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STG3157
Single-Pole Double-Throw Analog Switch

STG3157 STG3157 Product Page

Many applications such as switching between process control monitors, professional video systems, or accessing multiple measurement stations, continue to use analog switch matrices for design flexibility, and quick time-to-market.
The STG3157 is a new analog switch intended mainly for the mobile sector. In fact, most mobile appliances today allow the consumer to switch from the built-in speaker and microphone to an external source. In the case of a cell phone this might be an earpiece and a clip on a microphone for hands free operation.
This need extends to other applications such as handheld computers and portable consumer audio products like CD and MP3 players. Previously the switching from an internal to external source was made using mechanical relays. This solution was more costly, took up more space and was proven unreliable over the lifetime of the product.

Application Example
Cellular applicationThe STG3157 is used to switch between the internal and external microphone or speaker. In particular, the STG3157 is a high performance, single-pole double-throw (SPDT) Analog Switch or 2:1 Multiplexer / Demultiplexer Bus Switch.

Order Codes

P / N Package
STG3157CTR SOT323-6L (SC70-6L)

Features
b Useful in both analog and digital applications
b Space saving SOT323-6L (SC70) surface mount package
b Low On Resistance; <9ý at Vcc= 3.3V
b Broad Vcc operating range; 1.65V to 5.5V
b Rail-to rail signal handling
b Break before make enable circuitry to ensure no audio popping or clicking during transitions
b 250MHz -3dB bandwidth
b Low current drain: 1µA (max.)
b Excellent isolation and unwanted signal rejection off isolation -57dB at 10MHz; crosstalk -54dB at 10MHz