. A wide dimming range can be implemented by using low-frequency PWM dimming.

The MAX16801/MAX16802 feature an input undervoltage lockout (UVLO) for programming the input-supply start voltage, and to ensure proper operation during brownout conditions. The MAX16801 has an internal-bootstrap undervoltage lockout circuit with a large hysteresis that simplifies offline LED driver designs. The MAX16802 does not have this internal bootstrap circuit and can be biased directly from a +12V rail.

The 262kHz fixed switching frequency is internally trimmed, allowing for optimization of the magnetic and filter components, resulting in a compact, cost-effective LED driver. The MAX16801A/MAX16802A are offered with 50% maximum duty cycle. The MAX16801B/MAX16802B are offered with 75% maximum duty cycle. These devices are available in an 8-pin µMAX

package and operate

over the -40°C to +85°C temperature range.

Applications

Features

♦ Suitable for Buck, Boost, Flyback, SEPIC, and

Other Topologies

♦ Up to 50W or Higher Output Power ♦ Universal Offline Input Voltage Range: Rectified

85VAC to 265VAC (MAX16801)

♦ IN Pin Directly Driven From 10.8VDC to 24VDC

Input (MAX16802)

♦ Internal Error Amplifier with 1% Accurate

Reference for Precise LED Current Regulation

♦ PWM or Linear Dimming ♦ Fixed Switching Frequency of 262kHz ±12% ♦ Thermal Shutdown ♦ Digital Soft-Start ♦ Programmable Input Startup Voltage ♦ Internal Bootstrap UVLO with Large Hysteresis

(MAX16801)

♦ 45µA (typ) Startup Supply Current, 1.4mA (typ)

Operating Supply Current

♦ 50% (MAX16801A/MAX16802A) or 75%

(MAX16801B/MAX16802B) Maximum Duty Cycle

♦ Available in a Tiny 8-Pin µMAX Package

MAX16801A/B/MAX16802A/B

Offline and DC-DC PWM Controllers for

High-Brightness LED Drivers

________________________________________________________________ Maxim Integrated Products 1

Ordering Information

19-3880; Rev 1; 1/06

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

TEMP

RANGE

PINPACKAGE

MAX16801AEUA+ -40°C to +85°C 8 µMAX

MAX16801BEUA+ -40°C to +85°C 8 µMAX

MAX16802AEUA+ -40°C to +85°C 8 µMAX

MAX16802BEUA+ -40°C to +85°C 8 µMAX

+Denotes lead-free package.

Offline and DC-DC LED Drivers

RGB Back Light for LCD TVs and Monitors

Commercial and Industrial Lighting

Decorative and Architectural Lighting

EVALUATION KIT

AVAILABLE

MAX16802B

10.8VDC TO 24VDC

PWM

GND

C1 R1

LEDs

COMP

DIM/FB

UVLO/EN IN

VCC

NDRV

GND

ENABLE

Typical Operating Circuit

Warning: The MAX16801/MAX16802 are designed to work with high voltages. Exercise caution.

µMAX is a registered trademark of Maxim Integrated Products, Inc.

MAX16801A/B/MAX16802A/B

Offline and DC-DC PWM Controllers for High-Brightness LED Drivers

2 _______________________________________________________________________________________

ABSOLUTE MAXIMUM RATINGS

ELECTRICAL CHARACTERISTICS

(VIN= +12V (MAX16801: VINmust first be brought up to +23.6V for startup), 10nF bypass capacitors at IN and VCC, C

NDRV

= 0,

UVLO

= +1.4V, V

DIM/FB

= +1.0V, COMP = unconnected, VCS= 0V, TA= -40°C to +85°C, unless otherwise noted. Typical values are

at T

= +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 to GND

..........................................................................

-0.3V to +30V

VCC to GND

.....................................................................

-0.3V to +13V

DIM/FB, COMP, UVLO, CS to GND..........................-0.3V to +6V

NDRV to GND.............................................-0.3V to (V

+ 0.3V)

Continuous Power Dissipation (TA = +70°C)

8-Pin µMAX (derate 4.5mW/°C above +70°C) ..............362mW

Operating Temperature Range ...........................-40°C to +85°C

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

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

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

PARAMETER

CONDITIONS

UNDERVOLTAGE LOCKOUT/STARTUP

Bootstrap UVLO Wake-Up Level

SUVR

VIN rising (MAX16801 only)

Bootstrap UVLO Shutdown Level

SUVF

VIN falling (MAX16801 only)

UVLO/EN Wake-Up Threshold V

ULR2

UVLO/EN rising

UVLO/EN Shutdown Threshold V

ULF2

UVLO/EN falling

UVLO/EN Input Current I

UVLO

TJ = +125°C 25 nA

UVLO/EN Hysteresis 50 mV

IN Supply Current In Undervoltage Lockout

START

VIN = +19V, for MAX16801 only when in bootstrap UVLO

45 90 µA

IN Voltage Range V

24 V

EXTR

UVLO/EN steps up from +1.1V to +1.4V 12

UVLO/EN Propagation Delay

EXTF

UVLO/EN steps down from +1.4V to +1.1V 1.8

µs

BUVR

VIN steps up from +9V to +24V 5

Bootstrap UVLO Propagation Delay

BUVF

VIN steps down from +24V to +9V 1

µs

INTERNAL SUPPLY

VCC Regulator Set Point V

CCSP

VIN = +10.8V to +24V, sinking 1µA to 20mA from V

IN Supply Current After Startup I

VIN = +24V 1.4 2.5 mA

Shutdown Supply Current UVLO/EN = low 90 µA

GATE DRIVER

)

Measured at NDRV sinking, 100mA 2 4

Driver Output Impedance

)

Measured at NDRV sourcing, 20mA 4 12

Ω

Driver Peak Sink Current 1A

Driver Peak Source Current

PWM COMPARATOR

Comparator Offset Voltage

COMP

- V

CS Input Bias Current I

VCS = 0V -2 +2 µA

Comparator Propagation Delay t

PWM

VCS = +0.1V 60 ns

Minimum On-Time

)

SYMBOL

MIN TYP MAX UNITS

19.68 21.6 23.60

9.05 9.74 10.43

1.188 1.28 1.371

1.168 1.23 1.291

ON(LOW

ON(HIGH

PWM

ON(MIN

10.8

1.15 1.38 1.70

10.5

0.65

150

MAX16801A/B/MAX16802A/B

Offline and DC-DC PWM Controllers for

High-Brightness LED Drivers

_______________________________________________________________________________________ 3

Note 1: All devices are 100% tested at TA= +85°C. All limits over temperature are guaranteed by characterization. Note 2: V

REF

is measured with DIM/FB connected to the COMP pin (see the Functional Diagram).

Note 3: The MAX16801 is intended for use in universal input offline drivers. The internal clamp circuit is used to prevent the boot-

strap capacitor (C1 in Figure 5) from charging to a voltage beyond the absolute maximum rating of the device when EN/UVLO is low. The maximum current to IN (hence to clamp) when UVLO is low (device in shutdown), must be externally limited to 2mA (max). Clamp currents higher than 2mA may result in clamp voltage higher than +30V, thus exceeding the absolute maximum rating for IN. For the MAX16802, do not exceed the +24V maximum operating voltage of the device.

ELECTRICAL CHARACTERISTICS (continued)

(VIN= +12V (MAX16801: VINmust first be brought up to +23.6V for startup), 10nF bypass capacitors at IN and VCC, C

NDRV

= 0,

UVLO

= +1.4V, V

DIM/FB

= +1.0V, COMP = unconnected, VCS= 0V, TA= -40°C to +85°C, unless otherwise noted. Typical values are

at T

= +25°C.) (Note 1)

PARAMETER

CONDITIONS

CURRENT-SENSE COMPARATOR

Current-Sense Trip Threshold V

320 mV

CS Input Bias Current I

VCS = 0V -2 +2 µA

Propagation Delay From Comparator Input to NDRV

PWM

50mV overdrive 60 ns

Switching Frequency f

290 kHz

MAX1680_A 50

Maximum Duty Cycle D

MAX

MAX1680_B 75 76

IN CLAMP VOLTAGE

IN Clamp Voltage V

INC

2mA sink current, MAX16801 only (Note 3)

ERROR AMPLIFIER

Voltage Gain R

LOAD

= 100kΩ 80 dB

Unity-Gain Bandwidth R

LOAD

= 100kΩ, C

LOAD

= 200pF 2

Phase Margin R

LOAD

= 100kΩ, C

LOAD

= 200pF 65

DIM/FB Input Offset Voltage 3mV

High 2.2 3.5

COMP Clamp Voltage

Low 0.4 1.1

Source Current 0.5 mA

Sink Current 0.5 mA

Reference Voltage V

REF

(Note 2)

Input Bias Current 50 nA

COMP Short-Circuit Current 8mA

THERMAL SHUTDOWN

Thermal-Shutdown Temperature

°C

Thermal Hysteresis 25 °C

DIGITAL SOFT-START

Soft-Start Duration

clock

Reference Voltage Steps During Soft-Start

Reference Voltage Step 40 mV

SYMBOL

MIN TYP MAX UNITS

262 291

230 262

50.5

24.1 26.1 29.0

1.218 1.230 1.242

130

15,872

MHz

degrees

cycles

steps

MAX16801A/B/MAX16802A/B

Offline and DC-DC PWM Controllers for High-Brightness LED Drivers

4 _______________________________________________________________________________________

Typical Operating Characteristics

UVLO/EN

= +1.4V, VFB= +1V, COMP = unconnected, VCS= 0V, TA= +25°C, unless otherwise noted.)

BOOTSTRAP UVLO WAKE-UP LEVEL

vs. TEMPERATURE

MAX16801 toc01

TEMPERATURE (°C)

(V)

6040200-20

21.35

21.40

21.45

21.50

21.55

21.60

21.30

-40 80

MAX16801 VIN RISING

BOOTSTRAP UVLO SHUTDOWN LEVEL

vs. TEMPERATURE

MAX16801 toc02

TEMPERATURE (°C)

(V)

6040200-20

9.8

9.9

10.0

10.1

9.7

-40 80

MAX16801 VIN FALLING

UVLO/EN WAKE-UP THRESHOLD

vs. TEMPERATURE

MAX16801 toc03

TEMPERATURE (°C)

UVLO/EN (V)

6040200-20

1.255

1.260

1.265

1.270

1.275

1.280

1.250

-40 80

UVLO/EN RISING

UVLO/EN SHUTDOWN THRESHOLD

vs. TEMPERATURE

MAX16801 toc04

TEMPERATURE (°C)

UVLO/EN (V)

6040200-20

1.15

1.20

1.25

1.30

1.10

-40 80

UVLO/EN FALLING

VIN SUPPLY CURRENT IN UNDERVOLTAGE

LOCKOUT vs. TEMPERATURE

MAX16801 toc05

TEMPERATURE (°C)

START

(µA)

6040200-20

-40 80

VIN = 19V MAX16801 WHEN IN BOOTSTRAP UVLO MAX16802 WHEN UVLO/EN IS LOW

VIN SUPPLY CURRENT AFTER STARTUP

vs. TEMPERATURE

MAX16801 toc06

TEMPERATURE (°C)

(mA)

6040200-20

1.2

1.3

1.4

1.5

1.1

-40 80

VIN = 24V

VCC REGULATOR SET POINT

vs. TEMPERATURE

MAX16801 toc07

TEMPERATURE (°C)

(V)

6040200-20

9.3

9.5

9.4

9.7

9.6

9.8

9.2

-40 80

VIN = 19V NO LOAD

NDRV OUTPUT IS NOT SWITCHING, V

= 1.5V

NDRV OUTPUT IS SWITCHING

VCC REGULATOR SET POINT

vs. TEMPERATURE

MAX116801 toc08

TEMPERATURE (°C)

(V)

6040200-20

8.2

8.5

8.6

8.4

8.3

8.8

8.7

8.9

8.1

-40 80

VIN = 10.8V

10mA LOAD

20mA LOAD

CURRENT-SENSE THRESHOLD

vs. TEMPERATURE

MAX16801 toc09

TEMPERATURE (°C)

CURRENT-SENSE THRESHOLD (µV)

6040200-20

275

290

295

285

280

305

300

310

270

-40 80

+3σ

-3σ

MEAN

TOTAL NUMBER OF DEVICES = 100

MAX16801A/B/MAX16802A/B

Offline and DC-DC PWM Controllers for

High-Brightness LED Drivers

_______________________________________________________________________________________ 5

CURRENT-SENSE THRESHOLD

MAX16801 toc10

CURRENT-SENSE THRESHOLD (mV)

PERCENTAGE OF UNITS (%)

310300290280270

260 320

TOTAL NUMBER OF DEVICES = 200

SWITCHING FREQUENCY

vs. TEMPERATURE

MAX16801 toc11

TEMPERATURE (°C)

SWITCHING FREQUENCY (kHz)

6040200-20

245

260

265

255

250

275

270

280

240

-40 80

+3σ

-3σ

MEAN

TOTAL NUMBER OF DEVICES = 100

SWITCHING FREQUENCY

MAX16801 toc12

SWITCHING FREQUENCY (kHz)

PERCENTAGE OF UNITS (%)

280270260250240

230 290

TOTAL NUMBER OF DEVICES = 200

PROPAGATION DELAY FROM

CURRENT-SENSE COMPARATOR INPUT

TO NDRV vs. TEMPERATURE

MAX16801 toc13

TEMPERATURE (°C)

PWM

(ns)

6040200-20

-40 80

UVLO/EN PROPAGATION DELAY

vs. TEMPERATURE

MAX16801 toc14

TEMPERATURE (°C)

UNDERVOLTAGE LOCKOUT DELAY (µs)

6040200-20

4 3 2 1

7 6 5

13 12 11 10

9 8

-40 80

UVLO/EN RISING

UVLO/EN FALLING

REFERENCE VOLTAGE

vs. TEMPERATURE

MAX16801 toc15

TEMPERATURE (°C)

REFERENCE VOLTAGE (V)

6040200-20

1.226

1.227

1.228

1.229

1.230

1.225

-40 80

VIN = 12V

INPUT CURRENT

vs. INPUT CLAMP VOLTAGE

MAX16801 toc16

INPUT VOLTAGE (V)

INPUT CURRENT (mA)

27.525.020.0 22.515.0 17.512.5

10.0 30.0

INPUT CLAMP VOLTAGE

vs. TEMPERATURE

MAX16801 toc17

TEMPERATURE (°C)

INPUT CLAMP VOLTAGE (V)

6040200-20

25.2

25.4

25.6

25.8

26.0

26.2

26.4

26.6

26.8

27.0

25.0

-40 80

IIN = 2mA

NDRV OUTPUT IMPEDANCE

vs. TEMPERATURE

MAX16801 toc18

TEMPERATURE (°C)

(Ω)

6040200-20

1.3

1.4

1.5

1.6

1.7

1.8

1.9

2.0

2.1

2.2

1.2

-40 80

VIN = 24V SINKING 100mA

Typical Operating Characteristics (continued)

UVLO/EN

= +1.4V, VFB= +1V, COMP = unconnected, VCS= 0V, TA= +25°C, unless otherwise noted.)

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