A8304 Single LNB Supply and Control Voltage Regulator Features and Benefits Description Integrated boost MOSFET, current sensing, and The A8304 is a single channel low noise block regulator compensation (LNBR). The A8304 consists of a monolithic boost converter 704 kHz switching frequency for small low-cost followed by a low-drop linear regulator. It is specifically components designed to provide the power and the interface signals to an SLEEP pin for ultra-low power consumption mode LNB down converter via coaxial cable in satellite TV receiver Adjustable LNB output current limit (250 to 950 mA*) systems. limit with shutdown timer Covers wide array of application requirements The A8304 requires few external components, with the boost Minimizes component sizing to fit each application switch and compensation circuitry integrated inside of the For startup, reconfiguration, and continuous output device. The 704 kHz switching frequency and user-controlled Boost peak current limit scales with LNB current limit output current limit minimize the size of the passive filtering Optional temporary increased current limit (+25%) components. Compatible with DiSEqC1.x control 2 The I C-compatible interface provides control capabilities for complex system requirements, as well as diagnostic capabilities Continued on the next page for system fault reporting. Package: 16-contact QFN (suffix ES) A sleep pin is available to maximize power savings and to 2 quickly shut down the device if needed, without using I C control. The A8304 is provided in a small 3 3 mm QFN package with exposed pad for thermal dissipation. It is lead (Pb) free, with 100% matte tin leadframe plating. 3 mm 3 mm 0.75 mm Functional Block Diagram L1 D1 10 H V S C5 C6 C4 100 F 1 F 100 nF C2 100 F BOOST GNDLX LX VCP VIN V CLK FB D3 C1 VREG Charge IC 704 kHz Boost 100 nF A Pump Power Osc BOOST Regulator C3 REF 220 nF 0.8 V + GND LNB V OUT V IN Slew PAD LNB Ref REF Linear DAC Rate + Regulator Limiter VDD ILIM OC D4 TCAP C8 C10 C9 D2 A 100 nF 220 nF 10 nF Tone R1 R2 R3 R4 R5 C7 Generator 100 nF 4 ISET TONECTRL R SET VSEL3/2/1/0 Unlatched SDA Status PNG, CPOK 2 SCL I C Interface A D3 and D4 are used for surge protection. ADD SET Latched TSD Faults V IN SLEEP RST UVLO, OCP, Timer Read TSD 45 ms IRQ Fault For recommended external components, refer to table 5 8304-DSA8304 Single LNB Supply and Control Voltage Regulator Features and Benefits (continued) 2 2-wire I C-compatible interface for control and status Diagnostic features: PNG Programmable LNB output voltage levels (2% accuracy) Extensive protection features: UVLO, OCP, TSD Enable/disable output Flexible 22 kHz tone generation methods *maximum value depends on PCB thermal design SINK DIS bit for controlling the push-pull output sink current threshold Selection Guide a Part Number Packing Description 7 in. reel, 1500 pieces/reel QFN surface mount b A8304SESTR-T 12 mm carrier tape 3 mm 3 mm 0.75 mm nominal height a Contact Allegro for additional packing options. b Leadframe plating 100% matte tin. Absolute Maximum Ratings Characteristic Symbol Conditions RatingUnit Load Supply Voltage, VIN pin V 18 V IN Internally 1 Output Current I A LNB Limited Output Voltage BOOST pin 0.3 to 32 V 2 Output Voltage LNB pin Surge 1.0 to 32 V Output Voltage LX pin 0.3 to 30 V Output Voltage VCP pin 0.3 to 37 V TCAP, ISET, VREG Pins 0.3 to 6 V Logic Input Voltage 0.3 to 5.5 V Logic Output Voltage 0.3 to 5.5 V Operating Ambient Temperature T Range S 20 to 85 C A Junction Temperature T(max) 150 C J Storage Temperature T 55 to 150 C stg 1 Output current rating may be limited by duty cycle, ambient temperature, and heat sinking. Under any set of conditions, do not exceed the specified current ratings, or a junction temperature, T , of 150C. J 2 Use Allegro recommended application circuit. Package Thermal Characteristics* R JA Package PCB (C/W) ES 47 4-layer * Additional information is available on the Allegro website. Allegro MicroSystems, Inc. 2 115 Northeast Cutoff Worcester, Massachusetts 01615-0036 U.S.A. 1.508.853.5000 www.allegromicro.com