a8285 Allegro MicroSystems, Inc., a8285 Datasheet
a8285
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a8285 Summary of contents
Page 1
... TCAP 9 NC The A8285 is supplied in a 16-lead plastic power SOIC with internally fused leads for thermal dissipation. The A8287 is supplied in a 24-lead plastic power SOIC with internally fused leads. Both devices are also available in lead (Pb) free versions, with 100% matte tine leadframe ...
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... SCL Interface ADD Fault Monitor IRQ Overcurrent Overcurrent TSD Undervoltage Tone detector and leads TDI and TDO are not provided in 16-pin package (A8285). ID Characteristics C1 33 μ esr < 200 mΩ, I > 350 mA ripple C2, C5,C10 100 nF X5R or X7R C4 100 μ esr < 75 mΩ, I > ...
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... DIS Guaranteed turn-off OFF Guaranteed turn-on ON – set – reset T See note 1 J ΔT See note 1 J www.allegromicro.com 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 A8285/A8287 Min. Typ. Max. -4.5 0 4.5 – – 0mA – – 15 LOAD – 400 500 ...
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... See note1 Interface Timing Diagram 2 SU:DAT t See I C Interface Timing Diagram 2 HD:DAT t See I C Interface Timing Diagram 2 SU:STO www.allegromicro.com 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 A8285/A8287 Min. Typ. Max. Units kHz – – 1 μs 2 – ...
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... V (unless otherwise noted Symbol Test Conditions Address1 – – Address2 – Address3 Address4 – SU:DAT HD:DAT t HIGH www.allegromicro.com 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 A8285/A8287 Min. Typ. Max. Units 0 – 0.7 V 1.3 – 1.7 V – 2.3 2.7 V 3.3 – ...
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... When operating in this condition, care must be taken to ensure that the safe operating temperature range of the A8285/A8287 is not exceeded. For additional information, see Power Dissipation in the Application Infor- mation section. ...
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... When the IRQ fl activated during either of the above fault conditions, and the system master controller addresses the A8285/A8287 with the read/write bit set to 1, then the IRQ fl reset once the A8285/A8287 acknowledges the address. When the master controller reads the data and is acknowledged, the status registers are updated ...
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... LNB Supply and Control Voltage Regulator Application Information to occur at any time during a data transfer. The A8285/A8287 always responds by resetting the data transfer sequence The Read/Write bit is used to determine the data transfer direction. If the Read/Write bit is high, the master reads one or more bytes from the A8285/A8287 ...
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... IRQ Fault Event LNB Supply and Control Voltage Regulator register are defi ned such that the all-zero condition indicates that the A8285/A8287 is fully active with no fault conditions. When V is initially applied, the I IN respond to any requests until the internal logic supply V has reached its operating level ...
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... LNB output. Bit 5 also is set, and the A8285/A8287 does not re-enable the output until so instructed (by having the relevant bit written into the Control register). The status of the undervoltage con- dition is sampled on the rising edge of the ninth clock pulse in the data read sequence ...
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... Note: For maximum effectiveness, the PCB area underneath the IC should be fi lled copper and connected to pins 4 and 13 for A8285, and pins 6, 7, 18, and 19 for A8287. Where a PCB with two or more layers is used, apply thermal vias, placing them adjacent to each of the above pins, and under- neath the IC ...
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... IN × Pd_lin = 0.7 0.5 = 350 mW and therefore P = 0.192 + 0.07 + 0.18 + 0.35 = 0.792 W TOT The thermal resistance required is: (110 – 70) / 0.792 = 50.5ºC/W A8285, 16-Pin SOIC 100 LNB Supply and Control Voltage Regulator Note: For the case of the A8287, the area of copper required on each layer is approximately 1 ...
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... C8 Control 0V S ADR R A READ T Master Responds to IRQ Reads Status VUV = 1 VUV reset www.allegromicro.com 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 A8285/A8287 Tracking 0V Plane Thermal Via Cut in 0V Plane R1 L2 OUTPUT READ N ADR W A ...
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... TSD reset S S READ N ADR W A WRITE P T Master Writes Re-enables LNB output OCP reset www.allegromicro.com 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 A8285/A8287 T JMAX - Δ JMAX J LNB ouput enabled ADR W A WRITE Master Writes ...
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... Inductor drive point GND Ground BOOST Tracking supply voltage to linear regulator VCP Gate supply voltage LNB Supply and Control Voltage Regulator Pin Description www.allegromicro.com 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 A8285/A8287 A8287SLB A8285SLB SOIC-24 SOIC- 4,5,6 ...
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... LNB Supply and Control Voltage Regulator A8285SLB 16-Pin Batwing SOIC 16 .299 7.59 .291 7.39 .414 10.52 .398 10. .020 0.51 .014 0.36 .050 BSC .026 0.66 REF Dimensions in inches Metric dimensions (mm) in brackets, for reference only Leads 4 and 13 are connected inside the device package. A8287SLB 24-Pin Batwing SOIC ...
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... Copyright©2003 AllegroMicrosystems, Inc. www.allegromicro.com 115 Northeast Cutoff, Box 15036 Worcester, Massachusetts 01615-0036 (508) 853-5000 A8285/A8287 2 C system, C Standard Specifi cation 2 17 ...