ST TSH512 User Manual
Hi-fi stereo/mono infrared transmitter
Features
■ Supply voltage: 2.3 to 5.5 V
■ Carrier frequency range: 0.4 to 11 MHz
■ High versatility: I/O pins for each section
■ Two FM transmitters for stereo
■ Sinusoidal carriers for high spectral purity
■ Micro- or line-level preamplifiers with ALC
■ VOX function to save on battery power
■ Transmitter TX2 standby for mono operation
Applications
■ Infrared hi-fi stereo transmitters
■ Infrared headsets
■ Stereo sub-carriers for video transmitters
■ Voice-operated wireless webcams
■ FM IF transmit systems
Description
The TSH512 is a 0.4- to 11-MHz dual FM
transmitter. Access pins to each section give high
versatility and allow for several different
applications: stereo headphone, multimedia
headset, audio sub-carrier generator.
The TSH512 integrates in a single chip low-noise
audio preamplifiers with ALC (automatic level
control), frequency-modulated oscillators, and
linear output buffers to drive the external
transistors. The sinusoidal carriers facilitate the
filtering and allow high performance audio
transmission.
TSH512
and stereo sub-carrier generator
F
TQFP44
10 x 10 mm
Pin connections (top view)
36
36
Monostable
Monostable
3435
3435
33
33
32
32
31
31
30
30
29
29
28
28
27
27
26
26
25
25
24
24
23
23
3738394041
PEA
PEA
-
+
+
-
-+-
VOX
VOX
PEA
PEA
TX2
TX2
TX1
TX1
3738394041
VCO
VCO
VCO
VCO
Output
Output
buffer
buffer
Output
Output
buffer
buffer
424344
424344
1
1
2
2
3
3
4
4
5
5
6
6
7
7
8
8
9
9
10
10
11
11
-
+
ALC
ALC
LNA
LNA
TSH512
TSH512
-
-
+
+
LNA
LNA
+
ALC
ALC
-+
--+
12 13 14 15 16 17 18 19 20 21 22
12 13 14 15 16 17 18 19 20 21 22
The TSH512 forms a chipset with the dual
receiver TSH511.
The VOX (voice operated transmit) circuitry
disables the output buffer when there is no audio
signal to save battery power. For MONO
applications, the STANDBY pin enables one
transmitter only, reducing the supply current.
May 2009 Doc ID 8120 Rev 7 1/31
www.st.com
31
Contents TSH512
Contents
1 Absolute maximum ratings and operating conditions . . . . . . . . . . . . . 3
2 Device diagrams and schematics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
3 Electrical characteristics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 7
3.1 Supply section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3.2 Audio section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10
3.3 RF section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13
4 Application information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14
4.1 Infrared stereo transmitter application (stereo headphones) . . . . . . . . . . 14
4.2 Sub-carrier generator application: voice-operated wireless camera . . . . 16
4.3 Multimedia application . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
4.3.1 Headset side . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 16
4.3.2 Computer side . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 17
5 General description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
5.1 LNA section: low noise amplifier . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 18
5.2 Electret condenser microphone source . . . . . . . . . . . . . . . . . . . . . . . . . . 19
5.3 MIC-BIAS section: microphone bias voltage . . . . . . . . . . . . . . . . . . . . . . 20
5.4 ALC section: automatic level control . . . . . . . . . . . . . . . . . . . . . . . . . . . . 21
5.5 VOX description: voice operated transmit . . . . . . . . . . . . . . . . . . . . . . . . 21
5.6 PEA section: pre-emphasis . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 24
5.7 VCO section: voltage-controlled oscillator . . . . . . . . . . . . . . . . . . . . . . . . 25
5.8 Output buffer section . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
5.9 SBY pin: standby for mono operation . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
6 Package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
6.1 TQFP44 package information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
7 Ordering information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29
8 Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 30
2/31 Doc ID 8120 Rev 7
TSH512 Absolute maximum ratings and operating conditions
1 Absolute maximum ratings and operating conditions
Table 1. Absolute maximum ratings
Symbol Parameter Value Unit
V
CC
T
oper
T
stg
T
j
R
thjc
R
thja
Latch-up Class
Supply voltage
Operating free air temperature range -40 to +85 °C
Storage temperature -65 to +150 °C
Maximum junction temperature 150 °C
Thermal resistance junction to case 14 °C/W
Thermal resistance junction to ambient area 45 °C/W
(2)
ESD sensitive device: handling precautions required
ESD
except pins 20 and
36
1. All voltage values, except differential voltage, are with respect to network ground terminal.
2. Corporate ST Microelectronics procedure number 0018695.
3. Human body model: a 100 pF capacitor is charged to the specified voltage, then discharged through a
1.5 kΩ resistor between two pins of the device. This is done for all couples of connected pin combinations
while the other pins are floating.
4. Charged device model: all pins and the package are charged together to the specified voltage and then
discharged directly to the ground through only one pin. This is done for all pins.
5. Machine model: a 200 pF capacitor is charged to the specified voltage, then discharged directly between
two pins of the device with no external series resistor (internal resistor < 5 Ω). This is done for all couples of
connected pin combinations while the other pins are floating.
HBM: human body model
CDM: charged device model
MM: machine model
(1)
(5)
(3)
(4)
7V
A
2
1
kV
0.2
Table 2. Operating conditions
Symbol Parameter Value Unit
V
CC
f
audio
f
carrier
Supply voltage 2.3 to 5.5 V
Audio frequency range 20 to 20,000 Hz
Carrier frequency range 0.4 to 11 MHz
Doc ID 8120 Rev 7 3/31
Device diagrams and schematics TSH512
2 Device diagrams and schematics
This section contains a detailed block diagram of the TSH512 (Figure 1), with an
accompanying pin description (Table 3 on page 5), as well as the schematics of a typical
application (Figure 2 on page 6).
Figure 1. Block diagram
DEC2
DEC2
MIC-BIAS2
MIC-BIAS2
GND
GND
VCC
VCC
SBY
SBY
VOX-INTS
VOX-INTS
VOX-SENS
VOX-SENS
VCC
VCC
GND
GND
MIC-BIAS1
MIC-BIAS1
DEC1
DEC1
VCO-BIAS2
LNA-INP2
LNA-INP2
1
1
2
2
3
3
LNA
LNA
4
4
5
5
6
6
7
7
8
8
LNA
LNA
9
9
10
10
11
11
12 13 14 15 16 17 18 19 20 21 22
12 13 14 15 16 17 18 19 20 21 22
LNA-OUT2
ALC-INT2
LNA-OUT2
LNA-INN 2
LNA-INN 2
-
+
+
-+
--+
ALC-INT2
PEA-INN2
PEA-INN2
424344
424344
ALC
ALC
TSH512
TSH512
-
-
+
+
ALC
ALC
PEA-OUT2
PEA-OUT2
PEA
PEA
-
+
+
VOX
VOX
-
-+-
PEA
PEA
VCO-BIAS2
TX2
TX2
TX1
TX1
3738394041
3738394041
VCO
VCO
VCO
VCO
VCC
VCC
VCO-A2
VCO-A2
36
36
Output
Output
buffer
buffer
Output
Output
buffer
buffer
Monostable
Monostable
VCO-OUT2
VCO-OUT2
VCO-B2
VCO-B2
3435
3435
33
33
GND
GND
32
32
BUF-IN2
BUF-IN2
31
31
BUF-OUT2
BUF-OUT2
30
30
GND
GND
29
29
VOX-TIMER
VOX-TIMER
28
28
VOX-INTN
VOX-INTN
27
27
VOX-MUTE
VOX-MUTE
26
26
VCC
VCC
25
25
BUF-OUT1
BUF-OUT1
BUF-IN1
BUF-IN1
24
24
23
23
GND
GND
LNA-INP1
LNA-INP1
LNA-INN 1
LNA-INN 1
LNA-OUT1
LNA-OUT1
4/31 Doc ID 8120 Rev 7
VCC
VCC
VCO-A1
VCO-B1
VCO-A1
ALC-INT1
PEA-INN1
ALC-INT1
PEA-INN1
PEA-OUT1
PEA-OUT1
VCO-BIAS1
VCO-BIAS1
VCO-B1
VCO-OUT1
VCO-OUT1
TSH512 Device diagrams and schematics
Table 3. Pin descriptions
Pin Pin name Related to Direction
(1)
Pin description
1 DEC2 TX2 - Decoupling capacitor for internal voltage reference
2 MIC-BIAS2 TX2 O Microphone bias
3 GND - - Ground
4 VCC - - Supply voltage
5 SBY TX1 & TX2 I Standby control (input pin)
6 VOX-INTS TX1 & TX2 - Time constant terminal for audio signal integrator in VOX
7 VOX-SENS TX1 & TX2 - Gain adjustment for VOX input sensitivity
8 VCC - - Supply voltage
9 GND - - Ground
10 MIC-BIAS1 TX1 O Microphone bias
11 DEC1 TX1 - Decoupling capacitor for internal voltage reference
12 LNA-INP1 TX1 I LNA positive input
13 LNA-INN1 TX1 I LNA negative input
14 LNA-OUT1 TX1 O LNA output
15 ALC-INT1 TX1 - Time constant terminal for integrator in ALC
16 PEA-INN1 TX1 I Pre-emphasis amplifier negative input
17 PEA-OUT1 TX1 O Pre-emphasis amplifier output
18 VCO-BIAS1 TX1 O Bias for external VCO components
19 VCC - - Supply voltage
20 VCO-A1 TX1 - Oscillator component connection
21 VCO-B1 TX1 - Oscillator component connection
22 VCO-OUT1 TX1 O VCO output
23 GND - - Ground
24 BUF-IN1 TX1 I Input to the output buffer
25 BUF-OUT1 TX1 O Output of the output buffer
26 VCC - - Supply voltage
27 VOX-MUTE TX1 & TX2 O Mute control (output pin) in VOX
28 VOX-INTN TX1 & TX2 - Time constant terminal for noise integrator in VOX
29 VOX-TIMER TX1 & TX2 - Rise time for timer in VOX
30 GND - - Ground
31 BUF-OUT2 TX2 O Output of the output buffer
32 BUF-IN2 TX2 I Input to the output buffer
33 GND - - Ground
34 VCO-OUT2 TX2 O VCO output
35 VCO-B2 TX2 - Oscillator component connection
Doc ID 8120 Rev 7 5/31
Device diagrams and schematics TSH512
Table 3. Pin descriptions (continued)
Pin Pin name Related to Direction
36 VCO-A2 TX2 - Oscillator component connection
37 VCC - - Supply voltage
38 VCO-BIAS2 TX2 O Bias for external VCO components
39 PEA-OUT2 TX2 O Pre-emphasis amplifier output
40 PEA-INN2 TX2 I Pre-emphasis amplifier negative input
41 ALC-INT2 TX2 - Time constant terminal for internal peak detector in ALC
42 LNA-OUT2 TX2 O LNA output
43 LNA-INN2 TX2 I LNA negative input
44 LNA-INP2 TX2 I LNA positive input
1. Pin directions: I = input pin, O = output pin, - = pin to connect to supply or decoupling capacitors or external components.
(1)
Pin description
Figure 2. Typical application schematics for stereo infrared transmitter
6/31 Doc ID 8120 Rev 7
TSH512 Electrical characteristics
3 Electrical characteristics
Table 4. Electrical characteristics for VCC = 2.7 V, T
(unless otherwise specified)
(1)
= 25° C, f
amb
audio
= 1 kHz, f
carrier
= 2.8 MHz
Symbol Parameter Test conditions Min. Typ. Max. Unit
Overall circuit
TX1 on, TX2 on, MIC-BIAS1 and
MIC-BIAS2 not used:
I
CC_TOT
Current consumption
TX1 and TX2 are on
VOX-MUTE=1 output buffers on
VOX-MUTE=0, output buffers off
-40° C < T
<+85°C
amb
VOX-MUTE=1 output buffers on
VOX-MUTE=0, output buffers off
161118.6
12.8
19.6
13.8
TX1 on, TX2 off, MIC-BIAS1 and
MIC-BIAS2 not used:
I
CC_SBY
Current consumption with
TX2 in standby: SBY (pin5)
active
VOX-MUTE=1,output buffers on
VOX-MUTE=0, output buffers off
-40° C < T
<+85°C
amb
VOX-MUTE=1, output buffers on
VOX-MUTE=0, output buffers off
10711.5
8
12.1
8.6
LNA sections (for TX1 and TX2)
GBP
Gain bandwidth product No external load 7 MHz
LNA
Input resistance on positive
Rin
LNA
input:
(LNA-INP1 pin 12 or
30 kΩ
LNA-INP2 pin 44)
THD
En
Total harmonic distortion
LNA
Equivalent input noise
voltage
=0dB, Vout
LNA
-40° C < T
G
LNA
R
S
amb
=40dB, at f=1kHz
=390Ω, R
< +85° C 0.05
feedback
LNA
= 700 mV
=39kΩ
PP
0.01 0.05
6nV/√Hz
G
Automatic level control (ALC) section
G
ALC
V
ALC_OUT
Voltage gain 20 dB
Regulated output level
600 710 800
(at positive input of the PEA
amplifier)
-40° C < T
< +85° C 597 803
amb
Pre-emphasis amplifier (PEA) section
mA
mA
%
mVpp
Gain bandwidth product
GBP
(PEA-OUT1 pin 17 or
PEA
No load 9 MHz
PEA-OUT2 pin 39)
V
Opp-PEA
Output voltage RL = 22 kΩ 550 mVpp
Doc ID 8120 Rev 7 7/31
Electrical characteristics TSH512
Table 4. Electrical characteristics for VCC = 2.7 V, T
(unless otherwise specified) (continued)
(1)
amb
= 25° C, f
audio
= 1 kHz, f
carrier
= 2.8 MHz
Symbol Parameter Test conditions Min. Typ. Max. Unit
Audio LNA+ALC+PEA sections
G
= 0 dB, f = 1 kHz
LNA
(V
in)ALC
< 25 mV
(-30 dBu)
rms
RL = 22 kΩ tied to GND
0.05 0.15
THD
Total harmonic distortion in
linear region on PEA-OUT1
ALC
pin17 or PEA-OUT2 pin 39
< +85° C 0.25
amb
= 36 mV
= 100 mV
amb
= 36 mV
= 100 mV
(-27 dBu)
rms
(-18 dBu)
rms
<+85°C
(-27 dBu)
rms
(-18 dBu)
rms
1.331.7
4
2.5
5.3
70 °
THD
ΦΜ
AGC
PEA
Total harmonic distortion in
compression region
Phase margin at
PEA-OUT1 pin 17 or
PEA-OUT2 pin 39
-40° C < T
(V
in)ALC
(Vin)
ALC
= 22 kΩ tied to GND
R
L
-40° C < T
(V
in)ALC
(Vin)
ALC
=22kΩ
R
L
LNA and PEA at unity gain
= 40 mV
V
in
Microphone biasing section
V
MIC-BIAS
Microphone biasing voltage
(Section 5.3 on page 20)
I
MIC-BIAS
-40° C < T
= 2.5 mA 2.15 2.25 2.35
< +85° C 2.14 2.36
amb
Over temp. range:
ΔV
I
MIC-BIAS
PSRR
MIC-BIAS
MIC-BIAS
V
MIC-BIAS
coefficient
MIC-BIAS current capability Over VCC range [2.3 V–5.5 V] 2.5 mA
Power supply rejection ratio
of MIC-BIAS
temperature
[0, 70° C]
[-40, 85° C]
I
MIC-BIAS
= 2.5 mA
At 1 kHz and V
ripple
= 25 mV
RMS
260
460
50 dB
%
%
V
ppm/°C
en
MIC-BIAS
Equivalent input noise of
MIC-BIAS
VCC=2.7V
VCC=5.0V
Vox operated switch (VOX) section
I
VOX-TIME R
VTH
VOX-TIME R
V
MUTE_L
Monostable current source
(VOX-TIMER pin 29)
Threshold voltage of the
Monostable (time constant)
Low level output voltage
(VOX-MUTE pin 27)
= 2.7V 5 µA
V
CC
= 2 kΩ 0.2
R
L
-40° C < T
RL = 2 kΩ VCC-0.3
V
MUTE_H
High level output voltage
(VOX-MUTE pin 27)
-40° C < T
8/31 Doc ID 8120 Rev 7
22
42
1.4 V
<+85°C 0.2
amb
-
V
<+85°C
amb
CC
0.32
nV/√Hz
V
V
TSH512 Electrical characteristics
Table 4. Electrical characteristics for VCC = 2.7 V, T
(unless otherwise specified) (continued)
(1)
amb
= 25° C, f
audio
= 1 kHz, f
carrier
= 2.8 MHz
Symbol Parameter Test conditions Min. Typ. Max. Unit
Standby
V
SBY_IL
maximum
V
SBY_IH
minimum
Maximum low level input
voltage of standby input
(SBY pin 5)
Minimum high level input
voltage of standby input
(SBY pin 5)
0.1xV
0.9xV
CC
CC
VCO section
V
VCO-BIAS
I
VCO-BIAS
δV
VCO-BIAS
PN
SVR
LO
VCO-BIAS
VCO-BIAS output voltage
(VCO-BIAS1 pin 18 or
VCO-BIAS2 pin 38)
VCO-BIAS output current
capability
VCO-BIAS voltage drift
Phase noise
Supply voltage rejection
ratio of VCO-BIAS
With no load 1.43 1.47 1.51
-40° C < T
V
VCO-BIAS
2.3 V < V
[0, 70° C] VCC=2.7V
[0, 70° C] V
[-40, 85° C] VCC=2.7V
[-40, 85° C] VCC=5.0V
At 1 kHz, L = 120 µH (Q = 30) and
R
not connected
VCO
< +85° C 1.38 1.56
amb
> 1.38 V 40 µA
< 5.5 V
CC
8
+265
CC
=5.0V
+356
+265
+356
-80 dBc
With no load 43 dB
VCO output impedance
Z
VCO-OUT
(VCO-OUT1 pin 22 or
400 Ω
VCO-OUT2 pin 34)
ZL
VCO-OUT
minimum
Minimum load impedance 1 kΩ
V
V
V
DC
mV/V
ppm/°C
ppm/°C
ppm/°C
ppm/°C
V
VCO-OUT
Output buffer
Z
BUF-IN
G
OB
V
BUF-OUT
AC
L= 120µH (Q=30)
VCO output level
VCO output connected to output
buffer input R
-40° C < T
= 100 kΩ
VCO
< +85° C 569 671
amb
580 620 660
mVpp
Input impedance
(BUF-IN1 pin 24 or BUF-IN2
400 kΩ
pin 32)
Linear voltage gain 10 dB
Output AC voltage at 1dB
compression point
Output AC voltage
ZL=2kΩ 1.3
ZL=2kΩ V
= 0.60 Vpp 1.35 1.5 1.7
BUF-IN
Vpp
(BUF-OUT1 pin 25 or
BUF-OUT2 pin 31)
-40° C < T
< +85° C 1.33 1.72
amb
Doc ID 8120 Rev 7 9/31
Electrical characteristics TSH512
Table 4. Electrical characteristics for V
(unless otherwise specified) (continued)
= 2.7 V, T
CC
(1)
amb
= 25° C, f
audio
= 1 kHz, f
carrier
= 2.8 MHz
Symbol Parameter Test conditions Min. Typ. Max. Unit
V
BUF-OUT
H2
BUF-OUT
H3
BUF-OUT
DC
Output DC voltage DC output current = 0.4 mA 1.25 V
2nd harmonic level V
3rd harmonic level V
BUF-OUT
BUF-OUT
= 1.2 Vpp and ZL=2kΩ -40 dBc
=1.2Vpp and ZL=2kΩ -30 dBc
1. Limits over -40° C < Tamb < +85° C range are guaranteed by statistical correlation.
3.1 Supply section
Figure 3. Supply current vs. supply voltage
18
TX1+TX2+Buffers
16
TX1+TX2
14
TX1+Buffers
12
10
(mA)
8
CC
I
6
4
2
0
0123456
TX1
VCC(V)
DC
3.2 Audio section
Figure 4. LNA distortion vs. frequency Figure 5. LNA distortion vs. LNA output
+N (%)
LNA
THD
10/31 Doc ID 8120 Rev 7
1
VCC = 2.7V
G
= 0dB
LNA
V
OUT-LNA
0.1
0.01
10 100 1000 10000
Frequency (Hz)
= 700mV
voltage
100
G
= 0dB
LNA
pp
10
1
+N (%)
LNA
0.1
THD
0.01
1E-3
0 200 400 600 800 1000 1200 1400 1600
VCC = 2.3V
V
OUT-LNA
(mVpp)
VCC = 2.7V
VCC = 5.5V
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