1. Zetex Switching Audio Amplifiers

2. ZX Series Class D amplifiers
ZXCD1000: Analog input class D amplifier
Best in class sound performance
Used in applications from 25W to 100W
Applications range from DVD-Receiver to sound reinforcement amplifier

3. ZXCD1000 Analog input Class D amplifier controller

4. The ZXCD1000 modulator device
Mono BTL output drive
Stereo Single-ended drive
Precision triangle generator
PWM comparators
QSOP16 package

5. ZXCD1000: Performance Exceptional open loop linearity
Very high efficiency
Low noise
Excellent frequency response
No high order crossover artifacts
Closed loop solutions possible

6. ZXCD1000: Performance (open loop)
1W 0.05%
90% power 0.2%
Noise floor -115dB
Frequency response flat 20Hz to 20kHz
Output power 25W to 200W
Efficiency >90%
Anti-pop Yes
Mute Yes
Protection Yes

7. Performance : Distortion
Exceptional linearity
THD+N<0.2% open loop
THD+N<0.05% closed loop (10dB feedback)

8. Performance: Efficiency
Greater than 90% efficient
Maximum efficiency over full output power range
Smaller power supply
Smaller solution & less heat
0.00
10.00
20.00
30.00
40.00
50.00
60.00
70.00
80.00
90.00
100.00
5.00
15.00
25.00
Output Power (W)
Efficiency (%)
Zetex Class D Solution Efficiency
Typ Class A-B Efficiency

9. Performance: Noise floor
Noise floor at -115dB
FFT shows flat noise floor
Only clock harmonics visible at -80dB
Most linear amps only achieve -90dB
-130
-20
-125
-120
-115
-110
-105
-100
-95
-90
-85
-80
-75
-70
-65
-60
-55
-50
-45
-40
-35
-30
-25 dB 2k
20k 4k 6k 8k
10k
12k
14k
16k
18k
Frequency Hz

10. Performance: Frequency response
Flat response from 20Hz to 22KHz

11. Zetex Class-D Amplifier Design Requirement
Zetex’s Class-D Designs for 25W ~100W Output
Analog Audio Input (L / R)
ZXCD1000
ZXCD1000
Full protection features included.
MCU software control free! (Plug & Play!).
High design flexibility for different power requirement.
Enhancement of sound quality.
Low signal conversion loss (Analog  PWM only)

12. Competitor’s Digital Class-D Designs
PCM
Analog Audio Input (L / R)
A-D Converter
PCM to PWM DSP
PWM
MCU
Required MCU software control.
Limited protection features and design flexibility due using fixed power stage.
Fixed sound quality.
High signal conversion loss (Analog  PCM  PWM) that lead lower S/N ration
and higher THD+N

13. Zetex Class D THD+N Vs Competitor’s….
Apoxxx/ T.X. Digital Amp. - 1
0.1
0.2
0.3
0.4
0.5
0.6
0.7
0.8
0.9 % 2
100 5 10 20 50 W -0
0.2
0.4
0.6
0.8 1
1.2
1.4
1.6
1.8 %
100m
200
200m
500m 2 5 10 20 50
100 W
DX Audxxx ($50 Module)
Zetex
Clear advantage of Zetex solution
Excellent performance with difficult speaker loads

14. Zetex Class D Frequency response Vs Competitors….
Apoxxx / T.X. Digital - 5 +1
4.5 4
3.5 3
2.5 2
1.5 1
0.5
+0.5 d B r 20
40k 50
100
200
500 1k 2k 5k
10k
20k Hz -4 +1
-3.5 -3
-2.5 -2
-1.5 -1
-0.5 +0
+0.5 d B r A 20
20k 50
100
200
500 1k 2k 5k
10k Hz
DX Axxio ($50 module)
Zetex
Zetex -3dB point extended by 22kHz
Compatibility with emerging standards

15. ZXCD1000: Reference designs
Reference designs are key to success
Circuit designs are available
Full bill of materials available
Layout (Gerber) files available
Demonstration boards available
Current reference designs
25W solution (mono)
25W solution (stereo)
50W solution (stereo)
50W solution (5.1)
100W (mono)