LTC1297DCN8#PBF

ADCs/DACs - Special Purpose Overview

The LTC1297DCN8#PBF is a single-chip 12-bit data acquisition system featuring a switched-capacitor successive approximation A/D converter, differential input sample-and-hold, and serial I/O. It operates on a single 5V supply with a typical active supply current of 6.0mA. The device includes a power shutdown mode that reduces supply current to 5mA when idle between conversions. It supports a maximum throughput rate determined by the clock frequency, up to 1MHz, and provides a direct 3-wire interface to microprocessor serial ports or parallel ports. The component is housed in an 8-lead plastic DIP package.

ADCs/DACs - Special Purpose Feature Summary

• 12-bit resolution with built-in sample-and-hold on the positive input
• Power shutdown capability reducing supply current to 5mA typically
• Single 5V supply operation with analog inputs common mode to supply rails
• Direct 3-wire synchronous serial interface compatible with most MPU ports

ADCs/DACs - Special Purpose Applications

• Remote data acquisition systems requiring low interconnect count
• Battery-powered instrumentation benefiting from power shutdown features
• Microprocessor-based control systems interfacing via SPI or MICROWIRE
• DSP applications requiring digitization of analog signals

ADCs/DACs - Special Purpose Procurement Notes

Verify the ordering suffix #PBF indicates lead-free compliance and RoHS adherence as per Analog Devices standards. Confirm the DC suffix corresponds to the commercial temperature range (0°C to 70°C) and N8 denotes the 8-lead plastic DIP package. Ensure the source document matches the specific part number for accurate electrical specifications.

ADCs/DACs - Special Purpose Selection Notes

Select the LTC1297 over the LTC1292 if power consumption during idle periods is critical, due to its automatic power shutdown feature. Ensure the microprocessor interface supports the required 3-wire synchronous serial protocol or can emulate it using parallel GPIO lines. Verify that the source resistance allows the analog inputs to settle within the sample time defined by the clock frequency and setup requirements.

ADCs/DACs - Special Purpose Part Context

The LTC1297 is part of the LTC1292/LTC1297 family of 12-bit data acquisition systems. While the LTC1292 offers continuous conversion capabilities at up to 60kHz, the LTC1297 optimizes power efficiency through its shutdown mode. Both devices share identical pinouts, interfaces, and core ADC architecture, differing primarily in power management behavior between conversion cycles.

ADCs/DACs - Special Purpose Replacement Considerations

Publicly confirmed substitute part numbers are not available in the provided datasheet. Designers should evaluate other 12-bit SAR ADCs with similar serial interfaces and power characteristics if replacement is necessary.

ADCs/DACs - Special Purpose FAQ

How does the LTC1297 achieve lower power consumption compared to the LTC1292?

The LTC1297 automatically powers down after each conversion cycle when the Chip Select (CS) line is brought high, reducing the typical supply current from 6.0mA to 5mA.

What is the minimum setup time required for the CS signal before the first clock pulse for the LTC1297?

The LTC1297 requires a setup time (tsuCS) of 5.5ms to wake up from power shutdown mode before the first CLK pulse can enable the DOUT output.

Can the LTC1297 interface directly with microprocessors lacking dedicated serial ports?

Yes, the device can interface with all MPU parallel ports by programming three port lines to generate the CS, CLK, and read DOUT signals, effectively emulating the serial interface.