LNBH21

LNBH21 LNB SUPPLY AND CONTROL IC WITH STEP-UP CONVERTER AND I2C INTERFACE s s s s s s s s s s s COMPLETE INTERFACE BETWEEN LNB AND I2CTM BUS BUILT-IN DC/DC CONTROLLER FOR SINGLE 12V SUPPLY OPERATION AND HIGH EFFICIENCY (Typ. 94% @ 750mA) TWO SELECTABLE OUTPUT CURRENT LIMIT (450mA / 750mA) BOTH COMPLIANT WITH EUTELSAT AND DIRECT OUTPUT VOLTAGE SPECIFICATION ACCURATE BUILT-IN 22KHz TONE OSCILLATOR SUITS WIDELY ACCEPTED STANDARDS FAST OSCILLATOR START-UP FACILITATES DiSEqCTM ENCODING BUILT-IN 22KHz TONE DETECTOR SUPPORTS BI-DIRECTIONAL DiSEqCTM2.0 SEMI-LOWDROP POST REGULATOR AND HIGH EFFICIENCY STEP-UP PWM FOR LOW POWER LOSS: Typ. 0.56W @ 125mA TWO OUTPUT PINS SUITABLE TO BYPASS THE OUTPUT R-L FILTER AND AVOID ANY TONE DISTORSION (R-L FILTER AS PER DiSEqC 2.0 SPECs, see application circuit on pag. 5) CABLE LENGTH DIGITAL COMPENSATION OVERLOAD AND OVER-TEMPERATURE INTERNAL PROTECTIONS PowerSO-20 s s s OVERLOAD AND OVER-TEMPERATURE I2C DIAGNOSTIC BITs LNB SHORT CIRCUIT SOA PROTECTION WITH I2C DIAGNOSTIC BIT +/- 4KV ESD TOLERANT ON INPUT/ OUTPUT POWER PINS DESCRIPTION Intended for analog and digital satellite STB receivers/SatTV, sets/PC cards, the LNBH21 is a monolithic voltage regulator and interface IC, assembled in POWER SO-20, specifically designed to provide the 13/18V power supply and the 22KHz tone signalling to the LNB downconverter in the antenna or to the multiswitch box. In this application field, it offers a complete solution with extremely low component count, low power dissipation together with simple design and I2CTM standard interfacing. BLOCK DIAGRAM Gate LNBH21 Step-up PWM Controller Vup-Feedback Sense VoTX Vup VoRX Vcc Byp Preregul.+ U.V.lockout +P.ON res. Linear Post-reg +Modulator +Protections ISEL EXTM SDA SCL V Select I²C interf. Enable Diagnostics ADDR TEN 22KHz Oscill. Tone Detector DETIN DSQOUT DSQIN April 2004 1/20 LNBH21 ORDERING CODES TYPE LNBH21 PowerSO-20 (Tube) LNBH21PD PowerSO-20 (Tape & Reel) LNBH21PD-TR ABSOLUTE MAXIMUM RATINGS Symbol VCC VUP IO VOTX/RX VI VDETIN VOH IGATE VSENSE Tstg Top DC Input Voltage DC Input Voltage Output Current DC Output Pins Voltage Logic Input Voltage (SDA, SCL, DSQIN, ISEL) Detector Input Signal Amplitude Logic High Output Voltage (DSQOUT) Gate Current Current Sense Voltage Storage Temperature Range Operating Junction Temperature Range Parameter Value -0.3 to 16 -0.3 to 25 Internally Limited -0.3 to 25 -0.3 to 7 -0.3 to 2 -0.3 to 7 ± 400 -0.3 to 1 -0.3 to 7 -40 to +150 -40 to +125 Unit V V mA V V VPP V mA V V °C °C VADDRESS Address Pin Voltage Absolute Maximum Ratings are those values beyond which damage to the device may occur. Functional operation under these condition is not implied. THERMAL DATA Symbol Rthj-case Parameter Thermal Resistance Junction-case Value 2 Unit °C/W PIN CONFIGUARATION (top view) 2/20 LNBH21 TABLE A: PIN CONFIGURATIONS PIN N° 18 17 16 19 SYMBOL VCC GATE SENSE VUP NAME Supply Input External Switch Gate Current Sense Input Step-up Voltage FUNCTION 8V to 15V IC supply. A 220µF bypass capacitor to GND with a 470nF (ceramic) in parallel is recommended External MOS switch Gate connection of the step-up converter DC/DC Current Sense comparator input. Connected to current sensing resistor Input of the linear post-regulator. The voltage on this pin is monitored by internal step-ut controller to keep a minimum dropout across the linear pass transistor RX Output to the LNB in DiSEqC 2.0 application. See truth tables for voltage selections on page 8 and description on page 5. Bidirectional data from/to I2C bus. Clock from I2C bus. When the TEN bit of the System Register is LOW, this pin will accept the DiSEqC code from the main µcontroller. The LNBH21 will use this code to modulate the internally generated 22kHz carrier. Set to GND this pin if not used. 22kHz Tone Detector Input. Must be AC coupled to the DiSEcQ 2.0 bus. Open drain output of the tone Detector to the main µcontroller for DiSEcQ 2.0 data decoding. It is LOW when tone is detected. External Modulation Input acts on VOTX. Needs DC decoupling to the AC source. If not used, can be left open. Pins Connected to Ground. Needed for internal preregulator filtering Set high or floating for Iout