TSH511CF STMicroelectronics, TSH511CF Datasheet - Page 18

• Manufacturer Part Number: TSH511CF
• Description: IC RECEIVER DUAL FM 44-TQFP
• Manufacturer: STMicroelectronics

Specifications of TSH511CF

• Frequency: 2.3MHz and 2.8MHz
• Sensitivity: -95dBm
• Modulation Or Protocol: FM
• Applications: Infrared Headsets, Infrared Hi-Fi Stereo Transmitters
• Current - Receiving: 15mA
• Data Interface: PCB, Surface Mount
• Antenna Connector: PCB, Surface Mount
• Voltage - Supply: 2.3 V ~ 5.5 V
• Operating Temperature: -40°C ~ 85°C
• Package / Case: 44-TQFP, 44-VQFP
• For Use With: 497-8516 - BLANK PCB W/ BOM FOR TSH511/12
• Lead Free Status / RoHS Status: Lead free / RoHS Compliant
• Features: -
• Memory Size: -
• Data Rate - Maximum: -
• Other names: 497-2322

General description
8.1
18/25
The demodulated signal can be amplified by the audio buffer section after de-emphasis.
Each audio buffer can drive a 16Ω headphone with 20mW power.
The two standby pins SBY1 & SBY2 allow the second receiver RX2 to be put into standby
for mono operation. In mono mode, it is possible to use both audio buffers or only one
depending on the combination on SBY1 & SBY2.
To avoid noise at the audio output, a squelch section mutes the audio buffers when no
carrier is received. The squelch section uses the demodulated signal of the first receiver
(RX1). This signal is high-pass filtered, rectified and compared to a threshold to produce the
Mute signal (pin 25). When no carrier is received on RX1, the wideband ’FM noise’ on the
demodulator increases and the Mute signal mutes both audio buffers. When the carrier is
present, the wideband noise on the demodulator output decreases, enabling the audio
buffer.
Table 5.
LNA section: low noise amplifier
The low noise amplifier (LNA) has a typical gain of 22dB to amplify the incoming RF signal
from the photo diode. The LNA is common to both receiver sections RX1 and RX2.
Figure 26. LNA schematics
Infrared audio frequencies
IR frequency in MHz
1.6
1.7
2.3
2.8
FM left channel or mono
FM right channel
Applications
AM mono
FM mono
TSH511