STMICROELECTRONICS TS4972EIJT1

TS4972
1.2W Audio Power Amplifier with Standby Mode Active High
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Operating from VCC = 2.5V to 5.5V
Rail-to-rail output
1.2W output power @ Vcc=5V, THD=1%,
F=1kHz, with 8Ω load
Ultra low consumption in standby mode
(10nA)
75dB PSRR @ 217Hz from 2.5 to 5V
Low pop & click
Ultra low distortion (0.05%)
Unity gain stable
Flip-chip package 8 x 300µm bumps
Pin Connections (top view)
TS4972JT - FLIP CHIP
7
+
Vin
8
6
5
Vcc
Stdby
Vout2
Vout1
Vin
Gnd
Bypass
1
2
3
Description
4
The TS4972 is an Audio Power Amplifier capable
of delivering 1.6W of continuous RMS ouput
power into a 4Ω 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
shutdown protection is provided.
The TS4972 has been designed for high quality
audio applications such as mobile phones and to
minimize the number of external components.
TYPICAL APPLICATION SCHEMATIC
Cfeed
Rfeed
VCC
Cs
6
VCC
Audio
Input
Rin
1
Vin-
-
7
Vin+
+
Vout 1
Cin
The unity-gain stable amplifier can be configured
by external gain setting resistors.
RL
8 Ohms
VCC
Applications
■
■
■
■
8
AV = -1
3
Bypass
5
Standby
Vout 2
4
+
Rstb
Mobile phones (cellular / cordless)
PDAs
Laptop/notebook computers
Portable audio devices
Bias
GND
Cb
TS4972
2
Order Codes
Part Number
Temperature Range
Package
Packing
Marking
TS4972IJT
TS4972EIJT1
-40, +85°C
Flip-Chip
Tape & Reel
4972
1) Lead free Flip-Chip part number
October 2004
Revision 2
1/30
TS4972
1
Absolute Maximum Ratings
Absolute Maximum Ratings
Table 1: Key parameters and their absolute maximum ratings
Symbol
VCC
Vi
Parameter
Supply voltage
Value
1
2
Unit
6
V
V
-40 to + 85
°C
Toper
Input Voltage
Operating Free Air Temperature Range
GND to VCC
Tstg
Storage Temperature
-65 to +150
°C
150
°C
200
°C/W
Tj
Rthja
Pd
Maximum Junction Temperature
Thermal Resistance Junction to Ambient 3
Power Dissipation
ESD
Human Body Model
ESD
Machine Model
Latch-up Latch-up Immunity
Lead Temperature (soldering, 10sec)
Internally Limited4
2
200
Class A
250
kV
V
°C
1) All voltages values are measured with respect to the ground pin.
2) The magnitude of input signal must never exceed VCC + 0.3V / GND - 0.3V
3) Device is protected in case of over temperature by a thermal shutdown active @ 150°C.
4) Exceeding the power derating curves during a long period, involves abnormal operating condition.
Table 2: Operating Conditions
Symbol
Parameter
VCC
VICM
Supply Voltage
Common Mode Input Voltage Range
VSTB
Standby Voltage Input :
Device ON
Device OFF
RL
Rthja
Load Resistor
Thermal Resistance Junction to Ambient 1
1) With Heat Sink Surface = 125mm2
2/30
Value
Unit
2.5 to 5.5
GND to VCC - 1.2V
V
GND ≤ VSTB ≤ 0.5V
VCC - 0.5V ≤ VSTB ≤ VCC
V
V
4 - 32
Ω
90
°C/W
Electrical Characteristics
2
TS4972
Electrical Characteristics
Table 3: 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 = Vcc, 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
1.2
W
Total Harmonic Distortion + Noise
Po = 250mW rms, Gv = 2, 20Hz < f < 20kHz, RL = 8Ω
0.1
%
Power Supply Rejection Ratio2
f = 217Hz, RL = 8Ω, RFeed = 22KΩ, Vripple = 200mV rms
75
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 Vcc
2) Dynamic measurements - 20*log(rms(Vout)/rms(Vripple)). Vripple is an added sinus signal to Vcc @ f = 217Hz
3/30
TS4972
Electrical Characteristics
Table 4: VCC = +3.3V, GND = 0V, Tamb = 25°C (unless otherwise specified)3)
Symbol
Typ.
Max.
Unit
Supply Current
No input signal, no load
5.5
8
mA
Standby Current 1
No input signal, Vstdby = Vcc, 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
500
mW
Total Harmonic Distortion + Noise
Po = 250mW rms, Gv = 2, 20Hz < f < 20kHz, RL = 8Ω
0.1
%
Power Supply Rejection Ratio2
f = 217Hz, RL = 8Ω, RFeed = 22KΩ, Vripple = 200mV rms
75
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 Vcc
2) Dynamic measurements - 20*log(rms(Vout)/rms(Vripple)). Vripple is an added sinus signal to Vcc @ f = 217Hz
3. All electrical values are made by correlation between 2.6V and 5V measurements
4/30
Electrical Characteristics
TS4972
Table 5: VCC = 2.6V, 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 = Vcc, 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
300
mW
Total Harmonic Distortion + Noise
Po = 200mW rms, Gv = 2, 20Hz < f < 20kHz, RL = 8Ω
0.1
%
Power Supply Rejection Ratio2
f = 217Hz, RL = 8Ω, RFeed = 22KΩ, Vripple = 200mV rms
75
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 Vcc
2) Dynamic measurements - 20*log(rms(Vout)/rms(Vripple)). Vripple is an added sinus signal to Vcc @ f = 217Hz
Table 6: Components description
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
Low pass filter capacitor allowing to cut the high frequency
(low pass filter cut-off frequency 1 / (2 x Pi x Rfeed x Cfeed))
Rstb
Pull-up resistor which fixes the right supply level on the standby pin
Gv
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.
2. External resistors are not needed for having better stability when supply @ Vcc down to 3V. By the
way, the quiescent current remains the same.
3. The standby response time is about 1µs.
5/30
TS4972
Electrical Characteristics
Figure 1: Open Loop Frequency Response
Figure 4: Open Loop Frequency Response
0
-40
-60
40
-80
-100
20
-120
-140
0
Vcc = 5V
ZL = 8Ω + 560pF
Tamb = 25°C
-120
-140
0
-160
-180
-20
-200
1
10
100
1000
10000
-200
-220
-40
0.3
1
10
Frequency (kHz)
Figure 2: Open Loop Frequency Response
80
-60
-80
Phase
-100
20
-120
-140
0
-160
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
Figure 3: Open Loop Frequency Response
80
Gain
60
60
-40
-60
-120
20
-140
-160
0
10000
Vcc = 2.6V
ZL = 8Ω + 560pF
Tamb = 25°C
Phase
-200
6/30
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
Gain
-80
Phase
10
80
-20
Phase (Deg)
Gain (dB)
40
1
Figure 6: Open Loop Frequency Response
0
Vcc = 2.6V
RL = 8Ω
Tamb = 25°C
-60
-120
0
-200
1
-40
-100
20
-220
-40
0.3
-20
-80
40
-180
-20
-220
0
Gain
60
-40
Phase (Deg)
Gain (dB)
40
10000
80
-20
Gain (dB)
60
Vcc = 33V
RL = 8Ω
Tamb = 25°C
100
1000
Frequency (kHz)
Figure 5: Open Loop Frequency Response
0
Gain
-60
-100
20
-180
-40
0.3
-40
-80
Phase
-160
-20
-20
Phase (Deg)
Phase
Gain
Phase (Deg)
60
-40
0.3
1
10
100
1000
Frequency (kHz)
10000
-240
Phase (Deg)
Gain (dB)
40
0
-20
Gain (dB)
Vcc = 5V
RL = 8Ω
Tamb = 25°C
Gain
Phase (Deg)
60
Electrical Characteristics
TS4972
Figure 7: Open Loop Frequency Response
100
-80
80
-100
Phase
20
-180
Vcc = 5V
CL = 560pF
Tamb = 25°C
1
10
PSRR (dB)
-160
Phase (Deg)
Gain (dB)
-140
40
-40
0.3
-50
-220
100
1000
Frequency (kHz)
-80
10
10000
-80
-10
80
-100
-20
Phase
Cb=10µF
-160
20
-180
0
10
10000
Phase
-10
-100
-20
-160
20
-180
-200
Vcc = 3.3V
CL = 560pF
Tamb = 25°C
1
10
100
1000
Frequency (kHz)
10000
-30
PSRR (dB)
-140
Phase (Deg)
Gain
Gain (dB)
-80
40
-40
0.3
100
1000
10000
100000
Figure 12: Power Supply Rejection Ratio
(PSRR) vs Feedback Resistor
-120
60
0
Cb=100µF
Frequency (Hz)
100
-20
Cb=47µF
-50
-80
10
-240
Figure 9: Open Loop Frequency Response
80
Vcc = 5, 3.3 & 2.6V
Rfeed = 22k
Rin = 22k, Cin = 1µF
Rg = 100Ω, RL = 8Ω
Tamb = 25°C
-40
-70
-220
100
1000
Frequency (kHz)
100000
-60
-200
Vcc = 2.6V
CL = 560pF
Tamb = 25°C
1
-30
PSRR (dB)
-140
40
Phase (Deg)
Gain (dB)
Gain
1000
10000
Frequency (Hz)
Cb=1µF
-120
60
100
Figure 11: Power Supply Rejection Ratio
(PSRR) vs Bypass Capacitor
100
-40
0.3
Vcc = 5V, 3.3V & 2.6V
Cb = 1µF & 0.1µF
-60
-70
-200
Figure 8: Open Loop Frequency Response
-20
Vripple = 200mVrms
Rfeed = 22Ω
Input = floating
RL = 8Ω
Tamb = 25°C
-120
Gain
-20
-30
-40
60
0
Figure 10: Power Supply Rejection Ratio
(PSRR) vs Power supply
-40
Vcc = 5, 3.3 & 2.6V
Cb = 1µF & 0.1µF
Vripple = 200mVrms
Input = floating
RL = 8Ω
Tamb = 25°C
Rfeed=110kΩ
Rfeed=47kΩ
-50
-60
Rfeed=22kΩ
-220
-70
-240
-80
10
Rfeed=10kΩ
100
1000
10000
Frequency (Hz)
100000
7/30
TS4972
Electrical Characteristics
Figure 13: Power Supply Rejection Ratio
(PSRR) vs Feedback Capacitor
Figure 16: Power Dissipation vs Pout
1.4
-10
PSRR (dB)
-30
-40
Vcc = 5, 3.3 & 2.6V
Cb = 1µF & 0.1µF
Rfeed = 22kΩ
Vripple = 200mVrms
Input = floating
RL = 8Ω
Tamb = 25°C
Vcc=5V
1.2 F=1kHz
THD+N<1%
Cfeed=0
Power Dissipation (W)
-20
Cfeed=150pF
Cfeed=330pF
-50
-60
-70
RL=4Ω
1.0
0.8
0.6
RL=8Ω
0.4
0.2
Cfeed=680pF
RL=16Ω
-80
10
100
1000
10000
Frequency (Hz)
Figure 14: Power Supply Rejection Ratio
(PSRR) vs Input Capacitor
Vcc = 5, 3.3 & 2.6V
Rfeed = 22kΩ, Rin = 22k
Cb = 1µF
Rg = 100Ω, RL = 8Ω
Tamb = 25°C
Cin=330nF
PSRR (dB)
Cin=220nF
-30
0.35
-40
Cin=100nF
-50
0.4
Vcc=2.6V
F=1kHz
THD+N<1%
100
1000
10000
100000
0.20
0.15
RL=8Ω
0.10
RL=16Ω
0.00
0.0
0.1
0.3
0.4
Figure 18: Pout @ THD + N = 10% vs Supply
Voltage vs RL
2.0
1.6
Gv = 2 & 10
Cb = 1µF
F = 1kHz
BW < 125kHz
Tamb = 25°C
8Ω
Output power @ 10% THD + N (W)
Output power @ 1% THD + N (W)
0.2
Output Power (W)
Figure 15: Pout @ THD + N = 1% vs Supply
Voltage vs RL
6Ω
4Ω
0.8
16 Ω
0.6
0.4
0.2
0.0
2.5
8/30
1.6
0.25
Frequency (Hz)
1.0
1.4
RL=4Ω
0.30
0.05
1.2
0.8
1.0
1.2
Output Power (W)
Cin=22nF
-60
10
1.4
0.6
0.40
Cin=1µF
-20
0.2
Figure 17: Power Dissipation vs Pout
Power Dissipation (W)
-10
0.0
0.0
100000
32 Ω
3.0
3.5
4.0
Power Supply (V)
4.5
5.0
1.8
1.6
1.4
Gv = 2 & 10
Cb = 1µF
F = 1kHz
BW < 125kHz
Tamb = 25°C
8Ω
4Ω
6Ω
1.2
1.0
16 Ω
0.8
0.6
0.4
0.2
0.0
2.5
32 Ω
3.0
3.5
4.0
Power Supply (V)
4.5
5.0
Electrical Characteristics
TS4972
Figure 19: Power Dissipation vs Pout
Figure 22: THD + N vs Output Power
10
0.6
RL = 4Ω, Vcc = 3.3V
Gv = 2
Cb = Cin = 1µF
BW < 125kHz
Tamb = 25°C
RL=4Ω
1
THD + N (%)
Power Dissipation (W)
Vcc=3.3V
F=1kHz
0.5 THD+N<1%
0.4
0.3
0.2
20kHz
0.1
RL=8Ω
0.1
RL=16Ω
0.0
0.0
0.1
20Hz
0.2
0.3
0.4
0.5
0.6
0.7
0.01
1E-3
Output Power (W)
1.4
10
Heat sink surface = 125mm
(See demoboard)
1.2
2
1.0
0.8
0.6
1
RL = 4Ω, Vcc = 2.6V
Gv = 2
Cb = Cin = 1µF
BW < 125kHz
Tamb = 25°C
20kHz
0.1
0.4
No Heat sink
0.2
0.0
20Hz
0
25
50
75
100
125
150
0.01
1E-3
Ambiant Temperature ( C)
10
10
RL = 4Ω
Vcc = 5V
Gv = 2
Cb = Cin = 1µF
BW < 125kHz
Tamb = 25°C
RL = 4Ω, Vcc = 5V
Gv = 10
Cb = Cin = 1µF
BW < 125kHz, Tamb = 25°C
THD + N (%)
1
1kHz
0.01
0.1
Output Power (W)
Figure 24: THD + N vs Output Power
Figure 21: THD + N vs Output Power
THD + N (%)
1
Figure 23: THD + N vs Output Power
THD + N (%)
Flip-Chip Package Power Dissipation (W)
Figure 20: Power Derating Curves
1kHz
0.01
0.1
Output Power (W)
20kHz
0.1
0.1
20Hz
20Hz
0.01
1E-3
20kHz
1
0.01
0.1
Output Power (W)
1kHz
1kHz
1
0.01
1E-3
0.01
0.1
Output Power (W)
1
9/30
TS4972
Electrical Characteristics
Figure 25: THD + N vs Output Power
Figure 28: THD + N vs Output Power
10
10
RL = 4Ω, Vcc = 3.3V
Gv = 10
Cb = Cin = 1µF
BW < 125kHz
Tamb = 25°C
20kHz
20Hz
0.1
1
THD + N (%)
THD + N (%)
1
RL = 8Ω, Vcc = 3.3V
Gv = 2
Cb = Cin = 1µF
BW < 125kHz
Tamb = 25°C
20kHz
20Hz
0.1
1kHz
1kHz
0.01
1E-3
0.01
0.1
Output Power (W)
1
Figure 26: THD + N vs Output Power
0.01
1E-3
10
THD + N (%)
THD + N (%)
RL = 4Ω, Vcc = 2.6V
Gv = 10
Cb = Cin = 1µF
BW < 125kHz
Tamb = 25°C
20Hz
20kHz
0.1
1
RL = 8Ω, Vcc = 2.6V
Gv = 2
Cb = Cin = 1µF
BW < 125kHz
Tamb = 25°C
0.01
0.1
Output Power (W)
Figure 30: THD + N vs Output Power
10
10
RL = 8Ω
Vcc = 5V
Gv = 2
Cb = Cin = 1µF
1 BW < 125kHz
Tamb = 25°C
THD + N (%)
THD + N (%)
20kHz
1kHz
0.01
1E-3
0.01
0.1
Output Power (W)
Figure 27: THD + N vs Output Power
20kHz
RL = 8Ω
Vcc = 5V
Gv = 10
Cb = Cin = 1µF
1 BW < 125kHz
Tamb = 25°C
20kHz
0.1
0.1
20Hz
1kHz
20Hz
0.01
1E-3
20Hz
0.1
1kHz
0.01
1E-3
10/30
1
Figure 29: THD + N vs Output Power
10
1
0.01
0.1
Output Power (W)
0.01
0.1
Output Power (W)
1
0.01
1E-3
0.01
0.1
Output Power (W)
1kHz
1
Electrical Characteristics
TS4972
Figure 31: THD + N vs Output Power
Figure 34: THD + N vs Output Power
10
10
THD + N (%)
1
20Hz
0.1
RL = 8Ω, Vcc = 3.3V
Gv = 2
Cb = 0.1µF, Cin = 1µF
BW < 125kHz
Tamb = 25°C
1
THD + N (%)
RL = 8Ω, Vcc = 3.3V
Gv = 10
Cb = Cin = 1µF
BW < 125kHz
Tamb = 25°C
20Hz
0.1
20kHz
20kHz
1kHz
0.01
1E-3
1kHz
0.01
0.1
Output Power (W)
1
Figure 32: THD + N vs Output Power
0.01
1E-3
10
RL = 8Ω, Vcc = 2.6V
Gv = 10
Cb = Cin = 1µF
BW < 125kHz
Tamb = 25°C
THD + N (%)
THD + N (%)
1
Figure 35: THD + N vs Output Power
10
1
0.01
0.1
Output Power (W)
20Hz
1
RL = 8Ω, Vcc = 2.6V
Gv = 2
Cb = 0.1µF, Cin = 1µF
BW < 125kHz
Tamb = 25°C
20Hz
0.1
0.1
20kHz
20kHz
1kHz
0.01
1E-3
1kHz
0.01
1E-3
0.01
0.1
Output Power (W)
Figure 36: THD + N vs Output Power
Figure 33: THD + N vs Output Power
10
RL = 8Ω
Vcc = 5V
Gv = 2
Cb = 0.1µF, Cin = 1µF
BW < 125kHz
Tamb = 25°C
RL = 8Ω, Vcc = 5V, Gv = 10
Cb = 0.1µF, Cin = 1µF
BW < 125kHz, Tamb = 25°C
THD + N (%)
THD + N (%)
10
1
0.01
0.1
Output Power (W)
20Hz
1
20Hz
0.1
0.1
20kHz
20kHz
0.01
1E-3
1kHz
1kHz
0.01
0.1
Output Power (W)
1
0.01
1E-3
0.01
0.1
Output Power (W)
1
11/30
TS4972
Electrical Characteristics
Figure 37: THD + N vs Output Power
Figure 40: THD + N vs Output Power
10
10
RL = 8Ω, Vcc = 3.3V, Gv = 10
Cb = 0.1µF, Cin = 1µF
BW < 125kHz, Tamb = 25°C
1
THD + N (%)
1
THD + N (%)
RL = 16Ω, Vcc = 3.3V
Gv = 2
Cb = Cin = 1µF
BW < 125kHz
Tamb = 25°C
20Hz
20kHz
0.1
0.1
20Hz
20kHz
1kHz
1kHz
0.01
0.01
1E-3
0.01
0.1
Output Power (W)
1
Figure 38: THD + N vs Output Power
1E-3
0.1
Figure 41: THD + N vs Output Power
10
10
RL = 8Ω, Vcc = 2.6V, Gv = 10
Cb = 0.1µF, Cin = 1µF
BW < 125kHz, Tamb = 25°C
RL = 16Ω
Vcc = 2.6V
Gv = 2
Cb = Cin = 1µF
BW < 125kHz
Tamb = 25°C
1
1
THD + N (%)
THD + N (%)
0.01
Output Power (W)
20Hz
20kHz
0.1
20Hz
0.1
20kHz
1kHz
1kHz
0.01
0.01
1E-3
0.01
Output Power (W)
1E-3
0.1
10
10
RL = 16Ω, Vcc = 5V
Gv = 2
Cb = Cin = 1µF
BW < 125kHz
Tamb = 25°C
0.1
20Hz
THD + N (%)
THD + N (%)
0.1
Figure 42: THD + N vs Output Power
Figure 39: THD + N vs Output Power
1
0.01
Output Power (W)
20kHz
1
RL = 16Ω, Vcc = 5V
Gv = 10
Cb = Cin = 1µF
BW < 125kHz
Tamb = 25°C
20kHz
0.1
20Hz
0.01
1E-3
12/30
1kHz
1kHz
0.01
0.1
Output Power (W)
1
0.01
1E-3
0.01
0.1
Output Power (W)
1
Electrical Characteristics
TS4972
Figure 43: THD + N vs Output Power
Figure 46: THD + N vs Frequency
1
RL = 16Ω
Vcc = 3.3V
Gv = 10
Cb = Cin = 1µF
BW < 125kHz
Tamb = 25°C
1
THD + N (%)
THD + N (%)
10
20Hz
0.1
RL = 4Ω, Vcc = 3.3V
Gv = 2
Cb = 1µF
BW < 125kHz
Tamb = 25°C
Pout = 560mW
0.1
20kHz
Pout = 280mW
1kHz
0.01
1E-3
0.01
Output Power (W)
0.01
20
0.1
Figure 44: THD + N vs Output Power
RL = 16Ω
Vcc = 2.6V
Gv = 10
Cb = Cin = 1µF
BW < 125kHz
Tamb = 25°C
1
THD + N (%)
THD + N (%)
1000
Frequency (Hz)
10000
Figure 47: THD + N vs Frequency
10
1
100
20Hz
RL = 4Ω, Vcc = 2.6V
Gv = 2
Cb = 1µF
BW < 125kHz
Tamb = 25°C
Pout = 240 & 120mW
0.1
0.1
20kHz
1kHz
0.01
1E-3
0.01
Output Power (W)
0.01
20
0.1
Pout = 1.3W
Pout = 1.3W
0.1
0.1
100
1000
Frequency (Hz)
10000
Pout = 650mW
RL = 4Ω, Vcc = 5V
Gv = 10
Cb = 1µF
BW < 125kHz
Tamb = 25°C
Pout = 650mW
0.01
20
10000
1
THD + N (%)
THD + N (%)
RL = 4Ω, Vcc = 5V
Gv = 2
Cb = 1µF
BW < 125kHz
Tamb = 25°C
1000
Frequency (Hz)
Figure 48: THD + N vs Frequency
Figure 45: THD + N vs Frequency
1
100
0.01
20
100
1000
Frequency (Hz)
10000
13/30
TS4972
Electrical Characteristics
Figure 49: THD + N vs Frequency
RL = 4Ω, Vcc = 3.3V
Gv = 10
Cb = 1µF
BW < 125kHz
Tamb = 25°C
Pout = 560mW
Cb = 0.1µF
1
THD + N (%)
1
THD + N (%)
Figure 52: THD + N vs Frequency
0.1
RL = 8Ω, Vcc = 5V
Gv = 10
Pout = 920mW
BW < 125kHz
Tamb = 25°C
0.1
Pout = 280mW
Cb = 1µF
0.01
20
100
1000
Frequency (Hz)
0.01
20
10000
Figure 50: THD + N vs Frequency
100
1000
Frequency (Hz)
10000
Figure 53: THD + N vs Frequency
1
RL = 4Ω, Vcc = 2.6V
Gv = 10
Cb = 1µF
BW < 125kHz
Tamb = 25°C
Cb = 0.1µF
THD + N (%)
THD + N (%)
1
0.1
RL = 8Ω, Vcc = 3.3V
Gv = 2
Pout = 420mW
BW < 125kHz
Tamb = 25°C
0.1
Pout = 240 & 120mW
Cb = 1µF
0.01
20
100
1000
Frequency (Hz)
0.01
20
10000
RL = 8Ω
Vcc = 5V
Gv = 2
Pout = 920mW
BW < 125kHz
Tamb = 25°C
0.1
Cb = 0.1µF
THD + N (%)
Cb = 0.1µF
THD + N (%)
10000
1
1
RL = 8Ω
Vcc = 5V
Gv = 2
Pout = 460mW
BW < 125kHz
Tamb = 25°C
0.1
Cb = 1µF
Cb = 1µF
14/30
1000
Frequency (Hz)
Figure 54: THD + N vs Frequency
Figure 51: THD + N vs Frequency
0.01
20
100
100
1000
Frequency (Hz)
10000
0.01
20
100
1000
Frequency (Hz)
10000
Electrical Characteristics
TS4972
Figure 55: THD + N vs Frequency
Figure 58: THD + N vs Frequency
THD + N (%)
RL = 8Ω, Vcc = 5V
Gv = 10
Pout = 460mW
BW < 125kHz
Tamb = 25°C
0.1
THD + N (%)
1
Cb = 0.1µF
1
Cb = 0.1µF
RL = 8Ω, Vcc = 2.6V
Gv = 2
Pout = 220mW
BW < 125kHz
Tamb = 25°C
0.1
Cb = 1µF
Cb = 1µF
0.01
20
100
1000
Frequency (Hz)
0.01
20
10000
Figure 56: THD + N vs Frequency
100
1000
Frequency (Hz)
10000
Figure 59: THD + N vs Frequency
1
0.1
Cb = 0.1µF
1
THD + N (%)
THD + N (%)
Cb = 0.1µF
RL = 8Ω, Vcc = 3.3V
Gv = 2
Pout = 210mW
BW < 125kHz
Tamb = 25°C
RL = 8Ω, Vcc = 2.6V
Gv = 10
Pout = 220mW
BW < 125kHz
Tamb = 25°C
0.1
Cb = 1µF
Cb = 1µF
100
1000
Frequency (Hz)
Cb = 0.1µF
THD + N (%)
RL = 8Ω, Vcc = 3.3V
Gv = 10
Pout = 420mW
BW < 125kHz
Tamb = 25°C
0.1
100
1000
Frequency (Hz)
Cb = 0.1µF
1
10000
RL = 8Ω, Vcc = 3.3V
Gv = 10
Pout = 210mW
BW < 125kHz
Tamb = 25°C
0.1
Cb = 1µF
Cb = 1µF
0.01
20
100
Figure 60: THD + N vs Frequency
Figure 57: THD + N vs Frequency
1
0.01
20
10000
THD + N (%)
0.01
20
1000
Frequency (Hz)
10000
0.01
20
100
1000
Frequency (Hz)
10000
15/30
TS4972
Electrical Characteristics
Figure 61: THD + N vs Frequency
Figure 64: THD + N vs Frequency
0.1
Cb = 0.1µF
RL = 8Ω, Vcc = 2.6V
Gv = 10
Pout = 110mW
BW < 125kHz
Tamb = 25°C
0.1
THD + N (%)
THD + N (%)
1
Pout = 140mW
0.01
RL = 16Ω, Vcc = 3.3V
Gv = 2, Cb = 1µF
BW < 125kHz
Tamb = 25°C
Pout = 280mW
Cb = 1µF
0.01
20
100
1000
Frequency (Hz)
1E-3
20
10000
Figure 62: THD + N vs Frequency
100
1000
Frequency (Hz)
10000
Figure 65: THD + N vs Frequency
THD + N (%)
Cb = 0.1µF
RL = 8Ω, Vcc = 2.6V
Gv = 10
Pout = 110mW
BW < 125kHz
Tamb = 25°C
0.1
THD + N (%)
0.1
1
Pout = 80mW
0.01
Pout = 160mW
RL = 16Ω, Vcc = 2.6V
Gv = 2, Cb = 1µF
BW < 125kHz
Tamb = 25°C
Cb = 1µF
0.01
20
100
1000
Frequency (Hz)
1E-3
20
10000
0.1
THD + N (%)
THD + N (%)
0.01
16/30
100
10000
RL = 16Ω, Vcc = 5V
Gv = 10, Cb = 1µF
BW < 125kHz
Tamb = 25°C
Pout = 315mW
1E-3
20
1000
Frequency (Hz)
Figure 66: THD + N vs Frequency
Figure 63: THD + N vs Frequency
Pout = 630mW
100
RL = 16Ω, Vcc = 5V
Gv = 2, Cb = 1µF
BW < 125kHz
Tamb = 25°C
1000
Frequency (Hz)
10000
0.1
Pout = 315mW
Pout = 630mW
0.01
20
100
1000
Frequency (Hz)
10000
Electrical Characteristics
TS4972
Figure 67: THD + N vs Frequency
Figure 70: Signal to Noise Ratio vs Power
Supply with Weighted Filter Type A
110
1
100
Pout = 280mW
0.1
Pout = 140mW
RL=4Ω
RL=8Ω
RL=16Ω
90
SNR (dB)
THD + N (%)
RL = 16Ω, Vcc = 3.3V
Gv = 10, Cb = 1µF
BW < 125kHz
Tamb = 25°C
80
Gv = 2
Cb = Cin = 1µF
THD+N < 0.4%
Tamb = 25°C
70
0.01
20
100
1000
Frequency (Hz)
60
2.5
10000
3.5
4.0
5.0
Figure 71: Frequency Response Gain vs Cin,
& Cfeed
10
1
RL = 16Ω, Vcc = 2.6V
Gv = 10, Cb = 1µF
BW < 125kHz
Tamb = 25°C
5
0
Gain (dB)
Pout = 160mW
0.1
Cfeed = 330pF
Cfeed = 680pF
-5
-10
-20
Cfeed = 2.2nF
Cin = 470nF
-15
Cin = 22nF
Rin = Rfeed = 22kΩ
Tamb = 25°C
Cin = 82nF
Pout = 80mW
0.01
20
4.5
Vcc (V)
Figure 68: THD + N vs Frequency
THD + N (%)
3.0
100
1000
Frequency (Hz)
-25
10
10000
Figure 69: Signal to Noise Ratio vs Power
Supply with Unweighted Filter (20Hz
to 20kHz)
100
1000
Frequency (Hz)
10000
Figure 72: Signal to Noise Ratio vs Power
Supply with Unweighted Filter (20Hz
to 20kHz)
100
90
90
80
RL=4Ω
RL=8Ω
SNR (dB)
SNR (dB)
RL=16Ω
80
70
Gv = 2
Cb = Cin = 1µF
THD+N < 0.4%
Tamb = 25°C
60
50
2.5
3.0
3.5
4.0
Vcc (V)
4.5
5.0
RL=8Ω
70
RL=16Ω
RL=4Ω
Gv = 10
Cb = Cin = 1µF
THD+N < 0.7%
Tamb = 25°C
60
50
2.5
3.0
3.5
4.0
4.5
5.0
Vcc (V)
17/30
TS4972
Electrical Characteristics
Figure 73: Signal to Noise Ratio vs Power
Supply with Weighted Filter Type A
Figure 76: Current Consumption vs Standby
Voltage @ Vcc = 2.6V
6
100
Vcc = 2.6V
Tamb = 25°C
5
90
Icc (mA)
SNR (dB)
4
RL=8Ω
RL=16Ω
80
RL=4Ω
3
2
Gv = 10
Cb = Cin = 1µF
THD+N < 0.7%
Tamb = 25°C
70
60
2.5
3.0
3.5
4.0
4.5
1
0
0.0
5.0
0.5
1.0
1.5
Vstandby (V)
Vcc (V)
Figure 74: Current Consumption vs Power
Supply Voltage
0.7
Vstandby = 0V
Tamb = 25°C
Vout1 & Vout2
Clipping Voltage Low side (V)
6
Icc (mA)
5
4
3
2
1
0
1
2
3
4
0.6
0.5
0.4
RL = 8Ω
0.3
0.2
0.1
RL = 16Ω
0.0
2.5
5
RL = 4Ω
Tamb = 25°C
3.0
Vcc (V)
3.5
4.0
4.5
5.0
Power supply Voltage (V)
Figure 75: Current Consumption vs Standby
Voltage @ Vcc = 5V
Figure 78: Current Consumption vs Standby
Voltage @ Vcc = 3.3V
6
7
Vcc = 5V
Tamb = 25°C
6
Vcc = 3.3V
Tamb = 25°C
5
5
4
Icc (mA)
Icc (mA)
2.5
Figure 77: Clipping Voltage vs Power Supply
Voltage and Load Resistor
7
0
2.0
4
3
3
2
2
1
1
0
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
Vstandby (V)
18/30
4.0
4.5
5.0
0
0.0
0.5
1.0
1.5
2.0
Vstandby (V)
2.5
3.0
Electrical Characteristics
TS4972
Figure 79: Clipping Voltage vs Power Supply
Voltage and Load Resistor
Vout1 & Vout2
Clipping Voltage High side (V)
0.6
Tamb = 25°C
RL = 4Ω
0.5
0.4
RL = 8Ω
0.3
0.2
0.1
RL = 16Ω
0.0
2.5
3.0
3.5
4.0
4.5
5.0
Power supply Voltage (V)
19/30
TS4972
3
Application Information
Application Information
Figure 80: Demoboard Schematic
S1
VCC
VCC
C1
Vcc
S2
GND
R2
C2
GND
R1
VCC
+
C6
100µ
P1
Neg. Input
C7
100n
U1
6
C3
R3
S6
C5
R4
1
Vin-
P2
OUT1
VC
C
-
C9
Vout 1
Pos. Input
C4
R5
7
Vin+
8
+
470µ
R6
S7
Positive Input mode
AV = -1
VCC
R7
100k
3
Bypass
5
Standby
C10
Vout 2
4
+
Bias
G
Standby
C11
+
C12
+
1u
2 ND
C8
100n
Figure 81: Flip-Chip 300µm Demoboard Components Side
+
470µ
S8
R8
20/30
GND
S4
GND
S5
1k
S3
+
TS4972
OUT2
Application Information
Figure 82: Flip-Chip 300µm Demoboard Top
Solder Layer
TS4972
The output power is:
Pout =
(2 Vout RMS ) 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)
The differential output voltage is:
Rfeed
Vout2 – Vout1 = 2Vin -------------------- (V)
Rin
Figure 83: Flip-Chip 300µm Demoboard
Bottom Solder Layer
The differential gain named gain (Gv) for more
convenient usage is:
Vout2 – Vout1
Rfeed
Gv = --------------------------------------- = 2 -------------------Rin
Vin
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
In low frequency region, the effect of Cin starts.
Cin with Rin forms a high pass filter with a -3dB
cut off frequency.
1
F C L = -------------------------------- ( Hz )
2π Rin Cin
■
BTL Configuration Principle
The TS4972 is a monolithic power amplifier with a
BTL output type. BTL (Bridge Tied Load)
means that each end of the load is 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)
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
F CH = ----------------------------------------------- ( Hz )
2 π Rfeed Cfeed
■
Power dissipation and efficiency
Hypothesis :
• Voltage and current in the load are
sinusoidal (Vout and Iout)
• Supply voltage is a pure DC source (Vcc)
21/30
TS4972
Application Information
Regarding the load we have:
V O U T = V PEAK sinωt (V)
and
VOUT
I O UT = ----------------- (A)
RL
and
V P EAK 2
P O U T = ---------------------- (W)
2R L
Then, the average current delivered by the supply
voltage is:
V PE AK
I CC AVG = 2 -------------------- (A)
πR L
The power delivered by the supply voltage is
Psupply = Vcc IccAVG (W)
Then, the power dissipated by the amplifier is
Pdiss = Psupply - Pout (W)
2 2Vcc
P diss = ---------------------- P O U T – P O U T (W)
π RL
and the maximum value is obtained when:
∂Pdiss
---------------------- = 0
∂P O U T
and its value is:
Pdiss max =
2 Vcc 2
π2RL
(W)
Remark : This maximum value is only depending
on power supply voltage and load values.
The efficiency is the ratio between the output
power and the power supply
πV PEAK
P OUT
η = ------------------------ = ----------------------Psupp ly
4V CC
The maximum theoretical value is reached when
Vpeak = Vcc, so
π
----- = 78.5%
4
■
Decoupling of the circuit
Two capacitors are needed to bypass properly the
TS4972, a power supply bypass capacitor Cs and
a bias voltage bypass capacitor Cb.
22/30
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.
If Cs is lower than 100µF, in high frequency
increases, 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 curve : fig.12).
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
Pop and Click performance is intimately linked
with the size of the input capacitor Cin and the
bias voltage bypass capacitor Cb.
Size of Cin is due to the lower cut-off frequency
and PSRR value requested. Size of Cb is due to
THD+N and PSRR requested always in lower
frequency.
Moreover, Cb determines the speed that the
amplifier turns ON. The slower the speed is, the
softer the turn ON noise is.
The charge time of Cb is directly proportional to
the internal generator resistance 50kΩ.
Then, the charge time constant for Cb is
τb = 50kΩxCb (s)
As Cb is directly connected to the non-inverting
input (pin 2 & 3) and if we want to minimize, in
amplitude and duration, the output spike on Vout1
(pin 5), Cin must be charged faster than Cb. The
charge time constant of Cin is
τin = (Rin+Rfeed)xCin (s)
Application Information
Thus we have the relation
τin << τb (s)
The respect of this relation permits to minimize
the pop and click noise.
Remark : Minimize Cin and Cb has a benefit on
pop and click phenomena but also on cost and
size of the application.
Example : your target for the -3dB cut off
frequency is 100 Hz. With Rin=Rfeed=22 kΩ,
Cin=72nF (in fact 82nF or 100nF).
With Cb=1µF, if you choose the one of the latest
two values of Cin, the pop and click phenomena at
power supply ON or standby function ON/OFF will
be very small
50 kΩx1µF >> 44kΩx100nF (50ms >> 4.4ms).
Increasing Cin value increases the pop and click
phenomena to an unpleasant sound at power
supply ON and standby function ON/OFF.
Why Cs is not important in pop and click
consideration ?
Hypothesis :
• Cs = 100µF
• Supply voltage = 5V
• Supply voltage internal resistor = 0.1Ω
• Supply current of the amplifier Icc = 6mA
At power ON of the supply, the supply capacitor is
charged through the internal power supply
resistor. So, to reach 5V you need about five to
ten times the charging time constant of Cs (τs =
0.1xCs (s)).
Then, this time equal 50µs to 100µs << τb in the
majority of application.
At power OFF of the supply, Cs is discharged by a
constant current Icc. The discharge time from 5V
to 0V of Cs is:
5Cs
t Di schC s = -------------- = 83 ms
Icc
Now, we must consider the discharge time of Cb.
At power OFF or standby ON, Cb is discharged by
a 100kΩ resistor. So the discharge time is about
τbDisch ≈ 3xCbx100kΩ (s).
In the majority of application, Cb=1µF, then
τbDisch≈300ms >> tdischCs.
Power amplifier design examples
TS4972
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)
• Ambient temperature max = 50°C
• SO8 package
First of all, we must calculate the minimum power
supply voltage to obtain 0.5W into 8Ω. With
curves in fig. 15, we can read 3.5V. Thus, the
power supply voltage value min. will be 3.5V.
Following
equation
the
maximum
Pdiss max =
power
2 Vcc 2
π2RL
dissipation
(W)
with 3.5V we have Pdissmax=0.31W.
Refer to power derating curves (fig. 20), with
0.31W the maximum ambient temperature will be
100°C. This last value could be higher if you follow
the example layout shown on the demoboard
(better dissipation).
The gain of the amplifier in flat region will be:
V OUT PP 2 2R L P OUT
G V = --------------------- = ------------------------------------ = 5.65
V IN PP
V IN PP
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.
In lower frequency we want 20 Hz (-3dB cut off
frequency). Then:
1
C IN = ------------------------------ = 795nF
2π RinF CL
So, we could use for Cin a 1µF capacitor value
which gives 16Hz.
In Higher frequency we want 20kHz (-3dB cut off
frequency). The Gain Bandwidth Product of the
TS4972 is 2MHz typical and doesn't change when
the amplifier delivers power into the load.
The first amplifier has a gain of:
Rfeed
----------------- = 3
Rin
23/30
TS4972
Application Information
and the theoretical value of the -3dB cut-off higher
frequency is 2MHz/3 = 660kHz.
We can keep this value or limit the bandwidth by
adding a capacitor Cfeed, in parallel on Rfeed.
Then:
1
C F EED = --------------------------------------- = 265pF
2π R F EE D F C H
So, we could use for Cfeed a 220pF capacitor
value that gives 24kHz.
Now, we can calculate the value of Cb with the
formula τb = 50kΩxCb >> τin = (Rin+Rfeed)xCin
which permits to reduce the pop and click effects.
Then Cb >> 0.8µF.
We can choose for Cb a normalized value of
2.2µF that gives good results in THD+N and
PSRR.
In the following tables, you could find three
another examples with values required for the
demoboard.
Application n°1 : 20Hz to 20kHz bandwidth
and 6dB gain BTL power amplifier
Components:
Designator
Application n°2 : 20Hz to 20kHz bandwidth
and 20dB gain BTL power amplifier
Components:
Designator
Part Type
R1
110k / 0.125W
R4
22k / 0.125W
R6
Short Cicuit
R7
100k / 0.125W
R8
Short Cicuit
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
SMB Plug
Part Type
R1
22k / 0.125W
P1
R4
22k / 0.125W
Application n°3 : 50Hz to 10kHz bandwidth
and 10dB gain BTL power amplifier
R6
Short Cicuit
R7
100k / 0.125W
R8
Short Circuit
C5
470nF
C6
100µF
C7
100nF
C9
Short Circuit
Components:
Designator
C10
Short Circuit
C12
1µF
S1, S2, S6, S7
2mm insulated Plug
10.16mm pitch
S8
3 pts connector 2.54mm
pitch
P1
SMB Plug
24/30
Part Type
R1
33k / 0.125W
R2
Short Circuit
R4
22k / 0.125W
R6
Short Cicuit
R7
100k / 0.125W
R8
Short Cicuit
C2
470pF
C5
150nF
C6
100µF
C7
100nF
C9
Short Circuit
Application Information
TS4972
C10
Short Circuit
For Vcc=5V, a 20Hz to 20kHz bandwidth and
20dB gain BTL power amplifier you could follow
the bill of material below.
C12
1µF
Components:
S1, S2, S6, S7
2mm insulated Plug
10.16mm pitch
R1
110k / 0.125W
S8
3 pts connector 2.54mm
pitch
R4
22k / 0.125W
SMB Plug
R5
22k / 0.125W
R6
110k / 0.125W
Designator
P1
Part Type
Designator
Application n°4 : Differential inputs BTL power
amplifier
Part Type
R7
100k / 0.125W
In this configuration, we need to place these
components : R1, R4, R5, R6, R7, C4, C5, C12.
R8
Short circuit
We have also : R4 = R5, R1 = R6, C4 = C5.
C4
470nF
The differential gain of the amplifier is:
C5
470nF
C6
100µF
C7
100nF
R1
G VDI F F = 2 -------R4
Note : Due to the VICM range (see Operating
Condition), GVDIFF must have a minimum value
shown in figure 84.
C9
Short Circuit
C10
Short Circuit
Figure 84: Minimum Differential Gain vs
Power Supply Voltage
C12
1µF
S1, S2, S6, S7
2mm insulated Plug
10.16mm pitch
S8
3 pts connector 2.54mm
pitch
P1, P2
SMB Plug
40
Differential Gain min. (dB)
35
30
25
20
15
10
2.5
3.0
3.5
4.0
4.5
Power Supply Voltage (V)
5.0
5.5
25/30
TS4972
■
Application Information
Note on how to use the PSRR curves
(page 7)
How we measure the PSRR ?
Figure 86: PSRR measurement schematic
We have finished a design and we have chosen
the components values :
Rfeed
• Rin=Rfeed=22kΩ
• Cin=100nF
• Cb=1µF
Vripple
VCC
6
Vcc
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. 13 to the curve on fig. 12.
The measurement result is shown on the next
figure.
Figure 85: PSRR changes with Cb
1
Vin-
-
7
Vin+
+
Vout 1
Now, on fig. 13, 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. 12 we can see the effect of Cb on the
PSRR (input grounded) vs. frequency. With
Cb=100µF, we can reach the -70dB value.
Rin
8
Vs-
RL
Cin
AV = -1
Bypass
5
Standby
Vout 2
4
Vs+
+
Bias
GND
Rg
100 Ohms
3
TS4972
Cb
■
2
Principle of operation
• We fixed the DC voltage supply (Vcc)
• We fixed the AC sinusoidal ripple voltage
(Vripple)
• No bypass capacitor Cs is used
The PSRR value for each frequency is:
PSRR (dB)
-40
Rms ( V ri ppl e )
PSRR ( dB ) = 20 x Log 10 -------------------------------------------Rms ( Vs + - Vs - )
Vcc = 5, 3.3 & 2.6V
Rfeed = 22k, Rin = 22k
Rg = 100Ω, RL = 8Ω
Tamb = 25°C
-30
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.
26/30
Mechanical Data
4
TS4972
Mechanical Data
Figure 87: TS4972 Footprint Recommendation (Non Solder Mask Defined)
500µm
500µm
75µm min.
100µm max.
Track
Φ=400µm
150µm min.
500µm
500µm
Φ=250µm
Solder mask opening
Pad in Cu 35µm with Flash NiAu (6µm, 0.15µm)
Figure 88: Top View Of The Daisy Chain Mechanical Data ( all drawings dimensions are in millimeters
8
7
6
5
Vin+
Vcc
Stdby
Vout1
Vout2
Vin
Gnd
1
2
4 1.6 mm
Bypass
3
2.26 mm
Remarks:
Daisy chain sample is featuring pins connection two by two. The schematic above is illustrating the way
connecting pins each other. This sample is used for testing continuity on board. PCB needs to be
designed on the opposite way, where pin connections are not done on daisy chain samples. By that way,
just connecting an Ohmeter between pin 8 and pin 1, the soldering process continuity can be tested.
Order Codes
Package
Part Number
Temperature Range
Marking
J
TSDC03IJT
-40, +85°C
•
DC3
27/30
TS4972
Mechanical Data
Figure 89: Tape & reel specification (top view)
1.5
4
1
1
A
m
µ0
7
+
Y
zeis
ieD
8
A
Die size X + 70µm
4
All dimensions are in mm
User direction of feed
28/30
Package Mechanical Data
5
TS4972
Package Mechanical Data
5.1 Flip-Chip - 8 BUMPS
0.5
0.5
0.5
1.6
0.5
■
■
■
■
■
Die size : (2.26mm ±10%) x (1.6mm ±10%)
Die height (including bumps) : 650µm ± 50
Bumps diameter : 315µm ±15µm
Silicon thickness : 400µm ±25µm
Pitch: 500µm ±10µm
2.26
400µm
650µm
250µm
Figure 90: Pin Out (top view)
Figure 91: Marking (top view)
E
A72
YWW
■ Balls are underneath
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TS4972
Package Mechanical Data
Revision History
Date
Revision
Description of Changes
January 2003
1
First Release
October 2004
2
Update Mechanical Data for Flip-Chip package
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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