Freescale Semiconductor Tower System TWR-ADCDAC-LTC Demonstration Board TWR-ADCDAC-LTC TWR-ADCDAC-LTC User Manual
Product codes
TWR-ADCDAC-LTC
TWRADCDACLTCUM
TWR-ADCDAC-LTC Tower Module User's Manual
Page 7 of 17
A Sleep command allows any combination of DACs to be powered down. There is also a reset flag and
an offset adjustment pin for each channel.
an offset adjustment pin for each channel.
2.1.3 LTC2498
The LTC2498 is a 16-channel (8-differential) 24-bit No Latency ΔΣ ADC with Easy Drive technology. The
patented sampling scheme eliminates dynamic input current errors and the shortcomings of on-chip
buffering through automatic cancellation of differential input current. This allows large external source
impedances, and rail-to-rail input signals to be directly digitized while maintaining exceptional DC
accuracy.
The LTC2498 includes a high accuracy temperature sensor and an integrated oscillator. This device can
be configured to measure an external signal (from combinations of 16 analog input channels operating
in single ended or differential modes) or its internal temperature sensor. The integrated temperature
sensor offers 1/30th °C resolution and 2°C absolute accuracy.
The LTC2498 allows a wide common mode input range (0V to VCC), independent of the reference
voltage. Any combination of single-ended or differential inputs can be selected and the first conversion
after a new channel is selected is valid. Access to the multiplexer output enables optional external
amplifiers to be shared between all analog inputs and auto calibration continuously removes their
associated offset and drift.
patented sampling scheme eliminates dynamic input current errors and the shortcomings of on-chip
buffering through automatic cancellation of differential input current. This allows large external source
impedances, and rail-to-rail input signals to be directly digitized while maintaining exceptional DC
accuracy.
The LTC2498 includes a high accuracy temperature sensor and an integrated oscillator. This device can
be configured to measure an external signal (from combinations of 16 analog input channels operating
in single ended or differential modes) or its internal temperature sensor. The integrated temperature
sensor offers 1/30th °C resolution and 2°C absolute accuracy.
The LTC2498 allows a wide common mode input range (0V to VCC), independent of the reference
voltage. Any combination of single-ended or differential inputs can be selected and the first conversion
after a new channel is selected is valid. Access to the multiplexer output enables optional external
amplifiers to be shared between all analog inputs and auto calibration continuously removes their
associated offset and drift.
2.1.4 LTC1859
The LTC1857/LTC1858/LTC1859 are 8-channel, low power, 12-/14-/16-bit, 100ksps, analog-to-digital
converters (ADCs). These SoftSpan™ ADCs can be software programmed for 0V to 5V, 0V to 10V, ±5V
or ±10V input spans and operate from a single 5V supply. The 8-channel multiplexer can be
programmed for single-ended inputs or pairs of differential inputs or combinations of both. In addition,
all channels are fault protected to ±25V. A fault condition on any channel will not affect the conversion
result of the selected channel.
An onboard high performance sample-and-hold and precision reference minimize external
components. The low 40mW power dissipation is made even more attractive with two user selectable
power shutdown modes. DC specifications include ±3LSB INL for the LTC1859, ±1.5LSB INL for the
LTC1858 and ±1LSB for the LTC1857.
The internal clock is trimmed for 5µs maximum conversion time and the sampling rate is guaranteed at
100ksps. A separate convert start input and data ready signal (BUSY) ease connections to FIFOs, DSPs
and microprocessors.
converters (ADCs). These SoftSpan™ ADCs can be software programmed for 0V to 5V, 0V to 10V, ±5V
or ±10V input spans and operate from a single 5V supply. The 8-channel multiplexer can be
programmed for single-ended inputs or pairs of differential inputs or combinations of both. In addition,
all channels are fault protected to ±25V. A fault condition on any channel will not affect the conversion
result of the selected channel.
An onboard high performance sample-and-hold and precision reference minimize external
components. The low 40mW power dissipation is made even more attractive with two user selectable
power shutdown modes. DC specifications include ±3LSB INL for the LTC1859, ±1.5LSB INL for the
LTC1858 and ±1LSB for the LTC1857.
The internal clock is trimmed for 5µs maximum conversion time and the sampling rate is guaranteed at
100ksps. A separate convert start input and data ready signal (BUSY) ease connections to FIFOs, DSPs
and microprocessors.
2.1.5 LTC3471
The LT3471 dual switching regulator combines two 42V, 1.3A switches with error amplifiers that can
sense to ground providing boost and inverting capability. The low VCESAT bipolar switches enable the
device to deliver high current outputs in a small footprint. The LT3471 switches at 1.2MHz, allowing the
use of tiny, low cost and low profile inductors and capacitors. High inrush current at start-up is
eliminated using the programmable soft-start function, where an external RC sets the current ramp
rate. A constant frequency current mode PWM architecture results in low, predictable output noise
that is easy to filter.
sense to ground providing boost and inverting capability. The low VCESAT bipolar switches enable the
device to deliver high current outputs in a small footprint. The LT3471 switches at 1.2MHz, allowing the
use of tiny, low cost and low profile inductors and capacitors. High inrush current at start-up is
eliminated using the programmable soft-start function, where an external RC sets the current ramp
rate. A constant frequency current mode PWM architecture results in low, predictable output noise
that is easy to filter.