ISL6421AERZ Renesas

DATASHEET ISL6421A FN9167 Rev 3.00 Single Output LNB Supply and Control Voltage Regulator with I2C Interface for Mar 9, 2006 Advanced Satellite Set-top Box Designs The ISL6421A is a highly integrated solution for providing Features power and control signals from advanced satellite set-top Switch-Mode Power Converter for Lowest Dissipation box (STB) modules to the low noise block (LNB). The - Boost PWM with >92% Efficiency internal architecture of this device contains a current-mode - Selectable 13V or 18V Outputs boost PWM and a low-noise linear regulator, along with the 2 circuitry required for I C device interfacing and for providing - Digital Cable Length Compensation (1V) DiSEqC standard control signals to the LNB. - Vsw tracks Vout ensures low dissipation 2 A regulated output voltage is available at the output terminal I C Compatible Interface for Remote Device Control (VOUT) to support the operation of the antenna port in - Registered Slave Address 0001 00XX advanced satellite STB applications. The regulated output - Fully Functional 3.3V, 5V Operation up to 400kHz may be set to either 13V or 18V by use of the voltage select 2 Built-In Tone Oscillator Factory Trimmed to 22kHz command bit (VSEL) through the I C bus. Additionally, to compensate for the voltage drop in the coaxial cable, the - Facilitates DiSEqC (EUTELSAT) Encoding voltage may be increased by 1V with the line length - External Modulation input DSQIN compensation bit (LLC) feature. The device can be put into a Internal Over Temperature Protection and Diagnostics standby mode by means of the enable bit (EN), this disables the PWM and Linear regulator combination and helps Internal Overload and Over Temperature Flags 2 conserve power. (Visible on I C) The input to the linear regulator is derived from the current Output Back-Bias Protection to 24V mode boost converter, such that the required voltage is the LNB Short-Circuit Protection and Diagnostics sum of the output voltage and the linear regulator drop (1.0V typical). This ensures that the power dissipation is minimized QFN Package and maintains a constant voltage drop across the linear pass - Compliant to JEDEC PUB95 MO-220 QFN - Quad Flat element, while permitting an adequate voltage range for tone No Leads - Product Outline injection. - Near Chip-Scale Package Footprint The device is capable of providing 450mA (typical). The External Pins to Select 13V/18V Options overcurrent limit is either digitally or resistor programmable. Pb-Free Available (RoHS Compliant) ISL6421A (QFN) TOP VIEW Pinout Applications LNB Power Supply and Control for Satellite Set-Top Box 32 31 30 29 28 27 26 25 References Tech Brief 389 (TB389) - PCB Land Pattern Design and PGND 1 24 CPSWOUT Surface Mount Guidelines for QFN Packages Available NC 2 23 NC on the Intersil website, www.intersil.com SGND 3 22 NC Ordering Information SEL18V 4 21 NC TEMP. PART PART RANGE PKG. NC 5 20 AGND NUMBER* MARKING (C) PACKAGE DWG. BYPASS 6 19 VOUT ISL6421AER ISL6421AER -20 to 85 32 Ld 5x5 QFN L32.5x5 PGND 7 18 DSQIN ISL6421AERZ ISL6421AERZ -20 to 85 32 Ld 5x5 QFN L32.5x5 (Note) (Pb-free) GATE 8 17 TCAP *Add -T for tape and reel package. 9 1011 12 13 1415 16 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. FN9167 Rev 3.00 Page 1 of 12 Mar 9, 2006 CS NC FB NC COMP NC VSW NC NC NC SDA VCC ADDR CPVOUT SCL CPSWINISL6421A + FN9167 Rev 3.00 Page 2 of 12 Mar 9, 2006 Block Diagram SEL18V OLF OVERCURRENT COUNTER PROTECTION DCL LOGIC SCHEME 1 PWM OC LOGIC GATE Q CLK S SDA OLF SDA ISEL ADDR PGND ADDR EN 2 SCL I C SCL INTERFACE ENT ILIM OTF CS DCL LLC VSEL AMP CS OSC. CLK SLOPE 220kHz BAND GAP COMPENSATION REF VOLTAGE COMP BGV 10 AND WAVE SHAPING REF FB VOLTAGE ADJ 22kHz VREF TONE ENT TONE INJ DSQIN CKT VSW VOUT + - THERMAL OTF SHUTDOWN ON CHIP VCC LINEAR CPVOUT UVLO SGND POR SOFT-START INT 5V CPSWIN CHARGE PUMP SOFT-START EN CPSWOUT BYPASS + AGND TCAP - -