12-Bit, I2C SAR ADC Measures Eight Inputs And Dissipates 1.5mW

Milpitas, CA - Linear Technology Corporation introduces the LTC2309, a 12-bit analog-to-digital converter (ADC) that communicates via an I2C-compatible 2-wire interface with 14ksps throughput rate. This flexible ADC features an 8-channel integrated multiplexer to measure eight single-ended input channels, four differential channels, or combinations of both. The input channels are software selectable for unipolar or bipolar ranges.

Operating from a single 5V supply, the LTC2309 draws just 1.5mW at a 1ksps throughput rate and only 35uW in shutdown mode.Packaged in a tiny 4mm x 4mm QFN-24 with internal reference, the LTC2309 is a great fit for portable instrumentation and space-constrained designs using I2C.

The LTC2309 achieves excellent DC specifications when measuring unipolar or bipolar input signals, including ±1LSB INL and DNL, ±6LSB (max) zero-scale error and ±6LSB (max) full-scale error. The LTC2309 also excels when digitizing AC input signals, measuring 73dB SINAD and -88dB THD at 1kHz.

The LTC2309 allows I2C data transfers up to 100kHz in standard mode and 400kHz in fast mode. The ADC includes two address select pins that may be tied low, high or left floating, thus providing nine unique I2C addresses. This is ideal for applications that require measurements of more than eight input channels, as designers can easily communicate with multiple LTC2309 devices.

The LTC2309 is available today in both commercial and industrial temperature grades.

Summary of Features: LTC2309

• 12-Bit Resolution
• I2C-Compatible, 2-Wire Interface
• Fast 1.3us Conversion Time
• 14ksps Throughput Rate
• Low Power Dissipation:o 1.5mW at 1ksps
• 35uW Sleep Mode
• 8-Channel Multiplexer (8 Single-Ended Channels, 4 Differential Channels)
• 5V Single Supply Operation
• Tiny QFN-24 (4mm x 4mm) Package
• Internal Reference, Internal Conversion Clock
• 73dB SINAD at 1kHz
• Unipolar or Bipolar Input Ranges
• Two 3-State Address Select Pins Allow Nine Unique Addresses

SOURCE: Linear Technology Corporation