aoz1935 Alpha & Omega Semiconductor, aoz1935 Datasheet

no-image

aoz1935

Manufacturer Part Number
aoz1935
Description
High Efficiency Boost 20-, 30- Led Driver
Manufacturer
Alpha & Omega Semiconductor
Datasheet

Available stocks

Company
Part Number
Manufacturer
Quantity
Price
Part Number:
aoz1935QI
Manufacturer:
ALPHA
Quantity:
20 000
General Description
The AOZ1934/5 is an ideal power solution for white LED
backlighting for medium to small size LCD panels. It is a
highly integrated step up DC-DC converter with input
voltage range from 2.7V to 25V, accommodating
1-, 2-, 3-, or 4-cell lithium ion batteries or 3.3V, 5V, 12V
or 20V regulated supplies. The AOZ1934/5 integrates a
40V power MOSFET as well as compensation and soft
start circuitry, which results in a simpler and smaller
solution with much fewer external components. A high
switching frequency (800kHz) allows the use of a smaller
inductor and capacitor to further reduce the solution size.
Each of the regulated current sinks in the AOZ1934/5
provides 20mA factory programmed current. With a
maximum of 40V at the output of the step-up converter,
each string can connect up to ten LEDs in series, for a
total of 20 LEDs for AOZ1934 and 30 LEDs for AOZ1935.
The AOZ1934/5 is equipped with fast PWM dimming
control for wide dimming range and has an enable pin for
IC ON/OFF control. Various protection features are built
into the AOZ1934/5, including cycle-by-cycle input
current limit protection, output over-voltage protection,
LED fault (open or short) protection and thermal
shutdown protection. The leakage current in shutdown
mode is 0.1µA.
The AOZ1934/5 is available in a 16-lead 3 x 3 x 0.75mm
thin QFN package.
Rev. 1.0 August 2010
www.aosmd.com
Features
Applications
Wide input range: 2.7V to 25V
Drive up to 30 LEDs
Up to 92% efficiency
High frequency step-up converter (800kHz)
Highly integrated solution
Integrated current sinks:
AOZ1934 – 2 channels, AOZ1935 – 3 channels
PWM dimming with <1µs delay time
Low operating quiescent current (500µA)
LED open/short protection
Both internal fixed and external adjustable
Over-voltage protection
Cycle-by-cycle inductor current limit (2.5A)
0.1µA shutdown current
Green Package: 3 x 3 QFN-16
-40°C to +85°C temperature range
Netbook
Tablet PCs
GPS
Portable media players
1-, 2-, 3-, 4-cell Li Ion LED applications
AOZ1934 up to 20 LEDs (10s2p)
AOZ1935 up to 30 LEDs (10s3p)
Integrated 40V Power MOSFET
Internal compensation and soft start
±2% Typ. current accuracy
1.5% Typ. current matching
High Efficiency Boost 20-, 30- LED Driver
AOZ1934/1935
Page 1 of 14

Related parts for aoz1935

aoz1935 Summary of contents

Page 1

... LEDs in series, for a total of 20 LEDs for AOZ1934 and 30 LEDs for AOZ1935. The AOZ1934/5 is equipped with fast PWM dimming control for wide dimming range and has an enable pin for IC ON/OFF control ...

Page 2

... AOS Green Products use reduced levels of Halogens, and are also RoHS compliant. Please visit www.aosmd.com/web/quality/rohs_compliant.jsp Rev. 1.0 August 2010 L = 4.7µH C OUT 1µF AOZ1935 LX OV VOUT PAD PGND Package 3x3 QFN-16 3x3 QFN-16 for additional information. www.aosmd.com AOZ1935 White LEDs serie s Environmental Green Product Green Product Page ...

Page 3

... Input supply pin for the IC 15, 16 PGND Power Ground pin PAD Exposed Backside Paddle. Connect to ground for electrical and thermal usage. PAD is internally connected to Analog Ground pin. *S3 is only for the AOZ1935. Rev. 1.0 August 2010 VIN AVCC PGND PGND ...

Page 4

... ICC Supply Vref 2.7V to 5.5V GND Enable EN PWM PWN Brightness Control Rev. 1.0 August 2010 VOUT Over OV Converter Voltage Control Control S1 Voltage Optimizing S2 Control S3* *S3 is only for the AOZ1935 Constant Logic Current Control Control AOZ1934/35 www.aosmd.com AOZ1935 Backlight Unit LEDs in Series Page ...

Page 5

... Junction to Ambient thermal resistance is highly dependent on PCB layout. Values are based on thermal properties of the device when soldered board. Rev. 1.0 August 2010 (1) =25°C unless otherwise noted A Description Description (2) ≤ 25° 25°C A www.aosmd.com AOZ1935 Value Unit - -0.3 to AVCC+0.3 V °C -40 to 150 ° ...

Page 6

... Rev. 1.0 August 2010 Condition Rising Edge Not Switching Switching EN = GND EN = GND Threshold Current Setting = 20mA (DATA = 1), T =25°C A Current Setting = 20mA (DATA = 1) (3) Current Setting = 20mA (DATA = 1) PWM 100% Duty Cycle www.aosmd.com AOZ1935 Min. Typ. Max. Units 2 2.7 5.5 V 2.5 2.65 V 0.15 V 0.5 mA 1.15 mA ...

Page 7

... Rev. 1.0 August 2010 Electrical Efficiency Vin (V) LED Current Regulation 7.7 12.7 17.7 Input Voltage (V) PWM Dimming Linearity DBRIT = 1kHZ DBRIT = 100HZ DBRIT = 30kHZ PWM Duty Cycle(%) www.aosmd.com AOZ1935 100 Page ...

Page 8

... IN LX 20V/div IL 1A/div 1µs/div Rev. 1.0 August 2010 (Continued) LX 20V/div IL 1A/div LX 20V/div IL 1A/div LX 20V/div IL 1A/div www.aosmd.com AOZ1935 Switching Waveform (V = 2.7V, Full Brightness) IN 1µs/div Switching Waveform (V = 5V, Full Brightness) IN 1µs/div Switching Waveform (V = 25-V, Full Brightness) IN 1µs/div Page ...

Page 9

... DPWM 5V/div V S1 20V/div I S1 20mA/div IL 1A/div (V DPWM 5V/div V S1 20V/div I S1 20mA/div IL 1A/div www.aosmd.com AOZ1935 PWM Dimming 10% = 5V, Frequency = 20kHz) 10µs/div PWM Dimming 50% = 5V, Frequency = 20kHz) IN 10µs/div PWM Dimming 90% = 5V, Frequency = 20kHz) IN 10µs/div Page ...

Page 10

... I S3 20mA/div IL 1A/div 40ms/div V S3 5V/div Vout 20V/div I S3 20mA/div IL 1A/div Rev. 1.0 August 2010 (Continued 5V/div Vout 20V/div I S3 20mA/div IL 1A/div LED Short Protection (V = 5V, Full Brightness) IN 20ms/div www.aosmd.com AOZ1935 LED Open Protection (V = 5V, Full Brightness) IN 2s/div Page ...

Page 11

... Detailed Description The AOZ1934 unique current regulated step-up (boost) converter. Two (or three for AOZ1935) current regulating devices are integrated to drive two or three strings of LEDs. Unused channels need to be connected to ground (GND). The voltage step-up is accomplished by a boost topology, using an inductor-based DC-DC switching converter, in which the inductor serves as an energy storage device in the system ...

Page 12

... IC to get the best decoupling. The path of the inductor, schottky diode and output capacitor should be kept as short as possible to minimize noise and ringing. Please see the AOZ1934/5 evaluation document for detailed PCB layout guidelines. www.aosmd.com AOZ1935 F µ F output capacitor at µ Page ...

Page 13

... Ref. C 2.95 3.00 3.05 D 0.116 1.7 Ref. D1 2.95 3.00 3.05 E 0.116 1.7 Ref. E1 0.45 0.50 0.55 e 0.018 0.30 0.40 0.50 L 0.012 0.25 Ref S www.aosmd.com AOZ1935 Pin 1 Identification Detail "B" BOTTOM VIEW c S Detail “B” Nom. Max. 0.030 0.033 0.001 0.002 0.008 0.011 0.009 0.012 0.012 Ref. ...

Page 14

... Week Code & Year Code Assembly Location Code Option Code 2. A critical component in any component of a life support, device, or system whose failure to perform can be reasonably expected to cause the failure of the life support device or system affect its safety or effectiveness. www.aosmd.com AOZ1935 Page ...

Related keywords