Document
PT4401/2
3/4 Channel Parallel White/Blue LED Drivers
GENERAL DESCRIPTION
The PT4401/2 is a series of White/Blue LED drivers, with PT4401 capable of driving three LEDs and PT4402 driving four LEDs. There is no external component needed, which helps to simplify the system design and lower the system cost significantly. The circuit is optimized to provide over 90% efficiency. The PT4401/2 is ideal to drive white LEDs used for Li-ion battery powered LCD displays. The LED brightness can be adjusted in real time through a PWM signal at the EN pin. The target end applications are small color LCD displays in mobile phones, smart phone, digital cameras, PDA etc. PT4401 is available in SOT-23-6 package and PT4402 in MSOP-8 package, respectively.
FEATURES
z No external component required z Fixed 20mA or 15mA sinking current z Individual current sink circuit for each output to prevent short/open circuit on LEDs z PTC LED current for luminosity compensation z 3 channels (PT4401/SOT23-6) and 4 channels (PT4402/MSOP-8) available z PWM tuned LED brightness through EN pin z Supply voltage range 2.7V~6.0V z 0.1uA standby current
APPLICATIONS
z Mobile phone z PDAs z MP3s
TYPICAL APPLICATION
VDD
VDD PT440X GND EN
LED1 LED2
. . .
. . .
LEDn
Micro Bridge Technology Co.,Ltd.
www.micro-bridge.com
Page 1
PT4401/2
3/4 Channel Parallel White/Blue LED Drivers
ORDERING INFORMATION
PIN CONFIGURATION
PIN DESCRIPTIONS
Pin No.
SOT-23-6 1 2 3 4~6 MSOP8 3 4 1 2 5~8
Symbol
VDD GND PGND EN LED1~3/4 Power Supply Ground Power Ground
Description
Enable Input Logic, Enable High Output Pins. Connected to LED’s Cathode.
ABSOLUTE MAXIMUM RATINGS RECOMMANDED OPERATING RANGE
Symbol VDD VLEDN VEN PD1 PD2 Tjun TSTG TSOLDER PARAMETER VDD Supply Voltage VLED Output Voltage VEN Pin Input Voltage Maximum Power Dissipation, SOT-23-6 Maximum Power Dissipation, MSOP8 Junction Temperature Storage Temperature Soldering Temperature VALUE -0.3~6.5V -0.3~ VIN V -0.3~5.5V θJA 586mW TOPT 695mW 150℃ -50~150℃ 260℃, 10s Symbol VDD VEN PARAMETER VDD Range VEN Range Thermal Resistance, SOT-23-6 Thermal Resistance, MSOP8 Operation Temp. VALUE -0.3~6.0V -0.3~(VIN+0.3)<5.5V 220°C/W 180°C/W -40~85°C
Micro Bridge Technology Co.,Ltd.
www.micro-bridge.com
Page 2
PT4401/2
3/4 Channel Parallel White/Blue LED Drivers
ELECTRICAL CHARACTERISTICS
(VDD = 3.7V, VEN = VDD, TA = +25°C, unless otherwise specified)
Symbol VDD ILED VDO ∆ILED δILED IDD ISHUT IEN VIL VIH
Parameter
Input Voltage LED pin Maximum Sink Current LED pin Drop-Out Voltage LED pin Sink Current Tolerance LED pin Sink Current Deviation Supply Current Shutdown Current Input Leakage at EN pin Input Low Level at EN pin Input High Level at EN pin EN = 0V
Conditions
Min.
2.7
Typ.
Max.
6.0 20
Unit
V mA mV % % µA µA nA
ILED(nom)=20mA, VLED@ILED=90%xILED(nom) ILED(nom)=20mA, ILED/ILED(nom) [Max(ILEDn) – Min(ILEDn)] / Average(ILEDn)
75
90 ±5 ±3
260 0.1 1
380 1
0.4 2.0
V V
BLOCK DIAGRAM
Micro Bridge Technolog.