Datasheet

ManualsBrandsON SEMICONDUCTOR ManualsDev KitsPCB design board

August, 2006 − Rev. 0

1 Publication Order Number:

NCP5612/D

NCP5612

High Efficiency Ultra Small

Thinnest White LED Driver

The NCP5612 product is a dual output LED driver dedicated to the

LCD display backlighting.

The built−in DC/DC converter is based on a high efficient charge

pump structure with operating mode 1x and 1.5x. It provides a peak

87% efficiency together with a 0.2% LED to LED matching.

Features

• Support the Single Wire Serial Link Protocol

• Peak Efficiency 90% with 1x and 1.5x Mode

• Programmable Dimming ICON Function

• Built−in Short Circuit Protection

• Provides 16 steps Current Control

• Controlled Start−up Inrush Current

• Built−in Automatic Open Load Protection

• Tight 0.2% Matching Tolerance

• Accurate 1% Output Current Tolerance

• Smallest Available Package on the Market

• This is a Pb−Free Device

Typical Applications

• Portable Back Light

• Digital Cellular Phone Camera Photo Flash

• LCD and Key Board Simultaneous Drive

Figure 1. Typical Single Wire White LED Driver

220 nF/10 V

GND

LWY87S

10k

MCU

I/O pin

GND

LED1

LED/ICON

CNTL

C2P

C2N

C1P

C1N

NCP5612

bat

1 mF/6.3 V 1 mF/6.3 V

CC−cpu

220 nF/10 V

1 mF/10 V

bat

REF

out

GND

LLGA12 (2x2 mm)

MU SUFFIX

CASE 513AA

PIN CONNECTIONS

http://onsemi.com

MARKING

DIAGRAM

C1P

bat

REF

LED2

C2N

YD M G

YD = Specific Device Code

M = Date Code

G = Pb−Free Package

(Note: Microdot may be in either location)

2 12 11

LED1

CNTL

C2P

OUT

(Top View)

Device Package Shipping†

ORDERING INFORMATION

NCP5612MUTBG LLGA12

(Pb−Free)

3000/Tape & Ree

†For information on tape and reel specifications,

including part orientation and tape sizes, please

refer to our Tape and Reel Packaging Specification

Brochure, BRD8011/D.

GND C1N

Summary of content (11 pages)

PAGE 1
NCP5612 High Efficiency Ultra Small Thinnest White LED Driver The NCP5612 product is a dual output LED driver dedicated to the LCD display backlighting. The built−in DC/DC converter is based on a high efficient charge pump structure with operating mode 1x and 1.5x. It provides a peak 87% efficiency together with a 0.2% LED to LED matching. http://onsemi.com MARKING DIAGRAM Features • • • • • • • • • • • Support the Single Wire Serial Link Protocol Peak Efficiency 90% with 1x and 1.
PAGE 2
NCP5612 C1 C2 220 nF 220 nF 12 10 9 8 C4 1 mF/10 V Vbat GND C3 CHARGE PUMP DC/DC CONVERTER 11 1 mF/6.3 V 7 Vout GND OVERVOLTAGE CNTL LWY87S 5 LWY87S Vbat DIGITAL CONTROL 150 k Vbat CURRENT MIRRORS 2 GND R1 4 10 k GND D1 Q1 ANALOG CONTROL 1 GND GND NC 6 OVERTEMPERATURE Figure 2. Simplified Block Diagram http://onsemi.
PAGE 3
NCP5612 PIN FUNCTION DESCRIPTION Pin No. Symbol Function Description 1 GND POWER This pin is the GROUND signal for the power analog blocks and must be connected to the system ground. This pin is the GROUND reference for the DC/DC converter and the output current control. The pin must be connected to the system ground, a ground plane being strongly recommended.
PAGE 4
NCP5612 MAXIMUM RATINGS Symbol Value Unit Power Supply Rating VBAT 7.0 V Output Power Supply Vout 7.0 V Digital Input Voltage Digital Input Current CNTL −0.3 < V < VBAT 1.0 V mA Human Body Model: R = 1500 W, C = 100 pF (Note 3) Machine Model ESD 2.
PAGE 5
NCP5612 ANALOG SECTION (Typical values are referenced to TA = +25°C, Min & Max values are referenced −40°C to +85°C ambient temperature, operating conditions 2.85 V < Vbat < 5.5 V, unless otherwise noted.) Rating Pin Symbol Min Typ Max Unit Reference Current @ Vref = 600 mV (Note 7) 4 IREF 1.0 − 60 mA Reference Voltage (Note 7) 0°C < TA < +85°C 4 VREF −3% 600 +3% mV Base Reference Current (IREF) Current Ratio − ILEDR − 500 − − 6.
PAGE 6
NCP5612 APPLICATION INFORMATION ton toff twkp tf tr 90% 90% VIH 10% VIL Bit = 1 Bit = 0 Bit = 0 Figure 3. Timings Reference VOH @ Vccio = 3.0 V 2600 mV VOH @ Vccio = 2.6 V 2400 mV 1400 mV VOL @ MOTOROLA: 500 mV VOL @ QUALCOMM: 450 mV VOL @ INTEL: 400 mV VIHsw VIL 600 mV 100 mV/step GROUND Figure 4. Basic Cellular Phone Chip Set Digital Output Levels DC/DC Operation The converter is based on a charge pump technique to generate a DC voltage capable to supply the White LED load.
PAGE 7
NCP5612 VBandGap LED Return Pin 2 & 3 600 mV R1 IREF GND Pin 4 Note: the IREF pin must never be biased by an external voltage. GND Figure 5. Basic Reference Current Source Load Connection in the application (see Figure 6). In this case, the two current mirrors can be connected in parallel to drive a single powerful LED, thus yielding 60 mA current capability in a single LED.
PAGE 8
NCP5612 • The first four positive going pulses are used to control • • • • The system returns to zero if a pulse, delayed by the ICON (LED2): 1. Pulse #1 ³ ICON = 100 mA 2. Pulse #2 ³ ICON = 150 mA 3. Pulse #3 ³ ICON = 250 mA 4. Pulse #4 ³ ICON = 450 mA The fifth positive pulse will clear the ICON and activate the normal operation of LED1 and LED2 The pulses from the fifth to the twentieth will increase the LED current according to a pseudo logarithmic scale (see Figure 9).
PAGE 9
NCP5612 DIMMING The built−in Single Wire Serial Link interface provides a simple way to accurately control the output current flowing in the two LED. Provision have been made, at silicon level, to provide a full dimming of the backlight (NORMAL mode of operation), the ICON current being adjustable in four steps when it is activated. Bit Clock I−LED(mA) 1 2 Table 1.
PAGE 10
NCP5612 Figure 11. Typical LED to LED Current Matching C1 4.7 mF/10 V VBAT J1 2 1 220 nF/6.3 V 220 nF/6.3 V TP2 VOUT GND C2 POWER 12 GND J2 2 4 6 8 10 1 3 5 7 9 11 TP1 DATA 6 5 DATA 4 S−WIRE PORT GND 1 IREFBK R1 10 C3 C4 9 8 C1N C1P C2N C2P Vout Vbat NC 7 VOUT GND 1.0 mF/10 V U1 NCP5612 CNTL IREF GND LED1 LED/ICON 2 LED1 D1 LWY87S 3 LED2 LWY87S 10 k Z1 GND GND Figure 12. Demo Board Schematic Diagram http://onsemi.
PAGE 11
NCP5612 PACKAGE DIMENSIONS LLGA12 MU SUFFIX CASE 513AA−01 ISSUE O D A B NOTES: 1. DIMENSIONING AND TOLERANCING PER ASME Y14.5M, 1994 . 2. CONTROLLING DIMENSION: MILLIMETERS. 3. DIMENSION b APPLIES TO PLATED TERMINAL AND IS MEASURED BETWEEN 0.15 AND 0.20 MM FROM TERMINAL. 4. COPLANARITY APPLIES TO THE EXPOSED PAD AS WELL AS THE TERMINALS. PIN ONE REFERENCE ÇÇÇÇ ÇÇÇÇ ÇÇÇÇ 2X 0.10 C 2X 0.10 C E DIM A A1 b D D2 E E2 e K L L1 TOP VIEW 0.10 C MILLIMETERS MIN MAX 0.50 0.60 0.00 0.05 0.15 0.25 2.