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ISL6421A Datasheet(PDF) 1 Page - Intersil Corporation |
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ISL6421A Datasheet(HTML) 1 Page - Intersil Corporation |
1 / 12 page ![]() 1 ® FN9167.3 ISL6421A Single Output LNB Supply and Control Voltage Regulator with I2C Interface for Advanced Satellite Set-top Box Designs The ISL6421A is a highly integrated solution for providing power and control signals from advanced satellite set-top box (STB) modules to the low noise block (LNB). The internal architecture of this device contains a current-mode boost PWM and a low-noise linear regulator, along with the circuitry required for I2C device interfacing and for providing DiSEqC™ standard control signals to the LNB. A regulated output voltage is available at the output terminal (VOUT) to support the operation of the antenna port in advanced satellite STB applications. The regulated output may be set to either 13V or 18V by use of the voltage select command bit (VSEL) through the I2C bus. Additionally, to compensate for the voltage drop in the coaxial cable, the voltage may be increased by 1V with the line length compensation bit (LLC) feature. The device can be put into a standby mode by means of the enable bit (EN), this disables the PWM and Linear regulator combination and helps conserve power. The input to the linear regulator is derived from the current mode boost converter, such that the required voltage is the sum of the output voltage and the linear regulator drop (1.0V typical). This ensures that the power dissipation is minimized and maintains a constant voltage drop across the linear pass element, while permitting an adequate voltage range for tone injection. The device is capable of providing 450mA (typical). The overcurrent limit is either digitally or resistor programmable. Pinout ISL6421A (QFN) TOP VIEW Features • Switch-Mode Power Converter for Lowest Dissipation - Boost PWM with >92% Efficiency - Selectable 13V or 18V Outputs - Digital Cable Length Compensation (1V) - Vsw tracks Vout ensures low dissipation •I2C Compatible Interface for Remote Device Control - Registered Slave Address 0001 00XX - Fully Functional 3.3V, 5V Operation up to 400kHz • Built-In Tone Oscillator Factory Trimmed to 22kHz - Facilitates DiSEqC™ (EUTELSAT) Encoding - External Modulation input DSQIN • Internal Over Temperature Protection and Diagnostics • Internal Overload and Over Temperature Flags (Visible on I2C) • Output Back-Bias Protection to 24V • LNB Short-Circuit Protection and Diagnostics • QFN Package - Compliant to JEDEC PUB95 MO-220 QFN - Quad Flat No Leads - Product Outline - Near Chip-Scale Package Footprint • External Pins to Select 13V/18V Options • Pb-Free Available (RoHS Compliant) Applications • LNB Power Supply and Control for Satellite Set-Top Box References • Tech Brief 389 (TB389) - “PCB Land Pattern Design and Surface Mount Guidelines for QFN Packages”; Available on the Intersil website, www.intersil.com PGND NC SGND SEL18V NC BYPASS PGND GATE CPSWOUT NC NC NC AGND VOUT DSQIN TCAP 1 2 3 4 5 6 7 8 24 23 22 21 20 19 18 17 32 31 30 29 28 27 26 25 9 1011 12 13 1415 16 Ordering Information PART NUMBER* PART MARKING TEMP. RANGE (°C) PACKAGE PKG. DWG. # ISL6421AER ISL6421AER -20 to 85 32 Ld 5x5 QFN L32.5x5 ISL6421AERZ (Note) ISL6421AERZ -20 to 85 32 Ld 5x5 QFN (Pb-free) L32.5x5 *Add -T for tape and reel package. NOTE: Intersil Pb-free products employ special Pb-free material sets; molding compounds/die attach materials and 100% matte tin plate termination finish, which are RoHS compliant and compatible with both SnPb and Pb-free soldering operations. Intersil Pb-free products are MSL classified at Pb-free peak reflow temperatures that meet or exceed the Pb-free requirements of IPC/JEDEC J STD-020. Data Sheet CAUTION: These devices are sensitive to electrostatic discharge; follow proper IC Handling Procedures. 1-888-INTERSIL or 1-888-468-3774 | Intersil (and design) is a registered trademark of Intersil Americas Inc. Copyright Intersil Americas Inc. 2004-2006. All Rights Reserved All other trademarks mentioned are the property of their respective owners. March 9, 2006 |