TSH512
TSH512
HiFi stereo/mono infrared transmitter
HiFi stereo/mono infrared transmitter
Stereo sub-carrier gen er ator
Stereo sub-carrier gen er ator
■ Supply voltage: 2.3V to 5.5V
■ Carriers 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 2 Standby for mono operation
DESCRIPTION
The TSH512 is a 0.4 to 11 MHz dual FM transmitter. Access pins to each section give a high versatility and allow several applica tions: stereo headphone, multimedia headset, audio sub-carrier
generator.
The TSH512 integrates in one chip:
Low-noise audio preamplifiers with ALC (Automatic Level Control), frequency modulated oscillators,
and linear output buffers to drive external tr ansistors. The sinusoidal carriers facilitates the filtering
and allows high performance audio transmission.
The VOX (Voice Op erated Transmit) circui try disables the output buffer when there is no audio t o
save battery power.
For MONO applications, the STAND-BY pin enables one transmitter only, reducing the supply
current.
The TSH512 forms a chipse t with the dua l receiver TSH511.
APPLICATIONS
■ Infrared HiFi stereo transmitter
■ Infrared Headsets
■ Stereo sub-carrier for video transmitters
■ Voice operated wireless webcams
■ FM IF transmit systems
ORDER CODE
Part Number
TSH512CF -40°C to
TSH512CFT -40°C to
Temperature
Range
+85°C
+85°C
Package Conditionning Marking
TQFP44 Tray TSH512C
TQFP44 Tape & reel TSH512C
PACKAGE
F
TQFP44
10 x 10 mm
PIN CONNECTION (top view)
40
40
39
41424344
39
41424344
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
+
+-+
-
-
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
PEA
PEA
+
+-+
-
-
TX2
TX2
TSH512
TSH512
VOX
VOX
TX1
TX1
+
+-+
-
-
PEA
PEA
3738
3738
VCO
VCO
VCO
VCO
36
36
Output
Output
buffer
buffer
Output
Output
buffer
buffer
3435
3435
Monostable
Monostable
33
33
32
32
31
31
30
30
29
29
28
28
27
27
26
26
25
25
24
24
23
23
December 2002
1/19
TSH512
ABSOLUTE MAXIMUM RATINGS
Symbol Parameter Value Unit
Vcc
Supply voltage
Toper Operating free air temperature range -40 to +85 °C
Tstg Storage temperature -65 to +150 °C
Tj Maximum junction temperature 150 °C
Rthjc Thermal resistance juncti on to case 14 °C/W
Latch-up
Class
2)
ESD sensitive device: handling precautions required
ESD
except pin
20 & 36
1. All voltage s values, ex cept differential volt age, are wi th respect to network grou nd terminal
2. Corporate ST Microelectr oni cs proced ure number 0018695
3. ElectroS tatic Disch arge pulse (E SD pulse) sim ul ating a human body discharge of 10 0 pF through 1.5k
4. Discharge to Ground of a device that has been previously charged.
5. ElectroS tatic Disch arge pulse (E SD pulse) approximati ng a pulse of a ma chine or mec hanical equi pment.
HBM: Human Body Model
CDM: Charged Device Model
MM: Machine Model
OPERATING CONDITIONS
Symbol Parameter Value Unit
Vcc Supply voltage 2.3 to 5.5 V
f
audio
f
carrier
Audio frequency range 20 to 20,000 Hz
Carrier frequency range 0.4 to 11 MHz
1)
7V
A
3)
4)
5)
2
1
0.2
Ω
kV
BLOC DIAGRAM
VCO-OUT2
VCO-OUT2
VCO-A2
VCO-A2
VCO-A2
Monostable
Monostable
Monostable
VCO-A1
VCO-A1
VCO-A1
VCO-OUT2
VCO-B2
VCO-B2
VCO-B2
3435
3435
3435
GND
GND
GND
33
33
33
32
32
32
BUF-IN2
BUF-IN2
BUF-IN2
BUF-OUT2
BUF-OUT2
BUF-OUT2
31
31
31
GND
GND
GND
30
30
30
VOX-TIMER
VOX-TIMER
VOX-TIMER
29
29
29
28
28
28
VOX-INTN
VOX-INTN
VOX-INTN
27
27
27
VOX-MUTE
VOX-MUTE
VOX-MUTE
VCC
VCC
VCC
26
26
26
BUF-OUT1
BUF-OUT1
BUF-OUT1
25
25
25
24
24
24
BUF-IN1
BUF-IN1
BUF-IN1
GND
GND
GND
23
23
23
VCO-B1
VCO-B1
VCO-B1
VCO-OUT1
VCO-OUT1
VCO-OUT1
DEC2
DEC2
DEC2
MIC-BIAS2
MIC-BIAS2
MIC-BIAS2
GND
GND
GND
VCC
VCC
VCC
SBY
SBY
SBY
VOX-INTS
VOX-INTS
VOX-INTS
VOX-SENS
VOX-SENS
VOX-SENS
VCC
VCC
VCC
GND
GND
GND
MIC-BIAS1
MIC-BIAS1
MIC-BIAS1
DEC1
DEC1
DEC1
VCO-BIAS2
VCO-BIAS2
PEA-INN2
PEA-INN2
PEA-INN2
PEA-INN1
PEA-INN1
PEA-INN1
-
-
-
+
+
+-+
-
-
-
PEA-OUT2
PEA-OUT2
PEA-OUT2
PEA
PEA
PEA
+
+
+-+
VOX
VOX
VOX
PEA
PEA
PEA
PEA-OUT1
PEA-OUT1
PEA-OUT1
Bias
Bias
BiasBias
TX2
TX2
TX2
TX1
TX1
TX1
Bias
Bias
BiasBias
VCO-BIAS2
VCO-BIAS1
VCO-BIAS1
VCO-BIAS1
3738394041
3738394041
3738394041
VCC
VCC
VCC
VCO
VCO
VCO
VCO
VCO
VCO
VCC
VCC
VCC
36
36
36
Output
Output
Output
buffer
buffer
buffer
Output
Output
Output
buffer
buffer
buffer
ALC-INT2
ALC-INT2
ALC-INT2
LNA-OUT2
LNA-OUT2
LNA-OUT2
LNA-INP2
LNA-INN2
LNA-INP2
LNA-INN2
LNA-INP2
LNA-INN2
424344
424344
424344
1
1
1
2
2
2
3
3
3
4
4
4
5
5
5
6
6
6
7
7
7
8
8
8
9
9
9
10
10
10
11
11
11
+
+
+-+
-
-
-
ALC
ALC
ALC
LNA
LNA
LNA
Bias
Bias
BiasBias
Bias
Bias
BiasBias
LNA
LNA
LNA
+
+
+-+
-
-
-
12
12
12
13 14 15 16 17 18 19 20 21 22
13 14 15 16 17 18 19 20 21 22
13 14 15 16 17 18 19 20 21 22
LNA-INP1
LNA-INP1
LNA-INP1
LNA-INN1
LNA-INN1
LNA-INN1
+
+
+-+
-
-
-
LNA-OUT1
LNA-OUT1
LNA-OUT1
TSH512
TSH512
TSH512
ALC
ALC
ALC
ALC-I NT1
ALC-I NT1
ALC-I NT1
2/19
PIN DESCRIPTION
TSH512
Pin Pin name related to
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
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 direction: I = inp ut pi n, O = output pin, - = pi n t o connect to supply or deco upl i ng capacito rs or extern al components
direction
1)
Pin description
3/19
TSH512
TYPICAL SCHEMATIC
Stereo infrared transmitter
AUDIO IN TX2
44 42
1
+ +
MICRO BIAS TX2
STANDBY
Cpeak
Csens
VOX Delay
Rpeak
VOX Sensitivity
+
2
3
Vcc
4
5
+
6
7
Rsens
Vcc
8
.
Clna1
+
Rlna1
Clna2
ATTACK-DECAY TIME
Rlna2
LNA GAIN : 0dB to 40dB
43
Cpen1
Ralc
Calc
41 40 39 37 36 35 34
47k
Rpen1
PRE-EMPHASIS NETWORK
Rpen2
PEA
ALC
LNA
Transmitter 2 (TX2)
TSH512
100nF
Rbias1
Varicap
Cv
47k
Rbias2
51
Vcc
38
Varicap BIAS
Rvco
Cp
Cs
51pF 51pF
CL
L
51pF
Vcc
33
VCO TX2
IR
Vcc
IR
Varicap
MONO
STABLE
Pulse Width Adjust
32
31
30
29
28
27
26
Ctrig
Rcomp
Ccomp
VOX-MUTE
Vcc
BIAS
+
1M
+
10µF
MICRO BIAS TX1
.
AUDIO IN TX1
9
10
11
12 14
25
ALC
LNA
13
Rlna2
Rlna1
+
Clna1
LNA GAIN : 0dB to 40dB
Clna2
15 16 17
Calc
Ralc
ATTACK-DECAY TIME
Rpen2
Rpen1
Cpen1
PRE-EMPHASIS NETWORK
Transmitter 1 (TX1)
PEA
Varicap BIAS
18
51
47k
100nF
19 20 21
Vcc
Rvco
47k
Rbias2
Varicap
Rbias1
VCO TX1
51pF 51pF
Cs
Cp
Cv
24
OUTPUT BUFFER OUTPUT BUFFER
23
22
L
CL
51pF
BIAS
4/19
TSH512
INFRARED STEREO TRANSMITT ER APPLICATION (ie: stereo headphone)
The HiFi stereo audio is amplified and level regulated by ALC. The carrier of each transmitter TX1 or TX2
of the TSH512 is modulated in FM and bufferized to attack the LED final stage.
IR stereo HiFi transmitter Headphone side
IR stereo HiFi transmitter Headphone side
2.3 MHz
2.3 MHz
filter
filter
RX2
RX2
RX1
RX1
filter
filter
2.8 MHz
2.8 MHz
Right
Right
channel
channel
Line inputs
Line inputs
Left
Left
channel
channel
LNA + ALC
LNA + ALC
LNA + ALC
LNA + ALC
Power supply:
Power supply:
2.3 to 5.5V
2.3 to 5.5V
Icc < 20 mA stereo
Icc < 20 mA stereo
TSH512 TSH511
TSH512 TSH511
buffer2
TX2
TX2
VOX
VOX
TX1
TX1
buffer2
buffer1
buffer1
SBY
SBY
Vcc
Vcc
LED
LED
F
F
i
i
H
H
.
.
2
2
photodiode
photodiode
LNA
LNA
s
s
r
r
e
e
i
i
r
r
r
r
a
a
:
:
c
c
o
o
z
z
e
e
r
r
H
H
e
e
t
t
M
M
s
s
i
i
8
8
.
.
2
2
&
&
3
3
SBY1
SBY1
SQUELCH
SQUELCHSQUELCH
SBY2
SBY2
Vcc: 2.3 to 5.5V
Vcc: 2.3 to 5.5V
Current < 15 mA
Current < 15 mA
Audio
Audio
amp2
amp2
Audio
Audio
amp1
amp1
20 mW / 16 Ω
20 mW / 16 Ω
20 mW / 16 Ω
20 mW / 16 Ω
SUB-CARRIER GENERATOR APPLICATION: voice operated wireless camera
Thanks to the operating frequency the TSH512 offers the possibility to generate usual audio sub-carriers
for video application s. The camera can be voi ce activated us ing the V OX-MUTE output of the T SH512.
The TSH512 also provides bias, amplification, ALC for the electret microphone.
Miniature camera
Miniature camera
Video
Video
Σ
ΣΣ
Sub-carrier
buffer2
buffer2
SBY
SBY
buffer1
buffer1
Sub-carrier
Vcc
Vcc
VOX-MUTE
VOX-MUTE
6 or 6.5 MHz
6 or 6.5 MHz
Audio sub-carrier
Audio sub-carrier
Stand-By
Stand-By
Electret Condenser
Electret Condenser
Microphone
Microphone
TSH512
TSH512
LNA + ALC
LNA + ALC
MIC. BIAS
MIC. BIAS
MIC. BIAS
MIC. BIAS
LNA + ALC
LNA + ALC
TX2
TX2
VOX
VOX
TX1
TX1
6 or 6.5 MHz
6 or 6.5 MHz
filter
filter
FM 2.4 GHz
FM 2.4 GHz
transmitter
transmitter
Stand-By
Stand-By
5/19
TSH512
MULTIMEDIA APPLICATION: HEADSET SIDE
The TSH512 is used in mono to transmit the signal of the Electret Condenser Microphone of the headset.
The circuit is suppli ed by batteries and the VO X function s witche s off t he o utpu t stages t o s pa re energy .
The usual working frequency is 1.7 MHz for infrared mono operation.
TSH511 & 512 supply:
TSH511 & 512 supply:
2.3 to 5.5V, 25 mA
2.3 to 5.5V, 25 mA
Voicetransmittedto thePC
Voicetransmittedto thePC
TSH512
TSH512
LNA + ALC
LNA + ALC
MIC. BIAS
MIC. BIAS
MIC. BIAS
MIC. BIAS
LNA + ALC
LNA + ALC
TX2
TX2
VOX
VOX
TX1
TX1
1.7 MHz
1.7 MHz
Band-pass
Band-pass
filter
filter
buffer2
buffer2
buffer1
buffer1
SBY
SBY
HiFi stereo from the PC:
HiFi stereo from the PC:
2x 20 mW /16 Ω
2x 20 mW /16 Ω
Vcc
Vcc
Vcc
Vcc
LED
LED
TSH511
TSH511
Audio
Audio
amp2
amp2
Audio
Audio
amp1
amp1
1.7 MHz
1.7 MHz
reject
reject
filter
filter
RX2
RX2
SQUELCH
SQUELCH
RX1
RX1
SBY1
SBY2
SBY1
SBY2
filter
filter
1.7 MHz
1.7 MHz
reject
reject
Microphone Tx:
Microphone Tx:
1.7 MHz
1.7 MHz
carrier
carrier
2.3 MHz
2.3 MHz
Band-pass
Band-pass
filter
filter
filter
filter
2.8 MHz
2.8 MHz
Band-pass
Band-pass
LNA
LNA
photodiode
photodiode
Stereo Rx:
Stereo Rx:
2.3 & 2.8 MHz
2.3 & 2.8 MHz
MULTIMEDIA APPLICATION: COMPUTER SIDE
In multimedia application, the TSH512 transmits the HiFi stereo from the PC to the headset.
TSH511 & 512 supply:
TSH511 & 512 supply:
2.3 to 5.5V, 24 mA
2.3 to 5.5V, 24 mA
Voice from the headset microphoneHiFi stereo
mono Rx:
mono Rx:
1.7 MHz
1.7 MHz
HiFi stereo Tx:
HiFi stereo Tx:
2.3 & 2.8 MHz
2.3 & 2.8 MHz
LED
LED
buffer2
buffer2
SBY
SBY
buffer1
buffer1
TX2
TX2
VOX
VOX
TX1
TX1
TSH512
TSH512
LNA + ALC
LNA + ALC
LNA + ALC
LNA + ALC
photodiode
photodiode
Voice from the headset microphoneHiFi stereo
LNA
LNA
RX2
RX2
RX1
RX1
filter
filter
1.7 MHz
1.7 MHz
Band-pass
Band-pass
TSH511
TSH511
SQUELCH
SQUELCHSQUELCH
SBY2
SBY2
SBY1
SBY1
Vcc
Vcc
Audio
Audio
amp2
amp2
Audio
Audio
amp1
amp1
6/19