A6211 ALLEGRO [Allegro MicroSystems], A6211 Datasheet
A6211
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A6211 Summary of contents
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... kHz) A6211-DS Buck Regulator LED Driver Description The A6211 is a single IC switching regulator that provides constant-current output to drive high-power LEDs. It integrates a high-side N-channel DMOS switch for DC-to-DC step- down (buck) conversion. A true average current is output using a cycle-by-cycle, controlled on-time method. ...
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... A6211 Selection Guide Operating Ambient Part Number Temperature, T A6211GLJTR-T –40ºC to 105ºC Absolute Maximum Ratings Characteristic Supply Voltage Bootstrap Drive Voltage Switching Voltage Linear Regulator Terminal Enable and TON Voltage Current Sense Voltage Operating Ambient Temperature Maximum Junction Temperature Storage Temperature ...
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... A6211 V IN VIN On-Time Current TON Generator 0.4 V – 1 COMP + + 0.2 V – Constant-Current 3-Ampere PWM Dimmable Functional Block Diagram CVCC VCC V 5.3 V REG V CC UVLO Average Off-Time Gate Drive On-Time Timer UVLO Timer Shutdown Level Shift IC and Driver Control Logic ...
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... A6211 ELECTRICAL CHARACTERISTICS otherwise noted Characteristics Input Supply Voltage V Undervoltage Lockout Threshold IN V Undervoltage Lockout Hysteresis V IN VIN Pin Supply Current VIN Pin Shutdown Current BOOT Switch Current Limit Threshold Buck Switch On-Resistance BOOT Undervoltage Lockout Threshold V BOOT Undervoltage Lockout Hysteresis V ...
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... A6211 OUT C1,C2 i LED Panel 1A C1, Figure 1. Startup waveforms from off-state at various input voltages; note that the rise time of the LED current depends on input/output voltages, inductor value, and switching frequency • Operating conditions: LED voltage = 15 V, LED current = 1 ...
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... A6211 C1, C1, Figure 2. PWM operation at various duty cycles; note that there is no startup delay during PWM dimming operation • Operating conditions: at 200 Hz • CH1 (Red (10 V/div), CH2 (Blue CH3 (Green (500 mA/div), CH4 (Yellow) = Enable (5 V/div), time scale = 1 ms/div (panel 2A) and 50 μs/div (panel 2B) ...
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... A6211 OUT 5 OUT 3 OUT 0.5 1.0 1.5 LED Current, i Figure 3. Efficiency versus LED Current at various LED voltages Operating conditions MHz SW 1 0.1 0.01 0.001 0.1 Figure 5. Average LED Current versus PWM dimming percentage Operating conditions: V ...
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... A6211 The A6211 is a buck regulator designed for driving a high-current LED string. It utilizes average current mode control to maintain constant LED current and consistent brightness. The LED current level is easily programmable by selection of an external sense resistor, with a value determined as follows LED ...
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... A6211 at any time, a series resistor (1 kΩ) is required to limit the current flowing into the EN pin. This series resistor is not necessary driven from a logic input. PWM Dimming Ratio The brightness of the LED string can be reduced by adjusting the PWM duty cycle at the EN pin as follows: ...
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... OUT C2 i LED C3 t Figure 10. A6211 overcurrent protection tripped in the case of a fault caused by the sense resistor pin shorted to ground; shows switch node, V (ch1, 10 V/div.), output voltage, V (ch2, 10 V/div.), LED current, SW OUT i (ch3, 1 A/div.), t = 100 μs/div. LED Constant-Current 3-Ampere PWM Dimmable ...
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... Ripple current through LED string is proportional to ripple voltage at CS pin. Figure 12. Ripple current and voltage, with and without shunt capacitor Constant-Current 3-Ampere PWM Dimmable Output Filter Capacitor The A6211 is designed to operate without an output filter capaci- tor, in order to save cost. Adding a large output capacitor is not ). recommended some applications, it may be required to add a small filter capacitor (up to several μ ...
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... A6211 C1, C1, Figure 13. Waveforms showing the effects of adding a small filter capacitor across the LED string • Operating conditions: at 200 Hz • CH1 (Red (10 V/div), CH2 (Blue CH3 (Green (500 mA/div), CH4 (Yellow) = Enable (5 V/div), time scale = 1 ms/div ...
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... Part Number C1 EMZA500ADA470MF80G C2 UMK316BJ475KL-T L1 NR8040T100M D1 B250A-13-F R RL1632R-R150-F SENSE Constant-Current 3-Ampere PWM Dimmable Buck Regulator LED Driver ). The switching fre VIN SW A6211 0.1 μ TON BOOT 3 6 GND VCC C5 0.1 μF Manufacturer United Chemi-Con Taiyo Yuden Taiyo Yuden Diodes, Inc. ...
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... Figure 16 shows the three critical current loops that should be minimized and connected by relatively wide traces. 1) When the upper FET (integrated inside the A6211) is on, cur- rent flows from the input supply/capacitors, through the upper FET, into the load via the output inductor, and back to ground as shown in loop 1 ...
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... To improve thermal performance, use multiple layers for GND. Place as many vias as possible to the ground plane around the anode of the asynchronous diode. 11) The thermal pad under the A6211 must connect to the ground plane using multiple vias. More vias will insure lower operating temperature and higher efficiency. ...
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... A6211 8 2.41 NOM A 1 3.30 NOM 8X 0.10 C 0.51 0.31 1.27 BSC Constant-Current 3-Ampere PWM Dimmable Package LJ, 8-Pin Narrow SOIC with Exposed Thermal Pad 4.90 ±0.10 B 3.90 ±0.10 6.00 ±0.20 2 Branded Face C C SEATING SEATING PLANE PLANE For Reference Only; not for tooling use (reference MS-012BA) Dimensions in millimeters 1.70 MAX Dimensions exclusive of mold flash, gate burrs, and dambar protrusions ...
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... A6211 Copyright ©2010-2012, Allegro MicroSystems, Inc. Allegro MicroSystems, Inc. reserves the right to make, from time to time, such de par tures from the detail spec tions as may be required to per- mit improvements in the per for mance, reliability, or manufacturability of its products. Before placing an order, the user is cautioned to verify that the information being relied upon is current. Allegro’ ...