a8290 Allegro MicroSystems, Inc., a8290 Datasheet
a8290
Related parts for a8290
a8290 Summary of contents
Page 1
... C™ data The A8290 has integrated tone detection capability, to support full two-way DiSEqC™ communications. Several schemes are available for generating tone signals, all the way down to no-load, and using either the internal clock or an external time source. A DiSEqC™ ...
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... The device uses a 2-wire bidirectional serial interface, compatible with the I 2 C™ standard, that operates up to 400 kHz. The A8290 is supplied in a lead (Pb) free 28-lead MLP/QFN. Selection Guide Part Number 7 in. reel, 1500 pieces/reel A8290SETTR-T b ...
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... A8290 Single LNB Supply and Control Voltage Regulator Terminal List Table Name ADD BFC BFI BFO BOOST EXTM GND GNDLX IRQ LNB LX 4, 13, 15-18, NC 20, 21, 23 PAD SCL SDA TCAP TDI TDO VCP VIN VREG Device Pin-out Diagram BOOST 1 VCP 2 TCAP 3 PAD ...
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... A8290 Single LNB Supply and Control Voltage Regulator ELECTRICAL CHARACTERISTICS Characteristics General Set-Point Accuracy, Load and Line Regulation Supply Current Boost Switch On Resistance Switching Frequency Switch Current Limit Linear Regulator Voltage Drop TCAP Pin Current 2 Output Voltage Rise Time Output Voltage Pull-Down Time ...
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... A8290 Single LNB Supply and Control Voltage Regulator ELECTRICAL CHARACTERISTICS (continued) Characteristics Cable Disconnect Current Source Bypass FET Bypass FET Control (BFC) Logic Input Input Leakage Bypass FET On Resistance Turn On/Off Delay 2 Tone Tone Frequency Tone Amplitude, Peak-to-Peak Tone Duty Cycle ...
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... A8290 Single LNB Supply and Control Voltage Regulator ELECTRICAL CHARACTERISTICS (continued) Characteristics SCL Low Time SCL High Time Data Setup Time Data Hold Time Setup Time for Stop Condition 2 I C™ Address Setting ADD Voltage for Address 0001,000 ADD Voltage for Address 0001,001 ...
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... LNB output current is limited to 900 mA typical, and the IC will be shut down if the overcurrent condition lasts for more than 48 ms. If this occurs, the A8290 must be reenabled for normal operation. The system should provide sufficient time between successive restarts to limit internal power dissipation; a minimum recommended ...
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... Short Circuit Handling If the LNB output is shorted to ground, the LNB output current will be clamped to 900 mA, typical. If the short circuit condition lasts for more than 48 ms, the A8290 will be disabled and the OCP bit will be set. Auto-Restart After a short circuit condition occurs, the host controller should periodically reenable the A8290 to check if the short circuit has been removed ...
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... This is a serial interface that uses two bus lines, SCL and SDA, to access the internal Control and Status registers of the A8290. Data is exchanged between a microcontroller (master) and the A8290 (slave). The clock input to SCL is generated by the master, while SDA functions as either an input or an open drain output, depending on the direction of the data. ...
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... SDA low during the ninth clock cycle. During a data write from the master, the A8290 also pulls SDA low during the clock cycle that follows the data byte, in order to indicate that the data has been successfully received. In both cas- es, the master device must release the SDA line before the ninth clock cycle, in order to allow this handshaking to occur ...
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... C™ point is further defined in the Status Register section. The bits in the Status register are defined such that the all-zero condition in- dicates that the A8290 is fully active with no fault conditions. When V does not respond to any requests until the internal logic supply V has reached its operating level ...
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... Control Registers (I 2 C™-Compatible Write Register) All main functions of the A8290 are controlled through the I compatible interface via the 8-bit Control registers. As the A8290 contains numerous control options necessary to have two control registers. Each register contains bits of data (bit Table 2 ...
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... A8290 Single LNB Supply and Control Voltage Regulator Table 3. Control Register Address (I1, I0 and 11 Bit Bit 0 TMODE Tone Mode. Selects between the use of an external 22 kHz logic signal or the use of the internal 22 kHz oscillator to control the tone generation on the LNB output selects the external tone and a 1 selects the internal tone ...
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... A8290 Single LNB Supply and Control Voltage Regulator Table 4. Output Voltage Amplitude Selection VSEL3 VSEL2 VSEL1 VSEL0 ...
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... Status registers. In all fault cases, once the bit is set, it remains latched until the A8290 is read by the I master, assuming the fault has been resolved. The current status of the LNB output is indicated by the dis- able bit, DIS ...
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... V occurred disabling the LNB outputs. The disable bit, DIS, will also be set and the A8290 will not reenable the output until so instructed by writing the relevant bit into the control registers. The status of the undervoltage condition is sampled on the rising edge of the 9 present, then the VUV bit will be reset allowing the master to reenable the LNB out- put if required ...
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... A8290 Single LNB Supply and Control Voltage Regulator Table 7. Status Register 2 Bit Bit 0 CAD Cable between LNB and the LNB head is disconnected. When cable disconnect test mode is applied, the LNB linear regulator is disabled and current source is applied between the BOOST and LNB output. If the LNB volts rise above 21 V, CAD will be set to 1 ...
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... A8290 Single LNB Supply and Control Voltage Regulator Table 8. Component Selection Table Component C3 220 nF C8 C12 b 220 nF X5R or X7R, 0805 C1, C4 100 nF X5R or X7R, 0603 C2, C5 100 μ nF C10, C13 10 nF X5R or X7R, 0402 or 0603 C11 0.68 μ ...
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... A8290 Single LNB Supply and Control Voltage Regulator 29X 0.08 C +0.05 0.25 –0.07 +0.20 0.55 –0. C™ trademark of Philips Semiconductors. DiSEqC™ trademark of Eutelsat S.A. The products described here are manufactured under one or more U.S. patents or U.S. patents pending. 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 permit improvements in the per for mance, reliability, or manufacturability of its products ...