Diodes PAM2811 User Manual

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Description

The PAM2811 provides 4 regulated current sinks, capable of sinking

up to 20mA current to accommodate 4 white LEDs. It requires no

charge pump, has no noise and EMI, and significantly improves the

efficiency in Li battery range.

LED brightness can be controlled by single-wire dimming

techniques. The constant current sink is set by16-step.

The PAM2811 is available in QFN3x3-16L, MSOP-8L, SOT23-8L

and DFN2x2-8L packages.

Features

4-CHANNEL SINGLE-WIRE DIMMING LED DRIVE

with ULTRA LOW DROPOUT CURRENT SINK

Pin Assignments

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PAM2811

 Support up to 4 LEDs

 LED Sink Current 20mA

 Low Dropout Voltage

 Low Quiescent Supply Current:270µA(typ)

 No Noise and EMI

 Shutdown Current Less than 1µA

 Over Temperature Protection

 16-Step Brightness Control

 Small Package: QFN3x3-16L,MSOP-8L SOT23-8L,

DFN2X2-8L

 Pb-free Package

Applications

 Mobile Phone

 Digital Camera

 PDA MP3

Typical Applications Circuit

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PAM2811

Pin Descriptions

Pin

Name

QFN3x3-16L

P2811A

QFN3x3-16L

P2811B

NC 1 2 — — —
NC 2 3 — 2 —
NC 3 4 — — —

NC 4 5 — — —
AGND 5 — 4 3 4
PGND 6 12 1 — 1

VIN

VIN 7 —

7

EN 8 1 2 4 2

NC 9 8 — — —

LED4 10 13 8 8 5

LED3 11 14 7 7 6

LED2 12 15 6 6 7

LED1 13 16 5 5 8

NC 14 9 — — —

NC 15 10 — — —

NC 15 11 — — —

PAM2811

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Pin Number

MSOP-8L

P2811C

6

SOT23-8

P2811D

3

DFN2x2-8L

P2811E

1

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3

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Not Connected

Not Connected

Not Connected

Not Connected

Analog Ground

Power Ground

Supply Input

Supply Input

Enable Pin. Active high, with an internal 150kΩ pull-down
resistor.

Not Connected

LED4 Pin, Connect to the LED cathode, leave it to
connect GND or open if unused.

LED3 Pin, Connect to the LED cathode, leave it to
connect GND or open if unused.

LED2 Pin, Connect to the LED cathode, leave it to
connect GND or open if unused.

LED1 Pin, Connect to the LED cathode, leave it to
connect GND or open if unused.

Not Connected

Not Connected

Not Connected

Function

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Functional Block Diagram

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PAM2811

PAM2811

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Absolute Maximum Ratings (@T

= +25°C, unless otherwise specified.)

A

These are stress ratings only and functional operation is not implied. Exposure to absolute maximum ratings for prolonged time periods may
affect device reliability. All voltages are with respect to ground.

Parameter Rating Unit

Input Voltage Range -0.3 to +6.0

PWM Pin Voltage

-0.3 to (V

+0.3)/+6

IN

V

Maximum Junction Temperature 150

Storage Temperature -65 to +150

°C

Soldering Temperature 300, 5sec

Recommended Operating Conditions (@T

= +25°C, unless otherwise specified.)

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Parameter Rating Unit

Input Voltage 2.7 to 5.5 V

Junction Temperature Range -40 to +125

Ambient Temperature Range -40 to +85

°C

Thermal Information

Parameter Package Symbol Max Unit

QFN3x3-16L

Thermal Resistance (Junction to Ambient)

MSOP-8L 180

SOT23-8 250

θ

JA

DFN2x2-8L 80

QFN3x3-16L

Thermal Resistance (Junction to Case)

MSOP-8L 75

SOT23-8 130

θ

JC

DFN2x2-8L 20

Electrical Characteristics (@T

= +25°C, VIN = 3.6V, unless otherwise specified.)

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Parameter Symbol Test Conditions Min Typ Max Units

Input Voltage

Output Current

V

I

LED

IN

All LEDs 100% setting

Current Matching All LEDs 100% setting -3 +3 %

LED Dropout Voltage

Quiscent Current

Shutdown Current

Startup Time

EN Input Logic High

EN Input Logic Low

EN Low Time for Dimming

EN High Time for Dimming

Shutdown Delay Time

Thermal Shutdown Temperature

V

I

DO

I

I

Q

I

VEN = 0V, VIN = 5.5V

SD

T

ON

V

HI

V

LO

T

LO

T

HI

T

VEN = 0V

OFF

T

P

= 20mA

LED

= 0

LED

30 µs

1.5 V

0.4 V

0.5 500 µs

0.5 µs

150 °C

Hysteresis Temperature 30 °C

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14

°C/W

2.7 5.5 V

18 20 22 mA

60 mV

270 µA

0.1 1.0 µA

1000 2000 µs

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Typical Performance Characteristics (@T

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= +25°C, VIN = 5.0V, unless otherwise specified.)

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PAM2811

PAM2811

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Application Information

The PAM2811 is a 4-channel programmable white-LED driver. It is capable of supplying 20mA per channel with a total of 80mA output current

available. LED brightness control of PAM2811 can be achieved with a Pulses signal.

Enable Input

The EN input is used to enable or disable the PAM2811. Pulling the EN pin higher than 1.5V will enable the device. For producing constant,

nonpulsating output current compare to conventional pulse width modulation (PWM) dimming scheme. The PAM2811 incorporates a 4-bit DAC for

brightness control to program the output current at 16 continuous steps: 20 to1.25mA. Table1 shows details for current setting.

Table 1 Current Setting

Data

16 20.00 8 10.00

15 18.75 7 8.75

14 17.50 6 7.50

13 16.25 5 6.25

12 15.00 4 5.00

11 13.75 3 3.75

10 12.50 2 2.50

9 11.25 1 1.25

Page 2 shows the detail operation of 16-steps brightness control. When single-wire pulse counting dimming is used, the ready time is

recommended to be greater than 30µs for enabling the device, the pulse high time THI recommended to be greater than 0.5µs, and the pulse low

time T

shutdown feature reduces quiescent current to less than 0.1µA.

Current

(mA)

is recommended to be greater than0.5µs and less than 500µs. A constant current is sourced as long as the EN signal remains high. The

LO

Data

LED Connection

The PAM2811 supports up to 4 white LEDs. The four LEDs are connected from VIN to LEDx respectively. If the LED is not used, it should be

connected to GND or open.

Over Temperature Protection

The PAM2811 equips over temperature protection. When the junction temperature (TJ) exceeds +150°C, the current source turns off

automatically. The device will turn on again after the IC’s T

recommended.

Current

(mA)

cools down under +120°C. Operating at absolute maximum temperature is not

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Ordering Information

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PAM2811

Part Number Part Marking Package Type Standard Package

PAM2811AJER

PAM2811BJER

PAM2811CSCR

PAM2811DACR EAXYW SOT23-8 3000 Units/Tape & Reel

PAM2811EYCR

PAM2811

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P2811A
XXXYW

P2811B
XXXYW

P2811C
XXXYW

P2811E
XXXYW

QFN3x3-16L 3000 Units/Tape & Reel

QFN3x3-16L 3000 Units/Tape & Reel

MSOP-8L 2500 Units/Tape & Reel

DFN3x3-8L 3000 Units/Tape & Reel

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Marking Information

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PAM2811

PAM2811

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Package Outline Dimensions (All dimensions in mm.)

QFN3x3-16

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PAM2811

Notes: 1. Controlling dimensions are in millimeters (angles in degrees)

2. Coplanarity applies to the exposed pad as well as the terminals.

3. DAP is 1.90 x 1.90mm.

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Package Outline Dimensions (cont.) (All dimensions in mm.)

MSOP-8

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PAM2811

PAM2811

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Package Outline Dimensions (cont.) (All dimensions in mm.)

SOT23-8

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PAM2811

PAM2811

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Package Outline Dimensions (cont.) (All dimensions in mm.)

DFN2x2-8

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PAM2811

PAM2811

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PAM2811

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Copyright © 2012, Diodes Incorporated

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IMPORTANT NOTICE

LIFE SUPPORT

PAM2811

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