RI-TMS37122-TR中文资料

Description

The TMS37122 is a three channel LF Transceiver, which can handle up to three antennas for LF field detection indepen-dent of orientation. It provides a maximum sensitivity of typical 5mVpp, which allows extended read ranges up to a few meters. This is by far more compared to traditional transponder systems. Figure 1 shows the implemen-tation in a Passive Entry system and Figure 2 a typical applica-tion in a generic identification device. Two different read ranges can be achieved with the programmable wake patterns

and thresholds. This is used e.g.

for read range restrictions on

Indoor / Outdoor detection in

passive entry automotive

applications.

Also external devices can be

woken up with the WAKE UP

output. A simple serial interface

enables bi-directional LF data

transmission.

The IC provides a very low

current consumption of typically

5μA in standby mode with all 3

antennas active. To reduce

standby current consumption,

unused antennas can be

switched off and the standby

current goes down to typically

2μA with one antenna active.

This feature extends battery

lifetime and makes the device

well suited for battery-powered

applications. The device can

also operate in battery-less

backup mode, if battery power is

not available. Exact resonance

trimming of each antenna circuit

can be achieved with the on-chip

trimming capacitors.

Three Channel LF Transceiver (3D AFE) TMS37122

Features: Application Examples:

- Three Antenna input channels

- Orientation independent LF field detection - High sensitivity of typical 5mVpp - Read range up to a few meters

- Ultra low quiescent current of 100nA - Ultra low standby current ! typ. 5μA with three antennas active ! typ. 2 μA with one antenna active - Supports batteryless backup mode - Programmable LF threshold levels - Wake up function for external devices - Two programmable 16 bit wake patterns - Serial interface for data transmission - 120kHz - 140kHz LF frequency range

- TI 134 kHz / HDX Transponder compatible modulation

- On-chip antenna trimming for all three antennas

- Up to 4kBit Data Transmission rate - Small TSSOP16 SMD package

Automotive:

? Passive Entry / Passive Start ? Indoor / Outdoor recognition ? Immobilizer

? Sensor monitoring

Industry:

? Remote LF initiated measurement ? Payment systems ? Vehicle-asset tracking ? Supply chain automation ? Security / Access Systems

? Customer Relationship Management (CRM)

Specifications:

Texas Instruments reserves the right to change its products and services at any time without notice. TI provides customer assistance in various technical areas, but does not have full access to data concerning the uses and applications of customers products. Therefore, TI assumes no responsibility for customer product design or for infringement of patents and/or the rights of third parties, which may result from assistance provided by TI.

? Copyright 2001 Texas Instruments Incorporated.

11-07-22-002 12/01