STMICROELECTRONICS TS4890IST

TS4890
RAIL TO RAIL OUTPUT 1W AUDIO POWER AMPLIFIER WITH
STANDBY MODE ACTIVE LOW
■ OPERATING FROM VCC = 2.2V to 5.5V
■ 1W RAI L TO RAIL OUTPUT POWER @
PIN CONNECTIONS (Top View)
Vcc=5V, THD=1%, f=1kHz, with 8Ω Load
TS4890ID, TS4890IDT - SO8
■ ULTRA LOW CONSUMPTION IN STANDBY
MODE (10nA)
■ 75dB PSRR @ 217Hz from 5 to 2.2V
■ POP & CLICK REDUCTION CIRCUITRY
■ ULTRA LOW DISTORTION (0.1%)
■ UNITY GAIN STABLE
■ AVAILABLE IN SO8, MiniSO8 & DFN8
DESCRIPTION
The TS4890 (MiniSO8 & SO8) is an Audio Power
Amplifier capable of delivering 1W of continuous
RMS. ouput power into 8Ω load @ 5V.
This Audio Amplifier is exhibiting 0.1% distortion
level (THD) from a 5V supply for a Pout = 250mW
RMS. An external standby mode control reduces
the supply current to less than 10nA. An internal
thermal shutdown protection is also provided.
The TS4890 have been designed for high quality
audio applications such as mobile phones and to
minimize the number of external components.
Standby
1
8
VOUT2
Bypass
2
7
GND
VIN+
3
6
VCC
VIN-
4
5
VOUT1
TS4890IST - MiniSO8
Standby
1
8
VOUT2
Bypass
2
7
GND
VIN+
3
6
VCC
VIN-
4
5
VOUT1
TS4890IQT - DFN8
STANDBY
1
8
VOUT 2
BYPASS
2
7
GND
VIN+
3
6
Vcc
VIN-
4
5
VOUT 1
The unity-gain stable amplifier can be configured
by external gain setting resistors.
TYPICAL APPLICATION SCHEMATIC
APPLICATIONS
■ Mobile Phones (Cellular / Cordless)
■ Laptop / Notebook Computers
■ PDAs
■ Portable Audio Devices
Cfeed
Rfeed
Rin
-40, +85°C
-
Vout1 5
+
Q
•
•
4890I
4890
4890
2
Bypass
1
Standby
Av=-1
+
Rstb
Cb
Vout2
8
Bias
GND
D
Vin+
Vcc
Marking
S
Vin-
RL
8 Ohms
Package
•
TS4890
4
3
ORDER CODE
Cs
Vcc
Audio
Input
Cin
Part
Temperature
Number
Range
Vcc
6
TS4890
7
MiniSO & DFN only available in Tape & Reel: with T suffix.
SO is available in Tube (D) and of Tape & Reel (DT)
June 2003
1/32
TS4890
ABSOLUTE MAXIMUM RATINGS
Symbol
VCC
Vi
Supply voltage
2)
Value
Unit
6
V
GND to VCC
V
Toper
Operating Free Air Temperature Range
-40 to + 85
°C
Tstg
Storage Temperature
Tj
Rthja
Pd
ESD
ESD
1.
2.
3.
4.
Parameter
1)
Input Voltage
-65 to +150
°C
Maximum Junction Temperature
150
°C
Thermal Resistance Junction to Ambient3)
SO8
MiniSO8
DFN8
175
215
70
See Power Derating Curves
Fig. 24
2
200
Class A
260
Power Dissipation4)
Human Body Model
Machine Model
Latch-up Immunity
Lead Temperature (soldering, 10sec)
°C/W
W
kV
V
°C
All voltages values are measured with respect to the ground pin.
The magnitude of input signal must never exceed VCC + 0.3V / G ND - 0.3V
Device is protected in case of over temperature by a thermal shutdown active @ 150°C.
Exceeding the power derating curves during a long period may involve abnormal working of the device.
OPERATING CONDITIONS
Symbol
VCC
VICM
VSTB
RL
Parameter
Supply Voltage
Value
Unit
2.2 to 5.5
V
Common Mode Input Voltage Range
GND + 1V to VCC
V
Standby Voltage Input :
Device ON
Device OFF
1.5 ≤ VSTB ≤ VCC
GND ≤ VSTB ≤ 0.5
V
4 - 32
Ω
Load Resistor
1)
Rthja
Thermal Resistance Junction to Ambient
SO8
MiniSO8
DFN8 2)
1. This thermal resistance can be reduced with a suitable PCB layout (see Power Derating Curves Fig. 24)
2. When mounted on a 4 layers PCB
2/32
150
190
41
°C/W
TS4890
ELECTRICAL CHARACTERISTICS
VCC = +5V, GND = 0V, Tamb = 25°C (unless otherwise specified)
Symbol
Typ.
Max.
Unit
Supply Current
No input signal, no load
6
8
mA
Standby Current 1)
No input signal, Vstdby = GND, RL = 8Ω
10
1000
nA
Voo
Output Offset Voltage
No input signal, RL = 8Ω
5
20
mV
Po
Output Power
THD = 1% Max, f = 1kHz, RL = 8Ω
1
W
0.15
%
Power Supply Rejection Ratio2)
f = 217Hz, RL = 8Ω, RFeed = 22KΩ, Vripple = 200mV rms
77
dB
ΦM
Phase Margin at Unity Gain
RL = 8Ω, CL = 500pF
70
Degrees
GM
Gain Margin
RL = 8Ω, CL = 500pF
20
dB
GBP
Gain Bandwidth Product
RL = 8Ω
2
MHz
ICC
ISTANDBY
THD + N
PSRR
Parameter
Min.
Total Harmonic Distortion + Noise
Po = 250mW rms, Gv = 2, 20Hz < f < 20kHz, RL = 8Ω
1. Standby mode is actived when Vstdby is tied to GND
2. Dynamic measurements - 20*log(rms(Vout)/rms(Vripple)). Vripple is the surimposed sinus signal to Vcc @ f = 217Hz
VCC = +3.3V, GND = 0V, Tamb = 25°C (unless otherwise specified)
Symbol
Typ.
Max.
Unit
Supply Current
No input signal, no load
5.5
8
mA
Standby Current 1)
No input signal, Vstdby = GND, RL = 8Ω
10
1000
nA
Voo
Output Offset Voltage
No input signal, RL = 8Ω
5
20
mV
Po
Output Power
THD = 1% Max, f = 1kHz, RL = 8Ω
450
mW
Total Harmonic Distortion + Noise
Po = 250mW rms, Gv = 2, 20Hz < f < 20kHz, RL = 8Ω
0.15
%
Power Supply Rejection Ratio2)
f = 217Hz, RL = 8Ω, RFeed = 22KΩ, Vripple = 200mV rms
77
dB
ΦM
Phase Margin at Unity Gain
RL = 8Ω, CL = 500pF
70
Degrees
GM
Gain Margin
RL = 8Ω, CL = 500pF
20
dB
GBP
Gain Bandwidth Product
RL = 8Ω
2
MHz
ICC
ISTANDBY
THD + N
PSRR
Parameter
Min.
1. Standby mode is actived when Vstdby is tied to GND
2. Dynamic measurements - 20*log(rms(Vout)/rms(Vripple)). Vripple is the surimposed sinus signal to Vcc @ f = 217Hz
3/32
TS4890
VCC = 2.6V, GND = 0V, Tamb = 25°C (unless otherwise specified)
Symbol
Typ.
Max.
Unit
Supply Current
No input signal, no load
5
8
mA
Standby Current 1)
No input signal, Vstdby = GND, RL = 8Ω
10
1000
nA
Voo
Output Offset Voltage
No input signal, RL = 8Ω
5
20
mV
Po
Output Power
THD = 1% Max, f = 1kHz, RL = 8Ω
260
mW
Total Harmonic Distortion + Noise
Po = 200mW rms, Gv = 2, 20Hz < f < 20kHz, RL = 8Ω
0.15
%
Power Supply Rejection Ratio2)
f = 217Hz, RL = 8Ω, RFeed = 22KΩ, Vripple = 200mV rms
77
dB
ΦM
Phase Margin at Unity Gain
RL = 8Ω, CL = 500pF
70
Degrees
GM
Gain Margin
RL = 8Ω, CL = 500pF
20
dB
GBP
Gain Bandwidth Product
RL = 8Ω
2
MHz
ICC
ISTANDBY
THD + N
PSRR
Parameter
Min.
1. Standby mode is actived when Vstdby is tied to GND
2. Dynamic measurements - 20*log(rms(Vout)/rms(Vripple)). Vripple is the surimposed sinus signal to Vcc @ f = 217Hz
VCC = 2.2V, GND = 0V, Tamb = 25°C (unless otherwise specified)
Symbol
Typ.
Max.
Unit
Supply Current
No input signal, no load
5
8
mA
Standby Current 1)
No input signal, Vstdby = GND, RL = 8Ω
10
1000
nA
Voo
Output Offset Voltage
No input signal, RL = 8Ω
5
20
mV
Po
Output Power
THD = 1% Max, f = 1kHz, RL = 8Ω
180
mW
Total Harmonic Distortion + Noise
Po = 200mW rms, Gv = 2, 20Hz < f < 20kHz, RL = 8Ω
0.15
%
Power Supply Rejection Ratio2)
f = 217Hz, RL = 8Ω, RFeed = 22KΩ, Vripple = 100mV rms
77
dB
ΦM
Phase Margin at Unity Gain
RL = 8Ω, CL = 500pF
70
Degrees
GM
Gain Margin
RL = 8Ω, CL = 500pF
20
dB
GBP
Gain Bandwidth Product
RL = 8Ω
2
MHz
ICC
ISTANDBY
THD + N
PSRR
Parameter
Min.
1. Standby mode is actived when Vstdby is tied to GND
2. Dynamic measurements - 20*log(rms(Vout)/rms(Vripple)). Vripple is the surimposed sinus signal to Vcc @ f = 217Hz
4/32
TS4890
Components
Functional Description
Rin
Inverting input resistor which sets the closed loop gain in conjunction with Rfeed. This resistor also
forms a high pass filter with Cin (fc = 1 / (2 x Pi x Rin x Cin))
Cin
Input coupling capacitor which blocks the DC voltage at the amplifier input terminal
Rfeed
Feed back resistor which sets the closed loop gain in conjunction with Rin
Cs
Supply Bypass capacitor which provides power supply filtering
Cb
Bypass pin capacitor which provides half supply filtering
Cfeed
Rstb
Gv
Low pass filter capacitor allowing to cut the high frequency
(low pass filter cut-off frequency 1 / (2 x Pi x Rfeed x Cfeed))
Pull-down resistor which fixes the right supply level on the standby pin
Closed loop gain in BTL configuration = 2 x (Rfeed / Rin)
REMARKS
1. All measurements, except PSRR measurements, are made with a supply bypass capacitor Cs = 100µF.
1. External resistors are not needed for having better stability when supply @ Vcc down to 3V. The
quiescent current still remains the same.
2. The standby response time is about 1µs.
5/32
TS4890
Fig. 1 : Open Loop Frequency Response
Fig. 2 : Open Loop Frequency Response
0
-140
0
-120
-140
0
-160
-180
1
10
100
1000
10000
-180
-20
-200
-220
-40
0.3
1
10
Frequency (kHz)
Fig. 3 : Open Loop Frequency Response
Vcc = 3.3V
RL = 8Ω
Tamb = 25°C
-100
-120
20
-140
-160
0
Gain
-60
Phase (Deg)
Gain (dB)
Phase
Vcc = 3.3V
ZL = 8Ω + 560pF
Tamb = 25°C
Phase
10
100
1000
Frequency (kHz)
10000
-140
-160
-180
-200
-20
-220
-40
0.3
-240
Fig. 5 : Open Loop Frequency Response
Gain
60
Vcc = 2.6V
RL = 8Ω
Tamb = 25°C
Gain
-60
-120
20
-140
-160
0
10000
Vcc = 2.6V
ZL = 8Ω + 560pF
Tamb = 25°C
Phase
-200
6/32
1
10
100
1000
Frequency (kHz)
10000
-240
-40
-60
-120
-140
-160
0
-180
-200
-20
-220
-220
-40
0.3
-20
-100
20
-180
-20
-240
-80
40
Gain (dB)
-100
100
1000
Frequency (kHz)
0
60
-40
Phase (Deg)
Gain (dB)
Phase
10
80
-20
-80
40
1
Fig. 6 : Open Loop Frequency Response
0
80
-60
-120
0
-200
1
-40
-100
20
-220
-40
0.3
-20
-80
40
-180
-20
-220
0
60
-40
-80
40
10000
80
-20
Gain (dB)
Gain
60
100
1000
Frequency (kHz)
Fig. 4 : Open Loop Frequency Response
0
80
-60
-100
20
-200
-40
0.3
-40
-80
Phase
-160
-20
-20
Phase (Deg)
-120
40
Vcc = 5V
ZL = 8Ω + 560pF
Tamb = 25°C
Phase (Deg)
Gain (dB)
-60
-100
20
Gain
-40
-80
Phase
60
-40
0.3
1
10
100
1000
Frequency (kHz)
10000
-240
Phase (Deg)
40
0
-20
Gain (dB)
Vcc = 5V
RL = 8Ω
Tamb = 25°C
Gain
Phase (Deg)
60
TS4890
Fig. 7 : Open Loop Frequency Response
60
-60
-120
20
-140
-160
0
Gain (dB)
-100
Phase
-120
-140
-160
0
-180
-200
-20
-200
-220
-220
10
100
1000
Frequency (kHz)
10000
-40
0.3
-240
Fig. 9 : Open Loop Frequency Response
80
Phase
60
-80
100
-100
80
-120
60
Gain (dB)
Gain
-140
40
-160
20
0
-20
-40
0.3
-180
10
-80
100
-100
80
-140
40
-160
20
-180
0
-20
-40
0.3
-200
Vcc = 2.6V
CL = 560pF
Tamb = 25°C
1
10
100
1000
Frequency (kHz)
10000
-120
-140
-200
Vcc = 3.3V
CL = 560pF
Tamb = 25°C
1
10
-220
100
1000
Frequency (kHz)
10000
-240
-80
-100
Phase
-120
60
Phase (Deg)
Gain (dB)
Gain
-100
Phase
Fig. 12 : Open Loop Frequency Response
-120
60
-80
-180
-40
0.3
10000
Phase
-240
-160
-220
Fig. 11 : Open Loop Frequency Response
80
10000
20
-20
100
100
1000
Frequency (kHz)
40
-200
100
1000
Frequency (kHz)
10
Gain
0
Vcc = 5V
CL = 560pF
Tamb = 25°C
1
Phase (Deg)
100
1
Fig. 10 : Open Loop Frequency Response
Gain (dB)
1
Gain
Gain (dB)
-40
0.3
-60
-100
20
-180
-20
-40
-80
40
Phase (Deg)
Phase
-20
Phase (Deg)
-40
-80
40
Vcc = 2.2V
RL = 8Ω, + 560pF
Tamb = 25°C
Gain
Phase (Deg)
Gain
60
-20
-140
40
-160
20
-180
0
-220
-20
-240
-40
0.3
-200
Vcc = 2.2V
CL = 560pF
Tamb = 25°C
1
Phase (Deg)
Vcc = 2.2V
RL = 8Ω
Tamb = 25°C
0
80
0
80
Gain (dB)
Fig. 8 : Open Loop Frequency Response
-220
10
100
1000
Frequency (kHz)
10000
-240
7/32
TS4890
Fig. 13 : Power Supply Rejection Ratio (PSRR)
vs Power supply
Fig. 14 : Power Supply Rejection Ratio (PSRR)
vs Feedback Capacitor
-10
-30
-50
-60
-20
-30
PSRR (dB)
PSRR (dB)
-40
Vripple = 200mVrms
Rfeed = 22kΩ
Input = floating
RL = 8Ω
Tamb = 25°C
Vcc = 5V to 2.2V
Cb = 1µF & 0.1µF
-40
Vcc = 5 to 2.2V
Cb = 1µF & 0.1µF
Rfeed = 22kΩ
Vripple = 200mVrms
Input = floating
RL = 8Ω
Tamb = 25°C
Cfeed=0
Cfeed=150pF
Cfeed=330pF
-50
-60
-70
-70
Cfeed=680pF
-80
10
100
1000
10000
Frequency (Hz)
-80
10
100000
Fig. 15 : Power Supply Rejection Ratio (PSRR)
vs Bypass Capacitor
Cb=10µF
PSRR (dB)
-30
-40
Cin=1µF
-20
Cb=47µF
-50
100000
Vcc = 5 to 2.2V
Rfeed = 22k, Rin = 22k
Cb = 1µF
Rg = 100Ω, RL = 8Ω
Tamb = 25°C
Cin=330nF
PSRR (dB)
-20
-10
Vcc = 5 to 2.2V
Rfeed = 22k
Rin = 22k, Cin = 1µF
Rg = 100Ω, RL = 8Ω
Tamb = 25°C
1000
10000
Frequency (Hz)
Fig. 16 : Power Supply Rejection Ratio (PSRR)
vs Input Capacitor
-10
Cb=1µF
100
Cin=220nF
-30
-40
-60
Cin=100nF
-50
-70
Cin=22nF
Cb=100µF
-80
10
100
1000
10000
-60
10
100000
100
Frequency (Hz)
Fig. 17 : Power Supply Rejection Ratio (PSRR)
vs Feedback Resistor
-40
Rfeed=110kΩ
Rfeed=47kΩ
-50
-60
Rfeed=22kΩ
-70
-80
10
8/32
100000
1.4
Vcc = 5 to 2.2V
Cb = 1µF & 0.1µF
Vripple = 200mVrms
Input = floating
RL = 8Ω
Tamb = 25°C
Rfeed=10kΩ
100
1000
10000
Frequency (Hz)
100000
Output power @ 1% THD + N (W)
PSRR (dB)
-30
10000
Fig. 18 : Pout @ THD + N = 1% vs Supply
Voltage vs RL
-10
-20
1000
Frequency (Hz)
1.2
1.0
8Ω
Gv = 2 & 10
Cb = 1µF
F = 1kHz
BW < 125kHz
Tamb = 25°C
6Ω
4Ω
0.8
16Ω
0.6
0.4
0.2
32Ω
0.0
2.5
3.0
3.5
4.0
Vcc (V)
4.5
5.0
TS4890
Fig. 19 : Pout @ THD + N = 10% vs Supply
Voltage vs RL
Fig. 20 : Power Dissipation vs Pout
1.4
1.8
1.6
1.4
Gv = 2 & 10
Cb = 1µF
F = 1kHz
BW < 125kHz
Tamb = 25°C
8Ω
Power Dissipation (W)
Output power @ 10% THD + N (W)
2.0
6Ω
4Ω
1.2
1.0
16Ω
0.8
0.6
Vcc=5V
1.2 F=1kHz
THD+N<1%
RL=4Ω
1.0
0.8
0.6
RL=8Ω
0.4
0.4
0.2
0.0
2.5
0.2
32Ω
3.0
3.5
4.0
4.5
RL=16Ω
0.0
0.0
5.0
0.2
0.4
Vcc (V)
0.6
0.40
Vcc=3.3V
F=1kHz
0.5 THD+N<1%
0.35
RL=4Ω
0.4
0.3
0.2
RL=8Ω
0.4
0.6
0.25
0.20
0.15
RL=8Ω
RL=16Ω
0.00
0.0
0.8
0.1
0.2
0.3
0.4
Output Power (W)
Fig. 23 : Power Dissipation vs Pout
Fig. 24 : Power Derating Curves
0.40
2.0
Vcc=2.6V
0.35 F=1kHz
THD+N<1%
0.30
1.8
1.6
RL=4Ω
0.25
0.20
0.15
RL=8Ω
0.10
Power Dissipation (W)
Power Dissipation (W)
1.4
RL=4Ω
0.30
Output Power (W)
0.00
0.0
1.2
Vcc=2.6V
F=1kHz
THD+N<1%
0.05
RL=16Ω
0.05
1.0
0.10
0.1
0.2
0.8
Fig. 22 : Power Dissipation vs Pout
Power Dissipation (W)
Power Dissipation (W)
Fig. 21 : Power Dissipation vs Pout
0.0
0.0
0.6
Output Power (W)
QFN8
1.4
1.2
1.0
SO8
0.8
0.6
0.4
0.0
0.1
0.2
Output Power (W)
MiniSO8
0.2
RL=16Ω
0.3
0
25
50
75
100
125
150
Ambiant Temperature (°C)
9/32
TS4890
Fig. 25 : THD + N vs Output Power
Fig. 26 : THD + N vs Output Power
10
10
RL = 4Ω, Vcc = 5V
Gv = 10
Cb = Cin = 1µF
BW < 125kHz, Tamb = 25°C
THD + N (%)
THD + N (%)
Rl = 4Ω
Vcc = 5V
Gv = 2
Cb = Cin = 1µF
BW < 125kHz
Tamb = 25°C
1
20kHz
20kHz
1
20Hz
20Hz, 1kHz
0.1
1E-3
1kHz
0.01
0.1
Output Power (W)
0.1
1E-3
1
Fig. 27 : THD + N vs Output Power
1
Fig. 28 : THD + N vs Output Power
10
10
RL = 4Ω, Vcc = 3.3V
Gv = 2
Cb = Cin = 1µF
BW < 125kHz
Tamb = 25°C
THD + N (%)
THD + N (%)
0.01
0.1
Output Power (W)
1
RL = 4Ω, Vcc = 3.3V
Gv = 10
Cb = Cin = 1µF
BW < 125kHz
Tamb = 25°C
20kHz
1
20kHz
0.1
20Hz
1kHz
20Hz, 1kHz
0.1
1E-3
0.01
0.1
Output Power (W)
1
Fig. 29 : THD + N vs Output Power
0.01
0.1
Output Power (W)
10
RL = 4Ω, Vcc = 2.6V
Gv = 2
Cb = Cin = 1µF
BW < 125kHz
Tamb = 25°C
1
RL = 4Ω, Vcc = 2.6V
Gv = 10
Cb = Cin = 1µF
BW < 125kHz
Tamb = 25°C
1
20kHz
20kHz
20Hz
0.1
20Hz, 1kHz
0.1
1E-3
10/32
1
Fig. 30 : THD + N vs Output Power
THD + N (%)
THD + N (%)
10
1E-3
0.01
Output Power (W)
0.1
1E-3
1kHz
0.01
Output Power (W)
0.1
TS4890
Fig. 31 : THD + N vs Output Power
Fig. 32 : THD + N vs Output Power
10
10
RL = 4Ω, Vcc = 2.2V
Gv = 10
Cb = Cin = 1µF
BW < 125kHz
Tamb = 25°C
THD + N (%)
THD + N (%)
RL = 4Ω, Vcc = 2.2V
Gv = 2
Cb = Cin = 1µF
BW < 125kHz
Tamb = 25°C
1
20kHz
1
20kHz
20Hz
0.1
1kHz
20Hz, 1kHz
0.1
1E-3
0.01
Output Power (W)
0.1
1E-3
Fig. 33 : THD + N vs Output Power
0.1
Fig. 34 : THD + N vs Output Power
10
10
RL = 8Ω
Vcc = 5V
Gv = 2
Cb = Cin = 1µF
BW < 125kHz
Tamb = 25°C
1
20Hz, 1kHz
THD + N (%)
THD + N (%)
0.01
Output Power (W)
20kHz
RL = 8Ω
Vcc = 5V
Gv = 10
Cb = Cin = 1µF
BW < 125kHz
Tamb = 25°C
1
20Hz
20kHz
0.1
0.1
1kHz
1E-3
0.01
0.1
Output Power (W)
1E-3
1
1
Fig. 36 : THD + N vs Output Power
Fig. 35 : THD + N vs Output Power
10
10
RL = 8Ω, Vcc = 3.3V
Gv = 2
Cb = Cin = 1µF
BW < 125kHz
Tamb = 25°C
THD + N (%)
THD + N (%)
0.01
0.1
Output Power (W)
1
20Hz, 1kHz
RL = 8Ω, Vcc = 3.3V
Gv = 10
Cb = Cin = 1µF
BW < 125kHz
Tamb = 25°C
1
20Hz
20kHz
20kHz
0.1
0.1
1kHz
1E-3
0.01
0.1
Output Power (W)
1
1E-3
0.01
0.1
Output Power (W)
1
11/32
TS4890
Fig. 37 : THD + N vs Output Power
Fig. 38 : THD + N vs Output Power
10
RL = 8Ω, Vcc = 2.6V
Gv = 2
Cb = Cin = 1µF
BW < 125kHz
Tamb = 25°C
THD + N (%)
THD + N (%)
10
1
0.1
0.01
Output Power (W)
0.1
20kHz
1kHz
1E-3
Fig. 39 : THD + N vs Output Power
0.01
Output Power (W)
0.1
Fig. 40 : THD + N vs Output Power
10
10
RL = 8Ω, Vcc = 2.2V
Gv = 2
Cb = Cin = 1µF
BW < 125kHz
Tamb = 25°C
THD + N (%)
THD + N (%)
20Hz
0.1
1E-3
1
1kHz
RL = 8Ω, Vcc = 2.2V
Gv = 10
Cb = Cin = 1µF
BW < 125kHz
Tamb = 25°C
1
20Hz
20kHz
20kHz
20Hz
0.1
1kHz
0.1
1E-3
0.01
Output Power (W)
0.1
1E-3
Fig. 41 : THD + N vs Output Power
0.01
Output Power (W)
0.1
Fig. 42 : THD + N vs Output Power
10
10
RL = 8Ω
Vcc = 5V
Gv = 2
Cb = 0.1µF, Cin = 1µF
BW < 125kHz
Tamb = 25°C
20kHz
RL = 8Ω, Vcc = 5V, Gv = 10
Cb = 0.1µF, Cin = 1µF
BW < 125kHz, Tamb = 25°C
20Hz
THD + N (%)
THD + N (%)
1
20kHz
20Hz, 1kHz
1
RL = 8Ω, Vcc = 2.6V
Gv = 10
Cb = Cin = 1µF
BW < 125kHz
Tamb = 25°C
20Hz
1kHz
1
20kHz
1kHz
0.1
1E-3
12/32
0.1
0.01
0.1
Output Power (W)
1
1E-3
0.01
0.1
Output Power (W)
1
TS4890
Fig. 43 : THD + N vs Output Power
Fig. 44 : THD + N vs Output Power
10
RL = 8Ω, Vcc = 3.3V
Gv = 2
Cb = 0.1µF, Cin = 1µF
BW < 125kHz
Tamb = 25°C
RL = 8Ω, Vcc = 3.3V, Gv = 10
Cb = 0.1µF, Cin = 1µF
BW < 125kHz, Tamb = 25°C
THD + N (%)
THD + N (%)
10
1
20Hz
20kHz
1
20kHz
20Hz
1kHz
1kHz
0.1
0.1
1E-3
0.01
0.1
Output Power (W)
1
Fig. 45 : THD + N vs Output Power
1
10
RL = 8Ω, Vcc = 2.6V
Gv = 2
Cb = 0.1µF, Cin = 1µF
BW < 125kHz
Tamb = 25°C
RL = 8Ω, Vcc = 2.6V, Gv = 10
Cb = 0.1µF, Cin = 1µF
BW < 125kHz, Tamb = 25°C
1
20Hz
20kHz
1
20kHz
1kHz
0.1
1E-3
0.01
Output Power (W)
0.1
1E-3
Fig. 47 : THD + N vs Output Power
10
0.01
Output Power (W)
0.1
Fig. 48 : THD + N vs Output Power
10
RL = 8Ω, Vcc = 2.2V, Gv = 10
Cb = 0.1µF, Cin = 1µF
BW < 125kHz, Tamb = 25°C
THD + N (%)
RL = 8Ω, Vcc = 2.2V
Gv = 2
Cb = Cin = 1µF
BW < 125kHz
Tamb = 25°C
1
20Hz
20kHz
1
20kHz
1kHz
20Hz
1kHz
0.1
1E-3
20Hz
1kHz
0.1
THD + N (%)
0.01
0.1
Output Power (W)
Fig. 46 : THD + N vs Output Power
THD + N (%)
THD + N (%)
10
1E-3
0.1
0.01
Output Power (W)
0.1
1E-3
0.01
Output Power (W)
0.1
13/32
TS4890
Fig. 49 : THD + N vs Output Power
Fig. 50 : THD + N vs Output Power
10
10
20kHz
RL = 16Ω, Vcc = 5V
Gv = 10
Cb = Cin = 1µF
BW < 125kHz
Tamb = 25°C
1
THD + N (%)
THD + N (%)
1
RL = 16Ω, Vcc = 5V
Gv = 2
Cb = Cin = 1µF
BW < 125kHz
Tamb = 25°C
20kHz
0.1
0.1
1kHz
20Hz, 1kHz
0.01
1E-3
0.01
0.1
Output Power (W)
1
Fig. 51 : THD + N vs Output Power
0.01
1E-3
20kHz
0.1
1
RL = 16Ω
Vcc = 3.3V
Gv = 10
Cb = Cin = 1µF
BW < 125kHz
Tamb = 25°C
20kHz
0.1
1kHz
20Hz
20Hz, 1kHz
0.01
1E-3
0.01
Output Power (W)
0.01
1E-3
0.1
Fig. 53 : THD + N vs Output Power
THD + N (%)
THD + N (%)
0.1
10
RL = 16Ω
Vcc = 2.6V
Gv = 2
Cb = Cin = 1µF
BW < 125kHz
Tamb = 25°C
20kHz
0.1
1
RL = 16Ω
Vcc = 2.6V
Gv = 10
Cb = Cin = 1µF
BW < 125kHz
Tamb = 25°C
20Hz
20kHz
0.1
20Hz, 1kHz
0.01
1E-3
14/32
0.01
Output Power (W)
Fig. 54 : THD + N vs Output Power
10
1
1
10
RL = 16Ω, Vcc = 3.3V
Gv = 2
Cb = Cin = 1µF
BW < 125kHz
Tamb = 25°C
THD + N (%)
THD + N (%)
0.01
0.1
Output Power (W)
Fig. 52 : THD + N vs Output Power
10
1
20Hz
0.01
Output Power (W)
1kHz
0.1
0.01
1E-3
0.01
Output Power (W)
0.1
TS4890
Fig. 55 : THD + N vs Output Power
Fig. 56 : THD + N vs Output Power
1
10
RL = 16Ω Vcc = 2.2V
Gv = 10, Cb = Cin = 1µF
BW < 125kHz, Tamb = 25°C
RL = 16Ω
Vcc = 2.2V
Gv = 2
Cb = Cin = 1µF
BW < 125kHz
Tamb = 25°C
THD + N (%)
THD + N (%)
10
20kHz
20Hz
0.1
1
20kHz
0.1
20Hz
1kHz
0.01
1E-3
1kHz
0.01
Output Power (W)
0.1
Fig. 57 : THD + N vs Frequency
100
1
Pout = 1.2W
1000
Frequency (Hz)
RL = 4Ω, Vcc = 5V
Gv = 10
Cb = 1µF
BW < 125kHz
Tamb = 25°C
100
RL = 4Ω, Vcc = 3.3V
Gv = 2
Cb = 1µF
BW < 125kHz
Tamb = 25°C
1
Pout = 540mW
100
1000
Frequency (Hz)
10000
RL = 4Ω, Vcc = 3.3V
Gv = 10
Cb = 1µF
BW < 125kHz
Tamb = 25°C
Pout = 540mW
Pout = 270mW
0.1
20
1000
Frequency (Hz)
Fig. 60 : THD + N vs Frequency
THD + N (%)
THD + N (%)
Pout = 600mW
0.1
0.01
20
10000
Fig. 59 : THD + N vs Frequency
1
0.1
Pout = 1.2W
RL = 4Ω, Vcc = 5V
Gv = 2
Cb = 1µF
BW < 125kHz
Tamb = 25°C
Pout = 600mW
0.1
20
0.01
Output Power (W)
Fig. 58 : THD + N vs Frequency
THD + N (%)
THD + N (%)
1
0.01
1E-3
Pout = 270mW
10000
0.1
20
100
1000
Frequency (Hz)
10000
15/32
TS4890
Fig. 61 : THD + N vs Frequency
RL = 4Ω, Vcc = 2.6V
Gv = 2
Cb = 1µF
BW < 125kHz
Tamb = 25°C
RL = 4Ω, Vcc = 2.6V
Gv = 10
Cb = 1µF
BW < 125kHz
Tamb = 25°C
1
Pout = 240mW
THD + N (%)
THD + N (%)
1
Fig. 62 : THD + N vs Frequency
Pout = 240 & 120mW
Pout = 120mW
0.1
20
100
1000
Frequency (Hz)
Fig. 63 : THD + N vs Frequency
100
1000
Frequency (Hz)
10000
Fig. 64 : THD + N vs Frequency
RL = 4Ω, Vcc = 2.2V
Gv = 2
Cb = 1µF
BW < 125kHz
Tamb = 25°C
1
THD + N (%)
THD + N (%)
1
0.1
20
10000
Pout = 175mW
RL = 4Ω, Vcc = 2.2V
Gv = 10
Cb = 1µF
BW < 125kHz
Tamb = 25°C
Pout = 175mW
Pout = 88mW
Pout = 88mW
0.1
20
100
1000
Frequency (Hz)
0.1
20
10000
Fig. 65 : THD + N vs Frequency
100
1000
Frequency (Hz)
10000
Fig. 66 : THD + N vs Frequency
1
Cb = 0.1µF
Cb = 1µF
RL = 8Ω
Vcc = 5V
Gv = 2
Pout = 450mW
BW < 125kHz
Tamb = 25°C
THD + N (%)
THD + N (%)
1
RL = 8Ω
Vcc = 5V
Gv = 2
Pout = 900mW
BW < 125kHz
Tamb = 25°C
Cb = 0.1µF
Cb = 1µF
0.1
20
16/32
100
1000
Frequency (Hz)
10000
0.1
20
100
1000
Frequency (Hz)
10000
TS4890
Fig. 67 : THD + N vs Frequency
Fig. 68 : THD + N vs Frequency
THD + N (%)
1
Cb = 0.1µF
1
Cb = 0.1µF
Cb = 1µF
Cb = 1µF
0.1
20
0.1
100
1000
Frequency (Hz)
10000
Fig. 69 : THD + N vs Frequency
20
1000
Frequency (Hz)
10000
1
Cb = 0.1µF
Cb = 1µF
RL = 8Ω, Vcc = 3.3V
Gv = 2
Pout = 200mW
BW < 125kHz
Tamb = 25°C
THD + N (%)
THD + N (%)
RL = 8Ω, Vcc = 3.3V
Gv = 2
Pout = 400mW
BW < 125kHz
Tamb = 25°C
0.1
Cb = 0.1µF
Cb = 1µF
0.1
1000
Frequency (Hz)
10000
100
1000
Frequency (Hz)
10000
Fig. 72 : THD + N vs Frequency
RL = 8Ω, Vcc = 3.3V
Gv = 10
Pout = 400mW
BW < 125kHz
Tamb = 25°C
1
20
Cb = 0.1µF
Cb = 1µF
RL = 8Ω, Vcc = 3.3V
Gv = 10
Pout = 200mW
BW < 125kHz
Tamb = 25°C
1
THD + N (%)
100
Fig. 71 : THD + N vs Frequency
THD + N (%)
100
Fig. 70 : THD + N vs Frequency
1
20
RL = 8Ω, Vcc = 5V
Gv = 10
Pout = 450mW
BW < 125kHz
Tamb = 25°C
THD + N (%)
RL = 8Ω, Vcc = 5V
Gv = 10
Pout = 900mW
BW < 125kHz
Tamb = 25°C
Cb = 0.1µF
Cb = 1µF
0.1
0.1
20
100
1000
Frequency (Hz)
10000
20
100
1000
Frequency (Hz)
10000
17/32
TS4890
Fig. 73 : THD + N vs Frequency
Fig. 74 : THD + N vs Frequency
1
1
Cb = 1µF
RL = 8Ω, Vcc = 2.6V
Gv = 2
Pout = 110mW
BW < 125kHz
Tamb = 25°C
THD + N (%)
THD + N (%)
Cb = 0.1µF
RL = 8Ω, Vcc = 2.6V
Gv = 2
Pout = 220mW
BW < 125kHz
Tamb = 25°C
Cb = 0.1µF
Cb = 1µF
0.1
0.1
100
1000
Frequency (Hz)
10000
Fig. 75 : THD + N vs Frequency
THD + N (%)
100
1000
Frequency (Hz)
10000
Fig. 76 : THD + N vs Frequency
RL = 8Ω, Vcc = 2.6V
Gv = 10
Pout = 220mW
BW < 125kHz
Tamb = 25°C
1
20
Cb = 0.1µF
1
Cb = 0.1µF
THD + N (%)
20
RL = 8Ω, Vcc = 2.6V
Gv = 10
Pout = 110mW
BW < 125kHz
Tamb = 25°C
Cb = 1µF
Cb = 1µF
0.1
0.1
20
100
1000
Frequency (Hz)
10000
Fig. 77 : THD + N vs Frequency
20
100
1000
Frequency (Hz)
10000
Fig. 78 : THD + N vs Frequency
1
1
Cb = 1µF
RL = 8Ω, Vcc = 2.2V
Gv = 2
Pout = 75mW
BW < 125kHz
Tamb = 25°C
THD + N (%)
THD + N (%)
Cb = 0.1µF
RL = 8Ω, Vcc = 2.2V
Gv = 2
Pout = 150mW
BW < 125kHz
Tamb = 25°C
Cb = 0.1µF
Cb = 1µF
0.1
20
18/32
0.1
100
1000
Frequency (Hz)
10000
20
100
1000
Frequency (Hz)
10000
TS4890
Fig. 80 : THD + N vs Frequency
RL = 8Ω, Vcc = 2.2V
Gv = 10
Pout = 150mW
BW < 125kHz
Tamb = 25°C
THD + N (%)
1
Cb = 0.1µF
RL = 8Ω, Vcc = 2.2V
Gv = 10
Pout = 72mW
BW < 125kHz
Tamb = 25°C
1
Cb = 0.1µF
THD + N (%)
Fig. 79 : THD + N vs Frequency
Cb = 1µF
Cb = 1µF
0.1
0.1
20
100
1000
Frequency (Hz)
20
10000
1000
Frequency (Hz)
10000
Fig. 82 : THD + N vs Frequency
Fig. 81 : THD + N vs Frequency
1
1
RL = 16Ω, Vcc = 5V
Gv = 10, Cb = 1µF
BW < 125kHz
Tamb = 25°C
THD + N (%)
RL = 16Ω, Vcc = 5V
Gv = 2, Cb = 1µF
BW < 125kHz
Tamb = 25°C
THD + N (%)
100
Pout = 310mW
0.1
Pout = 620mW
0.1
Pout = 310mW
Pout = 620mW
0.01
20
100
1000
Frequency (Hz)
10000
0.01
20
1000
Frequency (Hz)
10000
Fig. 84 : THD + N vs Frequency
Fig. 83 : THD + N vs Frequency
1
1
THD + N (%)
RL = 16Ω, Vcc = 3.3V
Gv = 2, Cb = 1µF
BW < 125kHz
Tamb = 25°C
THD + N (%)
100
Pout = 270mW
0.1
RL = 16Ω, Vcc = 3.3V
Gv = 10
Cb = 1µF
BW < 125kHz
Tamb = 25°C
Pout = 270mW
0.1
Pout = 135mW
Pout = 135mW
0.01
20
100
1000
Frequency (Hz)
10000
20
100
1000
Frequency (Hz)
10000
19/32
TS4890
Fig. 85 : THD + N vs Frequency
Fig. 86 : THD + N vs Frequency
1
1
RL = 16Ω, Vcc = 2.6V
Gv = 2, Cb = 1µF
BW < 125kHz
Tamb = 25°C
Pout = 160mW
THD + N (%)
THD + N (%)
RL = 16Ω, Vcc = 2.6V
Gv = 10, Cb = 1µF
BW < 125kHz
Tamb = 25°C
0.1
Pout = 80mW
0.1
Pout = 80mW
0.01
20
100
1000
Frequency (Hz)
Pout = 160mW
0.01
20
10000
1000
Frequency (Hz)
10000
Fig. 88 : THD + N vs Frequency
Fig. 87 : THD + N vs Frequency
1
1
RL = 16Ω, Vcc = 2.2V
Gv = 10, Cb = 1µF
BW < 125kHz
Tamb = 25°C
THD + N (%)
RL = 16Ω, Vcc = 2.2V
Gv = 2, Cb = 1µF
BW < 125kHz
Tamb = 25°C
THD + N (%)
100
Pout = 50 & 100mW
0.1
Pout = 50mW
0.1
Pout = 100mW
0.01
20
100
1000
Frequency (Hz)
0.01
20
10000
Fig. 89 : Signal to Noise Ratio vs Power Supply
with Unweighted Filter (20Hz to 20kHz)
80
RL=8Ω
RL=4Ω
SNR (dB)
RL=16Ω
SNR (dB)
10000
90
90
80
70
Gv = 2
Cb = Cin = 1µF
THD+N < 0.4%
Tamb = 25°C
60
20/32
1000
Frequency (Hz)
Fig. 90 :Signal to Noise Ratio Vs Power Supply
with Unweighted Filter (20Hz to 20kHz)
100
50
2.2
100
2.5
3.0
3.5
Vcc (V)
4.0
4.5
5.0
RL=8Ω
70
RL=16Ω
RL=4Ω
Gv = 10
Cb = Cin = 1µF
THD+N < 0.4%
Tamb = 25°C
60
50
2.2
2.5
3.0
3.5
Vcc (V)
4.0
4.5
5.0
TS4890
Fig. 91 : Signal to Noise Ratio vs Power Supply
with Weighted Filter type A
Fig. 92 : Signal to Noise Ratio vs Power Supply
with Weighted Filter Type A
100
110
100
90
RL=4Ω
RL=16Ω
90
SNR (dB)
SNR (dB)
RL=8Ω
80
Gv = 2
Cb = Cin = 1µF
THD+N < 0.4%
Tamb = 25°C
70
60
2.2
2.5
3.0
3.5
Vcc (V)
4.0
4.5
5
6
-15
Icc (mA)
Gain (dB)
Cfeed = 680pF
Cin = 470nF
Cfeed = 2.2nF
100
1000
Frequency (Hz)
Vstandby = Vcc
Tamb = 25°C
0
1
2
3
4
5
Vcc (V)
Fig. 96 : Current Consumption vs Standby
Voltage @ Vcc = 3.3V
7
6
6
5
5
4
Icc (mA)
Icc (mA)
5.0
3
10000
Fig. 95 : Current Consumption vs Standby
Voltage @ Vcc = 5V
4
3
3
2
2
1
0
0.0
4.5
4
0
-25
10
4.0
1
Rin = Rfeed = 22kΩ
Tamb = 25°C
Cin = 82nF
3.5
Vcc (V)
2
Cin = 22nF
-20
3.0
5
Cfeed = 330pF
-10
2.5
Fig. 94 : Current Consumption vs Power
Supply Voltage (no load)
7
-5
RL=4Ω
Gv = 10
Cb = Cin = 1µF
THD+N < 0.4%
Tamb = 25°C
60
2.2
10
0
RL=16Ω
70
5.0
Fig. 93 : Frequency Response Gain vs Cin, &
Cfeed
RL=8Ω
80
Vcc = 5V
Tamb = 25°C
0.5
1.0
1.5
2.0
2.5 3.0 3.5
Vstandby (V)
4.0
4.5
5.0
1
0
0.0
Vcc = 3.3V
Tamb = 25°C
0.5
1.0
1.5
2.0
2.5
3.0
Vstandby (V)
21/32
TS4890
Fig. 97 : Current Consumption vs Standby
Voltage @ Vcc = 2.6V
Fig. 98 : Current Consumption vs Standby
Voltage @ Vcc = 2.2V
6
5
5
4
Icc (mA)
Icc (mA)
4
3
3
2
2
1
1
Vcc = 2.2V
Tamb = 25°C
Vcc = 2.6V
Tamb = 25°C
0
0.0
0.5
1.0
1.5
Vstandby (V)
2.0
0
0.0
2.5
Fig. 99 : Clipping Voltage vs Power Supply
Voltage and Load Resistor
Vout1 & Vout2
Clipping Voltage Low side (V)
Vout1 & Vout2
Clipping Voltage High side (V)
0.7
0.6
0.5
RL = 4Ω
RL = 8Ω
0.4
0.3
0.2
0.1
RL = 16Ω
2.5
Tamb = 25°C
0.9
0.8
3.0
3.5
4.0
4.5
0.8
0.7
0.6
RL = 4Ω
0.5
RL = 8Ω
0.4
0.3
0.2
0.1
RL = 16Ω
0.0
2.2
5.0
2.5
3.0
Power supply Voltage (V)
3.5
4.0
4.5
Fig. 102 : Vout1+Vout2 A-weighted Noise Floor
120
100
Av = 10
80
60
40
Standby mode
Av = 2
Output Noise Voltage ( V)
120
Vcc = 2.2V to 5V, Tamb = 25 C
Cb = Cin = 1 F
Input Grounded
BW = 20Hz to 20kHz (Unweighted)
Vcc = 2.2V to 5V, Tamb = 25 C
Cb = Cin = 1 F
Input Grounded
BW = 20Hz to 20kHz (A-Weighted)
100
80
Av = 10
60
40
Standby mode
Av = 2
20
20
0
0
20
100
1000
Frequency (Hz)
5.0
Power supply Voltage (V)
Fig. 101 : Vout1+Vout2 Unweighted Noise Floor
Output Noise Voltage ( V)
2.0
1.0
Tamb = 25°C
0.0
2.2
22/32
1.0
1.5
Vstandby (V)
Fig. 100 :Clipping Voltage vs Power Supply
Voltage and Load Resistor
1.0
0.9
0.5
10000
20
100
1000
Frequency (Hz)
10000
TS4890
APPLICATION INFORMATION
Fig. 103 : Demoboard Schematic
C1
R2
C2
R1
S1
Vcc
Vcc
Vcc
S2
GND
C6 +
100µ
R3
6
C3
C5
R4
C4
Pos input
S6
Vcc
Neg. input
P1
C7
100n
4
R5
VinVin+
3
-
Vout1 5
+
C9
+
470µ
S5
Positive Input mode
P2
Vcc
S8
Standby
R8
10k
GND
S4
GND
S7
R6
2
Bypass
1
Standby
Av=-1
+
Vout2
8
C10
+
470µ
Bias
GND
R7
1.5k
OUT1
S3
D1
PW ON
TS4890
7
+
C11
+
C12
1u
C8
Fig. 104 : SO8 & MiniSO8 Demoboard Components Side
23/32
TS4890
Fig. 105 : SO8 & MiniSO8 Demoboard Top
Solder Layer
The output power is :
Pout =
(2 VoutRMS )2
(W)
RL
For the same power supply voltage, the output
power in BTL configuration is four times higher
than the output power in single ended
configuration.
■ Gain In Typical Application Schematic
(cf. page 1)
In flat region (no effect of Cin), the output voltage
of the first stage is :
Rfeed
Vout1 = − Vin
(V)
Rin
For the second stage : Vout2 = -Vout1 (V)
Fig. 106 : SO8 & MiniSO8 Demoboard Bottom
Solder Layer
The differential output voltage is
Rfeed
Vout2 − Vout1 = 2 Vin
(V)
Rin
The differential gain named gain (Gv) for more
convenient usage is :
Gv =
Vout2 − Vout1
Rfeed
=2
Vin
Rin
Remark : Vout2 is in phase with Vin and Vout1 is
180 phased with Vin. It means that the positive
terminal of the loudspeaker should be connected
to Vout2 and the negative to Vout1.
■ Low and high frequency response
■ BTL Configuration Principle
The TS4890 is a monolithic power amplifier with a
BTL output type. BTL (Bridge Tied Load) means
that each end of the load are connected to two
single ended output amplifiers. Thus, we have :
Single ended output 1 = Vout1 = Vout (V)
Single ended output 2 = Vout2 = -Vout (V)
And Vout1 - Vout2 = 2Vout (V)
24/32
In low frequency region, the effect of Cin starts.
Cin with Rin forms a high pass filter with a -3dB cut
off frequency .
FCL =
1
2πRinCin
(Hz)
In high frequency region, you can limit the
bandwidth by adding a capacitor (Cfeed) in
parallel on Rfeed. Its form a low pass filter with a
-3dB cut off frequency .
1
FCH =
(Hz)
2π Rfeed Cfeed
TS4890
■ Power dissipation and efficiency
Hypothesis :
• Voltage and current in the load are sinusoidal
(Vout and Iout)
• Supply voltage is a pure DC source (Vcc)
Regarding the load we have :
VOUT = VPEAK sin ωt (V)
VOUT
( A)
RL
and
POUT
2
V
= PEAK (W)
2 RL
Then, the average current delivered by the supply
voltage is
Icc AVG = 2
VPEAK
( A)
π RL
The power delivered by the supply voltage is
Psupply = Vcc IccAVG (W)
Then, the power dissipated by the amplifier is
Pdiss = Psupply - Pout (W)
Pdiss =
2 2 Vcc
π RL
POUT − POUT (W )
and the maximum value is obtained when
∂Pdiss
=0
∂POUT
and its value is
Pdiss max =
2 Vcc 2
π2RL
π
= 78.5%
4
■ Decoupling of the circuit
Two capacitors are needed to bypass properly the
TS4890. A power supply bypass capacitor Cs and
a bias voltage bypass capacitor Cb.
Cs has especially an influence on the THD+N in
high frequency (above 7kHz) and indirectly on the
power supply disturbances.
With 100µF, you can expect similar THD+N
performances like shown in the datasheet.
and
IOUT =
The maximum theoretical value is reached when
Vpeak = Vcc, so
(W)
If Cs is lower than 100µF, in high frequency
increase THD+N and disturbances on the power
supply rail are less filtered.
To the contrary, if Cs is higher than 100µF, those
disturbances on the power supply rail are more
filtered.
Cb has an influence on THD+N in lower frequency,
but its function is critical on the final result of PSRR
with input grounded in lower frequency.
If Cb is lower than 1µF, THD+N increase in lower
frequency (see THD+N vs frequency curves) and
the PSRR worsens up
If Cb is higher than 1µF, the benefit on THD+N in
lower frequency is small but the benefit on PSRR
is substantial (see PSRR vs. Cb curves).
Note that Cin has a non-negligible effect on PSRR
in lower frequency. Lower is its value, higher is the
PSRR (see fig. 13).
■ Pop and Click performance
In order to have the best performances with the
pop and click circuitry, the formula below must be
follow :
τin ≤ τb
Remark : This maximum value is only depending
on power supply voltage and load values.
With
The efficiency is the ratio between the output
power and the power supply
and
η=
π VPEAK
POUT
=
P sup ply
4 Vcc
τin = (Rin + Rfeed ) × Cin (s)
τb = 50kΩ × Cb (s)
25/32
TS4890
■ Power amplifier design examples
The first amplifier has a gain of
Rfeed
=3
Rin
Given :
• Load impedance : 8Ω
• Output power @ 1% THD+N : 0.5W
• Input impedance : 10kΩ min.
• Input voltage peak to peak : 1Vpp
• Bandwidth frequency : 20Hz to 20kHz (0, -3dB)
• THD+N in 20Hz to 20kHz < 0.5% @Pout=0.45W
• Ambient temperature max = 50°C
• SO8 package
First of all, we must calculate the minimum power
supply voltage to obtain 0.5W into 8Ω. See curves
in fig. 15, we can read 3.5V. Thus, the power
supply voltage value min. will be 3.5V.
Following the
equation :
maximum
Pdiss max =
power
2 Vcc 2
π2RL
dissipation
(W)
with 3.5V we have Pdissmax=0.31W.
Refer to power derating curves (fig. 24), with
0.31W the maximum ambient temperature will be
100°C. This last value could be higher if you follow
the example layout shows on the demoboard
(better dissipation).
The gain of the amplifier in flat region will be :
GV =
VOUTPP 2 2RLPOUT
=
= 5.65
VINPP
VINPP
We have Rin > 10kΩ. Let's take Rin = 10kΩ, then
Rfeed = 28.25kΩ. We could use for Rfeed = 30kΩ
in normalized value and the gain will be Gv = 6.
and the theoretical value of the -3dB cut of higher
frequency is 2MHz/3 = 660kHz.
We can keep this value or limiting the bandwidth
by adding a capacitor Cfeed, in parallel on Rfeed.
Then
CFEED =
So, we could use for Cfeed a 220pF capacitor
value that gives 24kHz.
Now, we can choose the value of Cb with the
constraint THD+N in 20Hz to 20kHz < 0.5% @
Pout=0.45W. If you refer to the closest THD+N vs
frequency measurement : fig. 71 (Vcc=3.3V,
Gv=10), with Cb = 1µF, the THD+N vs frequency
is always below 0.4%. As the behaviour is the
same with Vcc = 5V (fig. 67), Vcc = 2.6V (fig. 67).
As the gain for these measurements is higher
(worst case), we can consider with Cb = 1µF, Vcc
= 3.5V and Gv = 6, that the THD+N in 20Hz to
20kHz range with Pout = 0.45W will be lower than
0.4%.
In the following tables, you could find three
another examples with values required for the
demoboard.
Remark : components with (*) marking are
optional.
Application n°1 : 20Hz to 20kHz bandwidth and
6dB gain BTL power amplifier.
Components :
In lower frequency we want 20 Hz (-3dB cut off
frequency). Then
CIN =
1
= 795nF
2π Rin FCL
So, we could use for Cin a 1µF capacitor value that
gives 16Hz.
In Higher frequency we want 20kHz (-3dB cut off
frequency). The Gain Bandwidth Product of the
TS4890 is 2MHz typical and doesn't change when
the amplifier delivers power into the load.
26/32
1
= 265pF
2π RFEED FCH
Designator
Part Type
R1
22k / 0.125W
R4
22k / 0.125W
R6
Short Cicuit
R7*
(Vcc-Vf_led)/If_led
R8
10k / 0.125W
C5
470nF
C6
100µF
TS4890
Designator
Part Type
C7
100nF
C9
Short Circuit
C10
Short Circuit
C12
1µF
S1, S2, S6, S7
2mm insulated Plug
10.16mm pitch
S8
3 pts connector 2.54mm
pitch
P1
PCB Phono Jack
D1*
Led 3mm
U1
TS4890ID or TS4890IS
Application n°3 : 50Hz to 10kHz bandwidth and
10dB gain BTL power amplifier.
Components :
Designator
Application n°2 : 20Hz to 20kHz bandwidth and
20dB gain BTL power amplifier.
Part Type
R1
33k / 0.125W
R2
Short Circuit
R4
22k / 0.125W
R6
Short Cicuit
R7*
(Vcc-Vf_led)/If_led
R8
10k / 0.125W
C2
470pF
C5
150nF
C6
100µF
C7
100nF
C9
Short Circuit
C10
Short Circuit
C12
1µF
S1, S2, S6, S7
2mm insulated Plug
10.16mm pitch
S8
3 pts connector 2.54mm
pitch
P1
PCB Phono Jack
D1*
Led 3mm
U1
TS4890ID or TS4890IS
Components :
Designator
Part Type
R1
110k / 0.125W
R4
22k / 0.125W
R6
Short Cicuit
R7*
(Vcc-Vf_led)/If_led
R8
10k / 0.125W
C5
470nF
C6
100µF
C7
100nF
C9
Short Circuit
C10
Short Circuit
C12
1µF
S1, S2, S6, S7
2mm insulated Plug
10.16mm pitch
S8
3 pts connector 2.54mm
pitch
P1
PCB Phono Jack
D1*
Led 3mm
U1
TS4890ID or TS4890IS
Application n°4 : Differential inputs BTL power
amplifier.
In this configuration, we need to place these
components : R1, R4, R5, R6, R7, C4, C5, C12.
We have also : R4 = R5, R1 = R6, C4 = C5.
The gain of the amplifier is:
R1
G V D I FF = 2 -------R4
For Vcc=5V, a 20Hz to 20kHz bandwidth and 20dB
gain BTL power amplifier you could follow the bill
of material below.
27/32
TS4890
Components :
Designator
Part Type
R1
110k / 0.125W
R4
22k / 0.125W
R5
22k / 0.125W
R6
110k / 0.125W
R7*
(Vcc-Vf_led)/If_led
R8
10k / 0.125W
C4
470nF
C5
470nF
C6
100µF
C7
100nF
C9
Short Circuit
C10
Short Circuit
C12
1µF
D1*
Led 3mm
S1, S2, S6, S7
2mm insulated Plug
10.16mm pitch
S8
3 pts connector 2.54mm
pitch
P1, P2
PCB Phono Jack
U1
TS4890ID or TS4890IS
28/32
TS4890
■ Note on how to use the PSRR curves
How do we measure the PSRR ?
(page 8)
We have finished a design and we have chosen for
the components :
• Rin=Rfeed=22kΩ
• Cin=100nF
• Cb=1µF
Fig. 108 : PSRR measurement schematic
Rfeed
6
Vcc
Vripple
Vcc
4
The process to obtain the final curve (Cb=100µF,
Cin=100nF, Rin=Rfeed=22kΩ) is a simple transfer
point by point on each frequency of the curve on
fig. 16 to the curve on fig. 15.
The measurement result is shown on the next
figure.
Rin
VinVin+
-
Vout1 5
Vs-
+
Cin
RL
Rg
100 Ohms
2
Bypass
1
Standby
Av=-1
+
Cb
Vout2
8
Vs+
Bias
GND
Now, on fig. 16, we can see the PSRR (input
grounded) vs frequency curves. At 217Hz, we
have a PSRR value of -36dB.
In reality we want a value about -70dB. So, we
need a gain of 34dB !
Now, on fig. 15 we can see the effect of Cb on the
PSRR (input grounded) vs. frequency. With
Cb=100µF, we can reach the -70dB value.
3
TS4890
7
■ Principle of operation
• We fixed the DC voltage supply (Vcc)
• We fixed the AC sinusoidal ripple voltage
(Vripple)
• No bypass capacitor Cs is used
Fig. 107 : PSRR changes with Cb
The PSRR value for each frequency is :
-30
PSRR (dB)
-40
 Rms (Vripple ) 
PSRR(dB) = 20 × Log10 

 Rms (Vs + − Vs − ) 
Vcc = 5 & 2.2V
Rfeed = 22k, Rin = 22k
Rg = 100Ω, RL = 8Ω
Tamb = 25°C
Cin=100nF
Cb=1µF
Remark : The measure of the Rms voltage is not a
Rms selective measure but a full range (2 Hz to
125 kHz) Rms measure. It means that we
measure the effective Rms signal + the noise.
-50
-60
Cin=100nF
Cb=100µF
-70
10
100
1000
10000
100000
Frequency (Hz)
■ Note on PSRR measurement
What is the PSRR ?
The PSRR is the Power Supply Rejection Ratio.
It's a kind of SVR in a determined frequency range.
The PSRR of a device, is the ratio between a
power supply disturbance and the result on the
output. We can say that the PSRR is the ability of
a device to minimize the impact of power supply
disturbances to the output.
29/32
TS4890
PACKAGE MECHANICAL DATA
SO-8 MECHANICAL DATA
DIM.
mm.
MIN.
TYP
inch
MAX.
MIN.
TYP.
MAX.
A
1.35
1.75
0.053
0.069
A1
0.10
0.25
0.04
0.010
A2
1.10
1.65
0.043
0.065
B
0.33
0.51
0.013
0.020
C
0.19
0.25
0.007
0.010
D
4.80
5.00
0.189
0.197
E
3.80
4.00
0.150
0.157
e
1.27
0.050
H
5.80
6.20
0.228
0.244
h
0.25
0.50
0.010
0.020
L
0.40
1.27
0.016
0.050
k
ddd
8˚ (max.)
0.1
0.04
0016023/C
30/32
TS4890
PACKAGE MECHANICAL DATA
31/32
TS4890
PACKAGE MECHANICAL DATA
Information furnished is believed to be accurate and reliable. However, STMicroelectronics assumes no responsibility for the
consequences of use of such information nor for any infringement of patents or other rights of third parties which may result from
its use. No license is granted by implication or otherwise under any patent or patent rights of STMicroelectronics. Specifications
mentioned in this publication are subject to change without notice. This publication supersedes and replaces all information
previously supplied. STMicroelectronics products are not authorized for use as critical components in life support devices or
systems without express written approval of STMicroelectronics.
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32/32