TSC TS34119CA

TS34119
Low Power Audio Amplifier
Supply Voltage Range 2 V to 16V
Gain Adjustable Range 0dB ~ 46dB
Output Power 400mW @Vcc=12V, RL=100Ω
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.
The TS34119 is offered in SOP-8 and DIP-8 package.
Features
Ordering Information
—
Wide operating supply voltage (2~16V)
Part No.
—
Chip disable input to power down the IC
TS34119CD
—
Low quiescent current for battery powered 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
TS34119CS
Operating Temp.
DIP-8
-20 ~ +70 oC
1-11
SOP-8
TSSOP-8
TS34119CA
Block Diagram
TS34119
Package
2004/09 rev. A
Absolute Maximum Rating
Description
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
TSTG
-65 ~ +150
Maximum Output Current at VO1, VO2
Storage Temperature Range
o
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
Description
Symbol
Value
Unit
Supply Voltage
Vcc
+2 ~ 16V
V
Load Impedance
RL
8 ~ 100
Ω
Peak Load Current
IL
200
mA
Differential Gain (5kHz bandwidth)
AVD
0 ~ 46
dB
Voltage @ CD (pin 1)
VCD
0 ~ Vcc
V
Operating Temperature, All Package Types
TSTG
-10 ~ +70
o
C
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.
Electrical Characteristics (VCD=0V, Ta =25 oC; unless otherwise specified.)
Parameter
Test Conditions
Min
Typ
Max
Unit
@ Vin
--
>30
--
MΩ
f<100Hz
80
--
--
dB
-0.35
0
+0.35
dB
--
1.5
--
MHz
Vcc=3V,RL=16Ω,THD≤10%
55
--
--
Vcc=6V,RL=32Ω,THD≤10%
250
--
--
Vcc=12V,RL=100Ω,THD≤10%
400
--
--
Vcc=6V, RL=32Ω, Po=125mW
--
0.5
1.0
Vcc≥3V, RL=8Ω, Po=20mW
--
0.5
--
Vcc≥12V, RL=32Ω, Po=200mW
--
0.6
--
C1=∞, C2=0.01uF
50
--
--
C1=0.1uF, C2=0, f=1KHz
--
12
--
C1=1uF, C2=5uF, f=1KHz
--
52
--
Vcc=6V, 1KHz ≤ f ≤ 20KHz,
--
>70
--
Symbol
Amplifiers (AC Characteristics)
AC Input Resistance
Open Loop Gain (Amp. #1)
Ri
AVOL1
Closed Loop Gain (Amp. #2)
AV2
Gain Bandwidth Product
GBW
Output Power
Pout
Total Harmonic Distortion
(f=1KHz)
THD
Power Supply Rejection
(Vcc=6.0V, ∆Vcc=3.0V)
Differential Muting
PSRR
GMT
Vcc=6V,f=1KHz, RL=32Ω
CD=2V
TS34119
2-11
2004/09 rev. A
mW
%
dB
dB
Electrical Characteristics (VCD=0V, Ta =25 oC; unless otherwise specified.)
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
Vo
Output Level
Output DC Offset Voltage
Vdc
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
Vcc-1.0 (typ)
Vdc
(VO1 – VO2)
fIB
Vcc=6.0V
--
-100
-200
nA
Equivalent Resistance @ FC1
RFC1
Vcc=6.0V
100
150
220
KΩ
Equivalent Resistance @ FC2
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
Input Bias Current @ Vin
Chip Disable (pin 1)
Vdc
Power Supply
Power Supply Current
Icc
mA
uA
Note: Currents into a pin are positive, currents out of a pin negative.
Typical Temperature Performance ( -10 oC < Ta < +70 oC)
Function
Condition
Typical Change
Units
±40
Pa / oC
+0.003
% / oC
o
uA / C
Input Bias Current
@ Vin
Total Harmonic Distortion
Vcc=6V, RL=32Ω, Po=120mW, f=1kHz
Power Supply Current
Vcc=3V, RL=∞, CD=0V
-2.5
Vcc=3V, RL=∞, CD=2V
-0.03
TS34119
3-11
2004/09 rev. A
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 2)
FC1
3
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
TS34119
4-11
2004/09 rev. A
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.
TS34119
5-11
2004/09 rev. A
Design Guideline
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:
o
PD= (140 C - Ta) / Өja
Where Ta is the ambient temperature; and Өja is the package thermal resistance (100 oC / 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
2
application, it is found from the following equation: PD= (VCC × ICC) + (IRMS × VCC) - (RL × IRMS )
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 internal power dissipation of
o
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.
Circuit Description
TS34119
6-11
2004/09 rev. A
Circuit Description
TS34119
7-11
2004/09 rev. A
Typical Application Circuit
TS34119
8-11
2004/09 rev. A
Typical Application Circuit (continues)
TS34119
9-11
2004/09 rev. A
Typical Application Circuit (continues)
TS34119
10-11
2004/09 rev. A
SOP-8 Mechanical Drawing
A
DIM
9
16
B
1
P
8
G
R
C
M
F
D
K
A
B
C
D
F
G
K
M
P
R
SOP-8 DIMENSION
MILLIMETERS
INCHES
MIN
MAX
MIN
MAX
4.80
5.00
0.189
0.196
3.80
4.00
0.150
0.157
1.35
1.75
0.054
0.068
0.35
0.49
0.014
0.019
0.40
1.25
0.016
0.049
1.27 (typ)
0.05 (typ)
0.10
0.25
0.004
0.009
0o
7o
0o
7o
5.80
6.20
0.229
0.244
0.25
0.50
0.010
0.019
DIP-8 Mechanical Drawing
A
8
DIM
5
B
4
1
L
C
J
A
B
C
D
G
J
K
L
M
DIP-8 DIMENSION
MILLIMETERS
INCHES
MIN
MAX
MIN
MAX
9.07
9.32
0.357
0.367
6.22
6.48
0.245
0.255
3.18
4.45
0.125
0.135
0.35
0.55
0.019
0.020
2.54 (typ)
0.10 (typ)
0.29
0.31
0.011
0.012
3.25
3.35
0.128
0.132
7.75
8.00
0.305
0.315
10o
10o
K
G
TS34119
D
M
11-11
2004/09 rev. A