a8292 Allegro MicroSystems, Inc., a8292 Datasheet
a8292
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a8292 Summary of contents
Page 1
... C™ data across the tracking regulators has been minimized. The A8292 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. Continued on the next page… ...
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... Contact Allegro for additional packing options. b Leadframe plating 100% matte tin. The device uses a 2-wire bidirectional serial interface, compatible with the I The A8292 is supplied in a lead (Pb) free 28-lead MLP/QFN with 100% matte tin leadframe plating. Symbol OUT ...
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... A8292 Dual LNB Supply and Control Voltage Regulator Terminal List Table Name Number GND – ADD 11 BOOST1 1 BOOST2 21 EXTM1 6 EXTM2 16 GND 8 PAD Pad GNDLX1 27 GNDLX2 23 IRQ 14 LNB1 28 LNB2 22 LX1 26 LX2 13, 18 SCL 12 SDA 10 TCAP1 3 TCAP2 19 TDI1 7 TDI2 15 TDO1 5 TDO2 17 VCP1 ...
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... A8292 Dual 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 Output Voltage Rise Time 2 Output Voltage Pull-Down Time ...
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... A8292 Dual LNB Supply and Control Voltage Regulator ELECTRICAL CHARACTERISTICS (continued) Characteristics Cable Disconnect Current Source Tone Tone Frequency Tone Amplitude, Peak-to-Peak Tone Duty Cycle Tone Rise Time Tone Fall Time EXTM Logic Input EXTM Input Leakage Tone Detector Tone Detect Input Amplitude Receive, Peak-to- ...
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... A8292 Dual LNB Supply and Control Voltage Regulator ELECTRICAL CHARACTERISTICS (continued) Characteristics I 2 C™ Address Setting ADD Voltage for Address 0001,000 ADD Voltage for Address 0001,001 ADD Voltage for Address 0001,010 ADD Voltage for Address 0001,011 1 Operation may be limited by power loss in the linear regulator. ...
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... Short Circuit Handling If the LNB output is shorted to ground, the LNB output current will be clamped to 600 mA, typical. If the short circuit condition lasts for more than 48 ms, the A8292 will be disabled and the OCP bit will be set. Auto-Restart After a short circuit condition occurs, the host controller should periodically re-enable the A8292 to check if the short circuit has been removed ...
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... Operating at this level for a longer period is not recommended. Tone Detection A 22 kHz tone detector is provided in each channel of the A8292 solution. The detector extracts the tone signal and provides open-drain signal on the TDO pins. The maximum tone out error is ± ...
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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 A8292. Data is exchanged between a microcontroller (master) and the A8292 (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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... Acknowledge bit, the A8292 responds by sending the data from register 2 to the master. Data bytes continue to be sent to the master until the master releases the SDA line during the Acknowl- edge bit. When this is detected, the A8292 stops sending data and waits for a stop signal. Interrupt Request The A8292 also provides an interrupt request pin, IRQ, which is an open-drain, active-low output ...
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... Once V REG point, the IRQ output goes active, and the VUV bit is set. After the A8292 acknowledges the address, the IRQ flag is reset. After the master reads the status registers, the registers are updated with the VUV reset. ...
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... Dual LNB Supply and Control Voltage Regulator Control Registers (I 2 C™-Compatible Write Register) All main functions of the A8292 are controlled through the I 2 C™-compatible interface via the 8-bit Control registers. As the A8292 contains numerous control options, as well as featuring two channels necessary to have four Control registers. Each Table 2 ...
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... A8292 Dual LNB Supply and Control Voltage Regulator Table 3. Control Registers with Address (I1, I0 and 11 Channel 1 Bit (Address Bit 0 TMODEx ToneMode. 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 LNBx output. ...
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... A8292 Dual LNB Supply and Control Voltage Regulator Table 4. Output Voltage Amplitude Selection VSEL VSEL VSEL ...
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... Status registers. In all fault cases, once the bit is set, it remains latched until the A8292 is read by the I master, assuming the fault has been resolved. The current status of each LNB output is indicated by the disable bit, DIS, for that channel ...
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... V occurred disabling the LNB outputs. The disable bits, DISx, will also be set, and the A8292 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 ris- ing edge of the 9 ger present, then the VUV bit will be reset allowing the master to reenable the LNB output if required ...
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... A8292 Dual LNB Supply and Control Voltage Regulator Table 7. Status Register 2 Bit Bit 0 CAD1 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 BOOST1 and LNB1 output. If the LNB volts rise above 21 V, CAD1 will be set to 1 ...
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... A8292 Dual LNB Supply and Control Voltage Regulator Table 8. Component Selection Table Component C3 220 nF C8 C12 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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... A8292 Dual 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 ...