AS3833-ZSOT

AS3833 AMSCO | Alldatasheet

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Technical content

Datasheet sections

• 1 General Description
• 2 Key Features
• 3 Applications
• 4 Pin Assignments (Top View)
• 4.1 Pin Descriptions
• 5 Absolute Maximum Ratings
• 6 Electrical Characteristics
• 7 Typical Operating Characteristics
• 8 Detailed Description
• 8.1 Precision current output
• 8.1.1 Phase shift
• 8.2 VDDH_HC resistor
• 8.3 Safety features
• 8.3.1 Undervoltage lockout
• 8.3.2 Overtemperature Shutdown
• 8.3.3 Short LED protection
• 8.3.4 Open LED detection
• 8.4 Boost controller
• 8.4.1 Setting the output voltage
• 8.4.2 Continuous Conduction Mode (CCM)
• 8.4.3 Duty Cycle
• 8.4.4 Inductor Current
• 8.4.5 Input Capacitor
• 8.4.6 Output Capacitor
• 8.4.7 Current Sense Resistor
• 8.4.8 Compensation Network
• 9 Package Drawings and Markings
• 10 Ordering Information

The technical content of this austriamicrosystems datasheet is still valid. Contact information: Headquarters: ams AG Tobelbaderstrasse 30

8141 Unterpremstaetten, Austria

Tel: +43 (0) 3136 500 0 e-Mail: ams_sales@ams.com Please visit our website at www.ams.com

1 General Description

optimized for 2D and 3D operation. voltage for the LED string supply. adjusting the LED string supply voltage. as well as open and short LED detection.

2 Key Features

Figure 1. AS3833

3 Applications

4 Pin Assignments (Top View)

Figure 2. Pin Assignments (Top View)

Revision 1.8 4 - 20 AS3833 Datasheet - P i n A s s i g n m e n t s ( To p V i e w )

4.1 Pin Descriptions

T able 1. Pin Descriptions Pin Number AS3833 TQFP-32 Pin Number AS3833 SOIC-28 Pin Name Pin Type Description 29 1 VSS P Analog Ground 30 2 B4 A_I/O Base 4. Connect to base of external transistor. 31 3 E4 A_I/O Emitter 4. Connect to emitter of external transistor. 1 4 xFAULT DO_OD Fault output. Active low. 2 5 ISET A_I/O Current setting. Connect current setting resistor. 3 6 UVLO A_I/O Undervoltage lockout input. 4 7 COMP A_I/O Compensation network. Connect compensation network. 5 8 SENSE A_I/O Current sense input. Provide a short, direct PCB path between this pin and the positive side of the current sense resistor. 6 9 FB A_I/O Output voltage feedback input. Input for voltage divider. Connect voltage divider output as short as possible to this pin 7 10 VDDL A_I/O Voltage regulator output 3.3V. Connect 2.2µ F decoupling capacitor to GND 8 11 GATE A_I/O Gate driver output. 10 12 PGND P Power Ground 11 13 VDDM P Voltage regulator output. Connect 2.2µ F decoupling capacitor to GND 12 14 VDDH P Supply voltage. Connect 1µ F decoupling capacitor to GND 14 15 VDDH_HC P Voltage regulator Input. Connect 2.2µ F decoupling capacitor to GND 15 16 VTH A_I/O Reference input for overtemperature detection. 16 17 PWM1 DI_PD PWM input 1. PWM input for channel 1 17 18 E6 A_I/O Emitter 6. Connect to emitter of external transistor. 18 19 B6 A_I/O Base 6. Connect to base of external transistor. 19 20 B5 A_I/O Base 5. Connect to base of external transistor. 20 21 E5 A_I/O Emitter 5. Connect to emitter of external transistor. 21 22 VSS P Analog Ground 22 23 E2 A_I/O Emitter 2. Connect to emitter of external transistor. 23 24 B2 A_I/O Base 2. Connect to base of external transistor. 24 25 B1 A_I/O Base 1. Connect to base of external transistor. 25 26 E1 A_I/O Emitter 1. Connect to emitter of external transistor. 26 27 E3 A_I/O Emitter 3. Connect to emitter of external transistor. 27 28 B3 A_I/O Base 3. Connect to base of external transistor. ams AG Technical content still valid

Revision 1.8 5 - 20 AS3833 Datasheet - A b s o l u t e M a x i m u m R a t i n g s

5 Absolute Maximum Ratings

Stresses beyond those listed in Table 2 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 Electrical Characteristics on page 6 is not implied. Exposure to absolute m aximum rating conditions for extended periods may affect device reliability. T able 2. Absolute Maximum Ratings Parameter Min Max Units Comments Electrical Parameters VDDH to VSS, VDDH_HC to VSS -0.3 55 V VDDM to VSS, GATE to VSS -0.3 25 V xFAULT to VSS -0.3 7 V VDDL to VSS -0.3 5 V Analog Pin Voltage to VSS1 1. Pins Vth, UVLO, Comp, Sense, FB, Iset, Ex, Bx -0.3 5 V Digital Pin Voltage to VSS2 2. Pins PWMx -0.3 5 V Input Current (latch-up immunity) -100 100 mA Norm: JEDEC 78 Electrostatic Discharge Electrostatic Discharge HBM +/- 1500 V Norm: MIL 883 E method 3015 Electrostatic Discharge MM +/- 200 V Norm: JESD22-A115C Continuos Power Dissipation (TA = +70°C) Continuos Power Dissipation 1.5 W PT3 for SOIC-28 Package 3. Depending on actual PCB layout and PCB used. Continuos Power Dissipation Derating Factor 13 mW / °C PDERATE4 4. P DERATE derating factor changes the total continuous power dissipation (PT) if the ambient temperature is not 25ºC. Therefore for e.g. TA=85ºC calculate PT at 85ºC = PT - PDERATE x (85ºC - 25ºC) Temperature Ranges and Storage Conditions Junction to ambient thermal resistance 76 ºC/W For more information about thermal metrics, see application note AN01 Thermal Characteristics. Junction Temperature (TJmax) +150 ºC Storage Temperature Range -55 +150 ºC Package Body Temperature +260 ºC The reflow peak soldering temperature (body temperature) specified is in accordance with IPC/ JEDEC J-STD-020“Moisture/Reflow Sensitivity Classification for Non-Hermetic Solid State Surface Mount Devices”. The lead finish for Pb-free leaded packages is matte tin (100% Sn). Humidity non-condensing 5 85 % Moisture Sensitive Level 1 Represents a max. floor life time of unlimited ams AG Technical content still valid

Revision 1.8 6 - 20 AS3833 Datasheet - E l e c t r i ca l C h a ra c t e r i s t i c s

6 Electrical Characteristics

VDDH = 24V, all voltages referenced to VSS, Typical values are at TA = +25°C (unless otherwise specified). All limits are guaranteed. The parameters with min. and max values are guaranteed with production tests or SQC (Statistical Quality Control) methods. T able 3. Electrical Characteristics Symbol Parameter Conditions Min Typ Max Units General TA Operating Temperature Range apply proper cooling to stay below maximum allowed TJ. -20 +85 °C TJ Operating Junction Temperature -20 +115 °C Power supply VDDH Supply Voltage +12 +50 V VDDM Driver supply voltage regulator output +9 V VDDL 3V voltage regulator output +3.3 V IDD Operating Current Consumption UVLO=2V, PWM1=0, Rset=6kΩ , Vth=0.47V 4.6 5.0 5.6 mA IDDQ Quiescent Current Consumption UVLO=0V, PWM1=0, Rset=6kΩ , Vth=0.47V 2.25 2.50 2.75 mA Current sink parameters ILED_100 Trimmed current accuracy ILED=100mA, Tj = 25°C excluding error of Rset -0.8 +0.8 % ILED_ALL current accuracy ILED=501 to 250mA, BJT β >50 ICH_100 Channel to channel accuracy ILED=100mA, Tj = 25°C -0.6 +0.6 % VIsetX Reference Voltage at pins Iset +1.18 +1.20 +1.22 V Ratio Ratio = ILED/Iset 500 IBX Base output current limit 5.5 7.5 mA Short detection comparator ACCshort Over-Temperature protection accuracy Accuracy of Vbe comparison with VTH level -10 +10 mV Power supply regulation Bth BJT beta threshold 45 48 52 Boost controller oscillator fosc Oscillator frequency 220 250 280 kHz Boost controller PWM DMAX Maximum duty cycle 85 87 89 % Boost controller error amplifier VFB Reference Voltage at pin FB +1.23 +1.25 +1.27 V AV Voltage gain 80 dB BW Bandwidth AV = 0dB 2 MHz IFB_in Voltage sense input current pins FB 0.1 0.2 µ A Icomp_out Compensation output current pins COMP, Vcomp = 1V 10 µ A Boost controller over current protection VSENSE Current sense threshold pin SENSE +600 +800 +1000 mV ams AG Technical content still valid

Revision 1.8 7 - 20 AS3833 Datasheet - E l e c t r i ca l C h a ra c t e r i s t i c s Boost controller driver Rdriver Driver resistance sink and source pin GATE 4 6 8 Ω Vdriver GATE maximum output voltage IGATE = 0mA VDDM V tRISE_driver GATE voltage rise time VGATE = 0 to 3V, CLOAD = 3nF 15 25 50 ns tFALL_driver GATE voltage fall time VGATE = 3 to 0V, CLOAD = 3nF 15 25 50 ns Boost controller under voltage lockout VUVLO Under voltage lockout threshold +1.28 +1.35 +1.42 V IUVLO_Hyst Under voltage lockout hysteresis current 20 µ A Digital pins VIH Logic high input threshold +1.8 V VIL Logic low input threshold +0.8 V VOL Logic low output level PIN xFAULT open drain. I = -2mA +0.3 V RPU Input resistance Pull-up inputs 300 kΩ RPD Input resistance Pull-down inputs 300 kΩ Thermal protection TOFF Thermal shutdown threshold 140 °C Thyst Thermal shutdown hysteresis 30 °C 1. Is is not recommended to set ILED < 50mA in order to minimize influences of offset voltages. T able 3. Electrical Characteristics (Continued) Symbol Parameter Conditions Min Typ Max Units ams AG Technical content still valid

7 Typical Operating Characteristics

VOUT Boost = 60V; IOUT = 1A, TAMB = +25ºC (unless otherwise specified). Figure 3. Boost - Efficiency vs. Output Current; VIN = 13V Figure 4. Boost - Efficiency vs. Output Current; V IN = 24V Figure 5. VOUT vs. IOUT ,VIN = 13V

8 Detailed Description

8.1 Precision current output

Figure 9. Current output stage Iset is protected against a short to ground. In the case of a ground short the current Iset is limited to 660uA and the LED-current to 330mA. 200kΩ, the LED-current is set to 0mA.

8.1.1 Phase shift

updated after the second period. The PWM-frequency must be in the range from 60Hz to 1kHz. Figure 10. Phase shift

8.2 VDDH_HC resistor

Figure 11. VDDH_HC resistor voltage at pin VDDH_HC is approximately 5V. The power dissipation of the RVDDH_HC hat to be considered.

8.3 Safety features

8.3.1 Undervoltage lockout

increases the UVLO voltage and so shifts the turn off voltage level. Figure 12. Undervoltage lockout

8.3.2 Overtemperature Shutdown

all blocks are turned on again.

8.3.3 Short LED protection

Figure 13. Short Led protection When the measured VBE gets lower than the voltage applied at pin Vth an overtemperature an hence an short LED condition is detected. Subsequently the fault output is activated (xFAULT = 0) and the corresponding output is deactivated.

8.3.4 Open LED detection

Figure 14. Open Led detection output is activated (xFAULT = 0) and the corresponding output is disconnected from the power supply feedback loop.

8.4 Boost controller

Figure 15. Boost controller

8.4.1 Setting the output voltage

Figure 16. Vout setting Note: The overall resistance should be in the range of 100kΩ to 200kΩ to avoid any noise issues. Keep FB-line as short as possible.

Revision 1.8 15 - 20 AS3833 Datasheet - D e t a i l e d D e s c r i p t i o n

8.4.2 Continuous Conduction Mode (CCM)

For normal operation the converter should stay in continuous conduction mode, to ensure that the inductor value must be bigger than LCRIT. Where: VIN ... Input voltage at VDDH VOUT ... Output voltage VD ... Diode forward voltage at D1 fSW ... Switching frequency R ... Load resistor, should be calculated with minimum current load R = VOUT / IOUT_min

8.4.3 Duty Cycle

Within CCM, the well known relation between input and output voltage is deriped in the following equation: this means for the duty cycle:

8.4.4 Inductor Current

The inductor current varies during a switching cycle. This variation can be expressed by the mean value of the inductor current and the delta rise/ fall current within each cycle (see Figure 17). F igure 17. Inductor Current Mean inductor current: Delta inductor current: (EQ 9)LC R I T VI N   V2 I N× R× 2 fS W× VO U T VD+( ) 2× (EQ 10) VO U T VD+ VI N (EQ 11)D 1 VI N (EQ 12)IL IO U T (EQ 13)IL∆ D V I N× ams AG Technical content still valid

Revision 1.8 16 - 20 AS3833 Datasheet - D e t a i l e d D e s c r i p t i o n Peak current: RMS inductor current: This peak current is flowing through MN1 during phase 1 and through D1 during phase 2 of each cycle. Therefore this peak current is important for a proper diode , MOSFET and inductor selection. Note: The saturation current of the inductor should be about 20 to 30% larger than the peak current

8.4.5 Input Capacitor

The input capacitor has to supply the delta inductor current and it should be selected according to:

8.4.6 Output Capacitor

The output capacitor must be chosen according to the max allowable output ripple at high load.

8.4.7 Current Sense Resistor

Note: Low inductance, specific designed current sensing resistors should be used, e.g. Stackpole Electronics CSR/CSRN series of sensing resistors with less than 0.2nH (typ.).

8.4.8 Compensation Network

A typical choice for values of the compensation network is C10 = 100pF, C11 = 10nF, R11 = 100KΩ . Use these values as initial choice and evaluate the transient response of the system to verify the behavior at output load change. (EQ 14)Ip k IL IL∆ (EQ 15)IR M S IL 2 1   2 + = (EQ 16)CI N IL∆ (EQ 17)E SR VI N∆ (EQ 18)CO U T IO U T m a x– D× (EQ 19)ES R VO U T∆ IO U T   (EQ 20)RS m a x– VS E N S E IL 0 5, IL∆ ×+ (EQ 21)PR S I2 L r m s– RS D× ×= ams AG Technical content still valid

9 Package Drawings and Markings

Figure 18. TQFP-32 Marking Figure 19. SOIC-28 Marking

Figure 20. TQFP-32 Package

Figure 21. SOIC-28 Package

Revision 1.8 20 - 20 AS3833 Datasheet - O r d e r i n g I n f o r m a t i o n The devices are available as the standard products shown in Table 6. N ote: All products are RoHS compliant and austriamicrosystems green. Buy our products or get free samples online at ICdirect: http://www.austriamicrosystems.com/ICdirect Technical Support is available at http://www.austriamicrosystems.com/Technical-Support For further information and requests, please contact us mailto: sales@austriamicrosystems.com or find your local distributor at http://www.austriamicrosystems.com/distributor T able 6. Ordering Information Ordering Code Marking Description Delivery Form Package AS3833-ZTQT AS3833 Tape & Reel TQFP-32 AS3833-ZSOT AS3833 Tape & Reel SOIC-28 ams AG Technical content still valid