AudioMAX TM LX1720 SWITCHING CLASS-D, STEREO POWER AMPLIFIER CONTROLLER IC T H E I N F I N I T E P O W E R O F I P N N O VA T I O N R O D U C T I O N DESCRIPTION The LX1720 is a highly-integrated, Switching Class-D Stereo Power Amplifier Controller IC with power and size features that make it ideal for multimedia computer applications, as well as other applications where high fidelity sound is required. With input voltage ranging from 7V15V, the LX1720 is designed to operate over the full 20Hz to 20kHz audio range. Signal distortion measurements using industry standard 1kHz signal yields THD + noise levels < 1% (10 watts output). Its high efficiency (>92%) eliminates the need for heat sinks — even while delivering more than 10WRMS across 8 ohms per channel (20WRMS stereo) with 0.1 ohm SO-8 power FETs. The LX1720's output power is limited only by external FETs and available supply voltage. While offering breakthrough performance capabilities for notebooks, the LX1720 is equally attractive for multimedia systems or to drive full-size home theatre speakers. PRODUCT HIGHLIGHT OF THE CLASS-D AMPLFIER Efficiency (%) H E E T ■ Integrated Switching (Class-D) Stereo Power Amplifier Controller IC ■ Delivers >10WRMS Across 8Ω /Channel (20WRMS stereo) ■ Output Power Limited Only By External FETs And Available Supply Voltage ■ Will Drive A Wide Range Of Speakers ■ High Efficiency (>92%) ■ Due To High Efficiency, Power FETs Do Not Require Heatsinking ■ Audio Bandwidth Of 20Hz to 20kHz ■ Wide Input Voltage Range Of 7V-15V ■ Low Output Signal Distortion <1% ■ High Operating Frequency (350kHz) Helps To Reduce Output Filter Size ■ Compact Design Minimizes EMI / RFI Notebook Computers: ■ Replaces existing internal low power linear amplifier with a high efficiency Class-D amplifier ■ Enables the use of virtually any external speaker without amplification ■ Precious battery life is extended ■ Fully protected power topology can withstand shorts or external speaker failures without damage, overheating or posing fire hazard - Average Power Out for 20sec. approx. 512mW - Across 8.6 Ohm Load Linfinity's LX1720 Class-D Amplifier Desktop Computers: 60 ■ Output power capability of up to 20WRMS per channel in an area less than 3"x3", without using expensive heatsinks ■ Greatly reduced power supply requirements when compared to a linear solution of same power capabilities ■ Any speakers can be used including conventional home stereo speakers ■ Very light weight circuitry will not add to the overall weight of the system ■ Multimedia amplifier can be directly incorporated on the motherboard using surface mount components 40 Highly Integrated Linear Amplifier 20 0 S APPLICATIONS / BENEFITS 100 80 A T A K E Y F E AT U R E S IMPORTANT: For the most current data, consult LinFinity's web site: http://www.linfinity.com. E F F I C I E N C Y C O M PA R I S O N D 5 0 Audio sample from "Hold On Tight" by Electric Light Orchestra 10 15 20 APPLICATION NOTE AN-11 Seconds available on our web site or call 1-800-LMI-7011 PA C K A G E O R D E R I N F O TJ (°C) Maximum VDD 0 to 70 15V SSOP DB Plastic 44-pin LX1720-01CDB Note: Available in Tape & Reel. Append the letter "T" to part number. (i.e. LX1720-01CDBT) Copyright © 1999 Rev. 1.0 9/99 LINFINITY MICROELECTRONICS INC. 11861 WESTERN AVENUE, GARDEN GROVE, CA. 92841, 714-898-8121, FAX: 714-893-2570 1 PRODUCT DATABOOK 1996/1997 AudioMAX LX1720 SWITCHING CLASS-D, STEREO POWER AMPLIFIER CONTROLLER IC P R O D U C T I O N A B S O L U T E M A X I M U M R AT I N G S D A T A S H E E T PA C K A G E P I N O U T S (Note 1) Supply Voltage (PVDD, VDD) ...................................................................... -0.3V to 18V RPWM .................................................................................................... -0.3V to VCN+0.3V INPUT (R), INPUT (L) .......................................................................... -0.3V to VCN+0.3V FBK+(R), FBK-(R), FBK+(L), FBK-(L), SLEEP .............................................. -0.3V to VDD MUTE (R), MUTE (L) .................................................................................... -0.3V to 6.0V EAOUT (R), EAOUT (L) ....................................................................... -0.3V to VCN+0.3V CPWM, CT ............................................................................................. -0.3V to VCN+0.3V IS+, LIS-, RIS+ ................................................................................................ VDD-2 to VDD Operating Junction Temperature Plastic (DB Package) ............................................................................................ 125ºC Storage Temperature Range ...................................................................... -65°C to 150°C Lead Temperature (Soldering, 10 seconds) ............................................................ 300°C Note 1. Exceeding these ratings could cause damage to the device. All voltages are with respect to Ground. Currents are positive into, negative out of the specified terminal. T H E R M A L D ATA DB PACKAGE: THERMAL RESISTANCE-JUNCTION TO AMBIENT, θJA 65°C/W RISLISIS+ RPWM CPWM CN N.C. CT RT RBIAS GND AGND INPUT (R) INPUT (L) SLEEP EAIN (R) N.C. EAOUT (R) FAOUT (R) EAOUT (L) EAIN (L) FAOUT (L) 1 44 2 43 3 42 4 41 5 40 6 39 7 38 8 37 9 36 10 35 11 34 12 33 13 32 14 31 15 30 16 29 17 28 18 27 19 26 20 25 21 24 22 23 FBK- (R) FBK+ (R) N.C. VDD CP PVDD PGND P- (R) N- (R) N+ (R) P+ (R) P- (L) N- (L) N+ (L) P+ (L) PGND PVDD FBK- (L) FBK+ (L) GND MUTE (L) MUTE (R) DB PACKAGE (Top View) Junction Temperature Calculation: TJ = TA + (PD x θJA). The θJA numbers are guidelines for the thermal performance of the device/pc-board system. All of the above assume no ambient airflow. FUNCTIONAL PIN DESCRIPTION Pin Name Description Pin Name Description RIS- Right Channel Current Sense Input FAOUT (R) Output of Right Feedback Amp LIS- Left Channel Current Sense Input EAOUT (L) Left Channel Error Amplifier Output IS+ Positive Current Sense Input RPWM PWM Resistor Connection CPWM PWM Capacitor Connection CN Supply Decoupling for NFET Drivers CT Oscillator Timing Capacitor Connection RT Oscillator Timing Resistor RBIAS Bias Setting Resistor for Error Amps GND Ground (2-pins) FAOUT (L) FBK+(R), FBK-(R) CP Supply Decoupling for PFET Drivers Analog Supply Voltage P+(R), N+(R), INPUT (R) Right Channel Input P+(L), N+(L), INPUT (L) Left Channel Input EAIN (R) Right Channel Feedback Inputs VDD PGND P-(R), N-(R) EAOUT (R) Output of Left Feedback Amp Output Driver Supply Voltage (2-pins) Audio Input Ground Sleep Input Inverting Input of Left Channel Error Amp PVDD AGND SLEEP 2 EAIN (L) IC Power Ground for the Output Drivers (2-pins) Right Channel Gate Drive Outputs Left Channel Gate Drive Outputs P-(L), N-(L) FBK+(L), FBK-(L) Inverting Input of Right Channel Error Amp MUTE (R), Right Channel Error Amplifier Output MUTE (L) Left Channel Feedback Inputs Mute Inputs Copyright © 1999 Rev. 1.0 9/99 TM PRODUCT DATABOOK 1996/1997 AudioMAX TM LX1720 SWITCHING CLASS-D, STEREO POWER AMPLIFIER CONTROLLER IC P R O D U C T I O N D A T A S H E E T ELECTRICAL CHARACTERISTICS (Unless otherwise specified, the following specifications apply over the operating ambient temperature 0°C ≤ TA ≤ 70°C. Test conditions: RT = 30k, CT = 100pF, VDD = PVDD = 15V.) Parameter Symbol Test Conditions Min. LX1720 Typ. Max. Units Oscillator Section Oscillator Frequency Oscillator Peak Voltage Oscillator Valley Voltage Oscillator Max. Frequency Voltage Stability Temperature Stability 280 330 2.5 200 1 1 2 380 2 kHz V mV MHz % % Error Amplifiers Input Offset Voltage DC Open Loop Gain Unity Gain Bandwidth High Output Voltage Low Output Voltage Input Common Mode Range Input Bias Current 5 60 7 IOUT = -100µA IOUT = +100µA 4 50 5 1 1 mV dB MHz V mV V µA Input Amplifiers Stage Gain Input Impedance Set by Internal Resistors 3.465 3.5 42 3.535 V/V kΩ Feedback Amplifiers High Output Voltage Low Output Voltage Common Mode Rejection Input Common Mode Range Input Impedance Stage Gain LX1720-01 IOUT = -250µA IOUT = +250µA 4 50 70 0 Set by Internal Resistors 89 VDD 388 91 93 V mV dB V kΩ mV/V Current Limit Comparators Voltage Sense Threshold Comparator Response Time 200 220 500 240 mV nsec PWM Comparators CPWM Delay To Output 250 nsec RPWM = 75k 75 20 µA Ω ISINK = 3mA ISINK = 75mA ISOURCE = 3mA ISOURCE = 75mA, CN = 5.2V (applied externally) 30 1 30 1 100 1.5 100 1.5 mV V mV V ISINK = 3mA ISINK = 75mA ISOURCE = 3mA ISOURCE = 75mA, CP = 5.2V (applied externally) 30 1 30 1 100 1.5 100 1.5 mV V mV V PWM Current Generator CPWM Charge Current Impedance of Internal Discharge FET Output Drivers For The N-Channel MOSFETs Ext. NFET Drivers, Low Level Voltage VOL Ext. NFET Drivers, High Level Voltage VOH Output Drivers For The P-Channel MOSFETs Ext. PFET Drivers, Low Level Voltage VOL Ext. PFET Drivers, High Level Voltage VOH Copyright © 1999 Rev. 1.0 9/99 3 PRODUCT DATABOOK 1996/1997 AudioMAX LX1720 SWITCHING CLASS-D, STEREO POWER AMPLIFIER CONTROLLER IC P R O D U C T I O N D A T A S H E E T ELECTRICAL CHARACTERISTICS Parameter Symbol (Continued) Test Conditions Min. LX1720 Typ. Max. Units Undervoltage Lockout Section 6.3 Start Threshold Voltage UV Lockout Hysteresis UVLO Delay To Output Enable 6.5 500 976 6.7 V mV clkcyc Supply Current Sleep Current Operating Current Sleep To Output Enable Sleep Threshold 1.2 20 5 976 1.45 1.6 µA mA clkcyc V 1.6 1.7 1.8 V SLEEP Input = 0V, TA = 25°C SLEEP Input = 2V, VIN = 15V, No MOSFETs Connected 7 Mute Section Mute Threshold 4 Copyright © 1999 Rev. 1.0 9/99 TM PRODUCT DATABOOK 1996/1997 AudioMAX TM LX1720 SWITCHING CLASS-D, STEREO POWER AMPLIFIER CONTROLLER IC P R O D U C T I O N D A T A S H E E T BLOCK DIAGRAM R T O S C C T P G N D C L K P V D D S L E E P V R B IA S V D D U V L O V R E F B IA S C N E A IN (R ) N - (R ) S Q E rro r A m p Q R F B K - (R ) P + (R ) C L K F e e d b a c k A m p F A O U T (R ) O U T D R IV A N P R O T E C IR C U IN P U T (R ) M U T E (R ) C P P - (R ) E A O U T (R ) F B K + (R ) R E G In p u t A m p P U E R D C T IT T N + (R ) S IO N R Y P - (L ) V D D V D D N - (L ) C L K R P W M C P W M P + (L ) S E A O U T (L ) R Q E A IN (L ) E rro r A m p F B K + (L ) Q N + (L ) C L K F B K - (L ) M U T E (L ) L IS - IN P U T (L ) R IS - IS + F A O U T (L ) F e e d b a c k A m p In p u t A m p FIGURE 1 — LX1720 Block Diagram Copyright © 1999 Rev. 1.0 9/99 5 PRODUCT DATABOOK 1996/1997 AudioMAX LX1720 SWITCHING CLASS-D, STEREO POWER AMPLIFIER CONTROLLER IC P R O D U C T I O N D A T A S H E E T T Y P I C A L A P P L I C AT I O N V IN = 7 V T O 1 5 V R 6 R C 1 9 C 1 8 C C 1 7 5 1 6 IS + P V D D L IS - R IS Q 1 P - (R ) L L 1 2 V D D Q 3 Q 4 P + (R ) IN P U T (L ) N + (R ) S L E E P S L E E P R M U T E R M U T E L M U T E L M U T E C C 2 0 R 7 2 1 R C C R E A IN (R ) 6 N - (L ) E A IN L R 1 0 F A O U T (L ) F B K - (R ) F B K + (R ) F B K + (R ) F B K - (L ) F B K - (L ) F B K + (L ) F B K + (L ) C P W M F B K - (R ) Q 7 Q 8 P + (L ) (L ) N + (L ) C 4 C 6 C 8 4 3 1 0 L 5 C 3 6 5 F B K -(L ) C E A O U T (L ) C F B K + (R ) 2 2 9 L 3 2 F A O U T (R ) R 2 3 Q E A O U T (R ) 8 R 5 2 9 L Q P - (L ) C 1 F B K -(R ) C 1 1 L 7 R 4 C F B K + (L ) L 8 C 7 1 2 A G N D P G N D L E F T IN IN P U T (R ) G N D 2 5 T C 1 C L X 1 7 2 0 C R R T R C N 2 4 2 R P W M C T C R IG H T IN Q N - (R ) C P P W M R IG H T P R L E F T C For detailed application information please refer to N T C C C P W M APPLICATION NOTE AN-11 available on our web site or call 1-800-LMI-7011 FIGURE 2 — Typical Class-D Stereo Switching Amplifier Circuit Application PRODUCTION DATA - Information contained in this document is proprietary to LinFinity, and is current as of publication date. This document may not be modified in any way without the express written consent of LinFinity. Product processing does not necessarily include testing of all parameters. Linfinity reserves the right to change the configuration and performance of the product and to discontinue product at any time. 6 Copyright © 1999 Rev. 1.0 9/99 TM