ZXCD1000EQ16TA ZETEX | Alldatasheet

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Technical content

DESCRIPTION

The ZXCD1000 provides complete control and modulation functions at the heart of a high efficiency high performance Class D switching audio amplifier solution. In combination with Zetex HDMOS MOSFET devices, the ZXCD1000 provides a high performance audio amplifier with all the inherent benefits of Class D. The ZXCD1000 solution uses proprietary circuit design to realise the true benefits of Class D without the traditional drawback of poor distortion performance. The combination of circuit design, magnetic component choice and layout are essential to realising these benefits.

FEATURES

  • >90% efficiency
  • 4 / 8 Ω drive capability
  • Noise Floor -115dB for solution
  • Flat response 20Hz - 20kHz
  • High gate drive capability ( 2200pF)
  • Very low THD + N 0.2% typical full 90% power, full band ( for the solution)
  • Complete absence of crossover artifacts
  • OSC output available for sync in multi-channel

applications

  • Available in a 16 pin exposed pad QSOP package
  • DVD Players
  • Automotive audio systems
  • Home Theatre
  • Multimedia
  • Wireless speakers
  • Portable audio
  • Sub woofer systems
  • Public Address system The ZXCD1000 reference designs give output powers up to 100W rms with typical open loop (no feedback) distortion of less than 0.2% TH D + N over the entire audio frequency range at 90% full output power. This gives an extremely linear system. The addition of a minimum amount of feedback (10dB) further reduces distortion figures to give < 0.1 % THD + N typical at 1kHz. From an acoustic point of view, even more important than the figures above, is that the residual distortion is almost totally free of any crossover artifacts. This allows the ZXCD1000 to be used in true hi-fi applications. This lack of crossover distortion, sets the ZXCD1000 solutions quite apart from most other presently available low cost solutions, which in general suffer from severe crossover distortion problems. ZXCD1000 ISSUE 2 - APRIL 2002 HIGH FIDELITY CLASS D AUDIO AMPLIFIER SOLUTION Output Power 10W THD + N (%) Distortion v Power 8Ω open loop at 1kHz. The plot shows Distortion v Power into an 8 Ω load at 1kHz. This plot clearly demonstrates the unequalled performance of the Zetex solution. Typical distortion of 0.05% at 1W can be seen with better than 0.15% at 10W. Truly world class performance.

Terminal Voltage with respect to GND VCC 20V Power Dissipation 1W Package Thermal Resistance (/H9052ja)5 4 /H11034C/W Operating Temperature Range -40 /H11034C to 70/H11034C Maximum Junction Temperature 125 /H11034C Storage Temperature Range -50°C to 85 /H11034C Stresses beyond those listed under “Absolute Maximum Ratings” may cause permanent damage to the device. These are stress ratings only, and functional operation of the device at these or any other conditions beyond those indicated in the operational sections of the specifications is not implied. Exposure to absolute maximum conditions for extended periods may affect device reliability. ZXCD1000 SYMBOL PARAMETER CONDITIONS LIMITS UNITS MIN TYP MAX VCC Operating Voltage Range 12 16 18 V Iss Operating Quiescent Current VCC = 12V VCC = 18V, 16V mA mA Fosc Switching Frequency Cosc = 330pF 150 200 250 kHz Fosc(tol) Frequency Tolerance Cosc = 330pF +/-25 % Vol OutA/B Low level output voltage No load 100 mV Voh OutA/B High level output voltage No load 7.5 V TDrive Output Drive Capability ( O U TA/BR ise/Fall) Load Capacitance = 2200pF 50 ns 5V5tol Internal Rail Tolerance 1µF Decoupling 5.23 5.5 5.77 V 9VA/Btol Internal Rail Tolerance 1µF Decoupling 8.32 8.75 9.18 V Audio A / B Input Impedence 1.35k 1.8k 2.3k /H9024 Triangle A/B Input Impedence 1.35k 1.8k 2.3k /H9024 Audio A / B Bias Level 2.95 3.1 3.25 V Triangle A/B Bias Level 2.95 3.1 3.25 V Osc A / B Amplitude 0.89 1.05 1.2 V

ELECTRICAL CHARACTERISTICS

TEST CONDITIONS (unless otherwise stated) VCC = 16V, TA = 25/H11034C

Pin number Pin Name Pin Description

1 Audio A Audio Input for Channel A

2 Triangle A Triangle Input for Channel A

3 Osc A Triangle Output

4 Dist No connection

osc External timing capacitor node (to set the switching frequency)

6 Osc B Triangle Output (for slave ZXCD1000 in stereo application)

7 Triangle B Triangle Input for Channel B

8 Audio B Audio Input for Channel B

9 Gnd Small Signal GND

10 OUT B Channel B PWM Output to drive external Bridge MOSFETs

11 Gnd2 Power GND (for Output Drivers)

12 9VB Internal Supply Rail (Decouple with 1µF Cap)

13 VCC Input Supply Pin (Max = 18V)

14 9VA Internal Supply Rail (Decouple with 1µF Cap).

15 OUT A Channel A PWM Output to drive external Bridge MOSFETs

16 5V5 Internal Supply Rail (Decouple with 1µF Cap) Pin Description

ZXCD1000 Class D controller IC A functional block diagram of the ZXCD1000 is shown in Figure 2. The on chip series regulators drop the external VCC supply (12V-18V) to the approximate 9V (9VA/9VB) and 5.5V (5V5) supplies required by the internal circuitry. A triangular waveform is generated on chip and is brought out at the OscA and OscB outputs. The frequency of this is set (to ~200kHz) by an external capacitor (Cosc) and on chip resistor. The triangular waveform must be externally AC coupled back into the ZXCD1000 at the TriangleA and TriangleB inputs. AC coupling ensures symmetrical operation resulting in minimal system DC offsets. TriangleA is connected to one of the inputs of a comparator and TriangleB is connected to one of the inputs of a second comparator. The other inputs of these two comparators are connected to the AudioA and AudioB inputs, which are anti-phase signals externally derived from the audio input. The triangular wave is an order higher in frequency than the audio input (max 20kHz). The outputs of the comparators toggle every time the TriangleA/B and the (relatively slow) AudioA/B signals cross. ZXCD1000 Oscillator & Ramp Generator Internal 5V5 Internal 9V PWMComp A PWM Comp B Pre- Driver Pre- Driver O/P Driver O/P Driver Audio A Audio B VCC Cosc Out A Out B 5V5 9VB 9VA Triangle B Triangle A Osc B Osc A Dist Gnd Gnd2 2345 6 7 1112 Osc Buffers Figure 2. Functional Block Diagram

Zetex Class D 25W Mono Open Loop Solution

Other Solutions - Stereo, Closed Loop and Higher Powers. STEREO It is possible to duplicate the above solution to give a 2 channel stereo solution. However if the oscillator frequencies are not locked together, a beat can occur which is acoustically audible. This is undesirable. A stereo solution which avoids this problem can be achieved by synchronising the operating frequencies of both ZXCD1000’s class D controller IC’s, by slaving one device from the other. This is illustrated in Figure 8. Great care must be taken when linking the triangle from the master to the slave. Any pickup can cause slicing errors and result in increased distortion. The best connection method is to run two tracks, side by side, from the master to the slave. One of these tracks would be the triangle itself, and the other would be the direct local ground linking the master pin9 ground to the slave pin 9 ground. A demonstration board, ZXCD1000EVSOL, is available for a stereo 25W solution. ZXCD1000 ISSUE 2 - APRIL 2002 MASTER SLAVE Figure 8 Frequency synchronisation for stereo applications

50W Master Channel with feed back

100W Mono Class D Solution

ZXCD1000 Solution performance figures Typical performance graphs for the Zetex 25W open loop solution are shown here for both 4 and 8Ω loads. These graphs further demonstrate the true high fidelity performance achieved by the Zetex solutions. ZXCD1000 ISSUE 2 - APRIL 2002 Output Power 10W THD + N (%) f(Hz) dB f(Hz) dB f(Hz) dB THD v Power into 8 at 1kHz FFT of distortion and noise floor at 1W (8 load) FFT of distortion and noise floor at 10W (8 load)Frequency response (8 load)

THD + N (%) dB f(Hz) f(Hz) dB f(Hz) dB FFT of distortion and noise floor at 20W (4 load)Frequency response (4 load) Note roll off. This can be corrected by using an alternative values for output filter components. THD v Power into 4 at 1kHz FFT of distortion and noise floor at 1W (4 load)

Oldham, OL9 8NP United Kingdom Telephone (44) 161 622 4422 Fax: (44) 161 622 4420 Zetex GmbH Streitfeldstraße1 9 D-81673 München Germany Telefon: (49) 89 45 49 49 0 Fax: (49) 89 45 49 49 49 Zetex Inc

700 Veterans Memorial Hwy

Hauppauge, NY11788 USA Telephone: (631) 360 2222 Fax: (631) 360 8222 Zetex (Asia) Ltd 3701-04 Metroplaza, Tower 1 Hing Fong Road Kwai Fong Hong Kong Telephone: (852) 26100 611 Fax: (852) 24250 494 These offices are supported by agents and distributors in major countries world-wide. This publication is issued to provide outline information only which (unless agreed by the Company in writing) may not be used, applied or reproduced for any purpose or form part of any order or contract or be regarded as a representation relating to the products or services concerned. The Company reserves the right to alter without notice the specification, design, price or conditions of supply of any product or service. For the latest product information, log on to www.zetex.com © Zetex plc 2001 ZXCD1000 ISSUE 2 - APRIL 2002 DETAIL "A" D A e OCC L h x 45 C b A1 SEATING PLANE 132 H TOP VIEW SIDE VIEW END VIEW S .010 BOTTOM VIEW E SEE DETAIL "A" SEATING PLANE EXPOSED PAD PACKAGE DIMENSIONS MIN. .001 .058 .055 E D A O L B M S Y .003 .058 .005 .061 DIMENSIONS IN INCHES NOM. .061 MAX. .066 .008b .012 .007c .010 .150 .154 .157 .194.189 .196 .005 .002 OCC S .007 .236 .025 BSC .013 .025 .228 e h L H .016 .010 .244 .035 .016 Device Description Package T&R Suffix ZXCD1000EQ16 Class D modulator eQSOP16 TA, TC

ORDERING INFORMATION

Information on Zetex reference designs, MOSFETs and demonstration boards can be obtain by contacting Zetex applications or by visiting www.zetex.com/audio