CS35L01/03 Product Datasheet

CS35L01/03
3.0 W Mono Class-D Audio Amplifier with Low Idle Current
CS35L01 and CS35L03 Features
General Description
 Filterless Hybrid Class-D Architecture
The CS35L01 and the CS35L03 are 3.0W high efficiency Hybrid Class-D audio amplifiers with low idle current
consumption.




– <1 mA Quiescent Current
– 1 x 3.0 W into 4  (10% THD+N)
– 1 x 2.4 W into 4  (1% THD+N)
– 1 x 1.7 W into 8  (10% THD+N)
– 1 x 1.4 W into 8  (1% THD+N)
Advanced  Closed-loop Modulation
– 98 dB Signal-to-Noise Ratio (A-Weighted)
– 0.02% THD+N @ 1 W (SD & HD Mode)
Integrated Protection and Automatic Recovery
for Output Short-circuit and Thermal Overload
Pin-compatible 9-ball WLCSP family for easy
upgrade path
– CS35L01: +6 dB default Gain
– CS35L03: +12 dB default Gain
Pop and Click Suppression
Common Applications
 Mobile Phones
 Laptops/Netbooks/Tablets
The CS35L01/03 features an advanced closed-loop architecture to provide 0.02% THD+N at 1 W and -87 dB
PSRR at 217 Hz.
A flexible Hybrid Class-D output stage offers four
modes of operation: Standard Class-D (SD) mode offers full audio bandwidth and high audio performance;
Hybrid Class-D (HD) mode offers a substantial reduction in idle power consumption with an integrated ClassH controller; Reduced Frequency Class-D (FSD) mode
reduces the output switching frequency, producing lower electromagnetic interference (EMI); and Reduced
Frequency Hybrid Class-D (FHD) mode produces both
the lower idle power consumption of HD mode and the
reduced EMI benefits of FSD mode.
Requiring minimal external components and PCB
space, the CS35L01 and CS35L03 are available in a
1.2 mm x 1.2 mm, 9-ball WLCSP package in Commercial grade (-10°C to +70°C). Please see “Ordering
Information” on page 33 for package options and gain
configurations.
 Portable Navigation Devices
 Active Speakers
 Portable Gaming
MODE
LDO Filter
Class-H
Controller
VBATT
2.5V - 5V
Low Drop-Out
Voltage Regulator
Shutdown
Gate Drivers
Audio In +
Gain
Advanced ΔΣ
Modulator
Speaker Out +
Speaker Out Gate Drivers
Audio In -
Gain
Internal
Oscillator
Short Circuit/Thermal
Protection
GND
http://www.cirrus.com
Copyright  Cirrus Logic, Inc. 2011
(All Rights Reserved)
JULY '11
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TABLE OF CONTENTS
1. BALL DESCRIPTIONS FOR CS35L01 & CS35L03 .............................................................................. 5
2. DIGITAL BALL CONFIGURATIONS ..................................................................................................... 6
3. TYPICAL CONNECTION DIAGRAMS ................................................................................................... 7
4. CHARACTERISTICS & SPECIFICATIONS ........................................................................................... 8
5. APPLICATIONS ................................................................................................................................... 15
5.1 MODE Descriptions ....................................................................................................................... 15
5.2 Reducing the Gain with External Series Resistors ........................................................................ 16
5.3 Output Filtering with the CS35L01/03 ............................................................................................ 17
5.4 Power-Up and Power-Down .......................................................................................................... 19
5.5 Over Temperature Protection ........................................................................................................ 20
6. TYPICAL PERFORMANCE PLOTS ..................................................................................................... 21
6.1 SD Mode Typical Performance Plots ............................................................................................. 21
6.2 FSD Mode Typical Performance Plots ........................................................................................... 23
6.3 HD Mode Typical Performance Plots ............................................................................................. 25
6.4 FHD Mode Typical Performance Plots ........................................................................................... 27
7. PARAMETER DEFINITIONS ................................................................................................................ 29
8. PACKAGING AND THERMAL INFORMATION .................................................................................. 30
8.1 Package Drawings and Dimensions (Note 20) .............................................................................. 30
8.2 Recommend PCB Footprint and Routing Configuration ................................................................ 31
8.3 Package Thermal Performance ..................................................................................................... 31
9. ORDERING INFORMATION ................................................................................................................ 33
10. REVISION HISTORY .......................................................................................................................... 33
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LIST OF FIGURES
Figure 1. Top View of WLCSP Pinout (Looking down through die) . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 5
Figure 2. Typical Connection Diagram for SD & FSD Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Figure 3. Typical Connection Diagram for HD & FHD Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
Figure 4. Adjusting Gain via External Series Resistance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
Figure 5. Optional Output Filter Components . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
Figure 6. Power-Up Timing with Input Zero-Crossing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Figure 7. Power Up Timing without Input Zero-Crossing . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 19
Figure 8. THD+N vs. Output Power - SD Mode RL = 8 W . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Figure 9. THD+N vs. Output Power - SD Mode RL = 4 W . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Figure 10. THD+N vs. Frequency - SD Mode VBATT = 5.0 V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Figure 11. THD+N vs. Frequency - SD Mode VBATT = 4.2 V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Figure 12. THD+N vs. Frequency - SD Mode VBATT = 3.7 V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Figure 13. Frequency Response - SD Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
Figure 14. Idle Current Draw vs. VBATT - SD Mode RL = 8 W + 33 mH (Note 16) . . . . . . . . . . . . . . . . . . . . . . . 22
Figure 15. Output Power vs. VBATT - SD Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Figure 16. Efficiency vs. Output Power - SD Mode RL = 8 W + 33 mH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Figure 17. Efficiency vs. Output Power - SD Mode RL = 4 W + 33 mH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Figure 18. Supply Current vs. Output Power - SD Mode RL = 8 W + 33 mH . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Figure 19. Supply Current vs. Output Power - SD Mode RL = 4 W + 33 mH . . . . . . . . . . . . . . . . . . . . . . . . . . . . 22
Figure 20. THD+N vs. Output Power - FSD Mode RL = 8 W . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Figure 21. THD+N vs. Output Power - FSD Mode RL = 4 W . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Figure 22. THD+N vs. Frequency - FSD Mode VBATT = 5.0 V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Figure 23. THD+N vs. Frequency - FSD Mode VBATT = 4.2 V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Figure 24. THD+N vs. Frequency - FSD Mode VBATT = 3.7 V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Figure 25. Frequency Response - FSD Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 23
Figure 26. Idle Current Draw vs. VBATT - FSD Mode RL = 8 W + 33 mH (Note 17) . . . . . . . . . . . . . . . . . . . . . . 24
Figure 27. Output Power vs. VBATT - FSD Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Figure 28. Efficiency vs. Output Power - FSD Mode RL = 8 W + 33 mH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Figure 29. Efficiency vs. Output Power - FSD Mode RL = 4 W + 33 mH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Figure 30. Supply Current vs. Output Power - FSD Mode RL = 8 W + 33 mH . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Figure 31. Supply Current vs. Output Power - FSD Mode RL = 4 W + 33 mH . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
Figure 32. THD+N vs. Output Power - HD Mode RL = 8 W . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Figure 33. THD+N vs. Output Power - HD Mode RL = 4 W . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Figure 34. THD+N vs. Frequency - HD Mode VBATT = 5.0 V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Figure 35. THD+N vs. Frequency - HD Mode VBATT = 4.2 V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Figure 36. THD+N vs. Frequency - HD Mode VBATT = 3.7 V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Figure 37. Frequency Response- HD Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 25
Figure 38. Idle Current Draw vs. VBATT - HD Mode RL = 8 W + 33 mH (Note 18) . . . . . . . . . . . . . . . . . . . . . . . 26
Figure 39. Output Power vs. VBATT - HD Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Figure 40. Efficiency vs. Output Power - HD Mode RL = 8 W + 33 mH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Figure 41. Efficiency vs. Output Power - HD Mode RL = 4 W + 33 mH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Figure 42. Supply Current vs. Output Power - HD Mode RL = 8 W + 33 mH . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Figure 43. Supply Current vs. Output Power - HD Mode RL = 4 W + 33 mH . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
Figure 44. THD+N vs. Output Power - FHD Mode RL = 8 W . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Figure 45. THD+N vs. Output Power - FHD Mode RL = 4 W . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Figure 46. THD+N vs. Frequency - FHD Mode VBATT = 5.0 V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Figure 47. THD+N vs. Frequency - FHD Mode VBATT = 4.2 V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Figure 48. THD+N vs. Frequency - FHD Mode VBATT = 3.7 V . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Figure 49. Frequency Response - FHD Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
Figure 50. Idle Current Draw vs. VBATT - FHD Mode RL = 8 W + 33 mH (Note 19) . . . . . . . . . . . . . . . . . . . . . . 28
Figure 51. Output Power vs. VBATT - FHD Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Figure 52. Efficiency vs. Output Power - FHD Mode RL = 8 W + 33 mH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
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CS35L01/03
Figure 53. Efficiency vs. Output Power - FHD Mode RL = 4 W + 33 mH . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Figure 54. Supply Current vs. Output Power - FHD Mode RL = 8 W + 33 mH . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Figure 55. Supply Current vs. Output Power - FHD Mode RL = 4 W + 33 mH . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
LIST OF TABLES
Table 1. LFILT+ and MODE Operation Configurations . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15
Table 2. JA Specification for Typical PCB Designs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31
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1. BALL DESCRIPTIONS FOR CS35L01 & CS35L03
A1
IN+
B1
A2
MODE
B2
LFILT +
VBATT
C1
C2
IN-
SD
A3
OUT-
B3
GND
C3
OUT+
Figure 1. Top View of WLCSP Pinout
(Looking down through die)
Ball Name
#
Description
IN+
A1
Positive Analog Input (Input) - Differential positive audio signal input.
MODE
A2
Switching Mode (Input) - Controls the output switching modes of the CS35L01/03.
OUT-
A3
Negative PWM Output (Output) - Differential negative PWM output.
LFILT+
B1
Low Drop Out Regulator Filter (Output) - Bypass capacitor connection point for internal LDO. Connecting this net to VBATT places the device into SD mode.
VBATT
B2
Positive Analog Power Supply (Input) - Positive power supply input.
GND
B3
Ground (Input) - Power supply ground.
IN-
C1
Negative Analog Input (Input) - Differential negative audio signal input.
SD
C2
Shutdown (Input) - Pulling this net low places the CS35L01/03 in shutdown.
OUT+
C3
Positive PWM Output (Output) - Differential Positive PWM output.
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CS35L01/03
2. DIGITAL BALL CONFIGURATIONS
See (Note 1) and (Note 2) below the table.
Power Supply
VBATT
I/O Name
Ball
Direction
Internal Connections
Configuration
SD
C2
Input
No Internal Pull Up
Hysteresis on CMOS Input
MODE
A2
Input
No Internal Pull Up
Hysteresis on CMOS Input
Note:
1. Refer to specification table “Digital Interface Specifications and Characteristics” on page 14 for details
on the digital I/O characteristics.
2. I/O voltage levels must not exceed the voltage listed in table “Absolute Maximum Ratings” on page 8.
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3. TYPICAL CONNECTION DIAGRAMS
2.5V - 5V
0.1uF
System
Controller
LFILT+
10uF
VBATT
MODE
SD
Audio In+
AIN+
Audio In-
AIN+
OUT+
OUT-
GND
Figure 2. Typical Connection Diagram for SD & FSD Mode
2.5V - 5V
(Note 3)
1uF
System
Controller
10uF
LFILT+
0.1uF
VBATT
MODE
SD
Audio In+
AIN+
Audio In-
AIN+
OUT+
OUT-
GND
Figure 3. Typical Connection Diagram for HD & FHD Mode
Note:
3. The value of the capacitance connected to the LFILT+ net should not exceed 4.7 F. Presence of a
capacitance above 4.7 F will prevent proper HD and FHD operation.
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4. CHARACTERISTICS & SPECIFICATIONS
Test Conditions (unless otherwise specified): GND = 0 V; All voltages with respect to ground; Input signal = 997 Hz
differential sine wave; TA = 25°C; VBATT = 5.0 V; RL = 8 ; 22 Hz to 20 kHz measurement bandwidth; Measurements taken with AES17 measurement filter and Audio Precision AUX-0025 passive filter.
RECOMMENDED OPERATING CONDITIONS
GND = 0 V; All voltages with respect to ground. Please see (Note 4).
Parameters
Symbol
Min
Typ
Max
Units
VBATT
2.5
5.0
5.5
V
Ambient Temperature
TA
-10
-
+70
°C
Junction Temperature
TJ
-10
-
+150
°C
DC Power Supply
Supply Voltage
Temperature
ABSOLUTE MAXIMUM RATINGS
GND = 0 V; All voltages with respect to ground.
Parameters
Symbol
Min
Max
Units
VBATT
IVDREG
-0.3
-
6.0
10
A
Iin
-
±10
mA
TA
Tstg
-20
-65
+125
+150
°C
°C
DC Power Supply
Supply Voltage
LFILT+ Current
(Note 5)
V
Inputs
Input Current
Temperature
Ambient Operating Temperature (power applied)
Storage Temperature
WARNING: Operation at or beyond these limits may result in permanent damage to the device.
Notes:
4. Functionality is not guaranteed or implied outside of these limits. Operation outside of these limits may
adversely affect device reliability.
5. No external loads should be connected to the LFILT+ net. Any connection of a load to this point may
result in errant operation or performance degradation in the device.
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CS35L01/03
ELECTRICAL CHARACTERISTICS - ALL OPERATIONAL MODES
Parameters
Min
Typ
ILFILT+
-
10
-
A
ZLFILT+
-
0.7
-

VBLIM
-
3.0
-
VDC
CS35L03
CS35L01
-
0.015•VBATT
0.029•VBATT
-
Vrms
Vrms
Input Level for Entering VBATT Operation in
CS35L03
V
HD/FHD Modes
(Note 9) IN-VBATT CS35L01
-
0.09
0.19
-
Vrms
Vrms
Max. Current from LFILT+
Symbol
(Note 6)
LFILT+ Output Impedance
VBATT Limit for HD/FHD Mode
(Note 7)
Input Level for Entering LDO Operation in
HD/FHD Modes
(Note 8)
VIN-LDO
Test Conditions
Max Units
LDO Entry Time Delay
tLDO
-
1200
-
ms
LDO Level for HD/FHD Modes
VLDO
-
1.0
-
V
-
+/-1.5
-
mV
VOFFSET Inputs AC coupled to GND
Output Offset Voltage
Amplifier Gain
Shutdown Supply Current
AV
CS35L03
CS35L01
-
12
6
-
dB
dB
IA(SD)
SD = Low
-
0.05
-
A
-
270
-
m
RDS(ON) Ibias = 0.5 A
MOSFET On Resistance
Thermal Error Threshold
(Note 10)
TTE
-
150
-
C
Thermal Error Retry Time
(Note 10)
RTE
-
100
-
ms
Under Voltage Lockout Threshold
(Note 11)
UVLO
-
2.0
-
V
VBATT = 5 VDC
-
92
-
%
VBATT = 3.7 VDC
-
91
-
%
VBATT = 5 VDC
-
87
-
%
VBATT = 3.7 VDC
-
86
-
%
Operating Efficiency

4 + 33H 8 + 33H
Load
Load
Output Levels at 10% THD+N
Note:
6. No external loads should be connected to the LFILT+ net. Any connection of a load to this point may
result in errant operation or performance degradation in the device.
7. When VBATT is below this threshold (VBLIM), operation is automatically restricted to SD mode.
8. When operating in HD or FHD mode and the differential input voltage remains below the input level
threshold (VIN-LDO) for a period of time (tLDO), the PWM outputs will be powered by the internally
generated LDO supply (VLDO).
9. When operating in HD or FHD mode and the differential input voltage is above this input level
threshold (VIN-VBATT), the PWM outputs will be powered directly from the VBATT supply.
10. Refer to Section 5.5 for more information on Thermal Error functionality.
11. Under Voltage Lockout is the threshold at which a decreasing VBATT supply will disable device
operation.
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CS35L01/03
ELECTRICAL CHARACTERISTICS - SD MODE
Parameters
Symbol
Output Power
(Continuous Average)
PO
Test Conditions
Min
Typ
Max Units
THD+N = 1%
RL = 8  (VBATT = 5.0/4.2/3.7 VDC)
RL = 4 (VBATT = 5.0/4.2/3.7 VDC)
-
1.39/0.98/0.76
2.41/1.69/1.30
-
W
W
THD+N = 10%
RL = 8  (VBATT = 5.0/4.2/3.7 VDC)
RL = 4 (VBATT = 5.0/4.2/3.7 VDC)
-
1.73/1.23/0.95
3.03/2.12/1.64
-
W
-
0.02
-
%
W
Total Harmonic Distortion + Noise
THD+N PO = 1.0 W
Power Supply Rejection Ratio
PSRR
Vripple = 200 mVPP, AINx AC coupled to GND
@ 217 Hz
@ 1 kHz
-
87
82
-
dB
dB
Common-Mode Rejection Ratio
CMRR
Vripple = 1 VPP, fripple = 217 Hz
-
73
-
dB
-
96
97
-
dB
dB
-
54
49
-
Vrms
Vrms
-
110
100
-
Vrms
Vrms
-0.1
0
0.4
dB
Signal to Noise Ratio
A-Weighted
SNRA
Inputs AC Coupled to Ground,
Referenced to 1% THD+N
(Note 13)
CS35L03
CS35L01
AIN+ connected to AIN-
Idle Channel Noise
A-Weighted
ICNA
CS35L03
CS35L01
AIN+ connected to AIN-
Idle Channel Noise
ICN
CS35L03
CS35L01
Frequency Response
FR
20 Hz to 20 kHz
Total Group Delay
GD
-
6
-
s
Output Switching Frequency
fsw1
-
192
-
kHz
AIN+ connected to AIN-, No Output Load
VBATT = 5.0 VDC
VBATT = 4.2 VDC
VBATT = 3.7 VDC
-
1.40
1.28
1.21
-
mA
mA
mA
CS35L03
CS35L01
-
65
100
-
k
k
RL = 8  (VBATT = 5.0/4.2/3.7 VDC)
CS35L03
CS35L01
-
0.85/0.72/0.63
1.71/1.44/1.26
-
Vrms
Vrms
Idle Current Draw
(Note 12)
Input Impedance, Single Ended
Input Voltage @ 1 % THD+N
10
IIDLE
ZIN
VICLIP
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ELECTRICAL CHARACTERISTICS - FSD MODE
Parameters
Symbol
Output Power
(Continuous Average)
PO
Test Conditions
Min
Typ
THD+N = 1%
RL = 8  (VBATT = 5.0/4.2/3.7 VDC)
RL = 4 (VBATT = 5.0/4.2/3.7 VDC)
-
1.32/0.94/0.72
2.30/1.62/1.24
-
W
W
THD+N = 10%
RL = 8  (VBATT = 5.0/4.2/3.7 VDC)
RL = 4 (VBATT = 5.0/4.2/3.7 VDC)
-
1.70/1.21/0.94
2.94/2.08/1.61
-
W
-
0.10
-
%
Total Harmonic Distortion + Noise THD+N PO = 1.0 W
Max Units
W
Power Supply Rejection Ratio
PSRR
Vripple = 200 mVPP, AINx AC coupled to GND
@ 217 Hz
@ 1 kHz
-
88
81
-
dB
dB
Common-Mode Rejection Ratio
CMRR
Vripple = 1 VPP, fripple = 217 Hz
-
71
-
dB
-
80
80
-
dB
dB
-
300
290
-
Vrms
Vrms
-
570
550
-
Vrms
Vrms
-4.0
0
0.5
dB
Signal to Noise Ratio
A-Weighted
SNRA
Inputs AC Coupled to Ground,
Referenced to 1% THD+N
(Note 13)
CS35L03
CS35L01
AIN+ connected to AIN-
Idle Channel Noise
A-Weighted
ICNA
CS35L03
CS35L01
AIN+ connected to AIN-
Idle Channel Noise
ICN
CS35L03
CS35L01
Frequency Response
FR
20 Hz to 20 kHz
Total Group Delay
GD
-
14
-
s
Output Switching Frequency
fsw2
-
76
-
kHz
AIN+ connected AIN-, No Output Load
VBATT = 5.0 VDC
VBATT = 4.2 VDC
VBATT = 3.7 VDC
-
1.04
0.98
0.95
-
mA
mA
mA
CS35L03
CS35L01
-
160
240
-
k
k
RL = 8  (VBATT = 5.0/4.2/3.7 VDC)
CS35L03
CS35L01
-
0.83/0.70/0.61
1.66/1.39/1.22
-
Vrms
Vrms
Idle Current Draw
(Note 12)
Input Impedance, Single Ended
Input Voltage @ 1 % THD+N
IIDLE
ZIN
VICLIP
Note:
12. Idle Current Draw (IIDLE) is specified without any output filtering. Refer to Section 5.3 on page 17 for
information on output filtering.
DS909F1
11
CS35L01/03
ELECTRICAL CHARACTERISTICS - HD MODE
Parameters
Symbol
Output Power
(Continuous Average)
PO
Test Conditions
Min
Typ
THD+N = 1%
RL = 8  (VBATT = 5.0/4.2/3.7 VDC)
RL = 4 (VBATT = 5.0/4.2/3.7 VDC)
-
1.39/0.99/0.76
2.41/1.69/1.30
-
W
W
THD+N = 10%
RL = 8  (VBATT = 5.0/4.2/3.7 VDC)
RL = 4 (VBATT = 5.0/4.2/3.7 VDC)
-
1.73/1.23/0.95
3.03/2.13/1.64
-
W
-
0.02
-
%
Total Harmonic Distortion + Noise THD+N PO = 1.0 W
Max Units
W
Power Supply Rejection Ratio
PSRR
Vripple = 200 mVPP, AINx AC coupled to GND
@ 217 Hz
@ 1 kHz
-
89
86
-
dB
dB
Common-Mode Rejection Ratio
CMRR
Vripple = 1 VPP, fripple = 217 Hz
-
73
-
dB
-
97
98
-
dB
dB
-
49
43
-
Vrms
Vrms
-
86
83
-
Vrms
Vrms
-0.1
0
0.4
dB
Signal to Noise Ratio
A-Weighted
SNRA
Inputs AC Coupled to Ground,
Referenced to 1% THD+N
(Note 13)
CS35L03
CS35L01
AIN+ connected to AIN-
Idle Channel Noise
A-Weighted
ICNA
CS35L03
CS35L01
AIN+ connected to AIN-
Idle Channel Noise
ICN
CS35L03
CS35L01
Frequency Response
FR
20 Hz to 20 kHz
Total Group Delay
GD
-
6
-
s
Output Switching Frequency
fsw1
-
192
-
kHz
AIN+ connected AIN-, No Output Load
VBATT = 5.0 VDC
VBATT = 4.2 VDC
VBATT = 3.7 VDC
-
1.09
1.04
1.01
-
mA
mA
mA
CS35L03
CS35L01
-
65
100
-
k
k
RL = 8  (VBATT = 5.0/4.2/3.7 VDC)
CS35L03
CS35L01
-
0.85/0.72/0.63
1.71/1.44/1.26
-
Vrms
Vrms
Idle Current Draw
(Note 14)
Input Impedance, Single Ended
Input Voltage @ 1% THD+N
12
IIDLE
ZIN
VICLIP
DS909F1
CS35L01/03
ELECTRICAL CHARACTERISTICS - FHD MODE
Parameters
Symbol
Output Power
(Continuous Average)
PO
Test Conditions
Min
Typ
THD+N = 1%
RL = 8  (VBATT = 5.0/4.2/3.7 VDC)
RL = 4 (VBATT = 5.0/4.2/3.7 VDC)
-
1.33/0.94/0.72
2.31/1.63/1.23
-
W
W
THD+N = 10%
RL = 8  (VBATT = 5.0/4.2/3.7 VDC)
RL = 4 (VBATT = 5.0/4.2/3.7 VDC)
-
1.71/1.21/0.94
2.95/2.09/1.61
-
W
-
0.11
-
%
Total Harmonic Distortion + Noise THD+N PO = 1.0 W
Max Units
W
Power Supply Rejection Ratio
PSRR
Vripple = 200 mVPP, AINx AC coupled to GND
@ 217 Hz
@ 1 kHz
-
89
85
-
dB
dB
Common-Mode Rejection Ratio
CMRR
Vripple = 1 VPP, fripple = 217 Hz
-
71
-
dB
-
93
94
-
dB
dB
-
71
63
-
Vrms
Vrms
-
125
115
-
Vrms
Vrms
Inputs AC Coupled to Ground,
Referenced to 1% THD+N
(Note 13)
Signal to Noise Ratio
A-Weighted
SNRA
Idle Channel Noise
A-Weighted
ICNA
Idle Channel Noise
ICN
CS35L03
CS35L01
Frequency Response
FR
20 Hz to 20 kHz
-4.0
0
0.5
dB
Output Switching Frequency
fsw1
LDO Operation
-
192
-
kHz
Total Group Delay
GD
-
14
-
s
Output Switching Frequency
fsw2
VBATT Operation
-
76
-
kHz
IIDLE
AIN+ connected AIN-, No Output Load
VBATT = 5.0 VDC
VBATT = 4.2 VDC
VBATT = 3.7 VDC
-
1.09
1.04
1.01
-
mA
mA
mA
CS35L03
CS35L01
-
160
240
-
k
k
RL = 8  (VBATT = 5.0/4.2/3.7 VDC)
CS35L03
CS35L01
-
0.83/0.70/0.62
1.66/1.39/1.22
-
Vrms
Vrms
CS35L03
CS35L01
AIN+ connected to AINCS35L03
CS35L01
AIN+ connected to AIN-
Idle Current Draw
(Note 14)
Input Impedance, Single Ended
Input Voltage @ 1 % THD+N
ZIN
VICLIP
Note:
13. SNRA dB is referenced to the output signal amplitude resulting in the specified output power at
THD+N < 1 %. See “Parameter Definitions” on page 29 for more information.
14. Idle Current Draw (IIDLE) is specified without any output filtering. Refer to Section 5.3 on page 17 for
information on output filtering. At idle, the output devices will switch at the same rate in HD and FHD
mode. FHD only changes the output switching frequency when the input levels are above the “Input
Level for Entering VBATT Operation in HD/FHD Modes (VIN-VBATT) given in “Electrical Characteristics
- All Operational Modes” on page 9.
DS909F1
13
CS35L01/03
DIGITAL INTERFACE SPECIFICATIONS AND CHARACTERISTICS
Parameters
Symbol
Min
Max
Units
Iin
-
±10
A
Input Capacitance
-
10
pF
SD Pulse Width Requirement
1
-
ms
Input Leakage Current
Logic I/Os (Applicable to GAIN_SEL, MODE, and SD)
High-Level Input Voltage
VIH
0.7•VBATT
-
V
Low-Level Input Voltage
VIL
-
0.3•VBATT
V
POWER-UP & POWER-DOWN CHARACTERISTICS
Parameters
Start-Up Time
Symbol
(Note 15)
Zero Crossing Power-Up Timeout
Power-Down Time
tstart
ttimeout
toff
Test Conditions
Min
Typ
Max Units
After low-to-high SD pin transition edge
-
18
-
ms
No audio input applied
-
25
-
ms
After high-to-low SD pin transition edge
-
1
-
ms
Note:
15. Start-Up Time (tstart) refers to the internal start-up time from when SD is released to when the device
is ready to activate the PWM outputs. The total power-up time from SD release to the PWM outputs
becoming active will vary based on the input signal, not exceeding the Start-Up Time + Zero Crossing
Power-Up Timeout (tstart + ttimeout). For more information, refer to Section 5.4.
14
DS909F1
CS35L01/03
5. APPLICATIONS
5.1
MODE Descriptions
The CS35L01/03 devices can be operated in one of four operating modes, determined by the MODE pin
and the LFILT+ pin. The four modes of operation are Standard Class-D operation (SD), Reduced Frequency
Standard Class-D operation (FSD), Hybrid Class-D operation (HD), and Reduced Frequency Hybrid ClassD operation (FHD). Each of these modes can be leveraged to optimize different performance criteria in an
array of applications.
LFILT+ connected to:
MODE connected to:
GND
VBATT
VBATT
Reduced Frequency Class-D Mode
(FSD)
Standard Class-D Mode
(SD)
Filter Cap to Ground
Reduced Frequency Hybrid Class-D Mode
(FHD)
Hybrid Class-D Mode
(HD)
Table 1. LFILT+ and MODE Operation Configurations
5.1.1
Standard Class-D Modes of Operation
5.1.1.1
SD Mode
Standard Class-D (SD) mode supports full audio bandwidth with very good SNR and THD+N performance. This mode of operation is characterized by a traditional closed loop, analog  modulated ClassD amplifier. With an output switching frequency of 192 kHz, this mode ensures flat frequency response
across the entire audio frequency range.
5.1.1.2
FSD Mode
The Reduced Frequency Class-D (FSD) mode provides competitive audio performance and a reduction
in radiated emissions by decreasing the switching frequency of the output devices to 76 kHz. This reduction in switching frequency reduces the high-frequency energy being created by the output switching
events. Idle channel noise is slightly higher in this mode of operation than SD mode, with the trade-off
being better EMI performance and power consumption.
5.1.2
Hybrid Class-D Modes of Operation
Hybrid Class-D and Reduced Frequency Hybrid Class-D modes of operation allows the rail voltage for the
output devices to switch between a high voltage net and a low voltage net depending on the audio content
being amplified. This is explained in more detail in Section 5.1.2.1 and Section 5.1.2.2. Operation in these
modes requires that the voltage present on the VBATT pin be above the level listed as “VBATT Limit for
HD/FHD Mode (VBLIM)” in “Electrical Characteristics - All Operational Modes” on page 9. If it is not, HD
and FHD modes of operation of the device will automatically be disabled and operation will be limited to
the SD mode of operation.
DS909F1
15
CS35L01/03
In both HD and FHD mode, the value of the capacitance connected to the LFILT+ pin must not exceed
4.7 F. If this value is greater than 4.7 F, it will prevent the rail voltage of the output devices from transitioning properly between VBATT and the internal LDO.
5.1.2.1
HD Mode
Hybrid Class-D mode (HD) provides competitive analog performance with a substantial reduction in idle
power dissipation and radiation emissions. In this mode, the output switches at 192 kHz and a secondary
supply is derived from VBATT using an internal 1.0-VDC low drop-out linear regulator (LDO). When the
output signal is at a low amplitude, the Class-D output stage begins to switch from the lower rail voltage
created by the internal LDO. This not only decreases idle power consumption when output capacitors are
used, but also reduces electromagnetic emissions by reducing the amplitude of the square waves being
created at the output of the CS35L01/03 when operating at low amplitude or idle power.
5.1.2.2
FHD Mode
The Reduced Frequency Hybrid Class-D (FHD) mode provides the best overall EMI performance and the
lowest power consumption with slightly decreased frequency response near the top frequency range of
the audio band, for high amplitude signals. In this mode of operation, the output switching frequency is
reduced to 76 kHz during high amplitude transients on the output. The threshold at which this transition
from 192-kHz to 76-kHz switching rate occurs is given as the Input Level Threshold for FHD Operation in
“Electrical Characteristics - FHD Mode” on page 13. Combined with the lower amplitude switching offered
by the Hybrid design, this reduction in switching energy dramatically reduces the emissions levels of the
output stage and its associated components.
5.2
Reducing the Gain with External Series Resistors
If necessary, it is possible to decrease the gain of the CS35L01/03 by adding series resistors to the audio
input signal as is shown in Figure 4 below.
Audio In+
Audio In-
RIN
RIN
x
AIN+
x
AIN-
Figure 4. Adjusting Gain via External Series Resistance
If input resistors are added, the new gain of the amplifier can be determined by the following equation:
Z IN
A V  adjusted  = A V – 20  log  --------------------------
 Z IN + Z EXT
Where:
AV(adjusted) = The new, adjusted gain of the system
ZIN = Input impedance of the device being used (See “Electrical Characteristics - SD Mode” on page 10,
“Electrical Characteristics - FSD Mode” on page 11, “Electrical Characteristics - HD Mode” on page 12, or
“Electrical Characteristics - FHD Mode” on page 13 for this value.)
ZEXT = Value of the resistor added in series with the inputs
16
DS909F1
CS35L01/03
AV = Original gain of the device being used (See “Electrical Characteristics - All Operational Modes” on
page 9 for this value.)
5.3
Output Filtering with the CS35L01/03
The CS35L01/03 is specifically designed to minimize radiated electromagnetic interference (EMI) signals.
All of the devices are capable of meeting all stated data sheet performance numbers with no special filtering
required. Additionally, the device has shown to be below the compliance limits of both FCC and CISPR testing with no external filtering required.
Ultimately, compliance with any radiated emissions requirements depends significantly on the entire system
under test. In applications where system-level trade-offs such as compromised component layout or lengthy
speaker wires have increased emissions levels, a passive output filter can be added to the outputs of the
device in order to decrease EMI levels.
5.3.1
Reduced Filter Order with the CS35L01/03
In applications which require an output filter, the unique design of the CS35L01/03 allows a much smaller,
less expensive output filter to be used than what is normally found in Class-D amplifiers. In contrast to a
second order filter implemented with a series inductive element (traditional inductor or ferrite beads) and
a shunt capacitive element, basic filtering for the CS35L01/03 is accomplished by a single-order capacitive element attached to the OUTx terminals. This is highlighted in Figure 5 below. Of course, if the system
requires more aggressive filtering, a ferrite bead can be added in series with the outputs to further attenuate system level noise.
OUT+
OUT-
OUT+
x
LFILT
C FILT
OUT-
x
LFILT
x
C FILT
x
C FILT
Traditional 2nd Order Optional Filter
C FILT
CS35L01/03’s Minimized Optional Filter
Figure 5. Optional Output Filter Components
5.3.2
Filter Component Selection
Usually, the need for output filtering is determined after the system under test has failed EMI testing. During this testing, problem frequencies are easily identified by the peaks which appear in the spectral plots
gathered in the EMI testing.
Selection of the filter components should ensure that shunt elements (i.e. CFILT in Figure 5) present a very
low impedance at the frequency corresponding to the tallest peak in the spectral plot. If needed, series
components such as ferrite beads (i.e. LFILT in Figure 5) should be chosen to present a very high impedance at the frequency corresponding to the tallest peak in the spectral plot.
Careful attention should be paid to the current-carrying capabilities of any included ferrite beads and the
impedance of the ferrite beads in the audio band. A proper trade-off in ferrite bead selection is one that
allows the ferrite bead to sufficiently attenuate the problematic high-frequency emissions without compromising audio performance.
DS909F1
17
CS35L01/03
5.3.3
Output Filter Power Dissipation Considerations
In systems without inductive series elements like inductors or ferrite beads, power losses in the output
filter are equal to the switching losses that occur in the system due to the cyclical charging and discharging
of capacitors connected to the amplifier outputs. In systems that require an inductive series element, conducted losses also occurs due to the series impedance added to the output path.
5.3.3.1
Conduction Losses for All modes of Operation
For all modes of operation (SD, FSD, HD, and FHD) of the CS35L01/03, the conduction losses are governed by the equation:
P = I2Z
Where:
P = Power dissipated in the series impedance.
I = RMS AC output current
Z = impedance of the series element at the frequency of the AC current
This equation neglects any series impedances presented by the PCB traces or speaker wires in the output
path.
5.3.3.2
Switching Losses in SD/FSD Mode
Switching losses in SD/FSD Mode are governed by the equation
1
P = --- CV 2 f
2
Where:
P = Power dissipated in the capacitor (neglecting parasites).
C = Value of filtering capacitor
V = Peak voltage developed across the capacitor
f = Switching frequency of the outputs
These calculations are straightforward, as the peak voltage is simply the voltage level attached to VBATT,
the capacitor is the value of capacitor that has been added for filtering (neglecting parasitic board capacitances), and the frequency is 192 kHz or 76 kHz for SD and FSD, respectively.
5.3.3.3
Switching Losses in HD/FHD.
Many factors affect the switching losses when the device is operated in HD/FHD mode. These factors include the frequency of the content being amplified, the voltage level of VBATT, and the amplitude of the
output signal will factor into both the voltage presented across the capacitors and the frequency at which
the capacitors are charged or discharged.
Static signals (i.e. sine waves at a fixed amplitude) are easier to consider than are dynamic signals (i.e.
musical content), as they are governed by the same equation as that listed in Section 5.3.3.1 and Section
5.3.3.2 on page 18. Modifications to that equation are limited to the voltage term (V) and the frequency
term (f), depending on whether the static input signal amplitude is causing the output devices to switch at
76 kHz or 192 kHz, and to operate off of the VBATT supply or off of the internally generated LDO.
18
DS909F1
CS35L01/03
It is important to note that the HD and FHD modes offer significant improvement over traditional Class-D
in idle power dissipation when an external output filter is necessary. This is because the voltage term (V)
is significantly reduced in HD and FHD mode. As can be seen in the equation, this is notable because
reduction in the operating voltage reduces power losses not linearly, but instead exponentially- due to the
voltage squared term (V2). It is also notable that when operated at high output levels, FHD modes also
offers unique improvement in output filter losses, due to reducing the switching frequency (f) at higher output levels.
5.4
Power-Up and Power-Down
When pulled to a logic low state, the SD pin tristates the outputs and shuts down the CS35L01/03 device,
putting it into a low power mode.
5.4.1
Recommended Power-Up Sequence
1. With the SD pin pulled low, apply power to the CS35L01/03 and wait for the power supply to be stable.
2. Set the SD pin high to begin normal operation.
5.4.1.1
Zero-Crossing on Power-Up Functionality
The CS35L01/03 implements an input-signal zero-crossing detection function that is enabled during power-up. This function is designed to prevent audible artifacts and eliminate any need to mute the amplifier’s
input audio signal during the power-up process.
After a minimum start-up time of tstart, the CS35L01/03 will begin to detect input-signal zero-crossings.
The amplifier will then enable its switching outputs at the time of the first detected input-signal zero-crossing transition. If no input-signal zero-crossing is detected before ttimeout, the zero-crossing function will timeout and the outputs will begin switching immediately.
Both tstart and ttimeout are specified in “Power-Up & Power-Down Characteristics” on page 14.
IN+/-
SD
IN+/VIH
SD
VIL
tstart
VIL
ttimeout
VBATT or VLDO
tstart
ttimeout
Internal
Start-Up
Device Ready: Waiting for Zero
Crossing Input Signal or t timeout
VBATT or VLDO
OUT+/-
OUT+/Shut-Down /
Low Power
Mode
Internal
Start-Up
Device Ready:
Waiting for Zero
Crossing Input
Signal or ttimeout
PWM OUT+/Active
Figure 6. Power-Up Timing with Input
Zero-Crossing
5.4.2
VIH
Shut-Down /
Low Power
Mode
PWM OUT+/Active
Figure 7. Power Up Timing without Input
Zero-Crossing
Recommended Power-Down Sequence
1. Mute the audio supplied to the CS35L01/03.
2. Pull the SD pin low in order to reset the device and put it into the low power mode.
3. The power supply to the CS35L01/03 can now be removed.
DS909F1
19
CS35L01/03
5.5
Over Temperature Protection
The CS35L01/03 is internally protected against thermal overload. Built in die temperature sensing circuitry
monitors the die temperature and will place the device into shut-down if thermal overload occurs. A thermal overload is characterized by the die temperature reaching the Thermal Error Threshold (TTE) at which
time the outputs will tristate and shut down.
If the device has entered into shut-down due to a thermal overload, the die temperature must remain below the Thermal Error Threshold (TTE) for the time specified by the Thermal Error Retry Time (RTE) in
order for the device to automatically return to normal operation.
Both TTE and RTE are specified in “Electrical Characteristics - All Operational Modes” on page 9.
20
DS909F1
CS35L01/03
6. TYPICAL PERFORMANCE PLOTS
Test Conditions (unless otherwise specified): GND = 0 V; All voltages with respect to ground; AV = 6 dB; Input signal = 997 Hz
differential sine wave; TA = 25°C; VBATT = 5.0 V; RL = 8 ; 10 Hz to 20 kHz Measurement Bandwidth; Measurements taken
with AES17 measurement filter and Audio Precision AUX-0025 passive filter.
6.1
SD Mode Typical Performance Plots
10
10
5
5
5.0 V
4.2 V
3.7 V
2
5.0 V
4.2 V
3.7 V
2
1
1
0.5
0.5
%
%
0.2
0.2
0.1
0.1
0.05
0.05
0.02
0.02
0.01
1m
2m
5m
10m
20m
50m
100m
200m
500m
1
0.01
1m
2
2m
5m
10m
20m
50m
10
500m
1
2
4
10
5
5
2
2
1
1
0.5
0.5
0.2
0.2
1.0 W
0.1
0.75 W
%
0.05
0.1
0.05
0.1 W
0.02
0.1 W
0.02
0.01
0.01
0.5 W
0.005
0.5 W
0.005
0.002
0.001
20
200m
Figure 9. THD+N vs. Output Power - SD Mode
RL = 4 
Figure 8. THD+N vs. Output Power - SD Mode
RL = 8 
%
100m
W
W
0.002
50
100
200
500
1k
2k
5k
10k
0.001
20
20k
Hz
50
100
200
500
1k
2k
5k
10k
20k
Hz
Figure 10. THD+N vs. Frequency - SD Mode
VBATT = 5.0 V
Figure 11. THD+N vs. Frequency - SD Mode
VBATT = 4.2 V
+4
10
+3.5
5
+3
2
+2.5
0.625 W
1
+2
+1.5
0.5
4
+1
0.2
%
d
B
r
0.1
A
0.05
0.1 W
+0.5
+0
-0.5
-1
0.02
8
-1.5
0.01
-2
0.5 W
0.005
-2.5
-3
0.002
0.001
20
-3.5
50
100
200
500
1k
2k
5k
10k
Hz
Figure 12. THD+N vs. Frequency - SD Mode
VBATT = 3.7 V
DS909F1
20k
-4
20
50
100
200
500
1k
2k
5k
10k
20k
Hz
Figure 13. Frequency Response - SD Mode
21
CS35L01/03
3.5
7.00
6.00
3.0
5.00
2.5
Output Power (W)
Idle Current Draw (mA)
2200 pF
4.00
1000 pF
3.00
RL = 4 
10% THD+N Ratio
2.0
RL = 4 
1% THD+N Ratio
1.5
2.00
1.0
1.00
0.5
RL = 8 
10% THD+N Ratio
RL = 8 
1% THD+N Ratio
470 pF
No Filter
0.00
0.0
2.5
3
3.5
4
4.5
5
5.5
2.5
3.0
3.5
VBATT Supply Voltage (V)
Figure 14. Idle Current Draw vs. VBATT - SD Mode
RL = 8  + 33 H (Note 16)
100%
90%
90%
80%
5.0 V
3.7 V
70%
60%
60%
Efficiency (%)
Efficiency (%)
5.0
5.5
80%
4.2 V
70%
50%
40%
5.0 V
4.2 V
50%
40%
30%
30%
20%
20%
10%
10%
0%
0%
0
250
500
750
1000
1250
1500
1750
2000
0
500
1000
Output Power (mW)
2000
2500
3000
3500
Figure 17. Efficiency vs. Output Power - SD Mode
RL = 4  + 33 H
450
800
400
700
350
1500
Output Power (mW)
Figure 16. Efficiency vs. Output Power - SD Mode
RL = 8  + 33 H
4.2 V
600
3.7 V
Current Consumption (mA)
300
Current Consumption (mA)
4.5
Figure 15. Output Power vs. VBATT - SD Mode
100%
3.7 V
4.0
VBATT Supply Voltage (V)
5.0 V
250
200
150
4.2 V
500
3.7 V
5.0 V
400
300
200
100
100
50
0
0
0
250
500
750
1000
1250
1500
1750
2000
Output Power (mW)
Figure 18. Supply Current vs. Output Power - SD Mode
RL = 8  + 33 H
0
500
1000
1500
2000
2500
3000
3500
Output Power (mW)
Figure 19. Supply Current vs. Output Power - SD Mode
RL = 4  + 33 H
Note:
16. “Idle Current Draw vs. VBATT - SD Mode” capacitor values refer to CFILT when configured as the
“CS35L01/03’s Minimized Optional Output Filter,” shown in Figure 5 on page 17.
22
DS909F1
CS35L01/03
6.2
FSD Mode Typical Performance Plots
10
10
5
5
5.0 V
4.2 V
3.7 V
2
5.0 V
4.2 V
3.7 V
2
1
1
0.5
0.5
%
%
0.2
0.2
0.1
0.1
0.05
0.05
0.02
0.02
0.01
1m
2m
5m
10m
20m
50m
100m
200m
500m
1
0.01
1m
2
2m
5m
10m
20m
50m
W
Figure 20. THD+N vs. Output Power - FSD Mode
RL = 8 
10
5
5
1.0 W
2
%
500m
1
2
4
0.75 W
2
1
1
0.5
0.5
0.1 W
0.1 W
0.2
0.1
%
0.05
0.1
0.05
0.5 W
0.02
0.5 W
0.02
0.01
0.01
0.005
0.005
0.002
0.001
20
200m
Figure 21. THD+N vs. Output Power - FSD Mode
RL = 4 
10
0.2
100m
W
0.002
50
100
200
500
1k
2k
5k
10k
0.001
20
20k
50
100
200
500
Hz
1k
2k
5k
10k
20k
Hz
Figure 23. THD+N vs.
Frequency - FSD Mode VBATT = 4.2 V
Figure 22. THD+N vs. Frequency - FSD Mode
VBATT = 5.0 V
10
+4
+3.5
5
+3
0.625 W
2
+2.5
1
+2
+1.5
0.5
4
+1
0.1 W
0.2
%
d
B
r
0.1
A
0.05
+0.5
+0
-0.5
-1
0.5 W
0.02
8
-1.5
0.01
-2
-2.5
0.005
-3
0.002
0.001
20
-3.5
50
100
200
500
1k
2k
5k
10k
20k
Hz
Figure 24. THD+N vs. Frequency - FSD Mode
VBATT = 3.7 V
DS909F1
-4
20
50
100
200
500
1k
2k
5k
10k
20k
Hz
Figure 25. Frequency Response - FSD Mode
23
CS35L01/03
3.50
3.5
3.0
2.50
2.5
Output Power (W)
Idle Current Draw (mA)
2200 pF
3.00
2.00
1000 pF
1.50
1.00
RL = 4 
10% THD+N Ratio
2.0
RL = 4 
1% THD+N Ratio
1.5
1.0
RL = 8 
10% THD+N Ratio
470 pF
No Filter
0.50
0.5
0.00
RL = 8 
1% THD+N Ratio
0.0
2.5
3
3.5
4
4.5
5
5.5
2.5
3.0
3.5
VBATT Supply Voltage (V)
Figure 26. Idle Current Draw vs. VBATT - FSD Mode
RL = 8  + 33 H (Note 17)
100%
100%
90%
90%
5.0
5.5
80%
3.7 V
4.2 V
4.2 V
3.7 V
5.0 V
70%
70%
60%
60%
Efficiency (%)
Efficiency (%)
4.5
Figure 27. Output Power vs. VBATT - FSD Mode
80%
50%
5.0 V
50%
40%
40%
30%
30%
20%
20%
10%
10%
0%
0%
0
250
500
750
1000
1250
1500
1750
0
2000
500
1000
1500
2000
2500
3000
3500
Output Power (mW)
Output Power (mW)
Figure 29. Efficiency vs. Output Power - FSD Mode
RL = 4  + 33 H
Figure 28. Efficiency vs. Output Power - FSD Mode
RL = 8  + 33 H
450
800
400
700
4.2 V
4.2 V
350
600
Current Consumption (mA)
3.7 V
300
Current Consumption (mA)
4.0
VBATT Supply Voltage (V)
5.0 V
250
200
150
3.7 V
500
5.0 V
400
300
200
100
100
50
0
0
0
250
500
750
1000
1250
1500
1750
2000
Output Power (mW)
Figure 30. Supply Current vs. Output Power - FSD Mode
RL = 8  + 33 H
0
500
1000
1500
2000
2500
3000
3500
Output Power (mW)
Figure 31. Supply Current vs. Output Power - FSD Mode
RL = 4  + 33 H
Note:
17. “Idle Current Draw vs. VBATT - FSD Mode” capacitor values refer to CFILT when configured as the
“CS35L01/03’s Minimized Optional Output Filter”, shown in Figure 5 on page 17.
24
DS909F1
CS35L01/03
6.3
HD Mode Typical Performance Plots
10
10
5
5
5.0 V
4.2 V
3.7 V
2
5.0 V
4.2 V
3.7 V
2
1
1
0.5
0.5
%
%
0.2
0.2
0.1
0.1
0.05
0.05
0.02
0.02
0.01
1m
2m
5m
10m
20m
50m
100m
200m
500m
1
0.01
1m
2
2m
5m
10m
20m
50m
W
10
10
5
5
2
2
1
1
0.5
0.5
1.0 W
0.2
%
1
2
4
0.1
0.05
0.1 W
0.02
0.1 W
0.02
0.01
0.01
0.5 W
0.5 W
0.005
0.005
0.002
0.001
20
500m
0.75 W
0.2
0.1
0.05
200m
Figure 33. THD+N vs. Output Power - HD Mode
RL = 4 
Figure 32. THD+N vs. Output Power - HD Mode
RL = 8 
%
100m
W
0.002
50
100
200
500
1k
2k
5k
10k
0.001
20
20k
50
100
200
500
Hz
1k
2k
5k
10k
20k
Hz
Figure 35. THD+N vs. Frequency - HD Mode
VBATT = 4.2 V
Figure 34. THD+N vs. Frequency - HD Mode
VBATT = 5.0 V
+4
10
+3.5
5
+3
2
+2.5
0.625 W
1
+2
+1.5
0.5
4
+1
0.2
%
d
B
r
0.1
A
0.05
0.1 W
+0.5
+0
-0.5
-1
0.02
-1.5
0.01
-2
-2.5
0.5 W
0.005
8
-3
0.002
0.001
20
-3.5
50
100
200
500
1k
2k
5k
10k
Hz
Figure 36. THD+N vs. Frequency - HD Mode
VBATT = 3.7 V
DS909F1
20k
-4
20
50
100
200
500
1k
2k
5k
10k
20k
Hz
Figure 37. Frequency Response- HD Mode
25
CS35L01/03
4.50
3.5
4.00
3.0
RL = 4 
10% THD+N Ratio
3.50
2.5
2.50
1000 pF
Output Power (W)
Idle Current Draw (mA)
3.00
2200 pF
2.00
2.0
RL = 4 
1% THD+N Ratio
1.5
1.50
1.0
RL = 8 
10% THD+N Ratio
1.00
470 pF
No Filter
0.5
RL = 8 
1% THD+N Ratio
0.50
0.00
0.0
2.5
3
3.5
4
4.5
5
5.5
2.5
3.0
3.5
VBATT Supply Voltage (V)
Figure 38. Idle Current Draw vs. VBATT - HD Mode
RL = 8  + 33 H (Note 18)
5.0
5.5
100%
90%
90%
80%
80%
4.2 V
3.7 V
5.0 V
5.0 V
4.2 V
3.7 V
70%
70%
60%
Efficiency (%)
60%
Efficiency (%)
4.5
Figure 39. Output Power vs. VBATT - HD Mode
100%
50%
40%
50%
40%
30%
30%
20%
20%
10%
10%
0%
0%
0
250
500
750
1000
1250
1500
1750
0
2000
500
1000
1500
2000
2500
3000
3500
Output Power (mW)
Output Power (mW)
Figure 41. Efficiency vs. Output Power - HD Mode
RL = 4  + 33 H
Figure 40. Efficiency vs. Output Power - HD Mode
RL = 8  + 33 H
450
800
400
700
4.2 V
350
4.2 V
600
Current Consumption (mA)
3.7 V
300
Current Consumption (mA)
4.0
VBATT Supply Voltage (V)
5.0 V
250
200
150
3.7 V
500
5.0 V
400
300
200
100
100
50
0
0
0
250
500
750
1000
1250
1500
1750
2000
Output Power (mW)
Figure 42. Supply Current vs. Output Power - HD Mode
RL = 8  + 33 H
0
500
1000
1500
2000
2500
3000
3500
Output Power (mW)
Figure 43. Supply Current vs. Output Power - HD Mode
RL = 4  + 33 H
Note:
18. “Idle Current Draw vs. VBATT - HD Mode” capacitor values refer to CFILT when configured as the
“CS35L01/03’s Minimized Optional Output Filter”, shown in Figure 5 on page 17. When VBATT is
below “VBATT Limit for HD/FHD Mode” (VBLIM), operation is restricted to SD Mode.
26
DS909F1
CS35L01/03
6.4
FHD Mode Typical Performance Plots
10
10
5
5
5.0 V
4.2 V
3.7 V
2
5.0 V
4.2 V
3.7 V
2
1
1
0.5
0.5
%
%
0.2
0.2
0.1
0.1
0.05
0.05
0.02
0.02
0.01
1m
2m
5m
10m
20m
50m
100m
200m
500m
1
0.01
1m
2
2m
5m
10m
20m
50m
W
100m
Figure 44. THD+N vs. Output Power - FHD Mode
RL = 8 
2
4
5
1.0 W
2
2
1
1
0.5
0.5
0.1 W
0.2
0.75 W
0.1 W
0.2
0.1
%
0.05
0.1
0.05
0.5 W
0.5 W
0.02
0.02
0.01
0.01
0.005
0.005
0.002
0.002
50
100
200
500
1k
2k
5k
10k
0.001
20
20k
50
100
200
500
Hz
1k
2k
5k
10k
20k
Hz
Figure 46. THD+N vs. Frequency - FHD Mode
VBATT = 5.0 V
Figure 47. THD+N vs. Frequency - FHD Mode
VBATT = 4.2 V
10
+4
5
+3.5
0.625 W
+3
2
+2.5
1
+2
0.5
+1.5
4
+1
0.1 W
0.2
%
1
10
5
0.001
20
500m
Figure 45. THD+N vs. Output Power - FHD Mode
RL = 4 
10
%
200m
W
d
B
r
0.1
A
0.05
0.5 W
+0.5
+0
-0.5
-1
0.02
8
-1.5
0.01
-2
0.005
-2.5
-3
0.002
0.001
20
-3.5
50
100
200
500
1k
2k
5k
10k
20k
Hz
Figure 48. THD+N vs. Frequency - FHD Mode
VBATT = 3.7 V
DS909F1
-4
20
50
100
200
500
1k
2k
5k
10k
20k
Hz
Figure 49. Frequency Response - FHD Mode
27
CS35L01/03
4.50
3.5
4.00
3.0
RL = 4 
10% THD+N Ratio
3.50
2.5
2.50
Output Power (W)
Idle Current Draw (mA)
3.00
2200 pF
1000 pF
2.00
2.0
RL = 4 
1% THD+N Ratio
1.5
1.50
1.0
RL = 8 
10% THD+N Ratio
1.00
470 pF
No Filter
0.50
0.5
0.00
2.5
3
3.5
4
4.5
5
RL = 8 
1% THD+N Ratio
0.0
5.5
2.5
3.0
3.5
VBATT Supply Voltage (V)
Figure 50. Idle Current Draw vs. VBATT - FHD Mode
RL = 8  + 33 H (Note 19)
100%
90%
90%
80%
70%
60%
60%
Efficiency (%)
Efficiency (%)
5.0
5.5
80%
5.0 V
4.2 V
70%
50%
40%
4.2 V
3.7 V
5.0 V
50%
40%
30%
30%
20%
20%
10%
10%
0%
0%
0
250
500
750
1000
1250
1500
1750
0
2000
500
1000
1500
2000
2500
3000
3500
Output Power (mW)
Output Power (mW)
Figure 52. Efficiency vs. Output Power - FHD Mode
RL = 8  + 33 H
Figure 53. Efficiency vs. Output Power - FHD Mode
RL = 4  + 33 H
450
800
400
700
350
4.2 V
4.2 V
600
Current Consumption (mA)
3.7 V
300
Current Consumption (mA)
4.5
Figure 51. Output
Power vs. VBATT - FHD Mode
100%
3.7 V
4.0
VBATT Supply Voltage (V)
5.0 V
250
200
150
5.0 V
3.7 V
500
400
300
200
100
100
50
0
0
0
250
500
750
1000
1250
1500
1750
2000
Output Power (mW)
Figure 54. Supply Current vs. Output Power - FHD Mode
RL = 8  + 33 H
0
500
1000
1500
2000
2500
3000
3500
Output Power (mW)
Figure 55. Supply Current vs. Output Power - FHD Mode
RL = 4  + 33 H
Note:
19. “Idle Current Draw vs. VBATT - FHD Mode” capacitor values refer to CFILT when configured as the
“CS35L01/03’s Minimized Optional Output Filtering” shown in Figure 5 on page 17. When VBATT is
below “VBATT Limit for HD/FHD Mode” (VBLIM), operation is restricted to SD Mode.
28
DS909F1
CS35L01/03
7. PARAMETER DEFINITIONS
Signal to Noise Ratio (SNR)
The ratio of the RMS value of the output signal, where Pout is equivalent to the specified output power at
THD+N<1%, to the RMS value of the noise floor with no input signal applied and measured over the specified bandwidth, typically 20 Hz to 20 kHz. This measurement technique has been accepted by the Electronic Industries Association of Japan, EIAJ CP-307. Expressed in decibels.
Total Harmonic Distortion + Noise (THD+N)
The ratio of the RMS value of the signal to the RMS sum of all other spectral components over the specified
band width (typically 10 Hz to 20 kHz), including distortion components. Expressed in decibels. Measured
at -1 and -20 dBFS as suggested in AES17-1991 Annex A.
Idle Channel Noise (ICN)
Measure of the signal present on the outputs of the device when no audio signal is presented to the input
pins. For this test, both input pins are shorted together, setting the differential signal to them to zero.
DS909F1
29
CS35L01/03
8. PACKAGING AND THERMAL INFORMATION
8.1
Package Drawings and Dimensions (Note 20)
9 BALL WLCSP
e
Y
e
b
9 solder spheres
X
A2
A
A1
DIM
MIN
X
Y
b
e
A
A1
A2
0.047
0.047
0.009
0.018
0.006
0.012
INCHES
NOM
0.048
0.048
0.011
0.015
0.020
0.007
0.013
NOTE
MAX
MIN
MILLIMETERS
NOM
MAX
0.049
0.049
0.012
0.022
0.008
0.014
1.195
1.195
0.240
0.475
0.175
0.300
1.215
1.215
0.270
0.400 BSC
0.515
0.190
0.325
1.235
1.235
0.300
0.555
0.205
0.350
20
20
20
20
20
20
JEDEC #: MO-220
Controlling Dimension is Millimeters.
Note:
20. Dimensioning and tolerance per ASME Y 14.5M-1994.
30
DS909F1
CS35L01/03
8.2
Recommend PCB Footprint and Routing Configuration
To ensure high-yield manufacturability, the PCB footprint for the CS35L01/03 should be constructed with
strict adherence to the specifications given in IPC-610. Departure from this specification significantly increases the probability of solder bridging and other manufacturing defects.
Routing of the traces into and out of the CS35L01/03 device should also be given consideration to avoid
manufacturing issues.
8.3
Package Thermal Performance
Class-D amplifiers, though highly efficient, will produce some amount of heat through the process of amplifying the audio signal. As is well understood, this amount of heat is very small compared to traditional Class
AB amplifiers. Even so, as power levels increase and package sizes decrease, careful consideration must
be given to ensure thermal energy is removed from the device as efficiently as possible so that its operating
temperature is kept under its Over-Temperature Error Threshold.
The thermal impedance, JA is a measurement of the impedance to the flow of thermal energy out of the
device to the environment surrounding the device. This specification is directly related to the ability of the
PCB to which the CS35L01/03 is attached to transfer the heat from the device. The thermal impedance from
the junction of the device to the ambient surrounding the device and the thermal impedance from the device
into the PCB is shown in Table 2.
.
Parameter (Note 21), (Note 22)
Junction to Ambient Thermal Impedance
Junction to Printed Circuit Board Thermal Impedance
Symbol
A
PCB
Min
Typical
Max
Units
-
92
-
°C/Watt
-
67
-
°C/Watt
Table 2. JA Specification for Typical PCB Designs
Note:
21. Test Printed Circuit Board Assembly (PCBA) constructed in accordance with JEDEC standard
JESD51-9. Two signal, two plane (2s2p) PCB utilized.
22. Test conducted with still air in accordance with JEDEC standards JESD51, JESD51-2A, and
JESD51-8.
DS909F1
31
CS35L01/03
8.3.1
Determining Maximum Ambient Temperature
To determine (to a first order approximation) the maximum ambient temperature in which the CS35L01/03
will operate, the following equations can be used:
T op =  JA    1 –    P max 
T max = T TE – T op
Where:
Tmax = The maximum ambient temperature in which the device can operate.
Top = The operating temperature of the device, given a dissipated power “Pmax” and a known thermal
impedance “JA”.
TTE = The Over-Temperature Error Threshold, given in the “Electrical Characteristics - All Operational
Modes” section on page 9.
JA = The thermal impedance of the device and PCB. (This value is highly subjective to a number of application specific scenarios. The numbers given in Table 2 on page 31 can be used for a first order approximation, but proper characterization of the application’s specific PCB and supporting mechanicals is
needed to increase the accuracy of the result achieved here.)
Pmax = The maximum power at which the amplifier will be operated continuously. (For conservative estimates, the 10% THD+N rated power given in “Electrical Characteristics - SD Mode” section on page 10,
“Electrical Characteristics - FSD Mode” section on page 11, “Electrical Characteristics - HD Mode” section
on page 12, or “Electrical Characteristics - FHD Mode” section on page 13 can be used. However, this
method will predict higher operating temperatures than what may be seen in the application, since power
content of audio signals is much smaller than that of the sine wave used to establish the power specifications.)
= The efficiency of the device at the power Pmax.
32
DS909F1
CS35L01/03
9. ORDERING INFORMATION
Product
Description
Package Pb-Free
Grade
Temp Range
Container
Order#
CS35L01 3.0 W Mono Audio 9Yes
Amplifier with default WLCSP
+6 dB gain
Commercial -10° to +70°C Tape and Reel CS35L01-CWZR
CS35L03 3.0 W Mono Audio 9Yes
Amplifier with default WLCSP
+12 dB gain
Commercial -10° to +70°C Tape and Reel CS35L03-CWZR
10.REVISION HISTORY
Release
F1
Changes
–
Initial release
Contacting Cirrus Logic Support
For all product questions and inquiries, contact a Cirrus Logic Sales Representative.
To find one nearest you, go to www.cirrus.com.
IMPORTANT NOTICE
Cirrus Logic, Inc. and its subsidiaries (“Cirrus”) believe that the information contained in this document is accurate and reliable. However, the information is subject
to change without notice and is provided “AS IS” without warranty of any kind (express or implied). Customers are advised to obtain the latest version of relevant
information to verify, before placing orders, that information being relied on is current and complete. All products are sold subject to the terms and conditions of sale
supplied at the time of order acknowledgment, including those pertaining to warranty, indemnification, and limitation of liability. No responsibility is assumed by Cirrus
for the use of this information, including use of this information as the basis for manufacture or sale of any items, or for infringement of patents or other rights of third
parties. This document is the property of Cirrus and by furnishing this information, Cirrus grants no license, express or implied under any patents, mask work rights,
copyrights, trademarks, trade secrets or other intellectual property rights. Cirrus owns the copyrights associated with the information contained herein and gives consent for copies to be made of the information only for use within your organization with respect to Cirrus integrated circuits or other products of Cirrus. This consent
does not extend to other copying such as copying for general distribution, advertising or promotional purposes, or for creating any work for resale
CERTAIN APPLICATIONS USING SEMICONDUCTOR PRODUCTS MAY INVOLVE POTENTIAL RISKS OF DEATH, PERSONAL INJURY, OR SEVERE PROPERTY OR ENVIRONMENTAL DAMAGE (“CRITICAL APPLICATIONS”). CIRRUS PRODUCTS ARE NOT DESIGNED, AUTHORIZED OR WARRANTED FOR USE
IN PRODUCTS SURGICALLY IMPLANTED INTO THE BODY, AUTOMOTIVE SAFETY OR SECURITY DEVICES, LIFE SUPPORT PRODUCTS OR OTHER CRITICAL APPLICATIONS. INCLUSION OF CIRRUS PRODUCTS IN SUCH APPLICATIONS IS UNDERSTOOD TO BE FULLY AT THE CUSTOMER’S RISK AND CIRRUS DISCLAIMS AND MAKES NO WARRANTY, EXPRESS, STATUTORY OR IMPLIED, INCLUDING THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
FITNESS FOR PARTICULAR PURPOSE, WITH REGARD TO ANY CIRRUS PRODUCT THAT IS USED IN SUCH A MANNER. IF THE CUSTOMER OR CUSTOMER’S CUSTOMER USES OR PERMITS THE USE OF CIRRUS PRODUCTS IN CRITICAL APPLICATIONS, CUSTOMER AGREES, BY SUCH USE, TO FULLY
INDEMNIFY CIRRUS, ITS OFFICERS, DIRECTORS, EMPLOYEES, DISTRIBUTORS AND OTHER AGENTS FROM ANY AND ALL LIABILITY, INCLUDING ATTORNEYS’ FEES AND COSTS, THAT MAY RESULT FROM OR ARISE IN CONNECTION WITH THESE USES.
Cirrus Logic, Cirrus, and the Cirrus Logic logo designs are trademarks of Cirrus Logic, Inc. All other brand and product names in this document may be trademarks
or service marks of their respective owners.
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