TS34119 Low Power Audio Amplifier General Description

TS34119  Low Power Audio Amplifier General Description
TS34119
Low Power Audio Amplifier
SOP-8
Pin assignment:
1. CD
8. VO2
2. FC2
7. Gnd
3. FC1
6. Vcc
4. Vin
5. VO1
General Description
The TS34119 is a low power audio amplifier, it integrated circuit intended (primarily) for telephone applications,
such as in speakerphones. It provides differential speaker outputs to maximize output swing at low supply
voltages (2.0V minimum). Coupling capacitors to the speaker are not required. Open loop gain is 80dB, and the
closed loop gain is set with two external resistors. A chip Disable pin permits powering down and/or muting the
input signal.
Features
●
Wide operating supply voltage (2~16V)
●
Chip disable input to power down the IC
●
Low quiescent current for battery powered
Ordering Information
Part No.
TS34119CS RL
Package
Packing
SOP-8
2.5Kpcs / 13” Reel
application
●
Lower power down quiescent current
●
Drives a wide range of speaker load (8~100Ω)
●
Output power exceed 250mW with 32Ωspeaker
●
Low total harmonic distortion
●
Gain adjustable for voice band
●
Requires few external components
Block Diagram
1/12
Version: B13
TS34119
Low Power Audio Amplifier
Absolute Maximum Rating
Parameter
Symbol
Value
Unit
Supply Voltage
Vcc
+1 ~ 18V
V
Maximum Input Voltage (FC1, FC2, CD, Vin)
Vin
-1.0 ~ Vcc+1.0
V
Applied Output Voltage to VO1, VO2 when disabled
Vvo
-1.0 ~ Vcc+1.0
V
Io
±250
mA
Maximum Output Current at VO1, VO2
o
Storage Temperature Range
TSTG
-65 ~ +150
C
Note: Maximum ratings are those values beyond which damage to the device may occur, functional operation
should be Restricted to the recommended operating conditions.
Recommended Operating Conditions
Parameter
Symbol
Value
Unit
Vcc
+2 ~ 16V
V
RL
8 ~ 100
Ω
Load Impedance
IL
200
mA
Peak Load Current
AVD
0
~
46
dB
Differential Gain (5kHz bandwidth)
V
VCD
0 ~ Vcc
Voltage @ CD (pin 1)
Note: This device contains protection circuitry to guard against damage due to high static voltage or electric fields.
However, precautions must be taken to avoid applications of any voltage higher than maximum rated voltage
to this high impedance circuit. For proper operation, Vin and Vout should be constrained to the range Gnd ≤
(Vin or Vout) ≤ Vcc. Unused inputs must always be tied to an appropriate logic voltage level (e.g., either Gnd
or Vcc), unused output must be left open.
Supply Voltage
Electrical Specifications (VCD=0V, Ta =25oC; unless otherwise noted.)
Parameter
Symbol
Amplifiers (AC Characteristics)
AC Input Resistance
Ri
Open Loop Gain (Amp. #1)
AVOL1
Closed Loop Gain (Amp. #2)
AV2
Gain Bandwidth Product
GBW
Output Power
Total Harmonic
(f=1KHz)
Pout
Distortion
Power Supply Rejection
(Vcc=6.0V, ∆Vcc=3.0V)
Differential Muting
THD
PSRR
GMT
Test Conditions
Min
Typ
Max
Unit
@ Vin
f<100Hz
Vcc=6V,f=1KHz, RL=32Ω
-80
-0.35
-55
250
400
---
>30
-0
1.5
---0.5
0.5
--+0.35
----1.0
--
MΩ
dB
dB
MHz
--
0.6
--
50
---
-12
52
----
dB
--
>70
--
dB
Vcc=3V,RL=16Ω,THD≤10%
Vcc=6V,RL=32Ω,THD≤10%
Vcc=12V,RL=100Ω,THD≤10%
Vcc=6V,RL=32Ω, Po=125mW
Vcc≥3V,RL=8Ω, Po=20mW
Vcc≥12V, RL=32Ω,
Po=200mW
C1=∞, C2=0.01uF
C1=0.1uF, C2=0, f=1KHz
C1=1uF, C2=5uF, f=1KHz
Vcc=6V, 1KHz ≤ f ≤ 20KHz,
CD=2V
2/12
mW
%
Version: B13
TS34119
Low Power Audio Amplifier
Electrical Specifications (Continue)
Parameter
Symbol
Test Conditions
Min
Typ
Max
VCC=3V, RL=16 (Rf =75K)
1.0
1.15
1.25
Vcc=6V, RL=16 (Rf =75K)
--
2.65
--
Vcc=12V, RL=16 (Rf =75K)
--
5.56
--
Unit
Amplifiers (DC Characteristics)
Output DC Level @
VO1,VO2
Output Level
Output DC Offset Voltage
(VO1 – VO2)
Input Bias Current @ Vin
Equivalent Resistance @
FC1
Equivalent Resistance @
Vo
VOH
Iout=-75mA, 2.0 ≤ Vcc ≤ 16V
VOL
Iout=75mA, 2.0 ≤ Vcc ≤ 16V
--
0.16
--
∆Vo
Vcc=6V, RL=75KΩ, RL=32Ω
-30
0
+30
mV
--
-100
-200
nA
100
150
220
fIB
Vcc=6.0V
RFC1
Vcc-1.0 (typ)
Vcc=6.0V
Vdc
KΩ
RFC2
18
25
40
Input Voltage Low
VIL
--
--
0.8
Input Voltage High
VIH
2.0
--
--
Vcc=3V, RL=∞, CD=0.8V
--
2.7
4.0
Vcc=16V, RL=∞, CD=0.8V
--
3.3
5.0
Vcc=3V, RL=∞, CD=2V
--
65
100
FC2
Vdc
Chip Disable (pin 1)
Vdc
Power Supply
Power Supply Current
Icc
mA
uA
Note: a. Currents into a pin are positive, currents out of a pin negative.
Typical Temperature Performance ( -20oC < Ta < +70oC)
Function
Condition
Input Bias Current
@ Vin
Total Harmonic Distortion
Vcc=6V, RL=32Ω, Po=120mW, f=1kHz
Power Supply Current
Typical Change
Units
±40
Pa/ C
+0.003
%/ C
Vcc=3V, RL=∞, CD=0V
-2.5
Vcc=3V, RL=∞, CD=2V
-0.03
3/12
o
o
o
uA/ C
Version: B13
TS34119
Low Power Audio Amplifier
Pin Function Description
Symbol
Pin
CD
1
FC2
2
Description
Chip Disable-Digital input. A logic ”0” (<0.8V) sets normal operation. A logic ”I”(≥2.0V)
sets the power down mode. Input impedance is nominally 90KΩ
A capacitor at this pin increases power supply rejection, and affects turn-on time. This pin
can be left open it the capacitor at FC1 is sufficient.
Analog ground for the amplifiers. A 1uF capacitor at this pin (with a 5uF capacitor at pin
FC1
3
2) provides 52dB(typically) of power supply rejection. Turn-on time of the circuit is
affected by the capacitor on this pin. This pin can be used as an alternate input.
Amplifier input. The input capacitor and resistor set low frequency roll off and input
Vin
4
VO1
5
Amplifier Output #1. The dc level is ≈ (VCC - 0.7) / 2
VCC
6
DC supply voltage (+2.0V ~ +16V) is applied to this pin.
GND
7
Ground pin for the entire circuit.
VO2
8
impedance. The feedback resistor is connected to this pin and VO1.
Amplifier Output #2. This signal is equal in amplitude, but 180° out-of-phase with that at
VO1. The dc level is ≈ (VCC - 0.7V) / 2.
Typical Application Circuit
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Version: B13
TS34119
Low Power Audio Amplifier
Design Guideline
GENERAL
The TS34119 is a low power audio amplifier capable of low voltage operation (Vcc=2.0V minimum) such as that
encountered in line-powered speakerphones. The circuit provides a differential output (VO1-VO2) to the speaker
to maximize the available voltage swing at low voltages. The different gain is set by two external resistors. Pins
FC1 and FC2 allow controlling the amount of power supply and noise rejection, as well as providing alternate
inputs to the amplifiers. The CD pin permits powering down the IC for muting purposes and to conserve power.
AMPLIFIERS
Referring to the block diagram, the internal configuration consists of two identical operational amplifiers. Amplifier
#1 has an open loop gain of ≥80Db (at f≤100Hz), and the closed loop gain is set by external resistor Rf and Rj.
The amplifier is unity gain stable, and has a unity gain frequency of approximately 1.5MHz. In order to adequately
cover the telephone voice band (300Hz to 3.4kHz), a maximum closed loop gain of 46dB is recommended.
Amplifier #2 is internally set to gain of –1.0 (0dB). The outputs of both amplifiers are capable of souring and
sinking a peak current of 200mA.The outputs can typically swing to within ≈ 0.4V above ground, and to
within≈1.3V below VCC, at the maximum current. See Figure 18 and 19 for VOH and VOL curves. The output dc
offset voltage (VO1-VO2) is primarily a function of the feedback resistor (Rf), and secondarily due to the
amplifiers’ input offset voltages. The input offset voltage of the two amplifiers will generally be similar for a
particular IC, and therefore nearly cancel each other at the outputs. Amplifier #1’s bias current, however, flows out
of Vin (pin 4) and through Rf, forcing VO1 to shift negative by an amount equal to (Rf × IIB), Vo2 is shifted posited
an equal amount. The output offset voltage, specified in the Electrical Characteristics is measured with the
feedback the feedback resistor shown in the Typical Application Circuit, and therefore takes into account the bias
current as wells internal offset voltages of the amplifiers. The bias current is constant with respect to VCC.
FC1 AND FC2
Power supply rejection is provided by the capacitors (C1 and C2 in the typical Application Circuit) at FC1 and
FC2. C2 is somewhat dominant at low frequencies, while C1 is dominant at high frequencies, as shown in the
graphs of Figure 4 to 7. The required values of C1 and C2 depend on the conditions of each application. A line
powered speakerphone, for example, will require more filtering than a circuit powered by a well regulated power
supply. The amount of rejection is function of the capacitors, and the equivalent impedance looking into FC1 and
FC2 (listed in the Electrical Characteristics as RFC1 and RFC2). In addition to providing filtering, C1 and C2 also
affect the turn-on time of the circuit at power-up, since the two capacitors must charge up through the internal 50K
and 125K resistors. The graph of Figure 1 indicates the turn-on time upon application of VCC of +6V. The turn-on
time is ≈ 60% longer for VCC =3V, and ≈ 20% less for VCC =9V. Turn-off time is <10uS upon removal of VCC.
CHIP DISABLE
The chip Disable (pin 1) can be used to power down the IC to conserve power, or for muting, or both. When at a
Logic “0” (0V to 0.8V), the TS34119 is enabled for normal operation. When pin 1 is a Logic ”1” (2V to VCC), the IC
is disabled. If pin 1 is open, that is equivalent to Logic “0” although good design proactive dictates that an input
should never be left open. Input impedance at pin 1 is a nominal 90KΩ. The power supply current (when disabled)
is shown in Figure 15. Muting, defined as the change in differential gain from normal operation to muted operation,
is in excess of 70dB. The turn-off time the audio output, from the application of the CD signal, is <2uS, and turn
on-time is 12 mS-15mS. Both times are independent of C1, C2, and VCC. When the TS34119 is disabled, the
voltage at FC1 and FC2 do not change as they are powered from Vcc. The outputs, VO1 and VO2, change to
high impedance condition, removing the signal from the speaker. If signals from other sources are to be applied to
the outputs (while disabled), they must be within the range of VCC and Ground.
LAYOUT CONSIDERATIONS
Normally a snobbier is not needed at the output of the TS34119, unlike many other audio amplifiers, However, the
PC board layout, stray capacitances, and the manner in which the speaker wires are configured, may dictate
otherwise. Generally, the speaker wires should be twisted tightly, and not more than a few inches in length.
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Version: B13
TS34119
Low Power Audio Amplifier
Design Guideline (Continue)
POWER DISSIPATION
Figure 8 to 10 indicate the device dissipation (within the IC) for various combinations of VCC, RL, and load power.
The maximum power which can safely be dissipated within the TS34119 is found from the following equation:
PD= (140oC - Ta) / Өja
o
Where Ta is the ambient temperature; and Өja is the package thermal resistance (100 C/W for the standard DIP
o
package, and 180 C/W for the surface mount package.) The power dissipated within the TS34119, in a given
application, it is found from the following equation: PD= (VCC × ICC) + (IRMS × VCC) - (RL × IRMS2)
Where ICC is obtained from Figure 15; and IRMS is the RMS current at the load; and RL is load resistance.
Figure 8 to 10, along with Figure 11 to 13 (distortion curves), and a peak working load current of ±200mA, define
the operating range for the TS34119. The operating range is further defined in terms of allowable load power in
Figure 14 for loads of 8Ω, 16Ω and 32Ω. The left (ascending) portion of each of the three curves is defined by the
power level at which 10% distortion occurs. The center flat portion of each curve is defined by the maximum
output current capability of the TS34119. The right (descending) portion of each curve is defined by the maximum
o
internal power dissipation of the IC at 25 C. At higher ambient temperatures, the maximum load power must be
reduced according to the above equations. Operating the device beyond the current and junction temperature
limits will degrade long-term reliability.
Electrical Characteristics Curve
Figure 1. Turn-On Time vs. C2, C2 at Power-On
Figure 2. Amplifier #1 Open Loop Gain and
Phase
Figure 3. Differential Gain vs. Frequency
Figure 4. PSRR vs. Frequency (C2=10uF)
6/12
Version: B13
TS34119
Low Power Audio Amplifier
Electrical Characteristics Curve (Continue)
Figure 5. PSRR vs. Frequency (C2=5uF)
Figure 6. PSRR vs. Frequency (C2=1uF)
Figure 7. PSRR vs. Frequency (C2=0uF)
Figure 8. Device Dissipation, 0.8Ω Load
Figure 9. Device Dissipation, 16Ω Load
Figure 10. Device Dissipation, 32Ω Load
7/12
Version: B13
TS34119
Low Power Audio Amplifier
Electrical Characteristics Curve (Continue)
Figure 11. Distortion vs. Power
(f=1kHz, AVD=34dB)
Figure 12. Distortion vs. Power
(f=3kHz, AVD=34dB)
Figure 13. Distortion vs. Power
(f=1, 3kHz, AVD=12dB)
Figure 14. Maximum Allowable Load Power
Figure 15. Power Supply Current
Figure 16. Small Signal Response
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Version: B13
TS34119
Low Power Audio Amplifier
Electrical Characteristics Curve (Continue)
Figure 17. Large Signal Response
Figure 18. Vcc-Voh @ Vo1, Vo2 vs. Load
Current
Figure 19. Vol @ Vo1, Vo2 vs. Load Current
Figure 20. Input Characteristics @ CD (Pin1)
Figure 21. Audio Amplifier with High Input Impedance
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Version: B13
TS34119
Low Power Audio Amplifier
Electrical Characteristics Curve (Continue)
Figure 22. Audio Amplifier with Bass Suppression
Figure 23. Frequency Response of Figure 22
Figure 24. Audio Amplifier with Bandpass
Figure 25. Frequency Response of Figure 24
Figure 26. Device Dissipation, 16Ω Load
10/12
Version: B13
TS34119
Low Power Audio Amplifier
SOP-8 Mechanical Drawing
Unit: Millimeters
Marking Diagram
Y = Year Code
M = Month Code
(A=Jan, B=Feb, C=Mar, D=Apl, E=May, F=Jun, G=Jul, H=Aug, I=Sep,
J=Oct, K=Nov, L=Dec)
L = Lot Code
11/12
Version: B13
TS34119
Low Power Audio Amplifier
Notice
Specifications of the products displayed herein are subject to change without notice. TSC or anyone on its behalf,
assumes no responsibility or liability for any errors or inaccuracies.
Information contained herein is intended to provide a product description only. No license, express or implied, to
any intellectual property rights is granted by this document. Except as provided in TSC’s terms and conditions of
sale for such products, TSC assumes no liability whatsoever, and disclaims any express or implied warranty,
relating to sale and/or use of TSC products including liability or warranties relating to fitness for a particular purpose,
merchantability, or infringement of any patent, copyright, or other intellectual property right.
The products shown herein are not designed for use in medical, life-saving, or life-sustaining applications.
Customers using or selling these products for use in such applications do so at their own risk and agree to fully
indemnify TSC for any damages resulting from such improper use or sale.
12/12
Version: B13
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